Principle E3/SS Standards

Principle E3/SS Standards
461F Performance Specs and Tailoring Requirements As noted, MIL-STD-464A and MIL-STD-461F have been approved as INTERFACE standards and there is no limitation on their use. Basically, it is up to the Program Manager to decide to use them or not. Details on the content of each standard follows. Another outcome of standards reform is the direction to state requirements in terms of system performance (what the system is to do), not to instruct the contractor how to design the system. MIL-STDs 464A and 461E are written in performance based language to make them more attractive to use. The NTIA manual is a compendium of regulations and procedures for Federal RF management and contains minimal Federal standards for spectrum usage. Lastly, requirements from and Standard should be tailored to fit the operating environment and mission needs. MIL-STDs 464A and 461F are essentially “self tailoring” with usage tables in the front describing which requirement should be applied to various systems.

MIL-STD-461F 461F Applies To Equipment and Subsystems
Conducted and Radiated Emissions, Susceptibility (CE,CS,RE,RS) Requirements, and Test Procedures Requirements Tailored to Equipment Characteristics and Installation Appendix and DIDs The purpose of MIL-STD-461F: Controls EMI characteristics of equipment/ subsystems procured by DoD GO/NO-GO or Pass/Fail Requirements Increases likelihood of compatibility in its EME Approved as interface standard Waiver not required for its use Applicability For items with: - Enclosures no larger than an equipment rack - Electrical interconnections that are discrete wiring harnesses between enclosures - Electrical power derived from prime power sources Not for platforms/systems or modules/parts Requirements depends on equipment/subsystem type and use Requirements and procedures may be tailored The appendix provides background information for each emission and susceptibility and associated test requirement in the main body of the standard. This information includes rationale for requirements, guidance in applying the requirements, and lessons learned from platform and laboratory experience. This information should help users understand the intent behind the requirements, should aid the procuring activity in tailoring emission and susceptibility requirements as necessary for particular applications, and should help users develop detailed test procedures in the EMITP based on the general test procedures in this document. This appendix is provided for guidance purposes and, as such, should not be interpreted as providing contractual requirements. 2 2

Changes from 461E Interchangeable Modular Equipment: Paragraph deals with interchangeable modular equipment, and is new in MIL-STD-461F. Prohibition of Use of Shielded Power Leads: Section ("Construction and arrangement of EUT cables") is more definitive than E, stating shielded power conductors may not be used unless the platform shields the power bus from point-of-origin to the load. Computer Controlled Instrumentation: has a title change from "Computer-controlled receivers" in 461E to "Computer-controlled instrumentation“, recognizing that more than emissions tests are automated. Emission Scanning Changes: Table II, "Bandwidth and measurement time," which underwent a minor revision from -461D to -461E, is modified to provide an alternative faster sweep speed with multiple sweeps in "max hold" mode. Susceptibility Scanning Changes: Above 1 GHz, the Table III step size has been increased, resulting in a much faster RS103 test in that frequency range. CE101: Now applicable for equipment used on surface ships. Interchangeable Modular Equipment: This new paragraph clarifies that equipment which is made up of line replaceable modules (LRM) must be requalified if an LRM is replaced by a new or different model, even if it is a form, fit and function replacement. Prohibition of Use of Shielded Power Leads: There have been problems with equipment manufacturers asking for and receiving shielded power leads from the point-of-distribution (typically a breaker box) to the load, but with the power bus from the breaker box back to the generator being unshielded. Computer Controlled Instrumentation: The new portion of the paragraph is basically software quality assurance: "If commercial software is being used then, as a minimum, the manufacturer, model and revision of the software needs to be provided. If the software is developed in-house, then documentation needs to be included that describes the methodology being used for the control of the test instrumentation and how the software revisions are handled." Emission Scanning Changes: Rather than one relatively slow scan according to the parameters of Table II, the spectrum analyzer or EMI receiver is allowed to scan using the minimum dwell time possible, which is the multiplicative inverse of the measurement bandwidth (note measurement bandwidths have not changed). Such high speed sweeps will be over in milliseconds, therefore it is necessary to sweep continuously in max hold mode for a period of time equal to or greater than the time that would have been spent sweeping per Table II. If a low duty cycle broadband signal is present, rather than catching one or two frequency components with the old technique, the new technique may find several components, building a better spectral signature. This can be very helpful in identifying possible problems whereas a few isolated spikes might not get the same attention. Susceptibility Scanning Changes: Susceptibility scans have undergone revisions in both "E" and "F" in an effort to make the testing more realistic. Step sizes have decreased from rev. D to E, and from E to F, reflecting no history of sharply tuned susceptibilities outside of intrinsically tuned circuits such as radio receivers. CE101: CE101 is now applicable for equipment used on surface ships. 3

Changes from 461E CS106, A New Requirement: 461F includes a Navy ships-only "CS106" requirement that is superficially similar to the obsolete MIL-STD-461A/B/C CS06. CS109: Now only applicable for surface ship equipments that have an operating frequency of 100 kHz or less and have the sensitivity to read a signal at or below 1 µV. CS114: For Navy ships and submarines, there is a low frequency add-on to this requirement that models common mode noise generated by new power systems. CS115: Only applicable for submarine and surface ship procurements when specified by the Procuring Activity. This change fits with the addition of CS106. CS116: There were previously two CS116 limits, there is now just one, the more stringent of the two, which peaks at 10 Amps. CS106: CS106 has little to do with electrical power quality except modeling coupling from power bus transients to signal lines within an equipment enclosure. It is now a special purpose cross-talk test limited to Navy procurements, particularly submarines, which requested and justified it. CS109: CS109 is now only applicable for surface ship equipments that have an operating frequency of 100 kHz or less and have the sensitivity to read a signal at or below 1 µV. CS114: For Navy ships and submarines, there is a low frequency add-on to this requirement that models common mode noise generated by new power systems. The add-on is a level of 77 dBuA from 4 kHz to 1 MHz. The reason for this new add-on is new dc power systems used on ships. A multi-kilovolt dc potential comes from an electromechanical generator, but there are many lower levels of dc power that are derived from the original high potential bus by solid-state dc-to-dc conversions which in turn generate these large amounts of common mode noise. Note that the extension only applies to complete power cables, not signal bundles. CS115: CS115 is only applicable for submarine and surface ship procurements when specified by the Procuring Activity. This change fits with the addition of CS106. CS116: This change reflects a concern that the 5 Amp limit was not stringent enough except perhaps under atypical conditions of very high platform-provided shielding. CS116 now has a limited applicability for equipment on submarines. The requirement applies only to cabling that exits the pressure hull. 4 4

Changes from 461E RE102 A universal change is in the use of the 41" rod antenna, used below 30 MHz; Figure RE102-6 is revised to show the antenna lowered so that the center point of the 41" rod element is 120 cm above the test chamber floor. Further, this figure shows that the coaxial cable emanating from the rod antenna base is carried directly to the floor and grounded there, with a ferrite bead installed between the rod base and the floor ground point. The ferrite bead should have between 20 – 30 Ohms impedance at 20 MHz.. If a rod antenna is used with a coax output connector shell that is isolated from the case, this isolation should be defeated by grounding it to the case. RE103: The requirement is now met if the harmonics do not exceed the applicable RE102 limit. RS101: RS101 for submarine procurements now applies only to equipment and subsystems that have an operating frequency of 100 kHz or less and have the sensitivity to read a signal at or below 1 µV. RS103: In paragraph d.1.c. It states: "Ensure that the E-field sensor is indicating the field from the fundamental frequency and not from the harmonics." MIL- STD-461F imposes a requirement that the radiated signal be demonstrated to be higher in amplitude than its harmonics. RE101: Since 1967, the RE01/RE101 loop probe design has remained the same, and in MIL-STD-461 (1967) was said to be based on the Stoddart Aircraft Radio Company AT-205/URM-6 loop design. The RE01/RE101 loop probe design for the past forty years has been 36 turns of 7-41 Litz wire (seven strands of AWG 41 magnet wire) wrapped on a 5.25" diameter coil, with an electrostatic shield surrounding the windings. Solar Electronics submitted a Standardization Document Improvement Proposal in 2007 that amounted to removing the requirement to use 7-41 Litz wire. The Solar Electronics Model uses 36 turns of AWG 30 wire instead. RE102: there are changes to specific Navy limits and applicability. Equipment slated for use on Navy ASW aircraft now need qualification from 10 kHz to 18 GHz. Other Navy aircraft require RE102 qualification from 2 MHz to 18 GHz. In Figure RE102-1, equipment slated for use below the decks of Navy surface ships get a 20 dB relaxation from the previous -461E limit which was the same for topside or below decks. RE103: The requirement is now met if the harmonics do not exceed the applicable RE102 limit. RS101: RS101 for submarine procurements now applies only to equipment and subsystems that have an operating frequency of 100 kHz or less and have the sensitivity to read a signal at or below 1 µV. RS103: When using wide-band field intensity sensors, there has always been a problem that if the harmonics of a signal come through higher than the fundamental, the probe senses the harmonic. This problem is most prevalent using the biconical antenna below 80 MHz, but can also be a problem using multi-band traveling wave tube (TWT) amplifiers. 5 5

Electromagnetic Interference Emanations to and From Equipment
Radiation into and out of Seams and Apertures Radiation from Panel Components RE and RS RE Power line radiation Interface cable radiation and entry (conduction) CS Power line conduction RE Emission and susceptibility designations. The emissions and susceptibility and associated test procedure requirements in this standard are designated in accordance with an alphanumeric coding system. Each requirement is identified by a two letter combination followed by a three digit number. The number is for reference purposes only. The meaning of the individual letters is as follows: C = Conducted R = Radiated E = Emission S = Susceptibility a. Conducted emissions requirements are designated by "CE---." b. Radiated emissions requirements are designated by "RE---." c. Conducted susceptibility requirements are designated by "CS---." d. Radiated susceptibility requirements are designated by "RS---." . CE and RS/CS 6 6 6

Emission and Susceptibility Requirements from MIL-STD-461F
Table IV Requirement Description CE101 Conducted Emissions, Power Leads, 30 Hz to 10 kHz CE102 Conducted Emissions, Power Leads, 10 kHz to 10 MHz CE106 Conducted Emissions, Antenna Terminal, 10 kHz to 40 GHz CS101 Conducted Susceptibility, Power Leads, 30 Hz to 150 kHz CS103 Conducted Susceptibility, Antenna Port, Intermodulation, 15 kHz to 10 GHz CS104 Conducted Susceptibility, Antenna Port, Rejection of Undesired Signals, 30 Hz to 20 GHz CS105 Conducted Susceptibility, Antenna Port, Cross‑Modulation, 30 Hz to 20 GHz CS106 Conducted Susceptibility, Transients, Power Leads CS109 Conducted Susceptibility, Structure Current, 60 Hz to 100 kHz CS114 Conducted Susceptibility, Bulk Cable Injection, 10 kHz to 200 MHz CS115 Conducted Susceptibility, Bulk Cable Injection, Impulse Excitation CS116 Conducted Susceptibility, Damped Sinusoidal Transients, Cables and Power Leads, 10 kHz to 100 MHz RE101 Radiated Emissions, Magnetic Field, 30 Hz to 100 kHz RE102 Radiated Emissions, Electric Field, 10 kHz to 18 GHz RE103 Radiated Emissions, Antenna Spurious and Harmonic Outputs, 10 kHz to 40 GHz RS101 Radiated Susceptibility, Magnetic Field, 30 Hz to 100 kHz RS103 Radiated Susceptibility, Electric Field, 2 MHz to 40 GHz RS105 Radiated Susceptibility, Transient Electromagnetic Field The applicability of individual requirements for a particular equipment or subsystem is dependent upon the platforms where the item will be used. The electromagnetic environments present on a platform together with potential degradation modes of electronic equipment items play a major role regarding which requirements are critical to an application. For example, emissions requirements are tied to protecting antenna-connected receivers on platforms. The operating frequency ranges and sensitivities of the particular receivers on-board a platform, therefore, influence the need for certain requirements. 7 7

Requirement Matrix Table V Requirement Applicability
Equipment and Subsystems Installed In, On, or Launched From the Following Platforms or Installations Requirement Applicability CE101 CE102 CE106 CS101 CS103 CS104 CS105 CS106 CS109 CS114 CS115 CS116 RE101 RE102 RE103 RS101 RS103 RS105 Surface Ships A L S Submarines Aircraft, Army, Including Flight Line Aircraft, Navy Aircraft, Air Force Space Systems, Including Launch Vehicles Ground, Army Ground, Navy Ground, Air Force The Requirements Matrix (Table V from 461F) summarizes the requirements for equipment and subsystems intended to be installed in, on, or launched from various military platforms or installations. When an equipment or subsystem is to be installed in more than one type of platform or installation, it shall comply with the most stringent of the applicable requirements and limits. An "A" entry in the table means the requirement is applicable. An "L" entry means the applicability of the requirement is limited as specified in the appropriate requirement paragraphs of this standard; the limits are contained herein. An "S" entry means the procuring activity must specify the applicability and limit requirements in the procurement specification. Absence of an entry means the requirement is not applicable. Legend: Applicable Limited as specified in the individual sections of this standard Procuring activity must specify in procurement documentation Requirement is not applicable. A L S 8 8

MIL-STD-461F General Test Configuration
Ground Plane EUT 2 m 10 cm 2 cm 5 cm Above Power Source Interconnecting Cable LISN 80-90 cm Access Panel Bond Strap Test Configuration and Setup Considerations (from 461E Outline) 4.3 Verification requirements Measurement tolerances Shielded enclosures Radio Frequency (RF) absorber material Other test sites Ambient electromagnetic level Ground plane Metallic ground plane Composite ground plane Power source impedance General test precautions Accessory equipment Excess personnel and equipment Overload precautions RF hazards Shock hazard Federal Communications Commission (FCC) restrictions EUT test configurations EUT design status Bonding of EUT Shock and vibration isolators Safety grounds 9 9

5.4. CE101, Conducted Emissions, Power Leads, 30 Hz to 10 kHz
During the measurement system check, the signal generator may need to be supplemented with a power amplifier to obtain the necessary current 6 dB below the applicable limit. Applicable to leads that obtain power from sources that are not part of the EUT. There is no requirement on output leads from power sources. Emission levels are determined by measuring the current present on each power lead. For surface ships and submarines, the intent is to control the effects of conducted emissions peculiar to the shipboard power distribution system For Army aircraft, the concern is to ensure that the EUT does not corrupt the power quality on platform power buses Navy aircraft applicable for installations using anti-submarine warfare (ASW) equipment. Applicability and limits: The requirements are applicable to leads that obtain power from sources that are not part of the EUT. There is no requirement on output leads from power sources. Since power quality standards are normally used to govern the characteristics of output power, there is no need for separate EMI requirements on output leads. For surface ships and submarines, the intent of this requirement is to control the effects of conducted emissions peculiar to the shipboard power distribution system. Harmonic line currents are limited for each electrical load connected to the power distribution system. Power quality for surface ships and submarines is controlled by MIL-STD A. The surface ships and submarine power distribution systems (ship's primary power) supplied by the ship’s alternators is 440 V, 60 Hz, 3-phase, 3-wire, ungrounded. Although ship's primary power is ungrounded, there exists a virtual alternating current (AC) ground at each electrical load due to capacitance to chassis. The unbalance between the virtual grounds at each electrical load causes AC currents to flow in the hull of the submarine. These hull currents can degrade the performance of electronic equipment, upset ground detectors, and counteract degaussing. Hull currents are controlled by limiting the amplitude of harmonic currents conducted on the power distribution system wiring for each electrical load. The limit is based on maintaining total harmonic voltage distortion of the ship power distribution system within 5% of the supply voltage with the contribution from any single harmonic being less than 3%. In addition to the hull current concern, total harmonic distortion of the supply voltage waveform greater than 5% is above the tolerance of most electronic equipment, induction motors, magnetic devices, and measuring devices. For Army aircraft, the primary concern is to ensure that the EUT does not corrupt the power quality (allowable voltage distortion) on the power buses present on the platform. The Army aircraft limits are based on relating the allowable current flowing into a 1.0 ohm impedance to MIL-STD-704 requirements on voltage distortion. The Army limit includes approximately a 20 dB margin with respect to MIL-STD-704 to allow for contributions from multiple emission sources. For Navy aircraft, the requirement is applicable for installations using anti-submarine warfare (ASW) equipment. The primary mission of ASW aircraft is to detect and locate submarines. Unacceptable levels of emission currents in the frequency range of this test would limit the detection and processing capabilities of the Magnetic Anomaly Detection (MAD) and Acoustic Sensor systems. The MAD systems must be able to isolate a magnetic disturbance in the earth's magnetic field of less than one part in 50,000. In present aircraft, the full sensitivity of the MAD systems is not available due to interference produced by onboard equipment. Low frequency interference effects in the 30 Hz to 10 kHz can be a problem for Acoustic Sensor systems. 10

Figure CE101-1 CE101 Limit For Submarine Applications, DC.
Figure CE101-1 shows the CE101 limits for submarine direct current applications. CE101 Limits: Conducted emissions on power leads shall not exceed the applicable values shown on Figures CE101-1, CE101-2 and CE101-3, as appropriate, for submarines and Figure CE101-4 for Army aircraft (including flight line) and Navy ASW aircraft CE101 Test Procedure: Measure the current present on each power lead. Line Impedance Stabilization Networks (LISNs) stabilize measurements near 10 kHz, but are not significant over the rest of the range. Current levels will be independent of power source impedance variations as long as the impedance of the emission source is significant in relation to the power source impedance. 11 11

Figure CE101-2 CE101 Limit For Submarine Applications, 60 Hz
Figure CE101-2 shows the CE101 limits for submarine 60 Hz applications. 12 12

Figure CE101-3 CE101 Limit For Submarine Applications, 400 Hz
Figure CE101-3 shows the CE101 limits for submarine 400 Hz applications. 13 13

Figure CE CE101 Limit For Navy ASW Aircraft And Army Aircraft (Including Flight Line) Applications Figure CE101-4 shows the CE101 limits for Navy ASW and Army aircraft (including flight line) applications. 14 14

5.5. CE102, Conducted Emissions, Power Leads, 10 kHz to 10 MHz
Lower frequency portion is to ensure EUT does not corrupt the power quality (allowable voltage distortion) on platform power buses Voltage distortion is the basis for power quality so CE102 limit is in terms of voltage. Emission levels determined by measuring voltage present at the output port of the LISN Emission levels are determined by measuring the voltage present at the output port on the LISN LISN Output port Applicability and limits: The requirements are applicable to leads that obtain power from sources that are not part of the EUT. There is no requirement on output leads from power sources. The basic concept in the lower frequency portion of the requirement is to ensure that the EUT does not corrupt the power quality (allowable voltage distortion) on the power buses present on the platform. Examples of power quality documents are MIL-STD-704 for aircraft, MIL-STD-1399 for ships, MIL-STD-1539 for space systems, and MIL-STD-1275 for military vehicles. Since power quality standards govern allowable distortion on output power, there is no need for separate EMI requirements on output leads. The output power leads are treated no differently than any other electrical interface. In the case of output power, the quality of the power must be specified over an appropriate frequency range so that the user of the power can properly design for its characteristics. This situation is true whether the power source is a primary source such as 115 V, 400 Hz, or a ± 15 VDC low current supply. A significant indirect control on spectral content exists in the RE102 limits which essentially require that appropriate waveform control and signal transmission techniques be used to prevent unacceptable radiation (see discussion on CE102 limit placement and RE102 relationship below). Since voltage distortion is the basis for establishing power quality requirements, the CE102 limit is in terms of voltage. The use of standardized line impedance over the frequency range of this test provides for the convenient measurement of the voltage as developed across this impedance. In previous versions of MIL-STD-461, a current measurement into a 10 μF feedthrough capacitor was specified. The intent of the capacitor was to provide an RF short of the power lead to the ground plane. It was difficult to interpret the significance of the current limit with respect to platform applications. The presence of standardized impedance is considered to reflect more closely the electrical characteristics of the power buses in platforms. 15 15

Figure CE102-1 CE102 Limit (EUT Power Leads, AC and DC) For All Applications
Figure CE102-1 shows the CE102 limit (EUT power leads, AC and DC) for all applications. 5.5.2 CE102 Limits: Conducted emissions on power leads shall not exceed the applicable values shown on Figure CE102-1 5.5.3 CE102 Test Procedure Emission levels determined by measuring voltage present at the output port of the LISN The upper frequency is limited to 10 MHz because of resonance conditions with respect to the length of the power leads between the EUT and LISN Be cautious of potential overload of measurement receiver due to line voltages at the power frequency 16 16

5.6. CE106, Conducted Emissions, Antenna Terminal, 10 kHz to 40 GHz
CE106 is applicable to the antenna terminals of transmitters, receivers, and amplifiers Intent is to protect receivers on and off the platform from being degraded by antenna radiation from the EUT. Suppression to meet requirements can be severe resulting in significant design penalties. The limits may be tailored by establishing levels based on platform coupling studies Attenuator Setup for Receivers and Transmitters in Stand-by Mode. Note: There are other test setups for low power and high average power transmitters. Measurement Receiver CE106 is applicable for transmitter antennas, receivers, and amplifiers; however, is NOT applicable to for equipment with antennas permanently mounted to the EUT. Requirement applies for transmitters, receivers, and amplifiers in all installations/platforms. The intent is to protect receivers on and off the platform from being degraded by antenna radiation from the EUT. Suppression to meet requirements can be severe resulting in significant design penalties. The limits may be tailored by establishing levels based on coupling studies on the intended platform, if known. Applicability and limits: The requirement is applicable for transmitters, receivers and amplifiers. The basic concern is to protect antenna-connected receivers both on and off the platform from being degraded due to radiated interference from the antenna associated with the EUT. The limit for transmitters in the transmit mode is placed primarily at levels which are considered to be reasonably obtainable for most types of equipment. Suppression levels that are required to eliminate all potential electromagnetic compatibility situations are often much more severe and could result in significant design penalties. The limit for receivers and transmitters in standby is placed at a level that provides reasonable assurance of compatibility with other equipment. Common requirements are specified for all applications since the concerns are the same for all platforms. Depending on the operating frequency of the EUT, the test start frequency is: Test Start Frequency EUT Operating Frequency Range 10 kHz 10 kHz – 3 MHz 100 kHz 3 MHz – 300 MHz 1 MHz MHz – 3 GHz and 10 MHz 3 GHz – 40 GHz (the end frequency is 40 GHz or 20 times the highest generated or received frequency within the EUT – whichever is less) RE103 may be used as an alternative for CE106 for testing transmitters with their operational antennas. Note: RE102 is applicable for emissions from antennas in the receive and standby modes for equipment with antennas permanently mounted to the EUT. Data Recording Device 17 17

5.6. CE106, Conducted Emissions, Antenna Terminal, 10 kHz to 40 GHz
5.6.3 CE106 Test Procedure Emissions are measured on a controlled impedance, shielded, transmission line; results independent of setup A direct coupled technique is used; antenna’s effects are eliminated Transmitter modulation and amplifier frequency, input power, and modulation influences the results Worst case emission spectrum must be used with the most complicated modulation Test parameters should be discussed in the EMITP Use RE103 for transmitters with an integral antenna Test procedures: Since the test procedures measure emissions present on a controlled impedance, shielded, transmission line, the measurement results should be largely independent of the test setup configuration. Therefore, it is not necessary to maintain the basic test setup described in the main body of this standard. The CE106 procedure uses a direct coupled technique and does not consider the effect that the antenna system characteristics will have on actual radiated levels. The selection of modulation for transmitters and frequency, input power levels, and modulation for amplifiers can influence the results. The procedure requires that parameters that produce the worst case emission spectrum be used. The most complicated modulation will typically produce the worst case spectrum. The highest allowable drive level for amplifiers usually produces the worst harmonics and spurious outputs. However, some amplifiers with automatic gain controls may produce higher distortion with drive signals set to the lowest allowable input due to the amplifier producing the highest gain levels. The details of the analysis on the selection of test parameters should be included in the EMITP. 18 18

5.7. CS101, Conducted Susceptibility, Power Lead, 30 kHz to 150 kHz
EUT Signal Injection – Three Phase Ungrounded Applicable to equipment and subsystem AC, limited to current draws ≤100 amperes per phase, and DC input power leads, not including returns. If the EUT is DC operated, requirement applicable over freq range 30 Hz to 150 kHz. If the EUT is AC operated, requirement is applicable from the second harmonic of the EUT power freq and extending to 150 kHz Ensures that performance is not degraded from ripple voltages on power source waveforms Limits are based on MIL-STD-704 The limit is approximately 6 dB above typical power quality limits EUT Signal Injection – DC or Single-Phase AC EUT Signal Injection – Three Phase Wye CS101, conducted susceptibility, power leads, 30 Hz to 150 kHz. Requirement is applicable for all installations. Applies to power input leads from sources not part of EUT Not applicable to power output leads Ensures that performance is not degraded from ripple voltages on power source waveforms Limits are based on MIL-STD-704 The limit is approximately 6 dB above typical power quality limits Margin between limit and power standard allows for variations in performance between items This requirement extended in 461E to150 kHz Applicability and limits: The requirement is applicable to power input leads that obtain power from other sources that are not part of the EUT. There is no requirement on power output leads. The basic concern is to ensure that equipment performance is not degraded from ripple voltages associated with allowable distortion of power source voltage waveforms. The required signal is applicable only to the high sides on the basis that the concern is developing a differential voltage across the power input leads to the EUT. The series injection technique in the test procedure results in the voltage dropping across the impedance of the EUT power input circuitry. The impedance of the power return wiring is normally insignificant with respect to the power input over most of the required frequency range. Common mode voltages evaluations are addressed by other susceptibility tests such as CS114 and RS103. Injection on a power return will result in the same differential voltage across the power input; however, the unrealistic condition will result in a large voltage at the return connection to the EUT with respect to the ground plane. CS101 is applicable to equipment and subsystem AC and DC input power leads. The requirement is applicable over a 30 Hz to 150 kHz frequency range if the EUT is DC operated, and from the 2nd harmonic of the EUT power source to 150 kHz if the equipment is AC operated. Test Procedure The voltage limit is measured across the power input leads to the EUT If the power return is not connected to the shielded room ground, the oscilloscope may need to be electrically “floated” using an isolation transformer to correctly measure the injected voltage There is a potential shock hazard during this test Note: if the power return is not connected to the shielded room ground, the oscilloscope may need to be electrically “floated” using an isolation transformer. 19

Figure CS101-1. CS101 Voltage Limit For All Applications
Figure CS101-1 shows the voltage limit for all applications for requirement CS101. 20 20

Figure CS101-2. CS101 Power Limit For All Applications
Figure CS101-2 shows the power limit for all applications for requirement CS101. 21 21

5.8. CS103, Conducted Susceptibility, Antenna Port, 15 kHz to 10 GHz
Intent is to control the response of antenna connected receiving subsystems to in-band signals resulting from potential intermodulation products of two signals outside of the intentional passband of the subsystem Most applicable to fixed frequency, tunable, superheterodyne receivers. The basic concept is to combine two out-of-band signals (one modulated and one CW) and apply to the antenna port of receiver while monitoring it for an undesired response CS103 General Test Setup CS103 is applicable to equipment and subsystem such as communications receivers, radio frequency (RF) amplifiers, transceivers, radar receivers, acoustic receivers, and electronic warfare receivers. The EUT should not exhibit any intermodulation products when subjected to the limit requirement provided in the individual procurement specification. CS103 controls receiver response to in-band signals resulting from potential IM products of two signals outside of its intentional passband Case-by-case applicability Must be called out in procurement specification Limits determined on a case-by-case basis and must be consistent with the signal processing characteristics and sensitivity of the EUT Applicability and limits: The intent of this requirement is to control the response of antenna connected receiving subsystems to in-band signals resulting from potential intermodulation products of two signals outside of the intentional passband of the subsystem produced by nonlinearities in the subsystem. The requirement can be applied to receivers, transceivers, amplifiers, and the like. Due to the wide diversity of subsystem designs being developed, the applicability of this type of requirement and appropriate limits need to be determined for each procurement. Also, requirements need to be specified that are consistent with the signal processing characteristics of the subsystem and the particular test procedures to be used to verify the requirement. For this requirement, tests need to be performed in an anechoic chamber for receivers with front-end mixing and filtering. Two out-of-band signals (one modulated and one CW) are combined and applied to the antenna port of the receiver while monitoring the EUT for an undesired response. The out-of-band signal frequencies should be f0 = 2f1 – f2 where f0 is the tuned frequency of the receiver and f1 and f2 are the signal source frequencies. 22

5.9. CS104, Conducted Susceptibility, Antenna Port, 30 Hz to 20 GHz
Intent of CS104 is to control response of antenna connected receiving subsystems to signals outside intentional passband of the subsystem. Most applicable to fixed frequency, tunable, superheterodyne receivers. Front-end rejection testing can be applied to a variety of receiving subsystems such as receivers, RF amplifiers, transceivers, and transponders. No test procedures are provided - The basic concept with this test procedure is to apply out-of-band signals to the antenna port of the receiver while monitoring the receiver for degradation. CS104 General Test Setup CS104 is applicable to equipment and subsystem such as communications receivers, radio frequency (RF) amplifiers, transceivers, radar receivers, acoustic receivers, and electronic warfare receivers. Applicability and limits: The intent of this requirement is to control the response of antenna connected receiving subsystems to signals outside of the intentional passband of the subsystem. The requirement can be applied to receivers, transceivers, amplifiers, and the like. Due to the wide diversity of subsystem designs being developed, the applicability of this type of requirement and appropriate limits need to be determined for each procurement. Also, requirements need to be specified that are consistent with the signal processing characteristics of the subsystem and the particular test procedures to be used to verify the requirement. The EUT should not exhibit any intermodulation products when subjected to the limit requirement provided in the individual procurement specification. For this requirement, tests need to be performed in an anechoic chamber for receivers with front-end mixing and filtering. The two most common techniques used for the CS104 test procedure is the two-signal source procedure used for most receivers and the one-signal procedure using a modulated out-of-band signal (appropriate for receivers that search for a signal to capture). There are some receivers that may need to be evaluated using both types of tests. 23 23

5.10. CS105, Conducted Susceptibility, Antenna Port, 30 Hz to 20 GHz
Intent is to control the response of antenna connected receiving subsystems to modulation being transferred from an out-of-band signal to an in-band signal. Results from a strong, out-of-band signal near the operating frequency of the receiver Should be considered only for receivers, transceivers, amplifiers, and the like, which extract information from the amplitude modulation of a carrier. Cross modulation testing should be applied only to receiving subsystems such as receivers, RF amplifiers, transceivers and transponders which extract information from the amplitude modulation of a carrier. Receiver CS105 General Test Setup The basic concept of this test is to apply a modulated signal out-of-band to the receiver and to determine whether the modulation is transferred to an unmodulated signal at the receiver's tuned frequency resulting in an undesired response. CS105 is applicable only to receivers that normally process amplitude-modulated (AM) RF signals when subjected to the limit requirement. Applicability and limits: The intent of this requirement is to control the response of antenna connected receiving subsystems to modulation being transferred from an out-of-band signal to an in-band signal. This effect results from a strong, out-of-band signal near the operating frequency of the receiver that modulates the gain in the front-end of the receiver and adds amplitude varying information to the desired signal. The requirement should be considered only for receivers, transceivers, amplifiers, and the like, which extract information from the amplitude modulation of a carrier. The basic concept with this test is to apply a modulated signal out-of-band to the receiver and to determine whether the modulation is transferred to an unmodulated signal at the receiver's tuned frequency resulting in an undesired response. There may be cases where the in-band signal needs to be modulated if the receiver characteristics so dictate. The level of the in-band signal is normally adjusted to be close to the receiver's sensitivity. The out-of-band signal is modulated with the modulation expected by the receiver. It is then swept over the appropriate frequency ranges while the receiver is monitored for unintended responses. During the test, the EUT should not exhibit any adverse or undesired responses due to cross modulation. During testing, a modulated signal out-of-band to the receiver should be applied to determine whether the modulation is transferred to an unmodulated signal at the receiver’s tuned frequency. In some cases, the in-band signal may need to be modulated if the receiver’s characteristics so dictate. Testing is performed over a frequency range that is ± the receiver intermediate frequency (IF) centered on the receiver’s tuned frequency. 24 24

5.11. CS106, Conducted Susceptibility, Transients, Power Leads
Source Applicable to power input leads on surface ships and submarines that obtain power from the platform’s primary power source that are not part of the EUT. Primary concern is to ensure that performance is not degraded from voltage transients from shipboard power systems The requirement is applicable to power input leads on surface ships and submarines that obtain power from the platform’s primary power source that are not part of the EUT. There is no requirement on power output leads. The primary concern is to ensure that equipment performance is not degraded from voltage transients experienced on shipboard power systems coupling to interface wiring inside enclosures. Electrical transients occur on all electrical distribution systems and can cause problems in circuitry which tend to be sensitive to voltage transients, such as latching circuits expecting a single trigger signal. On submarines and surface ships, these transients can be caused by switching of inductive loads, circuit breaker (or relay) bounce, and load feedback onto the power distribution system. Since the applied transient is coupled in series, Kirchhoff’s voltage law states that the voltage appearing across the transient generator output terminals must drop around the circuit loop formed by the EUT input and the power source impedance. The transient voltage level specified in the limit is measured across the EUT input because part of the induced voltage can be expected to drop across the source impedance. A 10 uF capacitor is added across the power source to reduce the voltage drop across the power source impedance. EUT Connected to Shielded Room Ground 25

5.11. CS109, Conducted Susceptibility, Structure Current, 60 Hz to 100 GHz
Specialized test intended for very sensitive equipment (1 uV or better) such as tuned receivers operating over the frequency range of the test. Intent is to ensure that equipment does not respond to magnetic fields caused by currents flowing in platform structure A current is imposed across the surface of the EUT to verify its ability to withstand structure currents EUT CS109 is applicable to equipment and subsystems that have an operating frequency range of 100 kHz or less and an operating sensitivity of 1 µV or less. Handheld equipment are exempt from this requirement. The intent is to protect equipment from magnetic fields caused by currents flowing in submarine structure and thru the EUT. Limit derived from operational problems due to current conducted on equipment cabinets and laboratory measurements on selected receivers. No tailoring is recommended Applicability and limits: This requirement is specialized and is intended to be applied only for very sensitive equipment (1 V or better) such as tuned receivers operating over the frequency range of the test. The basic concern of the requirement is to ensure that equipment does not respond to magnetic fields caused by currents flowing in platform structure and through EUT housing materials. The magnetic fields are sufficiently low that there is no concern with most circuitry. Electrical connection needs to be made to the external structure of the EUT and damage to the external finish should be minimized. Screws or protuberances at ground potential near the diagonal corners of the EUT should normally be used as test points. Connections should be made with clip or clamp type leads. If convenient test points are not available at the diagonal corners, a sharply pointed test probe should be used to penetrate the finish in place of the clip or clamp type lead. The EUT shall not exhibit and malfunction, degradation of performance, or deviation from specified indications (beyond the tolerances indicated in the equipment specification) when subjected to the values shown in slide 35 (Figure CS109-1). The test procedure for this requirement consists of imposing a current across the surface of the EUT to verify its ability to withstand structure currents. To do this, an electrical connection needs to be made to the external structure of the EUT. Screws or protuberances at ground potential near the diagonal corners of the EUT should be used as test points to minimize damage to the external finish. 26 26

Figure CS109-1. CS109 Limit For All Applications
Figure CS109-1 shows the CS109 requirement limit for all applications. 27 27

5.12. CS114, Conducted Susceptibility, Bulk Cable Injection, 10 kHz to 200 MHz
Applicable to all electrical cables interfacing with the EUT enclosures. Concept is to simulate currents developed on platform cabling from electromagnetic fields generated by antenna transmissions both on and off the platform. Aircraft carrier hangar deck EME test data from 9 aircraft carriers showed significant HF electric field Sig Gen Amp Levels are induced on all wires at connector interface simultaneously Monitor Probe CS114, conducted susceptibility, bulk cable injection, 10 kHz to 400 MHz. Requirement applies to all electrical cables that interface with the EUT for all platforms. This requirement simulates currents developed on platform cabling from EM fields generated by antenna transmissions on and off the platform. (110 dBA corresponds to 200 V/m). The frequency range may be tailored based on: operating frequencies of antenna-radiating equipment. transmitters that are not on the platform. The limit in the flat portion of the curve is from worst-case measurements on aircraft. The shape of the limit reflects the physics of the coupling with regard to resonant conditions, and the cable length with respect to the interfering frequency wavelength. The 10 dB/decade decrease in the limit at the upper frequencies is based on actual induced levels on various aircraft. For submarines, the limit depends on equipment location relative to the pressure hull. The “internal” curve above 30 MHz (curve #2) reflects the use of portable transmitters in the submarine. The “external” curves (2 & 5) closely reflect the EME and applies only to equipment required to be fully operational when located above the waterline. Less severe limits (#2) are specified for EUTs “external” to the pressure hull but within the submarine superstructure (metallic boundary). Applicability and limits: The requirements are applicable to all electrical cables interfacing with the EUT enclosures. The basic concept is to simulate currents that will be developed on platform cabling from electromagnetic fields generated by antenna transmissions both on and off the platform. An advantage of this type of requirement is that it provides data that can be directly related to induced current levels measured during platform-level evaluations. An increasingly popular technique is to illuminate the platform with a low level, relatively uniform field while monitoring induced levels on cables. Then, either laboratory data can be reviewed or current injection done at the platform with the measured currents scaled to the full threat level. This same philosophy has been applied to lightning and electromagnetic pulse testing. Power Inputs CS114 alternate test setup, three phase ungrounded power system. EUT 28 28

Table VI. CS114 Limit Curves
Limit Curve Numbers Shown in Figure CS And Limits Platform Frequency Range Aircraft (External or Safety Critical) Aircraft (Internal) All Ships (Above Decks) and Submarines (External)* Ships (Metallic) (Below Decks) Ships (Non-Metallic) (Below Decks) ** Submarine (Internal) Ground Space 4 kHz – 1 MHz Navy - 77 dBuA 10 kHz – 2 MHz Army 5 3 2 1 Air Force 2 MHz – 30 MHz 4 30 MHz – 200 MHz Table IV shows the CS114 limit curves. * For equipment located external to the pressure hull of a submarine but within the superstructure, use SHIPS (METALLIC) (BELOW DECKS) ** For equipment located in the hanger deck of Aircraft Carriers. 29 29

Table VI. CS114 Limit Curves
CS114 limits for Navy ships of all kinds (black) and extension of limit for power inputs (red dashed) 30 30

Figure CS114-1. CS114 Calibration Limit For All Applications
Figure CS114-1 shows the calibration limit for all applications. 31 31

5.13. CS115, Conducted Susceptibility, Bulk Cable Injection, Impulse Excitation
Applicable to all electrical cables interfacing with EUT enclosures. Concern is to protect equipment from fast rise and fall time transients that may be present due to platform switching operations and external transient environments such as lightning and electromagnetic pulse. Replaces "chattering relay" type requirements (RS06 in MIL- STD-461C) The excitation waveform from the generator is a trapezoidal pulse. A pulse generator required by CS115 is essentially the same as impulse generators used to calibrate measurement receivers except that the pulse width is much longer. A direct current power supply is used to charge the capacitance of an open-circuited 50 ohm coaxial line. The high voltage relay is then switched to the output coaxial line to produce the pulse. The pulse width is dependent upon the length of the charge line. The relay needs to have bounce-free contact operation. Requirements Guidance CS115, conducted susceptibility, bulk cable injection, impulse excitation. Applicable for aircraft, space, and ground EUT interconnecting cables, including power cables that interface with EUT enclosures. Applicable for surface ship and submarine when specified by the procuring activity. The intent is to protect equipment from transients due to platform switching operations and external environments, i.e. lightning and EMP. Replaces "chattering relay" requirement in 461C. The 2 ns rise time is consistent with waveforms created by inductive devices interrupted by switching actions. The 30 ns pulse width standardizes each pulse energy and separates the rise and fall portions of the pulse so that each act independently. The 5 ampere amplitude covers most induced levels observed during aircraft testing. The 30 Hz pulse rate ensures that a sufficient number of pulses are applied to increase confidence that the EUT will satisfactorily operate. Tailoring The amplitude may be tailored based on the expected transients in the platform. The pulse width may be adjusted based on a specific EME onboard a platform. When subjected to a pre-calibrated signal having a rise and fall times, pulse width, and amplitude specified in CS115.1 at a 30 Hz rate for one minute, the EUT shall not exhibit any malfunction, degradation of performance or deviation from specified indications. During CS115 tests, the test waveform used is a trapezoidal pulse; however, the actual waveform on the interconnecting cable depends on cable characteristics and EUT interface circuit parameters. To evaluate common mode coupling, testing is required on the entire power cable and power cables with the returns removed. Applicability and limits: The requirements are applicable to all electrical cables interfacing with EUT enclosures. The basic concern is to protect equipment from fast rise and fall time transients that may be present due to platform switching operations and external transient environments such as lightning and electromagnetic pulse. The requirement is intended to replace "chattering relay" type requirements (RS06 in MIL-STD-461C) commonly used in procurements of equipment for aircraft applications in the past. The chattering relay has been criticized as unscientific and non-repeatable. The CS115 requirement has a defined waveform and a repeatable coupling mechanism. The 2 nanosecond rise time is consistent with rise times possible for the waveforms created by inductive devices interrupted by switching actions. The 30 nanosecond pulse width standardizes the energy in individual pulses. In addition, it separates the rising and falling portions of the pulse so that each may act independently. Also, each portion may affect different circuits. The 5 ampere amplitude (500 volts across 100 ohm loop impedance calibration fixture) covers most induced levels that have been observed during system-level testing of aircraft to transient environments. The 30 Hz pulse rate is specified to ensure that a sufficient number of pulses are applied to provide confidence that the equipment will not be upset. 32 32

Figure CS115-1. CS115 Signal Characteristics For All Applications
Figure CS115-1 shows the signal characteristics for all applications. A pre-calibrated signal having a rise and fall time, pulse width, and amplitude at a 30 Hz rate for one minute 33 33

5.14. CS116, Conducted Susceptibility, Damped Sinusoidal Transients, Cables and Power Leads, 10 kHz to 100 MHz Applicable to electrical cables interfacing with each EUT enclosure and also on each power lead. Concept is to simulate electrical current and voltage waveforms occurring in platforms from excitation of natural resonances. Intent is to control waveform as a damped sine. Wide frequency coverage accounts for a wide range of conditions. Switching Transients within the platform can also result in similar waveforms. Test Procedure Common mode test on the cable bundle simulates the EM field coupling mechanisms Power lead test addresses differential type signals present from switching in the power system The signal can be applied to wires on individual connector pins or to individual circuits (twisted pairs, coaxial cables, etc.) EUT EUT The requirement measures EUTs ability to with-stand damped sinusoidal transients coupled onto its cables and power leads. Applies for all electrical cables interfacing with each EUT enclosure and on individual high side power lead. It applies for all EUTs on any platform. Simulates electrical waveforms in platforms from electrical switching and external stimuli such as: Lightning EMP Recovery time must be specified and whether a momentary upset is allowable. The amplitude may be tailored based on the degree of protection provided by the platform. Applicability and limits: The requirements are applicable to all electrical cables interfacing with each EUT enclosure and also individually on each power lead. The basic concept is to simulate electrical current and voltage waveforms occurring in platforms from excitation of natural resonances. In contrast to CS115 that excites natural resonances, the intent of this requirement is to control the waveform as a damped sine. Damped sine waveforms (sometimes complex combinations) are a common occurrence on platforms from both external stimuli such as lightning and electromagnetic pulse and from platform electrical switching phenomena. Waveforms appearing on cables can be due to the cable itself resonating or to voltage and current drives resulting from other resonances on the platform. Wide frequency coverage is included to account for a wide range of conditions. Transients caused from switching actions within the platform can also result in similar waveforms. A consideration for the requirement is whether momentary upsets are allowable if the EUT is capable of self-recovery to normal operation. Some upsets may occur that are not even noticed by an operator due to self-correcting mechanisms in the equipment. There may be cases where longer term upset is acceptable which may possibly require action by an operator to reset the equipment. The EMITP should address any instances where the contractor proposes that observable upsets be accepted. During CS116 tests, common mode cable test on cable bundles simulates the actual coupling mechanisms from electromagnetic (EM) field excitation on platforms. The individual power lead tests address differential type signals that are present because of switching in power systems on platforms. The test signal can be applied to wires on individual connector pins or to individual circuits (twisted pairs, coaxial cables, etc.) on a EUT. 34 34

Figure CS116-1. Typical CS116 Damped Sinusoidal Waveform
Figure CS116-1 shows the typical dampened sinusoidal waveform used in CS116 tests. 35 35

Figure CS116-2. CS116 Limit For All Applications
Figure CS116-2 shows the test limits for all applications. 36 36

5.15. RE101, Radiated Emissions, Magnetic Field, 30 Hz to 100 kHz
Applicable for radiated emissions from equipment and subsystem enclosures, including electrical cable interfaces. For Navy aircraft, this requirement is applicable only for aircraft with an ASW capability. Specialized, intended to control magnetic fields for applications where equipment is present in the installation which is potentially sensitive to magnetic induction at lower frequencies. A 13.3 cm loop is specified for the test. This standard limits measurements to electrical interface connectors. Connections EUT 13.3 cm loop Requirements Guidance (RE101) Applicable for equipment intended for Navy ships and submarines, Navy ASW, or Army aircraft. RE101 and RS101 are complimentary, imposed to control magnetic electromagnetic interference (EMI) to sensitive low frequency (LF) equipment. Navy Concerned with the potential effects to LF/very low frequency (VLF)/extremely low frequency (ELF) acoustic and communication systems and sensors with nano-volt sensitivities. Limit does not consider intentional magnetic fields from magnetic guns, magnetic launchers, etc Army Concerned with potential effects to engine, flight, and weapon turret control systems and sensors with millivolt sensitivities. Limit may be tailored for single-use EUTs located a sufficient distance from potentially susceptible items . Air Force May be required if an aircraft item will be installed close to an antenna connected to a VLF/LF receiver. Limit needs to be chosen based upon distances between the equipment and the antenna Applicability and limits: This requirement is specialized and is intended primarily to control magnetic fields for applications where equipment is present in the installation which is potentially sensitive to magnetic induction at lower frequencies. The most common example is a tuned receiver that operates within the frequency range of the test. RS101 is a complimentary requirement imposed on equipment to ensure compatibility with the anticipated magnetic fields. The RS101 limits are higher to allow for variations in performance between manufactured items and to account for the possibility that the emissions from the EUT may couple into a larger physical area than that evaluated under the RS101 test procedures. This change recognizes that the connectors are the most likely place for emissions associated with electrical interfaces to occur due to a number of reasons. One is that signal paths transition from normal cable construction techniques (such as twisted pairs) to parallel routing through the connector pins. Also, there are potential contributions from shield termination techniques. 37 37

Figure RE101-1. RE101 Limit For All Army Applications
Figure RE101-1 shows the test limits for all Army applications. 38 38

Figure RE101-2. RE101 Limit For All Navy Applications
Figure RE101-2 shows the test limits for all Navy applications. 39 39

5.16. RE102, Radiated Emissions, Electric Field, 10 kHz to 18 GHz
Applicable to electric field emissions from the EUT and associated cables. Intent is to protect sensitive receivers from interference coupled through the antennas associated with the receiver. Many tuned receivers have sensitivities on the order of 1 uV and are connected to intentional apertures (the antenna) that are constructed for efficient reception of energy in the operating range of the receiver. There is no implied relationship between this requirement and RS103 Test Setup Boundary Sig Gen Double Ridge Horn or Rod Antenna Shielded Enclosure Coax Cable Frequency Platform 12 MHz – 18 GHz * Ground 10 kHz – 18 GHz * Ships, Surface Submarines 10 kHz – 18 GHz Aircraft (Army) 2 MHz – 18 GHz * Aircraft (Air Force Navy) Space Requirements Guidance RE102, radiated emissions, electric field, 10 kHz to 18 GHz. Applicable to all EUTs case and cables on any platform. Requirement is to protect sensitive receivers from EMI coupled thru the receiver’s antennas. NO relationship between RE102 and RS103. Limits based on problems with antenna-connected receivers and typical shielding typically between antennas and EUT case and cables. For EUTs with enclosures or cables in various parts of a platform two different limits may be applicable Surface ship limit is based on case or cable radiation coupling to receiver antennas. Hand-held type transceivers below deck are causing EMI below deck. The limit is more stringent than NATO standards. Submarine equipment limit depends on EUT location, i.e. external or internal to the pressure hull. For aircraft and space installations: Limit for equipment in internal installations on fixed wing aircraft are based on air vehicles not having effective shielding across the range of the test. No limit below 2 MHz. Antennas below 2 MHz are usually magnetic loops with an electrostatic shield. The curve for equipment in external installations and helicopters is 10 dB more stringent because even minimal shielding is not available For ground installations The limits for Navy mobile (including Marines) and all Army ground equipment are the same. The limits for Navy fixed and all Air Force ground equipment are identical. The 20 dB difference between the two is due to their operational deployments. Navy fixed and most Air Force installations have less critical antenna coupling situations RE102 is applicable for radiated emission from equipment and subsystem enclosures, all interconnecting cables, and permanently mounted EUT antennas (receivers and transmitters in standby mode). This requirement however, does not apply at the transmitter fundamental frequencies. The applicable frequencies/platforms are: Applicability and limits: The requirements are applicable to electric field emissions from the EUT and associated cables. The basic intent of the requirement is to protect sensitive receivers from interference coupled through the antennas associated with the receiver. Many tuned receivers have sensitivities on the order of one microvolt and are connected to an intentional aperture (the antenna) which are constructed for efficient reception of energy in the operating range of the receiver. The potential for degradation requires relatively stringent requirements to prevent platform problems. There is no implied relationship between this requirement and RS103 that addresses radiated susceptibility to electric fields. Attempts have been made quite frequently in the past to compare electric field radiated emission and susceptibility type requirements as a justification for deviations and waivers. While RE102 is concerned with potential effects with antenna connected receivers, RS103 simulates fields resulting from antenna-connected transmitters. Recording Device 40 40

Figure RE102-1. RE102 Limit For Surface Ship Applications
Figure RE102-1 shows the test limits for surface ship applications. RE102 Test Procedure Measurements performed in a shielded enclosure with anechoic materials or in an open area test site. Specific antennas required for standardization and consistency between different test facilities. All the specified antennas are linearly polarized. Above 30 MHz, measure both horizontal and vertical components of the radiated field. Below 30 MHz, measurements are performed only for vertical polarization. 41 41

Figure RE102-2. RE102 Limit For Submarine Applications
Figure RE102-2 shows the test limits for submarine applications. 42 42

Figure RE102-3. RE102 Limit For Aircraft And Space System Applications
Figure RE102-3 shows the test limits for aircraft and space system applications. 43 43

Figure RE102-4. RE102 Limit For Ground Applications
Figure RE102-4 shows the test limits for ground applications. 44 44

5.17. RE103, Radiated Emissions, Antenna Spurious and Harmonic Outputs, 10 kHz to 40 GHz
Essentially identical with CE106 for transmitters in the transmit mode. No requirements for receivers or transmitters in the standby mode. The test procedure is laborious and will require a large open area to meet antenna separation distances. Minimum acceptable antenna separations are calculated based on antenna size and operating frequency of the EUT. Measurements in azimuth and elevation are required. Preamps may be required to enhance sensitivity. Coordinate with local frequency allocation authorities. RE103 Limits Harmonics, except the second and third, and all other spurious emissions shall be at least 80 dB down from the level at the fundamental The second and third harmonics shall be suppressed log p (where p = peak power output in watts, at the fundamental) or 80 dB, whichever requires less suppression Calibration and test setup for radiated harmonics and spurious emissions, 10 kHz to 1 GHz. Calibration and test setup for radiated harmonics and spurious emissions, 1 GHz to 40 GHz. Requirements Guidance RE103, radiated emissions, antenna spurious and harmonic outputs, 10 kHz to 40 GHz. Applicable for transmitters in the transmit mode with the intended antenna for all platforms. Not applicable for receivers or transmitters in the standby mode. See discussion under CE106. Unlike CE106, RE103 includes effects due to antenna characteristics. Applicability and limits: The requirements are essentially identical with CE106 for transmitters in the transmit mode. There are no requirements for receivers or transmitters in the standby mode. Most of the discussion under CE106 also applies to RE103. A distinction between the requirements is that RE103 testing includes effects due to antenna characteristics. The test itself is considerably more difficult. RE103 is applicable when testing transmitters and their intended antennas. RE103 can be used as an alternative for CE106; however, CE106 is the preferred requirement unless the equipment subsystem design characteristics precludes its use. RE103 is not applicable within the EUTs necessary bandwidth and within ± 5-percent of the fundamental frequency. The starting frequencies are as follows: Test Start EUT Operating Frequency Frequency Range 10 kHz 10 kHz – 3 MHz 100 kHz 3 MHz – 300 MHz 1 MHz 300 MHz – 3 GHz 10 MHz 3 GHz – 40 GHz Note: the end frequency is 40 GHz or 20 times the highest generated frequency within the EUT, whichever is less. The requirement does not apply below 8/10s of the waveguide cutoff frequency for EUT equipment using waveguides. Test procedures: Since the test procedure measures emissions radiating from an antenna connected to a controlled impedance, shielded, transmission line, the measurement results should be largely independent of the test setup configuration. Therefore, it is not necessary to maintain the basic test setup described in the main body of this standard. The RE103 test procedure is laborious and requires a large open area to meet antenna separation distance. Minimum antenna separation is based on antenna size and EUT operating frequency. In addition, measurements in antenna azimuth and elevation are required, preamps may be required, and coordination with local frequency allocation authorities may be necessary. 45 45

5.18. RS101, Radiated Susceptibility, Magnetic Field, 30 Hz to 100 kHz
Specialized test intended to ensure that performance of equipment susceptible to low frequency magnetic fields is not degraded. Due to its smaller size, the 4 cm loop sensor provides an accurate measure of the field near the axis of the radiating loop. Helmholtz coils generate a relatively uniform magnetic field that is more representative of the environment experienced on some platforms, particularly submarines. For this reason, the AC Helmholtz coil test option is preferred for submarine applications. Prior to initial use, the coils must be tested to ensure they are capable of generating the required magnetic flux densities from 30 Hz to 100 kHz. 4 cm loop or Helmholtz coil to Test each EUT connector EUT Requirements Guidance RS101, radiated susceptibility, magnetic fields, 30 Hz to 100 kHz. Applicability and limits: This requirement is specialized and intended primarily to ensure that performance of equipment potentially sensitive to low frequency magnetic fields is not degraded. RE101 is a complimentary requirement governing the radiated magnetic field emissions from equipment and subsystems. The RE101 discussion is also applicable to this requirement. The Navy RS101 limit was established by measurement of magnetic field radiation from power distribution components (transformers and cables), and the magnetic field environment of Navy platforms. The Navy RS101 limit from 30 Hz to 2 kHz was derived from the worst case. RS101 is applicable to equipment and subsystem enclosures (including electrical cable interfaces). RS101 is not applicable for electromagnetic coupling via antennas. The requirement only applies to Navy aircraft with ASW capability an Army ground equipment having minesweeping or mine detection capabilities. Requirement is applicable as follows: Navy: ships and submarines, ASW aircraft, ground equipment Army: aircraft, vehicles having a minesweeping or mine detection capability Air Force: NOT Applicable for any installations/platforms. Intended to ensure that equipment performance is not degraded by LF magnetic fields. The margin between RS101 and RE101 allows for: variations in manufacturing test distance differences differences between test area and actual installation 46 46

FIGURE RS101-1. RS101 Limit For All Navy Applications
Figure RS101-1 shows the RS101 test limit for all Navy applications. 47 47

Figure RS101-2. RS101 Limit For All Army Applications
Figure RS101-2 shows the RS101 test limits for all Army applications. 48 48

5.19. RS103, Radiated Susceptibility, Electric Field, 2 MHz to 40 GHz
Applicable to both the EUT enclosures and EUT associated cabling Concern is to ensure that equipment will operate without degradation in the presence of electromagnetic fields generated by antenna transmissions both onboard and external to the platform. Limits for different platforms are based on levels expected to be encountered during the service life of the equipment Not necessarily worst-case environment to which the equipment may be exposed. For aircraft and ships, different limits are specified depending on whether the equipment receives protection from platform structure. Requirements Guidance RS103, radiated susceptibility, electric field, 10 kHz to 40 GHz. Applicability and limits: The requirements are applicable to both the EUT enclosures and EUT associated cabling. The basic concern is to ensure that equipment will operate without degradation in the presence of electromagnetic fields generated by antenna transmissions both onboard and external to the platform. There is no implied relationship between this requirement and RE102. The RE102 limit is placed primarily to protect antenna-connected receivers while RS103 simulates fields resulting from antenna transmissions. The limits specified for different platforms are simply based on levels expected to be encountered during the service life of the equipment. They do not necessarily represent the worst-case environment to which the equipment may be exposed. RF environments can be highly variable, particularly for emitters not located on the platform. The limits are placed at levels that are considered to be adequate to cover most situations. The limits are placed at levels that are considered to be adequate to cover most situations, including design levels for “back door” effects (excluding direct coupling to platform antennas or externally mounted devices) resulting from RF high power threat emitters. Requirements apply to EUT enclosures and its cabling intended for use on any platform. This requirement is to ensure satisfactory performance in the presence of EM fields from antenna transmissions on and off platform. No relationship between RS103 and RE102. Limits generally based on levels expected to be seen during the service life of the equipment and location on platform but not worst-case EME. Possible tailoring: Levels and frequencies may be modified based on the emitters on and near the installation, distances between the emitters and the EUT, and intervening shielding. Revise EME levels based on hostile and friendly emitters likely to be encountered. The possible use of the EUT in other installations and the addition or relocation of RF emitters. Additional modulations may be used based on actual platform environments. If CS114 is not imposed, the requirement should be extended to include 10 kHz to 2 MHz 49 49

Table VII. RS103 Limits Limit Level (Volts/Meter) 50 50 2 MHz – 30 MHz
Platform Frequency Range Aircraft (External or Safety Critical) Aircraft (Internal) All Ships (Above Decks) and Submarines (External)* Ships (Metallic) (Below Decks) Ships (Non-Metallic) (Below Decks) ** Submarine (Internal) Ground Space 2 MHz – 30 MHz Army 200 10 50 5 20 Navy Air Force - 30 MHz – 1 GHz 1 GHz – 18 GHz 60 18 GHz – 40 GHz Table VII shows the radiated field limits for RS103 tests. Test facilities are permitted to select appropriate electric field generating apparatus. Any electric field generating device such as antenna, long wire, TEM cell, reverberating chamber (using mode tuned techniques) or parallel strip line capable of generating the required electric field may be used. Fields should be maintained as uniform as possible over the test setup boundary. Above 30 MHz, both horizontally and vertically polarized fields must be generated. This requirement may limit the use of certain types of apparatus. Only vertically polarized measurements are required below 30 MHz due to the difficulty of orienting available test equipment for horizontal measurements. Monitoring requirements emphasize measuring true electric field. While emission testing for radiated electric fields does not always measure true electric field, sensors with adequate sensitivity are available for field levels generated for susceptibility testing. Physically small and electrically short sensors are required so that the electric field does not vary substantially over the pickup element resulting in the measurement of a localized field. Broadband sensors not requiring tuning are available. Using circularly polarized fields is not allowed due to problems with using the spiral conical antennas specified in versions of MIL-STD-462 in the past. Circularly polarized fields were convenient since they avoided the need to rotate a linearly polarized antenna to obtain both polarizations of the radiated field. However, problems existed with this antenna. At some frequencies, the antenna pattern of the conical log spiral is not centered on the antenna axis. Also, the circular polarization of the conical log spiral creates confusion in its proper application. The EUT and associated cabling can be expected to respond more readily to linearly polarized fields. * For equipment located external to the pressure hull of a submarine but within the superstructure, use SHIPS (METALLIC) (BELOW DECKS) ** For equipment located in the hanger deck of Aircraft Carriers. 50 50

5.20. RS105, Radiated Susceptibility, Transient Electromagnetic Field
Intended for EUTs to withstand the fast rise time, free-field transient environment of EMP. Applies for equipment enclosures which are directly exposed to the incident field outside of the platform structure or for equipment inside poorly shielded or unshielded platforms. The electrical interface cabling should be protected in shielded conduit. The EMP field is simulated in the laboratory using bounded wave TEM radiators such as TEM cells and parallel plate transmission lines. Since the polarization of the incident EMP field in the installation is not known, the EUT must be tested in all orthogonal axes. Requirements GuidanceRS105, radiated susceptibility, transient, electromagnetic field. Requirement protects EUTs from an EMP. Applicable for EUT enclosures installed on Navy platforms and Army aircraft which are either: directly exposed to the field outside of the platform structure or inside poorly shielded or unshielded platforms. Cabling should be in shielded conduit. Responses due to cable coupling controlled by CS116. Tailor limit amplitude based on enhancement or protection provided in the installation. The limit is consistent with IEC EMP standards. Applicability and limits: This requirement is primarily intended for EUTs to withstand the fast rise time, free field, transient environment of an electromagnetic pulse (EMP). It applies for equipment enclosures which are directly exposed to the incident field outside of the platform structure or for equipment inside poorly shielded or unshielded platforms. This requirement may be tailored in adjustment of the curve amplitude either higher or lower based on degree of field enhancement or protection provided in the area of the platform where the equipment will be located. This requirement is applicable only for EUT enclosures. The electrical interface cabling should be protected in shielded conduit. Potential equipment responses due to cable coupling are controlled under CS116. 51 51

Figure RS105-1. RS105 Limit For All Applications
Figure RS105-1 shows the test limits for all applications. During RS105 testing, an EMP field is simulated using bounded wave radiators. The EUT must be tested in all orthogonal axes since the EMP field polarization in the installation is unknown. Testing must be initiated at lower levels to prevent damage or burnout to the EUT. The EUT may exhibit susceptibility at lower levels due to the presence of terminal protection devices (TPDs) that might not actuate until higher levels are experienced. 52 52

Commercial and Other E3 Standards
American National Standards Institute (ANSI), Institute of Electrical and Electronics Engineers (IEEE), Society of Automotive Engineers (SAE) Federal Communications Commission (FCC) Radio Technical Commission for Aeronautics (RTCA) DO-160D International European Union (EU) International Electro-technical Commission (IEC) International Special Committee on Radio Interference (CISPR) Comité Européen de Normalisation Électrotechnique (European Committee for Electrotechnical Standardization) (CENELEC) North Atlantic Treaty Organization (NATO) EPS Results Of Detailed Comparisons Of Individual EMC Requirements And Test Procedures Delineated In Major National And International Commercial Standards With Military Standard MIL-STD-461E Appendix E - MIL-HDBK-237 As mentioned earlier, use of commercial standards is highly desirable and there are a variety of commercial E3 standards available. In fact, there are too many! And no single commercial standard covers the wide variety of EM environments and requirements of the military. There are E3 related standards developed by professional societies such as American National Standards Institute (ANSI), Institute of Electrical and Electronics Engineers (IEEE), Society of Automotive Engineers (SAE), etc. The Federal Communications Commission (FCC) regulates emissions of commercial products, commonly referred to as Part 15 devices. Radio Technical Commission for Aeronautics (RTCA) DO-160D is the closest requirement to anything military, specifying EMI requirements for commercial aircraft equipment. Its very similar to MIL-STD-461. The JSC conducted a study a number of years ago, comparing many aspects of various commercial standards, with related requirements from MIL-STD-461D. The results showed that military requirements truly had no commercial equivalent. The report (ENGINEERING PRACTICE STUDY (EPC), March 2, 2001, Results Of Detailed Comparisons of Individual EMC Requirements and Test Procedures Delineated in Major National and International Commercial Standards With Military Standard MIL-STD-461E) is available on the JSC Defense Online and DAU ACC websites. 53

DIFFERENCES BETWEEN COMMERCIAL AND MILITARY STANDARDS
Major differences: Unique platform requirements because of critical dependence on the reception of certain frequencies More severe military RE limits due to: larger concentration high-power emitters more sensitive receivers in military platforms The military imposes higher susceptibility (immunity) requirements due to co-located intentional emitters 54

DIFFERENCES BETWEEN COMMERCIAL AND MILITARY STANDARDS
Major differences (continued) Military platforms have grounded conducting surfaces for mounting equipment; civilian items are usually mounted on ungrounded tables Military’s frequency ranges are more extensive than commercial No commercial standard equivalent to MIL-STD-461E 55

Differences Between Commercial And Military Standards
Evaluate anticipated EME vs. characteristics of the CI under consideration Determine: Which commercial standards apply to CI? Their adequacy for the intended use If additional tests and requirements should be imposed Decision process illustrated in Figure E (pg 167 of notes) 56

Defining Applicable EMI Requirements
Specify Mission Define performance characteristics taking into account mission and safety criticality Determine operational EME Are requirements in MIL-STD 461E appropriate? Can MIL-STD 461E requirements be tailored to meet operational requirements? Specify additional requirements Tailor requirements Is item produced for military or commercial use? Use EPS, as applicable to assess risks Evaluate risks using EPS recommendations, as applicable Does item meet requirements? Is retest necessary? Retest Is risk acceptable? Can equipment or installation be modified? ACCEPT REJECT Modify Y COM N MIL Is additional testing required? Perform tests 57 57

The E3 area addresses a number of interfacing issues with environments both external to the system and within the system. External to the system are electromagnetic effects such as lightning, EMP and man-made RF transmissions. Internal to the system are EM effects such as electronic noise emissions, self-generated RF transmissions from antennas, and cross-coupling of electrical currents. In addition, RF systems today are complex due to composite materials being used in Navy ships and aircraft. Many materials being used today are nonmetallic (composites) and have unique EM properties that require careful consideration. Electronic systems performing critical functions are common. Wide use of RF transmitters, sensitive receivers, and sensors create a potential for problems within the system and from external influences. Increasing use of commercial equipment in unique military operational environments poses special interface considerations. Each system must be compatible with itself, other systems, and the external environment to ensure required performance. This compatibility prevents costly system redesign for resolution of problems.

5.11 External Grounds MIL-STD-464A
Recognizes the impact of EME on the warfighting capability of the Armed Forces. Establishes requirements on how system need to interface with each other in the EME. Provides Detailed requirements for: 59

MIL-STD-464A What it provides: Basic E3 requirements and guidance.
Go/No-Go Pass/Fail Procedures What it doesn’t provide: Go/No Go or Pass/Fail test procedures. MIL-STD-464A does not provides procedures; it provides guidance and levels to measure against. Other standards or testing procedures are used to do the actual testing. Basic requirements and guidance on E3 considerations, including definitions, and acceptable levels of performance for various types of electromagnetic considerations, frequencies, and various platforms. Go/No Go or Pass/Fail procedures for testing, or delineation of systems and combinations of systems that should be tested. A standard to establish requirements on how systems need to interface with each other in the Electromagnetic Environmental Effects (E3) arena 60

MIL-STD-464A Format MAIN BODY APPENDIX
(Specifies a base line set of requirements) Definitions General Requirements Detailed Requirements Data Item Descriptions APPENDIX Requirements (repeats standard in italics) Rationale Guidance Lessons Learned Verification This standard contains two sections, the main body and an appendix. The main body of the standard specifies a baseline set of requirements. Defines E3 requirements and gives specifics to different categories, e.g. Intra system EMC, Shipboard internal EME, external RF EME and E3 Disciplines. “Notes” includes Data Item Descriptions, Tailoring guidance, references to similar NATO documentation and points of contact The appendix portion provides rationale, guidance, and lessons learned for each requirement to enable the procuring activity to tailor the baseline requirements for a particular application. The appendix also permits Government and Industry personnel to understand the purpose of the requirements and potential verification methodology for a design. The appendix is not a mandatory part of this document but is critical to understanding the standard. 61

MIL-STD-464A Contents Detailed Requirement Appendix Subject Para. Page
Margins 5.1 5 A5.1 33 Intra-system EMC 5.2 A5.2 36 External RF EME 5.3 6 A5.3 44 Lightning 5.4 9 A5.4 54 Electromagnetic Pulse (EMP) 5.5 A5.5 60 Subsystems & equipment EMI 5.6 A5.6 65 Electrostatic charge control 5.7 11 A5.7 72 Electromagnetic radiation hazard 5.8 A5.8 79 Life cycle, E3 hardness 5.9 13 A5.9 86 Electrical bonding 5.10 A5.10 91 Electrical grounds 5.11 14 A5.11 101 TEMPEST 5.12 A5.12 106 Emission control 5.13 A5.13 107 EM spectrum compatibility 5.14 15 A5.14 110 This chart illustrates where to go in the Standard for each E3 requirement, since the information is contained both in the Detailed Requirements and the Appendix. This is meant as a quick reference in the future to find the appropriate data. Basically, each requirement is provided in section 5 and then repeated in detail, with supporting information, in the Appendix. 62

5.2 Intra-System Electromagnetic Compatibility (EMC)
MIL-STD-464A Contents Each section has overall requirements similar to the one below for Intra-System EMC 5.2 Intra-System Electromagnetic Compatibility (EMC) The system shall be electromagnetically compatible within itself such that system operational performance requirements are met. Compliance shall be verified by system-level test, analysis, or a combination thereof. The system shall be electromagnetically compatible among all subsystems and equipment within the system and with environments caused by electromagnetic effects external to the system. Verification shall be accomplished as specified in this MIL-STD on production representative systems Safety critical functions verified to be electromagnetically compatible within the system and with external environments prior to use in those environments. Verification shall address all life cycle aspects of the system (e.g., normal operation, checkout, storage, transportation, loading/unloading, launch and normal operating procedures). MIL-STD-464A 63

EMC Requirements EMP Lightning External RF EME External to System
EME issues Cross coupling of electrical currents Self-generated RF transmissions from antennas E3 addresses a number of interfacing issues with internal and external environments as illustrated in the slide. External to the system are electromagnetic effects such as lightning, EMP and the external RF EME. Internal to the system are electromagnetic effects such as electronic noise emissions, self-generated RF transmissions from antennas, and cross-coupling of electrical currents between equipment and subsystems of the system. Systems today are complex from a materials usage and electronics standpoint. Many materials being used are nonmetallic and have unique electromagnetic properties which require careful consideration. Electronics performing critical functions are common. Wide use of RF transmitters, sensitive receivers, other sensors, and additional electronics creates a potential for problems within the system and from external influences. Increasing use of commercial equipment in unique military operational environments poses special interface considerations. Each system must be compatible with itself, other systems, and external environments to ensure required performance and to prevent costly redesigns for resolution of problems. Unintentional conducted and radiated EM emissions Internal to System 64

EMC Requirements (cont.)
MIL-STD-464A Format EMC Requirements (cont.) In addition to design requirements, MIL-STD-464A provides verification requirements Costly Delays during system development Mission Aborts Reduced system and equipment operational effectiveness It is important that assets required for verification of E3 requirements be identified early in the program to ensure their availability when needed. As examples: If the EMI qualification is not properly completed on subsystems and equipment, the failure in the overall system may not show up till late during the system development, necessitating the repeat of many test with the re-designed subsystem and equipment. If the subsystems and equipment are not placed in the modes of operation that will maximize the potential indication of interference or susceptibility, missions may have to be aborted when confronted with the type of interference that was not tested. If anomalies found are not evaluated to determine whether they are truly an E3 issue or some other type of malfunction or response, the systems could be degraded unexpectedly, reducing the operational effectiveness of the system, and the resultant mission. Up front identification of what is needed for verification is essential to ensure efficient and timely verification during the testing process. Identify assets for E3 requirement verification early! 65

5.2 Intra-System EMC: Verification Rationale
MIL-STD-464A Format 5.2 Intra-System EMC 5.2 Intra-System EMC: Verification Rationale The most basic element of demonstrating that E3 design efforts have been successful is verification of intra-system EMC through testing, supported by analysis. Verification of RF compatibility by test is essential to ensure an adequate design which is free from the unacceptable degradation caused by antenna-to-antenna coupled interference. Prior analysis and equipment-level testing are necessary to assess potential problems and to allow sufficient time for fixing subsystem/equipment problems. EMC Testing EMC Analysis 66

MIL-STD-464A Format 5.3 External RF EME
The system shall be electromagnetically compatible with its defined external RF EME such that its SOP requirements are met. The EME in which military systems and equipment must operate is created by a multitude of sources. The contribution of each emitter may be described in terms of its individual characteristics including: power level, modulation, frequency, bandwidth, antenna gain (mainbeam and sidelobe), antenna scanning, and so forth. These characteristics are important in determining the potential impact on system design. A high powered emitter may illuminate the system for only a very short time due to its search pattern or may operate at a frequency where effects are minimized. 67

MIL-STD-464A Format 5.3 External RF EME (cont.)
TABLE 1A. External EME for deck operations on ships TABLE 1B. External EME for shipboard operations in the main beam of transmitters For shipboard applications systems (including fixed and rotary wing aircraft) employed in, Table 1A shall be used for operations Above Deck, with Table 1B used for operations in the main beam of transmitters. Table 1A discussion: A composite of calculated and measured levels present on deck of various ships. Note that the deck levels in Table 1A are higher than the main beam values in Table 1B in some frequency bands. This situation is due to the Navy making a conscious decision to base the deck EME levels on the Permissible Exposure Levels (PELs) in DoDI in some bands to allow for situations where external emitters may be brought onboard a ship or emitters may be operated in a maintenance mode with the antenna in an unusual position. Table 1B Discussion Fields calculated 50’ from the main beam of transmitters onboard various ships. Navy deck EME levels are based on the Permissible Exposure Levels (PELs) in DoDI Allows external emitters to be brought onboard a ship or emitters operated in a maintenance mode with the antennas in an unusual positions. 68

MIL-STD-464A Format 5.3 External RF EME (cont.) 69
For space and launch vehicle systems applications, Table 1C shall be used. NASA CR 4776, “The On-Orbit Radio Frequency Environment,” used the JSC data base to evaluate environments at a 200 nm orbit and 900 inclination. Studies were conducted on Eastern and Western launch sites using the JSC data base; largest emitters verified and updated as necessary. For ground systems, Table 1D shall be used. EME derived from a ground scenario assuming certain separation distances from emitters. Dips in the EME were smoothed out. Actual EME may differ due to operational requirements or restrictions. 69

External EME for Army rotary wing aircraft
MIL-STD-464A Format 5.3 External RF EME (cont.) TABLE 1E. External EME for Army rotary wing aircraft 260 Table 1E. Applicable for Army rotary wing aircraft. Table 1E is the minimum baseline ground systems. The EME derived from the following: FAA rotorcraft severe environment, US Navy shipboard main beam field levels, and EME around other aircraft (U.S. and coalition partners), airfields, and special use and expeditionary airspace. Table E created from EMEs from several sources. Data bases include "red" and "gray" emitters in which rotorcraft may be operating. Minimum distance from ground emitters for low flights is 150 m and 50 m from other aircraft The value marked out and given a new value indicates an error in the MIL-STD. 70

MIL-STD-464A Format 5.3 External RF EME (cont.)
TABLE 1F: External EME for fixed wing aircraft, excluding shipboard operations Table 1F - Baseline for fixed wing military aircraft. Based SAE AE-4R and the European Working Group (EUROCAE) for fixed wing commercial aircraft. Tailoring is encouraged “Guide for the Certification of Aircraft in a High Intensity Radiated Field (HIRF) Environment” details approach for certification EUROCAE issued the guide as ED-107 SAE document has not been released Assumptions: Single, one-of-a-kind transmitters and those in restricted air space excluded. Assumes main beam illumination and max gain Does not consider modulation of transmitter HF ground reflections assumed to be in phase Non-cumulative field strength is calculated Does not consider simultaneous illumination by more than one antenna Near-field corrections for antennas are used For transmitters in special use airspace, fields are calculated at the perimeter of the airspace EME Levels calculated at minimum distances depending on transmitter and aircraft location (Airport , Air-to-air , Ship-to-air, Ground-to-air) 71

MIL-STD-464A Format 5.4 Lightning
The system shall meet its operational performance requirements for both direct and indirect effects of lightning Ordnance shall meet its operational performance requirements after experiencing a near strike in an exposed condition and a direct strike in a stored condition. Ordnance shall remain safe during and after experiencing a direct strike in an exposed condition Verification of lightning requirements is essential to demonstrate that the design protects the system from the lightning threat environment, but there is no single approach to verifying the design. A well structured test program supported by analysis is generally necessary. The use of non-metallic (composite) materials for parts such as fuel tanks and aircraft wings introduces the need for specific tests for sparking and arcing in these members. 72

MIL-STD-464A Format 5.4 Lightning (cont.)
Direct effects of lightning are: Burning Eroding Blasting Structural deformation High pressure shock waves Magnetic forces produced by the associated high currents Indirect effects are those resulting from the electromagnetic fields associated with lightning and the interaction of these electromagnetic fields with equipment in the system. Direct: Direct effects protection on all-metal aircraft has been generally limited to protection of the fuel system, antennas, and radomes. Most of the aircraft lost due to lightning strikes have been the result of fuel tank arcing and explosion. Indirect: In aircraft: lightning protection against indirect effects has become much more important due to the increased use of electrically and electronically controlled flight and engine systems Other losses have been caused by indirect effects arcing in electrical wiring in fuel tanks. Level of protection: While all airborne systems need to be protected against the effects of a lightning strike, not all systems require the same level of protection. As aircraft are built with nonmetallic structures, protection of the fuel system becomes much more difficult and stricter attention to details is required. For example, an air-launched missile may only need to be protected to the extent necessary to prevent damage to the aircraft carrying the missile. In general, some metal will have to be put back into nonmetallic structures to provide adequate lightning protection. 73

5.5 Electromagnetic Pulse (EMP)
MIL-STD-464A Format 5.5 Electromagnetic Pulse (EMP) High-altitude EMP (HEMP) is generated by a nuclear burst above the atmosphere which produces coverage over large areas and is relevant to many military systems. The entire continental US area can be exposed to high-level fields with a few bursts. EMP survivability requirements are normally specified, if required, in Acquisition documents, such as the ICD, CDD, CPD, etc. The system shall meet its operational performance requirements after being subjected to the EMP Environment. 74

5.5 Electromagnetic Pulse (EMP)
MIL-STD-464A Format 5.5 Electromagnetic Pulse (EMP) The following are elements of an iterative process for designing and verifying protection of a system’s electrical and electronic equipment against the effects of EMP. a. EMP coupling analysis b. Identification of relevant subsystems c. Equipment strength determination A coupling analysis is necessary to determine the EMP free-field coupling into the system. Existing coupling data on similar system designs should be used whenever possible. Subsystems and equipment that may be affected by EMP, and whose proper operations are critical or essential to the operation of the system, must be identified. The equipment locations within the system need to be determined. The inherent hardness of equipment without specific EMI susceptibility requirements needs to be determined. These results together with existing EMI requirements on equipment establish a lower bound on the upset and damage thresholds for each mission critical equipment. Verification that the system meets EMP design requirements is accomplished by demonstrating that the actual transient levels appearing at the equipment interfaces do not exceed the hardness levels of the individual equipment or subsystem and that the required design margins have been met. Verification should be accomplished by a combination of test and analysis. d. Specification compliance demonstration 75

5.6 Subsystems and Equipment EMI
MIL-STD-464A Format 5.6 Subsystems and Equipment EMI Intra-system EMC is the most basic element of E3 concerns. Individual subsystems and equipment shall meet interference control requirements so that the overall system complies with all applicable requirements of this standard Individual subsystems and equipment shall meet interference control requirements (such as the conducted emissions, radiated emissions, conducted susceptibility, and radiated susceptibility requirements of MIL-STD-461) so that the overall system complies with all applicable requirements of this standard. Compliance shall be verified by tests that are consistent with the individual requirement (such as testing to MIL-STD-461). Past experience has shown that equipment compliance with its EMI requirements assures a high degree of confidence of achieving system-level compatibility. Non-conformance to the EMI requirements often leads to system problems. The greater the noncompliance is with respect to the limits, the higher the probability is that a problem will develop. Since EMI requirements are a risk reduction initiative, adherence to the EMI requirements will afford the design team a high degree of confidence that the system and its associated subsystems will operate compatibly upon integration. But compliance with MIL-STD-461 does not guarantee compatibility within the overall system. 76

5.6 Subsystems and Equipment EMI (cont.)
MIL-STD-464A Format 5.6 Subsystems and Equipment EMI (cont.) Areas of EMI requirements Unintentional subsystem emissions EMI requirements are separated into two areas, unintentional emissions from the subsystem and susceptibility (referred to in the commercial world as immunity) to external influences. Each of these areas have conducted and radiated controls. Most emission requirements are frequency domain related and data are taken with spectral analysis equipment, Line impedance stabilization networks (LISNs), current probes for conducted measurements, and antennas for radiated measurements. Susceptibility requirements are usually defined in terms of conducted drive voltages and currents for transients and modulated sinusoids to evaluate power and signal interfaces and electromagnetic field levels for unintentional radiated signals. The electromagnetic environment within a system is complex and extremely variable depending upon the various operating modes and frequencies of the on-board equipment. Also, system configurations are continuously changing as new or upgraded equipment is installed. Some of the primary factors driving the need for controls are the presence of sensitive antenna connected receivers, which respond to interference generated within their tuning ranges, and the environments produced by on-board and external transmitters, lightning, and electromagnetic pulse. An application where emission requirements may need to be imposed that are more stringent than the default limits in MIL-STD-461 concerns platforms or ground installations that perform MIL-STD-464A intelligence, surveillance, and reconnaissance (ISR) missions. Susceptibility to external influences. Each of these areas can have conducted and radiated controls. 77

5.7 Electrostatic Charge Control
MIL-STD-464A Format 5.7 Electrostatic Charge Control The system shall control and dissipate the build-up of electrostatic charges caused by precipitation static (p-static) effects, fluid flow, air flow, exhaust gas flow, personnel charging, charging of launch vehicles (including pre-launch conditions) and space vehicles (post deployment), and other charge generating mechanisms to avoid fuel ignition and ordnance hazards, to protect personnel from shock hazards, and to prevent performance degradation or damage to electronics. The system shall control and dissipate the build-up of electrostatic charges caused by precipitation static (p-static) effects, fluid flow, air flow, exhaust gas flow, personnel charging, charging of launch vehicles (including pre-launch conditions) and space vehicles (post deployment), and other charge generating mechanisms to avoid fuel ignition and ordnance hazards, to protect personnel from shock hazards, and to prevent performance degradation or damage to electronics. 78

5.7 Electrostatic Charge Control
MIL-STD-464A Format 5.7 Electrostatic Charge Control Nature Dust Rain Snow Dust, rain, snow, and ice can cause an electrostatic charge buildup on the system structure due to charge separation and the phenomenon called precipitation static charging. Sloshing fuel in tanks and fuel flowing in lines can both create a charge buildup resulting in a possible fuel hazard due to sparking. Any other fluid or gas flowing in the system (such as cooling fluid or air) can likewise deposit a charge with potentially hazardous consequences. During maintenance, contact of personnel with the structure and various materials can create an electrostatic charge buildup on both the personnel and structure (particularly on non-conductive surfaces). This buildup can constitute a safety hazard to personnel or fuel or may damage electronics. Potentially susceptible electronic parts are microcircuits, discrete semiconductors, thick and thin film resistors, integrated circuits, hybrid devices, and piezoelectric crystals, dependent upon the magnitude and shape of the electrostatic discharge (ESD) pulse. Human Related System Related 79

5.7.1 Vertical Lift and In-Flight Refueling
MIL-STD-464A Format 5.7.1 Vertical Lift and In-Flight Refueling The system shall meet its operational performance requirements when subjected to a 300 kilovolt discharge. This requirement is applicable to vertical lift aircraft, in-flight refueling of any aircraft, and systems operated or transported externally by vertical lift aircraft. Compliance shall be verified by test (such as MIL-STD-331 for ordnance), analysis, inspections, or a combination thereof. The test configuration shall include electrostatic discharge in the vertical lift mode and in-flight refueling mode from a simulated aircraft capacitance of 1000 picofarad, through a maximum of one ohm resistance. Any type of aircraft can develop a static charge on the fuselage from p-static charging effects. Aircraft that have the capability for lifting cargo or performing in-flight refueling have special operational concerns. In the case of vertical lift, the accumulated charge can cause an arc between the hook and the cargo during pick-up or between the suspended cargo and the earth during delivery. In the case of in-flight refueling, the tanker aircraft can be at one voltage potential and the aircraft to be refueled will be at a different potential, possibly resulting in an arc during mating of the two aircraft. For vertical lift capability, the requirement should be applied to both the lifting aircraft and the system being lifted. For in-flight refueling, the requirement should be applied to the equipment and subsystems that are functioning during refueling. To protect personnel on the ground from receiving electrical shocks, it is standard practice for rotorcraft to touch the ground with the hook before it is connected to the cargo. For sling loaded ordnance, this requirement is applicable in addition to of MIL-STD-464. 80

5.7.2 Precipitation Static (P-Static)
MIL-STD-464A Format 5.7.2 Precipitation Static (P-Static) The system shall control p-static interference to antenna-connected receivers onboard the system or on the host platform such that system operational performance requirements are met. The system shall protect against puncture of structural materials and finishes and shock hazards from charge accumulation. Compliance shall be verified by test, analysis, inspections, or a combination thereof. Rationale: As systems in motion encounter dust, rain, snow, and ice, an electrostatic charge buildup on the structure results due to precipitation static charging. This buildup of static electricity causes significant voltages to be present which can result in interference to equipment, puncture of dielectric materials, and constitute a shock hazard to personnel. For aircraft applications, aircrew personnel may be affected during flight and ground personnel may be affected after landing. Guidance: Static electricity accumulates on aircraft in flight (p-static charging) because there is no direct electrical path to allow the charges to flow off the aircraft. Special control mechanisms become necessary to dissipate the charge. The accumulated charge develops a voltage on an aircraft with respect to the surrounding air. When the voltage becomes high enough, the air periodically breaks down in an impulse fashion at sharp contour points where the electric field is the highest. The sharp impulses produce broadband radiated interference which can degrade antenna-connected receivers, particularly lower frequency receivers. The impulses can occur so rapidly that the receivers produce only a hissing sound and become useless. Precipitation static dischargers are usually used to control this effect. These devices are designed to bleed the accumulated charge from the aircraft at levels low enough not to cause receiver interference. 81

MIL-STD-464A Format 5.7.3 Ordnance Subsystems
Explosive subsystems are used for many purposes including store ejection from aircraft, escape systems, rocket motors, and warhead initiation. Voltages and discharge energies associated with ESD can inadvertently ignite or fire these devices. The consequences can be hazardous. Ordnance subsystems shall not be inadvertently initiated or dudded by a 25 kilovolt electrostatic discharge caused by personnel handling. 82

5.8 Electromagnetic Radiation Hazard (EMRADHAZ)
MIL-STD-464A Format 5.8 Electromagnetic Radiation Hazard (EMRADHAZ) It has been firmly established that sufficiently high electromagnetic fields can harm personnel, ignite fuel, and fire electrically initiated devices (EIDs). Precautions must be exercised to ensure that unsafe conditions do not develop. The system design shall protect personnel, fuels, and ordnance from hazardous effects of electromagnetic radiation. 83

5.8.1 Hazards of Electromagnetic Radiation to Personnel (HERP)
MIL-STD-464A Format 5.8.1 Hazards of Electromagnetic Radiation to Personnel (HERP) The proven adverse biological effects of non-ionizing (electromagnetic) radiation are thermal, resulting from overheating of human body tissue. Overheating results when the body is unable to cope with or adequately dissipate heat generated by exposure to RF energy. The body’s response is dependent on the energy level, time of exposure (The exposure limit is time-averaged over a six-minute interval so that the human can be exposed to higher levels for a shorter period of time.) , and ambient temperature. Limits on personnel exposure and related personnel RADHAZ safety criteria is specified in DoDI , Protection of DoD Personnel from Exposure to Radiofrequency Radiation and Military Exempt Lasers. Radar and electronic warfare (EW) systems usually present the greatest potential personnel hazard due to high transmitter output powers and antenna characteristics and possible exposure of servicing personnel. Personnel assigned to repair, maintenance, and test facilities have a higher potential for being overexposed because of the variety of tasks, the proximity to radiating elements, and the pressures for rapid maintenance response. Safe distances can be determined from calculations based on RF emitter characteristics or through measurement. Safe distance calculations are often based on the assumption that far-field conditions exist for the antenna. These results will be conservative if near-field conditions actually exist. In addition to the main beam hazard, localized hot spots may be produced by reflections of the transmitted energy from any metal structure. These results can occur in areas having general power densities less than the maximum permissible exposure limits. The system shall comply with current DoD criteria for the protection of personnel against the effect of electromagnetic radiation. 84

5.8.2 Hazards of Electromagnetic Radiation to Fuel (HERF)
MIL-STD-464A Format 5.8.2 Hazards of Electromagnetic Radiation to Fuel (HERF) Rationale: Fuel vapors can be ignited by an arc induced by a strong RF field. It is worth noting that fuel hazard criteria are usually based on peak power measurements while personnel hazard criteria are based on average power. Guidance: The existence and extent of a fuel hazard are determined by comparing the actual RF power density to an established safety criteria. TO 31Z-10-4 and OP 3565 provide procedures for establishing safe operating distances. RF energy can induce currents into any metal object. The amount of current, and thus the strength of an arc or spark produced between two electrical conductors (or heating of small filaments) depends on both the field intensity of the RF energy and how well the conducting elements act as a receiving antenna. Many parts of a system, a refueling vehicle, and static grounding conductors can act as receiving antennas. The induced current depends mainly on the conductor length in relation to the wavelength of the RF energy and the orientation in the radiated field. It is not feasible to predict or control these factors. The hazard criteria must then be based on the assumption that an ideal receiving antenna could be inadvertently created with the conductors. Fuels shall not be inadvertently ignited by radiated EMEs. The EME includes onboard emitters and the external EME 85

5.8.3 Hazards of Electromagnetic Radiation to Ordnance (HERO)
MIL-STD-464A Format 5.8.3 Hazards of Electromagnetic Radiation to Ordnance (HERO) Electrically initiated devices (EIDs) in ordnance shall not be inadvertently actuated during or experience degraded performance characteristics after exposure to the external EME levels of Table 3A (Table 1E shall be used for the “Unrestricted” EME for Army rotorcraft operations), for both direct RF induced actuation of the EID and inadvertent activation of an electrically powered firing circuit. Relevant ordnance phases involving unrestricted and restricted levels in Table 3A are listed in Table 3B. EME levels within the system shall not exceed the restricted levels in Table 3A in physical areas where the restricted operations listed in Table 3B are being performed. Compliance shall be verified by test and analysis. Rationale: RF energy of sufficient magnitude to fire or dud EIDs can be coupled from the external EME via explosive subsystem wiring or capacitively coupled from nearby radiated objects. The possible consequences include both hazards to safety and performance degradation. Electrically initiated devices (EIDs) in ordnance shall not be inadvertently actuated during or experience degraded performance characteristics after exposure to the external EME levels… 86

MIL-STD-464A Format 5.8.3 HERO: Verification Guidance
Stockpile-to-Safe Separation Sequence (S4) Transportation/ Storage 1 Immediate Post Launch 6 Platform- Loaded 5 Assembly/ Disassembly 2 Handling/Loading 4 Staged 3 Ordnance should be exposed to the EME in all life cycle configurations, including packaging, handling, storage, transportation, checkout, loading and unloading, and launch. Operating procedures associated with those configurations should also be used. 87

Operational Employment Corrosion Control, Monitoring
MIL-STD-464A Format 5.9 Life Cycle, E3 Hardness RIP Retirement Operational Employment Maintenance, Repair, Corrosion Control, Monitoring Rationale: Advanced electronics and structural concepts are offering tremendous advantages in increased performance of high-technology systems. These advantages can be seriously compromised, however, if E3 protection concepts impact life cycle costs through excessive parts count, mandatory maintenance, or costly repair requirements. It is essential, therefore, that life-cycle considerations be included in the tradeoffs used to develop E3 protection. Acquisition The system operational performance and E3 requirements of this standard shall be met throughout the rated life cycle of the system shall include, but not be limited to, the following: maintenance, repair, surveillance, and corrosion control. 88

5.9 Life Cycle, E3 Hardness (cont.)
MIL-STD-464A Format 5.9 Life Cycle, E3 Hardness (cont.) Paint over spring fingers Missing spring fingers Guidance: E3 hardening features should either be accessible and maintainable or should survive the design lifetime of the system without mandatory maintenance or inspection. To ensure continued protection (hardness) throughout the system life-cycle, protection schemes and devices must be identified and maintenance intervals and procedures specified. Maintenance actions must also be addressed which are performed on non-critical items which are in the same area as the critical items to ensure that personnel do not inadvertently compromise the protection measures of the critical functions. In deployment, space-based equipment cannot be routinely inspected or serviced. Therefore, the space vehicle must have features that are designed for unattended operation and durability for the life of the mission. Bonding surfaces must provide conductivity. EMI Screens must be intact and good contact at edges. 89

MIL-STD-464A Format 5.10 Electrical Bonding
Rationale: Good electrical bonding practices have long been recognized as a key element of successful system design. An indicator of the importance of electrical bonding is that the first item often assessed when EMC problems occur is whether the bonding is adequate. Since electrical bonding involves obtaining good electrical contact between metallic surfaces while corrosion control measures often strive to avoid electrical continuity between dissimilar materials, it is essential that the (potentially conflicting) requirements of each discipline be fully considered in the system design. Guidance: The role of bonding is essentially to control voltage by providing low-impedance paths for current flow. Without proper bonding, lightning interaction with systems can produce voltages which can shock personnel, ignite fuel through arcing and sparking, ignite or dud ordnance, and upset or damage electronics. The system, subsystems, and equipment shall include the necessary electrical bonding to meet the E3 requirements of this standard. 90

Equipment to Frame Ground
5.11 External Grounds 5.11 External Grounds Equipment to Frame Ground Guidance: External grounds are necessary to provide fault current paths for protection of personnel from shock hazards and to dissipate static electricity for prevention of hazards to personnel, flammable vapors, ordnance and electronic hardware. All telecommunications and electronic facilities are inherently referenced to earth by capacitive coupling, accidental contact, and intentional connections. Therefore, “ground” must be looked at from a total system viewpoint, with various subsystems comprising the total facility ground system. The facility ground system is composed of an earth electrode subsystem, lightning protection subsystem, fault protection subsystem, and signal reference subsystem. For safety reasons, both the MIL-STD and the National Electrical Code in NFPA 70 require that electrical power systems and equipment be intentionally grounded. The intentional grounding of electrical power systems minimizes the magnitude and duration of over-voltages on an electrical circuit, thereby reducing the probability of personnel injury, insulation failure, or fire and consequent system, equipment, or building damage. Grounding provisions are often necessary under certain operations to provide a current path to prevent static electricity charges from accumulating, such as during ordnance handling, refueling or other flammable vapor operations, and maintenance actions on sensitive electronics. Frame to Facility Ground Facility to Earth Ground The system and associated subsystems shall provide external grounding provisions to control electrical current flow and static charging for protection of personnel from shock, prevention of inadvertent ignition of ordnance, fuel and flammable vapors, and protection of hardware from damage. 91

5.11 External Grounds 5.12 TEMPEST
Rationale: Compromising emanations are unintentional intelligence bearing signals, which if intercepted and analyzed, would disclose national security information transmitted, received, handled, or otherwise processed by any classified information processing system. The requirement for TEMPEST is found in DoDD (classified). For Air Force aircraft, this requirement is generally applied to the communications subsystem only. Guidance: The need to apply TEMPEST requirements is determined by the Certified TEMPEST Technical Authority (CTTA). The CTTA considers several vulnerability and threat factors to determine the residual risk to which the information is exposed. The CTTA then determines if countermeasures are required to reduce risk to an acceptable level and identifies the most cost effective approach to achieving imposed TEMPEST requirements. Requirements and test guidelines are contained in the following documents: NSTISSAM TEMPEST/1-92, NASCEM 5112, NSTISSAM TEMPEST/1-93, MIL-STD-1680(SH), NSTISSAM TEMPEST/2-95 Points of contact for the Services are as follows: Navy: NISE East, PO Box , North Charleston, SC Telephone: (800) Air Force: HQ AFCA/SYS, 203 West Losey Room 2040, Scott AFB, IL Telephone: (618) Army: Deputy Chief of Staff for Intelligence, ATTN: DAMI, 1000 Army Pentagon, Washington, DC Telephone: (703) National security information shall not be compromised by emanations from classified information processing equipment. 92

5.11 External Grounds 5.13 EMCON EMISSION CONTROL!
Unintentional electromagnetic radiated emissions shall not exceed -110 dBm/m2 at one nautical mile (-105 dBm/m2 at one kilometer) in any direction from the system over the frequency range of 500 kHz to 40 GHz, when using the resolution bandwidths listed in Table 4 Rationale: EMCON generally provides for protection against detection by hostile forces who may monitor the electromagnetic spectrum for any emissions that indicate that presence and operation of military electronics. These “unintentional” emissions may originate from spurious signals, such as local oscillators, being present at antennas or from electromagnetic interference emissions from platform cabling caused by items such as microprocessors. Operations on Naval ships are frequently conducted in electromagnetic silence which is the most stringent state of EMCON. Other systems located onboard the ship (such as aircraft, tow tractors, fire control radars, and ship communication systems) are not permitted to transmit on any radios, radars, and navigation equipment over the frequency range of 500 kHz to 40 GHz. After aircraft have been launched from the ship, EMCON is frequently used to avoid detection of the aircraft. Army surface systems impose EMCON requirements to minimize detection and provide interplatform compatibility between one system’s radios and another system’s unintentional emissions. The Air Force considers EMCON to be an aspect of enhancing “low observable” properties of a platform. Verification Guidance: The measurement of the EMCON level is normally conducted in a anechoic chamber at a distance close to the system where normal laboratory equipment can be used to detect the emissions. After several years of EMCON tests by the Naval Air community, the distance commonly used is 10 meters from the system. At this distance the values measured are related to the EMCON limit through the inverse square law of EM propagation. 93

5.14 EM Spectrum Compatibility
5.11 External Grounds 5.14 EM Spectrum Compatibility Air Expeditionary Force OVER 1,400 EMITTERS 70 KM 45 KM X XX OVER 10,700 EMITTERS 3150 SQ KM Army Heavy Division Carrier Battle Group OVER 2,400 EMITTERS Federal Spectrum Shared Spectrum Non-Federal Spectrum “Typical” Battleforce Use 300 MHz 1000 MHz 3000 MHz 6000 MHz SHF VHF UHF 10 GHz 30 GHz 60 GHz EHF Rationale: The availability of adequate spectrum to support military electronic systems and equipment is critical to maximizing mission effectiveness. Spectrum planning and frequency management must be given appropriate and timely consideration during the development, procurement, and deployment of military assets that utilize the electromagnetic spectrum. To ensure maximum compatibility among the various worldwide users of the electromagnetic spectrum, it is essential that antenna-connected equipment comply with spectrum usage and management requirements. The DoD’s use of the spectrum is constantly being challenged by the commercial sector. It is expected that the military’s control of the spectrum will diminish in favor of commercial use. As more and more spectrum is taken away, the available spectrum must be managed as efficiently as possible to ensure the success of all military operations. Systems, subsystems, and equipment shall comply with the DoD, national, and international regulations for the use of the electromagnetic spectrum (such as NTIA “Manual of Regulations and Procedures for Radio Frequency Management” and DoDD ). 94

Principle E3/SS Standards

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