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Space engineering Electromagnetic compatibility

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1. gt 30lem RF absorber placed above behind and on both sides of EUT from ceiling to ground plane RF absorber placed behind the test antenna from ceiling to floor i i i i i i i i i l i i i i i Test antenna i i I i i i i i i i i i i Figure 5 1 RF absorber loading diagram 24 ECSS E 20 07A Draft 4 April 2008 d Minimum performance of the material shall be as specified in Table 5 1 NOTE The manufacturer s specification of their RF absorber material basic material only not installed can be used Table 5 1 Absorption at normal incidence above 250 MHz 10 dB 5 3 2 3 Ambient electromagnetic level a The ambient electromagnetic level shall be measured with the EUT not operating and all auxiliary equipment turned on b During testing at least one of the following conditions shall be met the ambient is at least 6 dB below the individual test limits the EUT complies with the individual test limits it is shown that recorded data exceeding the limits cannot be generated by the EUT emission tests or cannot sensitize the EUT susceptibility tests C Background plots shall be reported for each test configuration unless all recorded data is at least 6dB below the individual test limits 5 3 2 4 Ambient conducted level Ambient conducted levels on power leads shall be measured with the leads disconnected from the EUT and connected to a resist
2. NOTE Charge equalization is needed prior to implementing other procedures or the application of power across the interface 20 ECSS E 20 07A Draft 4 April 2008 EE Connector Equipment lt 10 mQ oi Vehicle bonding attachment point lt 20 mQ Ground reference S nnint Main frame Nearby structure Vehicle structure erounding Figure 4 1 Bonding requirements Equipment bonding stud 4 2 12 Shielding excepted wires and cables 4 2 12 1 General When shielding is used to control EMC with the environment it can be provided by the basic space vehicle structure designed as a Faraday cage by enclosures of electronics boxes or by cable or bundle overshields 4 2 12 2 Requirement Electronics units and cables external to the basic space vehicle structure shall have individual shields providing attenuation to EMI NOTE It is important to consider apertures used for pressure drop during ascent and for outgassing 4 2 13 Wiring including wires and cables shielding 4 2 13 1 Classification of cables a Categorisation of harness and separate routings for wires of different categories shall be defined as follows l applicable to critical lines as defined in ECSS E 20B clause 6 3 1 Z made on the basis of the characteristics of the signals on the wire and hence the interference generated and on the susceptibility of the circuit to EMI b Wires falling into one category shall be assembled into a sam
3. a Remove the receive antenna and reposition the EUT in conformance with 5 5 11 3 5 5 11 3e b Set the signal source to 1 kHz pulse modulation 50 duty cycle establish an electric field at the test start frequency by using an amplifier and transmit antenna and gradually increase the input power level until 1t corresponds to the level recorded during the calibration routine c Repeat the test at all test frequencies while assuring the transmitter input power is adjusted in accordance with the calibration data collected and constantly monitor the EUT for susceptibility conditions 3 If susceptibility is noted determine the threshold level in accordance with 5 3 10 3 4 Perform testing over the frequency range with the transmit antenna vertically polarized and repeat the testing with the transmit antenna horizontally polarized NOTE The settings needed to achieve the specified field level in vertical polarization are reused as is for the test in horizontal polarization gt Repeat 5 5 11 4 c 4 for each transmit antenna position determined in one a ak 5 5 11 5 Data presentation In addition to 5 3 10 4 data presentation shall provide a graphical or tabular data listing receive antenna procedure only all calibration data collected to include input power requirements used versus frequency and results of system check in 5 5 11 4 5 5 11 4b 2 c and 5 5 11 4 5 5 11 4b 2 d b the correction factors used to adjust se
4. 5 4 4 Lightning Lightning protection specified in ECSS E20 clause 6 3 2 3 shall be verified by analysis from equipment demonstration NOTE 1 Testat system level need not be performed NOTE2 The bi exponential model defined in clause 4 2 3 2 is generally used 5 4 5 Spacecraft and static charging a Material use bonding of discharge elements thermal blankets or metallic items using a bond for static potential equalization shall be verified by inspection or measurement at assembly into structure b If the bond is only used for charging control the bonding resistance shall be measured with a dc current in the range 10 to 100 uA under only one polarity with a 2 wires ohmmeter NOTE If the bond is only used for charging control the clauses 5 4 10 5 4 10a and 5 4 10 5 4 10b do not apply 5 4 6 Spacecraft DC magnetic field emission Spacecraft DC magnetic field emission requirements shall be verified by a combination of analysis and tests 5 4 7 Intra system electromagnetic compatibility a For intra system EMC tests the support equipment shall provide the functionality of exercising culprits and victims and include the support equipment instructions b Wherever 0 dB EMISM is a requirement functional tests at spacecraft level may be accepted as a verification of EMC 5 4 8 Radiofrequency compatibility a Except for passive intermodulation products radiofrequency compatibility shall be verified by a test at system leve
5. NOTE Ten frequency steps per decade can be used as a basis Step sizes shall be decreased such to permit observation of a response NOTE For receivers it can make use of the frequency plan to adjust the number of points 5 3 10 2 Modulation of susceptibility signals a Susceptibility test signals shall be pulse modulated on off ratio of 40 dB minimum at a 1 kHz rate with a 50 duty cycle for susceptibility signals at a frequency larger than 100 kHz CW test signals shall be used for susceptibility signals at a frequency smaller than 100 kHz 5 3 10 3 Thresholds of susceptibility When susceptibility indications are noted in EUT operation a threshold level shall be determined as follows where the susceptible condition is no longer present a When a susceptibility condition is detected reduce the interference signal until the EUT recovers Reduce the interference signal by an additional 6 dB Gradually increase the interference signal until the susceptibility condition reoccurs The resulting level is the threshold of susceptibility Record this level frequency range of occurrence frequency and level of greatest susceptibility and the other test parameters 5 3 10 4 Susceptibility data presentation a The susceptibility criteria defined in the EMI test procedure shall be repeated in the test report or the as run EMI test procedure shall be an annex to the EMI test report Data showing the frequencies
6. Adjust the modulation in duty cycle and frequency 53 ECSS E 20 07A Draft 4 April 2008 c Increase the generator output to the level determined during calibration without exceeding the current limit specified by application of clause 4 2 8 and record the peak current obtained d Monitor the EUT for degradation of performance e If susceptibility is noted determine the threshold level as measured by the current monitor probe in accordance with 5 3 10 3 f Repeat 5 5 8 4c 2 a through 5 5 8 4 c 2 e for each test frequency 3 Repeat 5 5 8 4 c 2 applying the test signals to each bundle interfacing with each connector or all bundles taken together d The calibration need not be re performed before testing each EUT bundle a 1 External Signal gt pas l cae Power modulation generator lif source 50Q ai oa Monitor probe Oscilloscope 50Q input Jig i Fat or spectrum analyser EY Injection probe hg 50Q coaxial load Volt Time Burst length Period Figure 5 19 Signal test waveform 54 ECSS E 20 07A Draft 4 April 2008 External Power modulation generator amplifier l source 50Q Monitor probe Oscilloscope Data Spectrum recorder Figure 5 20 CS of power and signal leads bulk cable injection 5 5 9 CS power leads transients 5 5 9 1 Purpose This test procedure is used to verify the ability of the EUT to withstand short spikes coupled on EU
7. and techniques for controlling EMI from residual ESD ECSS E20B addresses management of spacecraft charging protection and system level performance under effects of spacecraft charging and related ESD or secondary arcs ECSS E20 06A addresses charging control and risks arising from spacecraft charging and other environmental effects on the spacecraft s electrical behaviour 4 2 4 2 EMI control requirements to system and equipment in relation with ESD a Analysis or tests at system level shall be performed for assessing the threat at subsystem or equipment level NOTE Analysis or tests can be defined in the time or frequency domain They are expected to evaluate the coupling level from the ESD source to critical points b EMI control from residual ESD shall be performed by a combination of shielding and passive or active filtering techniques implemented on the main structure at subsystem level or inside equipment 17 ECSS E 20 07A Draft 4 April 2008 E EMI control efficiency shall be verified by test at subsystem or equipment level 4 2 5 Spacecraft DC magnetic emission 4 2 5 1 Spacecraft with susceptible payload As part of the EMCCP a magnetic cleanliness control plan shall document a magnetic control guidelines b emission limits to magnetic sources C a magnetic budget d specific test methods applied to equipments for emission measurement and characterization NOTE The test method described in 5 5 5 pr
8. equipment that is viewed as an entity for purposes of analysis manufacturing maintenance or record keeping NOTE Hydraulic actuators valves batteries and individual electronic boxes such as on board computer inertial measurement unit reaction wheel star tracker power conditioning unit transmitters receivers or multiplexers 3 3 Abbreviated terms The following abbreviated terms are defined and used within this Standard Abbreviation Meaning AC alternating current ACS attitude control system AM amplitude modulation AWG American wire gauge BCI bulk cable injection CE conducted emission CS conducted susceptibility CW continuous wave DC direct current EED electro explosive device EGSE electrical ground support equipment EHF extremely high frequency 30 GHz 300 GHz EM electromagnetic EMC electromagnetic compatibility EMCAB electromagnetic compatibility advisory board EMCCP electromagnetic compatibility control plan EMEVP electromagnetic effects verification plan EMEVR electromagnetic effects verification report EMI electromagnetic interference EMISM electromagnetic interference safety margin 14 ESD EUT HV ICD LEO LF LISN MGSE PAM PCM RF RMS RS SHF ECSS E 20 07A Draft 4 April 2008 electrostatic discharge equipment under test high voltage interface control document low altitude earth orbiting low frequency line impedance stabilization network mechanical ground support equipmen
9. 4 and 5 5 5 3 Test conditions 5 3 1 Measurement tolerances The tolerance shall be as follows a Distance 10 b Frequency 2 23 ECSS E 20 07A Draft 4 April 2008 Amplitude measurement receiver 2 dB d Amplitude measurement system includes measurement receivers transducers cables connectors 3 dB e Time waveforms 10 i Resistors 5 g Capacitors 20 5 3 2 Test site 5 3 2 1 Overview Shielded enclosures or unshielded sites are used for testing Shielded enclosures prevent external environment signals from contaminating emission measurements and susceptibility test signals from interfering with electrical and electronic items near the test facility In unshielded sites the tests are performed during times and conditions when the electromagnetic ambient is at its lowest level 5 3 2 2 Shielded enclosures a The enclosures shall be large such that the EUT arrangement requirements of 5 3 6 and antenna positioning requirements described in the individual test procedures are satisfied b RF absorber material e g carbon impregnated foam pyramids and ferrite tiles shall be used when performing electric field radiated emissions or radiated susceptibility testing to reduce reflections of electromagnetic energy and to improve accuracy and repeatability G The RF absorber shall be placed above behind and on both sides of the EUT and behind the radiating or receiving antenna as shown in 0
10. 5 2 Bandwidth and measurement time Frequency Range 6 dB Dwell time Minimum measurement time bandwidth analogue measurement receiver 1 kHz 10 kHz 100 Hz 0 015 s 0 15 s kHz 32 ECSS E 20 07A Draft 4 April 2008 5 3 9 2 Emission identification All emissions regardless of characteristics shall be measured with the measurement receiver bandwidths specified in Table 5 2 5 3 9 3 Frequency scanning a For emission measurements the entire frequency range for each test shall be scanned Minimum measurement time for analogue measurement receivers during emission testing shall be as specified in Table 5 2 Synthesized measurement receivers shall step in one half bandwidth increments or less and the measurement dwell time shall be as specified in Table 5 2 For equipment that operates such that potential emissions are produced at only infrequent intervals times for frequency scanning shall be increased such than any emission is captured 5 3 9 4 Emission data presentation a Amplitude versus frequency profiles of emission data shall be automatically generated and displayed at the time of the test Except for verification of the validity of the output data shall not be gathered manually The information shall be displayed after application of correction factors including transducers attenuators and cable loss Data output of the EUT test result shall be in the form of amplitude over time for the time domain
11. 5 8 CS bulk cable injection 50 kHz to 100 MHz 5 5 8 1 Purpose This test procedure is used to verify the ability of the EUT to withstand sinusoidal waves coupled on the EUT associated cables and power leads 5 5 8 2 Test equipment The test equipment shall be as follows a Signal generator with amplitude or pulse modulation capability b pulse generator 1 kHz 100 kHz adjustable duty cycle C power amplifier 50 kHz 100 MHz d current injection probe 50 kHz 100 MHz a current measurement probe 50 kHz 100 MHz f one or two calibration fixture s jigs defined in 5 3 8 3 g one two channels oscilloscope 50 Q input impedance h waveform recording device 50 coaxial load J LISN defined in 5 3 4 p 0 k spectrum analyzer optional 52 ECSS E 20 07A Draft 4 April 2008 5 5 8 3 Setup The test setup shall be as follows a Maintain a basic test setup for the EUT as shown and described in 5 3 6 and Figure 5 3 For calibration l Configure the test equipment in accordance with Figure 5 18 2 Place the injection probe and the monitor probe around the central conductor of their respective jigs The monitor probe and associated jig are optional 3 Terminate one end of the jig with a 50Q coaxial load and connect the other end to a 50 Q input oscilloscope 4 If a current monitor probe is used connect it to another 50 Q oscilloscope input For testing the EUT l Configure t
12. a received signal of appropriate amplitude is present NOTE This evaluation is intended to provide a coarse indication that the antenna is functioning properly There is no requirement to measure accurately the signal level d Test the EUT by using the measurement path of Figure 5 13 and determining the radiated emissions from the EUT and its associated cabling as follows l Turn on the EUT and wait until it is stabilized pas Scan the measurement receiver for each applicable frequency range using the bandwidths and minimum measurement times in 5 3 9 1 3 Orient the antennas for both horizontally and vertically polarized fields 4 Repeat steps 5 5 6 4 d 2 and 5 5 6 4 d 3 for each antenna position determined under 5 5 6 3 5 5 6 3c 5 5 6 5 Data Presentation In addition to 5 3 9 4 data presentation shall provide a statement verifying the electrical continuity of the measurement antennas as determined in5 5 6 4 5 5 6 4c 2 48 ECSS E 20 07A Draft 4 April 2008 poco tc ccc ccc ccccc o Test setup boundary AV Shielded Signal enclosure generator Connected for measurement Connected for system check Measurement receiver Data recording device Figure 5 13 Electric field radiated emission Basic test setup Test setup boundary Ground plane 1 2m Figure 5 14 Electric field radiated emission Antenna positioning 49 ECSS E 20 07A Draft 4 April 2008 Test setup boundary
13. antenna to the coaxial cable as specified in Figure 5 28 set the signal source to 1 kHz pulse modulation 50 duty cycle establish an electric field at the test frequency by using a transmitting antenna and amplifier and gradually increase the electric field level until it reaches the limit specified by application of clause 4 2 8 Scan the test frequency range and record the input power levels to the transmit antenna to maintain the required field 62 ECSS E 20 07A Draft 4 April 2008 e Repeat procedures 5 5 11 4 b 2 a through 5 5 11 4 b 2 d whenever the test setup is modified or an antenna is changed NOTE The ground plane tends to short circuit horizontally polarized fields so that more power is needed to achieve the same field value in horizontal polarization as in vertical polarization C Test the EUT as follows l Procedure when using electric field sensors a Establish an unmodulated electric field at the test start frequency by using an amplifier and transmit antenna and gradually increase the electric field level until it reaches the limit specified by application of clause 4 2 8 b Set the signal source to 1 kHz pulse modulation 50 duty cycle and apply the modulation c Repeat the test at all frequency tests while maintaining field strength levels in accordance with the associated limit and monitor EUT performance for susceptibility effects 2 Procedure when calibrating with the receive antenna
14. comprises the intentional radiated electromagnetic fields and parasitic emission from on board equipment Both conducted and radiated emissions are concerned An electromagnetic interference safety margin is defined at system critical points by comparison of noise level and susceptibility at these points ECSS E 20 07A Draft 4 April 2008 3 Scope EMC policy and general system requirements are specified in ECSS E 20B This ECSS E 20 07 Standard addresses detailed system requirements Clause 4 general test conditions verification requirements at system level and test methods at subsystem and equipment level Clause 5 as well as informative limits Annex A Associated to ECSS E 20 07 1s ECSS E 20 06 which addresses charging control and risks arising from environmental and vehicle induced spacecraft charging when ECSS E 20 07 addresses electromagnetic effects of electrostatic discharges Annexes A to C of ECSS E 20B document EMC activities related to ECSS E 20 07 the EMC Control Plan Annex A defines the approach methods procedures resources and organization the Electromagnetic Effects Verification Plan Annex B defines and specifies the verification processes analyses and tests and the Electromagnetic Effects Verification Report Annex C document verification results The EMEVP and the EMEVR are the vehicles for tailoring this standard ECSS E 20 07A Draft 4 April 2008 2 Normative references The following d
15. in which the electrode of the high voltage test generator is held in contact with the discharge circuit and the discharge actuated by a discharge switch 3 2 5 electromagnetic environmental effects impact of the electromagnetic environment upon equipment systems and platforms NOTE It encompasses all electromagnetic disciplines including electromagnetic compatibility electromagnetic interference electromagnetic vulnerability hazards of 12 ECSS E 20 07A Draft 4 April 2008 electromagnetic radiation to personnel electro explosive devices volatile materials and natural phenomena effects 3 2 6 field strength resultant of the radiation induction and quasi static components of the electric or magnetic field NOTE The term electric field strength or magnetic field strength is used according to whether the resultant electric or magnetic field respectively is measured 3 2 7 ground plane metal sheet or plate used as a common reference point for circuit returns and electrical or signal potentials 3 2 8 improper response subsystem or equipment response which can be either inadvertent or unacceptable 3 2 9 inadvertent response proper subsystem functional response within normal range of limits actuated by electromagnetic interference but occurring at other than the normal operational cycle which in turn causes improper response to the total space system 3 2 10 line impedance stabilization network LIS
16. initial rise time and the full inrush response NOTE Typical time bases are 10 us full scale for the initial rise time and ms full scale for the full inrush response 43 ECSS E 20 07A Draft 4 April 2008 Oscilloscope Data recorder Coax T and bifilar transition Spike generator To power source Current Resistor probe Figure 5 10 Inrush current measurement system check setup Fast bounce free Current probe power switch J pos To power source EUT controller b ON OFF command Figure 5 11 Inrush current measurement setup 5 5 5 DC Magnetic field emission magnetic moment 5 5 5 1 General The described test method allows obtaining a rough estimate of the magnetic moment of the EUT centred dipole approximation It involves the constraint of measuring the magnetic field at distances typically more than three times the size of the EUT If a better model is needed making it possible to predict the field at closer distances or more precisely than the centred dipole approximation allows then either multiple dipole modelling techniques or spherical harmonics techniques shall be used NOTE It is the role of the EMCAB to assess the need for using such techniques based on mission requirements 5 5 5 2 Set Up a The EUT should be set in an earth field compensated area providing zero field conditions for the intrinsic moment determination 44 ECSS E 20 07A Draft 4 April 2008 NOTE
17. mode 30 Hz to 100 KHZ ce ceeceeeeeeeees 38 5 5 3 CE power and signal leads 100 KHz to 100 MHZ ce ceeccceeeceeceeeeeeeeeees 40 5 5 4 CE power leads inrush current cccccceececceeeeeceeeeeceeeeeeeeeeesseeeeeseeeesaeeeeas 42 5 5 5 DC Magnetic field emission magnetic moment cccccceeceeeeeeeeseeeeesaeees 44 5 5 6 R electric field 30 MHZ to 18 GHZ ceccccceeeeeeeceeeeeeeeeeeeeeseaeeeeesaaees 46 5 5 7 CS power leads 30 HZ to 100 KHZ ccccceccccccceeeeeeeeeeeeeeeeeeeeeesaeeeessaees 50 5 5 8 CS bulk cable injection 50 KHZ to 100 MHZ cc eecceceeeeeeeeeeeeeeeeeeeeeeees 52 5 5 9 CS power leads TINS OT Sac sts tes sarcesscraesecaiocincee onion sms nseeisaiesincenisaesincaasucsiosaasacnecate 55 5 5 10 RS magnetic field 30 HZ to 100 KHZ cece ceeccceeeeeeeseeeeeseeeeeseeeeeseeeeees 58 5 5 11 RS electric field 30 MHZ to 18 GHZ ccccccccceeeeceeeeeeeeeseeeeeeseeeeeeeaees 60 5 5 12 Susceptibility to electrostatic discharges cccecccccsseeeeeeeeeeeeeeeeeeeeneeeeeesaees 66 Figures Figure 4 1 Bonding requirements 21 Figure 5 1 RF absorber loading diagram 24 Figure 5 2 Line impedance stabilization network schematic 27 Figure 5 3 General test setup 28 Figure 5 4 Typical calibration fixture 32 Figure 5 5 Conducted emission 30 Hz to 100 kHz measurement system check 39 Figure 5 6 Conducted emission 30 Hz to 100 kHz measurement setup 39
18. on a dielectric stand at the position and height above the ground plane where the centre of the EUT will be located For testing EUT l Place the transmit antennas 1 m from the test setup boundary as follows a 30 MHz to 200 MHz For test setup boundaries lt 3 m including all enclosures of the EUT and the 2 m of exposed interconnecting and power leads specified in 5 3 6 6 center the antenna between the edges of the test setup boundary ensuring that the interconnecting leads 61 b ECSS E 20 07A Draft 4 April 2008 represent the actual platform installation and are shorter than 2m For test setup boundaries gt 3 m use multiple antenna positions N at spacings as specified in Figure 5 27 where the number of antenna positions N is determined by dividing the edge to edge boundary distance in metres by 3 and rounding up to an integer 200 MHz and above Use multiple antenna positions N as shown Figure 5 28 where the number of antenna positions N is determined as follows si For testing from 200 MHz up to 1 GHz place the antenna in a number of positions such that the entire width of each EUT enclosure and the first 35 cm of cables and leads interfacing with the EUT enclosure are within the 3 dB beamwidth of the antenna si For testing at 1 GHz and above place the antenna in a number of positions such that the entire width of each EUT enclosure and the first 7 cm of cables and leads interfacing with th
19. one time 5 4 System level 5 4 1 General Each item of equipment and subsystem shall have successfully passed functional acceptance test procedures as installed on the platform prior to system level EMC test 5 4 2 Safety margin demonstration for critical or EED circuits a A test performed to demonstrate compliance with the safety margin requirement shall use one or more of the following test approaches l Inject interference at critical system points at x dB higher level than exists while monitoring other system points for improper responses where x EMISM 2 Measure the susceptibility of critical system circuits for comparison to existing interference levels to determine the margin 3 Sensitize the system to render it x dB more susceptible to interference while monitoring for improper response where x EMISM b Safety margin demonstration for something that is susceptible to a time domain circuit including EED s shall use time domain methods 5 4 3 EMC with the launch system a If the spacecraft is not powered during launch EMC test with the launch system need not be performed b If the spacecraft is powered during launch the electric field radiation including intentional transmission shall be measured at locations specified in the Launcher User s Manual 35 ECSS E 20 07A Draft 4 April 2008 C In case of a transmitting spacecraft under fairing the EMISM applied to EED s shall be verified
20. plots and amplitude over frequency for frequency domain plots superimposed with the EMI test limit Units of measurement for frequency domain emissions measurements shall be reported in units of dB referenced to 1 uV 1 pA 1 uV m 1 pT depending on the unit defined in the test limit For time domain measurements oscilloscope plots shall include the amplitude physical unit V ou A conversion factors V into A if not done automatically by the oscilloscope and the oscilloscope sensitivity time base settings and measurement bandwidth For frequency domain plots emission data shall be reported in graphic form with frequency resolution of 1 percent or twice the measurement receiver bandwidth whichever is less stringent In the event of any emissions test result over the emission test limit above 100 MHz greater accuracy of its frequency shall be reported with resolution better than or equal to twice the measurement bandwidth Each plot of emission data shall be reported with a minimum amplitude resolution of 1 dB 5 3 10 Susceptibility testing 5 3 10 1 Frequency stepping a For susceptibility measurements the entire frequency range for each applicable test shall be scanned 33 ECSS E 20 07A Draft 4 April 2008 NOTE Stepped scans refer to signal sources that are sequentially tuned to discrete frequencies Stepped scans shall dwell at each tuned frequency for the greatest of three seconds or the EUT response time
21. present These are beyond the scope of the present standard For equipment having all internal rise times longer than 35 ns the specified upper frequency limit can be reduced to 1 GHz For non RF equipment if the emission is lower than 20 dB below the requirement between 500 MHz and 1 GHz the specified upper limit can be reduced to 1 GHz with the exception of notches above GHz still to be tested 74 ECSS E 20 07A Draft 4 April 2008 100 90 A 80 gt a 70 3S Q w 60 50 40 1 E 07 1 E 08 1 E 09 1 E 10 1 E 11 Frequency Hz Figure A 3 Radiated electric field limit A 10 CS powerleads differential mode 30 Hz to 100 kHz The following levels known to be achievable and already specified in other standards or project specifications are proposed for the susceptibility test on the power leads specified in clause 5 5 7 the injected voltage level is equal or larger than the level on Figure A 5 a limitation of the injected current before the specified voltage is reached is applied the limit of current is 1 Ams the voltage level when the current limit is reached is measured and reported The current applied is reported Independent power lines are tested separately NOTE Independent means connected to separate power sources Except in the case of structure return for each power line hot and return wires are tested separately NOTE In case of structure return the test is only ap
22. the applied signal until the oscilloscope indicates the voltage level specified by application of clause 4 2 8 verify that the output waveform is sinusoidal and verify that the indication given by the current probe is within 3 dB of the expected level derived from the 1 Q resistor voltage 3 Repeat 5 5 7 4 b 2 by setting the signal generator to the highest test frequency C Test the EUT as follows l Turn on the EUT and wait until it is stabilized 2 Set the signal generator to the lowest test frequency and increase the signal level until the testing voltage or current limit specified by application of clause 4 2 8 1s reached on the power lead 3 Repeat 5 5 7 4 c 2 at all frequency steps through the testing frequency range 4 Evaluate the susceptibility as follows a Monitor the EUT for degradation of performance b If susceptibility is noted determine the threshold level in accordance with 5 3 10 3 s Repeat 5 5 7 4 c 2 to 5 5 7 4 c 4 for each power lead Power amplifier Current Resistor probe Oscilloscope Data Oscilloscope differential probe Figure 5 16 CS power leads measurement system check set up 51 ECSS E 20 07A Draft 4 April 2008 Power amplifier Stimulation and monitoring of EUT 1 5 to 2 7Q Current Taree Power be _ B njection are pe I transformer P ee isn Oscilloscope Data Oscilloscope differential probe Figure 5 17 CS power leads signal injection 5
23. through the LISN for applying the same impedance through the probe as with the EUT 3 Check the spike current as measured with the probe by comparison with the voltage across the resistor 4 Perform the measurement with the current probe on an oscilloscope in the same manner as for EUT testing and verify that the data recording device indicates a level within 3 dB of the injected level ae If readings are obtained which deviate by more than 3 dB locate the source of the error and correct the deficiency prior to proceeding with the testing Test the EUT by determining the conducted emission from the EUT input power leads as follows l Select the positive lead for testing and clamp the current probe into position 2 Perform measurement by application of power on the EUT using a mercury relay Figure 5 11 a the internal EUT switch Figure 5 11 b or the power controller Figure 5 11 c NOTE The method for application of power is defined in the EMEVR 5 5 4 5 Data Presentation a In addition to 5 3 9 4 data presentation shall be a graphic output of current versus time displaying the transient characteristics with following conditions l amplitude resolution within 3 of the applicable limit 2 time base resolution within 10 of rise time for measurement of rise and fall slopes NOTE Rise time is the duration between 10 and 90 of peak to peak amplitude Two separate displays shall be provided showing respectively the
24. 00 4 2 Edition 1 2 NOTE Use of the ESD generator is less hazardous than use of the DC high voltage supply for test operators b The discharge primary circuit is constituted of l 6kV spark gap NOTE 1 An air spark gap or an overvoltage suppressor in a sealed pressurized envelop can be used NOTE2 An air spark gap is less stable and has longer rise time 2 50 pF capacitance high voltage capacitor with inductance less than 20 nH 3 47 Q damping resistor high voltage specification NOTE The value can be adjusted at critical damping depending on value of capacitance C and self inductance of the discharge circuit 4 10 kQ resistors high voltage specification NOTE Choke resistors prevent high frequency components of discharge from flowing in uncontrolled paths so the discharge parameters are not dependent on length and position of high voltage source wires G Monitoring devices l Two current probes 100 A peak capability and more than 100 MHz bandwidth 2 One high voltage probe 10 kV range 1 MHz bandwidth NOTE If the probe input impedance is not high enough it can prevent gap arcing by lowering the available voltage 3 One two channels digital oscilloscope with pretriggering capability NOTE Typical values are 100 ns pretrigger time display window in the range 1 to 10 us and resolution better than 4 ns 5 5 12 3 Setup The test setup shall be as follows a Maintain a basic test setup for the EUT as spe
25. 1 This is necessary in case the EUT contains a significant amount of soft magnetic material as without earth field compensation an induced magnetic moment would appear NOTE2 Earth field compensation is usually ensured by 2 or 3 sets of Helmholtz coils A right handed orthogonal coordinate system XYZ shall be assigned to the EUT geometric centre The magnetic sensor single axis magnetometer shall be installed successively on the 6 semi axes at two different reference distances r and r from the geometric centre of the EUT and shall measure the field projection along these lines NOTE The reference distances are typically more than three times the size of the EUT Alternatively the EUT may be installed on a turntable and rotated in front of a fixed magnetometer presenting each XYZ axis positive and negative successively aligned with the sensor axis The magnetic field shall be positive when orientated from the centre of the EUT towards the magnetometer 5 5 5 3 Test sequence The test sequence shall be as follows a EUT not operating initial measurements on the six semi axes at the reference distances Deperm l EUT not operating application of a deperming field in accordance with Figure 5 12 frequency 3 Hz maximum amplitude between 4000 and 5 000 uT successively on each XYZ axis of the EUT NOTE 1 This is usually done using Helmholtz coils NOTE2 A sequence of symmetrical sine periods of increasing and decreas
26. 5 4 2 Test equipment The test equipment shall be as follows a Two channels oscilloscope b Current probe E Spike generator d Data recording device Coaxial T connector f Coaxial to bifilar transition g 1 Q power metal film resistor with inductance lower 30 nH and peak power capability h LISN defined in 5 3 4 1 Switching device fast bounce free power switch or an actual power controller except if the ON OFF command is implemented in the EUT 5 5 4 3 Setup The test setup shall be as follows a Maintain a basic test setup for the EUT as specified in 5 3 6 and Figure 5 3 b Configure the test setup for the measurement system check as shown in Figure 5 10 C Configure the test setup for compliance testing of the EUT as shown in Figure 5 11 42 ECSS E 20 07A Draft 4 April 2008 5 5 4 4 Procedures The test procedures shall be as follows Turn on the measurement equipment and allow a sufficient time for stabilization If specified by the EMEVP check the measurement system by evaluating the overall measurement system from the current probe to the data output device l Apply a calibrated spike that is at least 6 dB below the applicable limit to the current probe 2 Apply through the current probe a DC current equivalent to the EUT supply current NOTE 1 A DC current is applied for verifying that the current probe will not be saturated by the EUT DC supply current NOTE2 This DC current is applied
27. 8 GHz if SHF or EHF payloads are present These are beyond the scope of the present standard 78 ECSS E 20 07A Draft E eS 4 April 2008 A 15 Susceptbility to electrostatic discharge The following dispositions known to be achievable and already specified in other standards or project specifications are proposed for the ESD test specified in clause 5 5 12 The test is performed on following equipment including or not digital circuits units comprising high voltage power sources units man handled during normal operation This condition applies to manned flight For man handled equipment an ESD test by the contact discharge method as defined in IEC 61000 4 2 is more appropriated units outside the main frame of the space vehicle designed as a Faraday cage e units connected to sensors actuators or other units located outside the main frame designed as a Faraday cage with the exception of the solar array power bus Specific tests defined in ECSS E33 11 are applied to EED s Test of models expected to be or to become flight models is not performed ESD testing can cause latent failures of test article 79 ECSS E 20 07A Draft 4 April 2008 Bibliography 1 MIL STD 461E Requirements for the control of electromagnetic interference characteristics of subsystems and equipment 20 August 1999 Department of Defence USA 80
28. E low frequency electric field From a few hertz to 30 MHz frequency range the electric field radiated emissions of units can be measured The frequency limits are determined by the EMCAB from payload specifications The electric field emission from the equipment is expressed in units of dB above 1 uV m at a distance of 1 m Measurements at several distances are performed for characterizing the decay law No limit is defined at equipment level The measurement is only for characterization and useful to verify compliance with system level requirements through analysis Techniques for fulfilling EMC requirement at system level are reduction of common mode conducted emission from bundles and electric shields or appropriate location of equipments on the space vehicle A 9 RE electric field 30 MHz to 18 GHz In the 30 MHz to 18 GHz frequency range electric field radiated emissions from equipment and subsystem including interconnecting cables can be limited under following conditions the limit applies to non RF equipment RF equipment connected to passive loads or EGSE in nominal mode at nominal power the limit is defined by the curve on Figure A 4 the limit is for both horizontally and vertically polarized fields the limit comprises notching lines for launchers or spacecraft receiving bands not represented on Figure A 4 Additional requirements can apply beyond 18 GHz if SHF or EHF payloads are
29. ECSS E 20 07A Draft 4 April 2008 EUROPEAN COOPERATION FOR SPACE STANDARDIZATION z Space engineering Electromagnetic compatibility This ECSS document is a draft standard circulated to the ECSS TA for approval for publication It is therefore subject to change and may not be referred to as an ECSS Standard until published as such End of TA approval for publication 17 April 2008 ECSS Secretariat ESA ESTEC Requirements amp Standards Division Noordwijk The Netherlands ECSS E 20 07A Draft 4 April 2008 This Standard is one of the series of ECSS Standards intended to be applied together for the management engineering and product assurance in space projects and applications ECSS is a cooperative effort of the European Space Agency national space agencies and European industry associations for the purpose of developing and maintaining common standards Requirements in this Standard are defined in terms of what shall be accomplished rather than in terms of how to organize and perform the necessary work This allows existing organizational structures and methods to be applied where they are effective and for the structures and methods to evolve as necessary without rewriting the standards This Standard has been prepared by the ECSS E 20 07A Working Group reviewed by the ECSS Executive Secretariat and approved by the ECSS Technical Authority Disclaimer ECSS does not provide any warranty whatsoever whether exp
30. Figure 5 7 Conducted emission measurement system check 41 Figure 5 8 Conducted emission measurement setup in differential mode 41 Figure 5 9 Conducted emission measurement setup in common mode 42 Figure 5 10 Inrush current measurement system check setup 44 Figure 5 11 Inrush current measurement setup 44 Figure 5 12 Smooth deperm procedure 46 Figure 5 13 Electric field radiated emission Basic test setup 49 Figure 5 14 Electric field radiated emission Antenna positioning 49 Figure 5 15 Electric field radiated emission Multiple antenna positions 50 Figure 5 16 CS power leads measurement system check set up 51 Figure 5 17 CS power leads signal injection 52 Figure 5 18 Bulk cable injection measurement system check set up 54 Figure 5 19 Signal test waveform 54 Figure 5 20 CS of power and signal leads bulk cable injection 55 Figure 5 21 CS of power leads transients calibration set up 57 Figure 5 22 CS of power leads spike series injection test setup 57 Figure 5 23 CS of power leads spike parallel injection test setup 57 Figure 5 24 Measurement system check configuration of the radiating system 60 E EN Figure 5 25 Basic test set up Figure 5 26 Test equipment configuration Figure 5 27 RS Electric field Multiple test antenna positions Figure 5 28 Receive antenna procedure Figure 5 29 Spacecraft charging ESD susceptibility test Figure 5 30 Susceptibility to ESD calibration configuration Fig
31. Hz to 100 MHz 2 part 5 5 9 RS magnetic field 30 Hz to 100 kHz 5 5 10 RS electric field 30 MHz to 18 GHz 5 5 11 Susceptibility to electrostatic discharge 5 5 12 37 ECSS E 20 07A Draft 4 April 2008 5 5 2 CE power leads differential mode 30 Hz to 100 kHz 5 5 2 1 Purpose This method is used for measuring conducted emissions in the frequency range 30 Hz to 100 kHz on all input power leads including returns 5 5 2 2 Test equipment The test equipment shall be as follows Measurement receiver 7 2 Current probe Signal generator with amplifier es op DC current supply Data recording device Oscilloscope Coaxial T connector and coaxial to bifilar transition gt 0 th o 1 Q and 10 Q power metal film resistors with inductance lower than 100 nH LISN defined in 5 3 4 peat 0 5 5 2 3 Setup The test setup shall be as follows a Maintain a basic test setup for the EUT as specified in 5 3 6 and Figure 5 3 b For measurement system check configure the test setup as shown in Figure 5 5 E For equipment testing configure the test setup as shown Figure 5 6 5 5 2 4 Procedure The test procedures shall be as follows Turn on the measurement equipment and wait until it is stabilized b If the EMEVP specifies to check the measurement system check it by evaluating the overall measurement system from the current probe to the data output device as follows l Apply a calibrated signal lev
32. I I Length x m N positions x 3 rounded up nearest C a o fim Antenna Antenna Antenna x 2N x 2N Shielded enclosure Figure 5 15 Electric field radiated emission Multiple antenna positions 5 5 7 CS power leads 30 Hz to 100 kHz 5 5 7 1 Purpose This test procedure is used to verify the ability of the EUT to withstand signals coupled on input power leads 5 5 7 2 Test equipment The test equipment shall be as follows Signal generator b Power amplifier 1 5 to 2 7 Q power metal film resistor with inductance lower 1000 nH and peak power capability d Oscilloscopes e Current probe f Differential high voltage probe g injection transformer h LISN defined in 5 3 4 optional 5 5 7 3 Setup The test setup shall be as follows Maintain a basic test setup for the EUT as specified in 5 3 6 and Figure 5 3 b Check measurement system by configuring the test equipment in accordance with Figure 5 16 and setting up the oscilloscope to monitor the voltage across the resistor C Test the EUT by configuring the test equipment as shown in Figure 5 17 50 ECSS E 20 07A Draft 4 April 2008 5 5 7 4 Procedures The test procedures shall be as follows Turn on the measurement equipment and wait until it is stabilized b Check the measurement system using the measurement system check setup for waveform verification as follows l Set the signal generator to the lowest test frequency 2 Increase
33. N network inserted in the supply leads of an apparatus to be tested which provides in a given frequency range a specified source impedance for the measurement of disturbance currents and voltages and which can isolate the apparatus from the supply mains in that frequency range 3 2 11 not operating condition wherein no power is applied to the equipment 3 2 12 overshield shield surrounding a bundle or a shielded cable 3 2 13 passive intermodulation product generation of a signal at frequency f n f m f from two signals at frequencies f and fp where n and m are positive or negative integers by a passive device usually an electrical contact 3 2 14 port place of access to a device or network where energy can be supplied or withdrawn or where the device or network variables can be observed or measured 3 2 15 power quality requirements requirements which define the conducted voltage noise or impedance the power user can expect NOTE Noise e g from load regulation spikes and sags 13 ECSS E 20 07A Draft 4 April 2008 3 2 16 soft magnetic material ferromagnetic material with a coercivity smaller than 100 A m 3 2 17 spurious emission electromagnetic emission from the intended output terminal of an electronic device but outside of the designed emission bandwidth 3 2 18 test antenna antenna of specified characteristics designated for use under specified conditions in conducting tests 3 2 19 unit
34. T by configuring the test equipment as specified in Figure 5 31 and meeting the following provisions l the high voltage probe used for calibration is removed z the EUT is mounted on a conductive ground plane using the space vehicle mount and attach points and operated using the actual electrical harness or an EMC test harness of identical construction to the actual harness NOTE It is preferable to use the actual electrical harness 2 the discharge circuit is supported 5 cm above the ground plane by a non conductive standoff with high voltage insulation capability 4 from calibration the discharge circuit is kept unchanged in size and shape and tightly electromagnetically coupled 20 cm along an EUT bundle held by dielectric bonds NOTE a maximum separation distance of lcm between the injection wire and the outer circumference of the bundle under test is a condition for achieving a tight electromagnetic coupling 5 a current probe is monitoring the primary current from the ESD source near the damping resistor 6 a current probe is monitoring the current in the EUT harness 5 cm from the EUT connector 5 5 12 4 Procedure The test procedures shall be as follows Turn on the measurement equipment and wait until it is stabilized b Perform a calibration using the calibration setup l Select the spark gap device or adjust the spark length at the voltage breakdown to be used for the test 2 Turn on the high voltage generat
35. T power leads including grounds and returns that are not grounded internally to the equipment or subsystem 5 5 9 2 Test equipment The test equipment shall be as follows a Spike generator with following characteristics l Pulse width of 10 us and 0 15us 2 Pulse repetition rate capability up to 10 pulses per second 3 Voltage output as required positive then negative 4 Output control 5 Adequate transformer current capacity commensurate with line being tested 6 Output impedance 5 Q or less for 0 15 us and 1 Q or less for 10us transient T External synchronization and triggering capability b Oscilloscope with 10 MHz bandwidth or greater Differential high voltage probe d Isolation transformer e 5 Q resistor power metal film resistor with inductance lower 100 nH and peak power capability f LISN defined in 5 3 4 with added inductor for a total inductance not less than 20 uH for parallel injection 5 5 9 3 Setup The test setup shall be as follows 55 ECSS E 20 07A Draft 4 April 2008 Maintain a basic test setup for the EUT as specified in 5 3 6 and Figure 5 3 b For calibration l Configure the test equipment in accordance with Figure 5 21 for verification of the waveform 2 Set up the oscilloscope to monitor the voltage across the 5 resistor C For EUT testing configure the test equipment as shown in Figure 5 22 series test method or Figure 5 23 parallel test method NOTE With series injection the
36. The requirement of 5 3 10 3 does not apply 1 EUT 2 EUT or EGSE 3 Access panel 4 Interconnecting cable 5 Non conductive standoff 6 Grounding plane 7 TINT sannan a Figure 5 29 Spacecraft charging ESD susceptibility test 68 ECSS E 20 07A Draft 4 April 2008 Iniection D amping resistor Spark ga N High Current voltage probe Choke resistor Choke resistor igh voltage ESD sparker or high voltage dc power cunni Figure 5 30 Susceptibility to ESD calibration configuration Current 20cm probe counlino Bundle under test Injection Damping Spark ga wire tightly resistor coupled to the hundle Current probe Choke a resistor High Choke J voltage resistor ESD sparker or high voltage dc power supply Figure 5 31 Susceptibility to ESD test equipment configuration 69 ECSS E 20 07A Draft 4 April 2008 Annex A informative Subsystem and equipment limits A 1 Overview There is no single method for achieving EMC Low susceptible equipment is for telecommunication spacecraft flying in a severe EMI environment due to on board large power and possible residual ESD Low emission equipment is for scientific spacecraft for preserving high sensitivity of detectors Therefore it is not possible to define a same set of limits for all equipments of all spacecraft and launchers The EMCCP is the vehicle for tailoring limits and
37. When current measurements are performed on the central line of a coaxial transmission line a transmission line with 50 characteristic impedance coaxial connections on both ends and space for an injection probe around the centre conductor shall be used for calibration NOTE 0 Figure 5 4 represents an arrangement described in MIL STD 461E 31 ECSS E 20 07A Draft 4 April 2008 NOTE VERTICAL CROSS SECTION AT CENTER OF FIXTURE SHOWN TOP SHALL BE REMOVEABLE 12 7 mm ALUMINUM 120 mm WIDE S TYPE N CONNECTORS 2 12 7 mm ALUMINUM 180 mm WIDE K 15 mm DIA BRASS PLASTIC COATED 70 mm 7 230 mm 260 mm l DIMENSIONS OF OPENING CRITICAL Figure 5 4 Typical calibration fixture 5 3 9 Emission testing 5 3 9 1 Bandwidths a The measurement receiver bandwidths listed in Table 5 2 shall be used for emission testing NOTE These bandwidths are specified at the 6 dB down points for the overall selectivity curve of the receivers b Video filtering shall not be used to bandwidth limit the receiver response C If a controlled video bandwidth is available on the measurement receiver it shall be set to its greatest value d If receiver bandwidths larger that those in Table 5 2 are used no bandwidth correction factors shall be applied to test data due to the use of larger bandwidths NOTE Larger bandwidths can result in higher measured emission levels Table
38. agnetic interference electromagnetic interference safety margin emission high voltage 11 ECSS E 20 07A Draft 4 April 2008 lightning indirect effects radiated emission radiofrequency susceptibility susceptibility threshold For the purposes of this document the following terms have a specific definition contained in ECSS E 20 06A electrostatic discharge ESD secondary arc For the purposes of this document the following term has a specific definition contained in ECSS E 33 11A electro explosive device EED 3 2 Terms specific to the present standard 3 2 1 ambient level level of radiated and conducted signal and noise that exist at the specified test location and time when the equipment under test is not operating NOTE Examples are atmospherics interference from other sources and circuit noise or other interference generated within the measuring set compose the ambient level 3 2 2 antenna factor factor that when properly applied to the voltage at the input terminals of the measuring instrument yields the electric or magnetic field strength NOTE1 This factor includes the effects of antenna effective length mismatch and transmission losses NOTE2 The electric field strength is normally expressed in V m and the magnetic field strength in A m or T 3 2 3 common mode voltage voltage difference between source and receiver ground references 3 2 4 contact discharge method method of testing
39. alibrated in absence of EUT in each of 3 rectangular semi axes in both directions Determination of the DC magnetic field emission is performed by either measurement or similarity Determination by similarity is applied to equipment or subsystems coming from other programs where re use as it is or re use with only little modification Assessment of the dipole model by measurement of magnetic induction B at least at two different distances r and comparing respective products r m B uT NOTE Distances in the range 0 5 m to 1 5 m can be used Magnitude of the magnetic dipole when the equipment is assimilated to a dipole either by its magnetic moment or by the magnetic induction at some distance of reference When the unit is assimilated to a dipole the inverse cube law dependence with distance applies the following relation worst case is used for the equivalence between the magnetic moment and the induction at the distance d B T 2 10 7 M Am2 d m3 characterization of the magnetic source when the dipole approximation is inadequate either by s a multiple moment model or a spherical harmonics model or the magnetic induction at the distance of measurement The distance of reference is specified by the EMCAB in function of the size of the space vehicle or of the actual distance between magnetic sources and susceptible equipment The magnetic induction is a rough indication that can be
40. and amplitudes at which the test was conducted shall be provided in graphical or tabular form Indications of compliance with the requirements shall be provided NOTE Such indications can be provision of oscilloscope plots of injected waveforms with test data Information shall be displayed after application of correction factors including transducers attenuators and cable loss Data shall be reported with frequency resolution of 1 percent Data shall be provided with a minimum amplitude resolution of 1 dB for each plot If susceptibility is observed determined levels of susceptibility shall be recorded in the test report 34 ECSS E 20 07A Draft 4 April 2008 5 3 11 Calibration of measuring equipment 5 3 11 1 General Measurement antennas current probes field sensors and other devices used in the measurement loop shall be calibrated at least every two years or when damaged 5 3 11 2 Measurement system test a At the start of each emission test the complete test system including measurement receivers cables attenuators couplers and so forth shall be verified by injecting a known signal as stated in the individual test procedure while monitoring system output for the proper indication b When the emission test involves an uninterrupted set of repeated measurements such as evaluating different operating modes of the EUT using the same measurement equipment the measurement system test may be accomplished only
41. ars in the design of detection chains Overshields shall be bonded to chassis ground l at both ends 2 using a 360 direct contact or a bond strap of less than 30 nH NOTE see NOTE of clause 4 2 11 2 4 2 11 2e Overshields should be bonded to chassis ground at intermediary points with a separation distance less than 1m between two grounding points 22 ECSS E 20 07A Draft 4 April 2008 5 Verification 5 1 Overview This Clause specifies general conditions for EMC testing requirements for verification at system level and detailed procedures for unit and subsystem level testing 5 2 General 5 2 1 Electromagnetic effects verification plan The electromagnetic effects verification plan EMEVP provides the instruction for conducting all activities needed to verify electromagnetic effects requirements This document defines the approach methods procedures and specific test conditions The content is specified in Annex B of ECSS E 20B The EMEVP is the vehicle for tailoring procedures and test conditions 5 2 2 Electromagnetic effects verification report The electromagnetic effects verification report EMEVR documents activities and report analysis or test results in relation with the verification of the electromagnetic effects It is established based on the electromagnetic effects verification plan EMEVP The content of the EMEVR is defined in Annex C of ECSS E 20B supplemented by specific requirements defined hereafter in 5
42. ated normative documents are called by the requirements of this ECSS Standard and therefore constitute requirements to it Subsequent amendments to or revisions of any of these publications do not apply NOTE However parties to agreements based on this ECSS Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below ECSS P 001B ECSS Glossary of terms ECSS E 20B Space engineering Electrical and electronic ECSS E 20 06A Space engineering Spacecraft charging ECSS E 33 11A Space engineering Explosive systems and devices ECSS E 50 14A Space engineering Discrete interfaces IEC 61000 4 2 Edition 1 2 Electromagnetic compatibility EMC Part 4 2 Testing and measurement techniques Electrostatic discharge immunity test 10 ECSS E 20 07A Draft 4 April 2008 3 Terms and definitions 3 1 Terms defined in other standards For the purpose of this Standard the terms and definitions from ECSS P 001B apply in particular for the following terms critical item customer equipment item launcher launch vehicle mission requirement safety critical function supplier spacecraft space vehicle subsystem system test verification For the purposes of this document the following terms have a specific definition contained in ECSS E 20B conducted emission electromagnetic compatibility electromagnetic compatibility control electrom
43. ceeding with the testing C Test the EUT by determining the conducted emission from the input power leads hot lines and returns separately and from each interconnecting bundle common mode including the ones with power leads as follows l Turn on the EUT and wait until it is stabilized 2 Select a lead or a bundle for testing and clamp the current probe into position 3 Scan the measurement receiver over the frequency range using the bandwidths and minimum measurement times specified in Table 5 2 clause 5 3 9 1 4 Repeat 5 5 3 4 c 2 and 5 5 3 4 c 3 for each power lead or for each bundle Oscilloscope Measurement Data 50Q input receiver eode 50Q coaxial load Current probe Signal inside jig iN generator IE 6dB To power source T connector Figure 5 7 Conducted emission measurement system check Measurement receiver Data recorder Current probe To power source Figure 5 8 Conducted emission measurement setup in differential mode 41 ECSS E 20 07A Draft 4 April 2008 iS SEn Data recorder receiver Power lines A To power source ee 6 ee LISN a Signal lines or EGSE EGSE Current probe Figure 5 9 Conducted emission measurement setup in common mode 5 5 4 CE power leads inrush current 5 5 4 1 Purpose This test procedure is used to verify that the inrush current of the EUT does not exceed the specified requirements for power input leads 5
44. cified in 5 3 6 and Figure 5 3 NOTE It is important at this point to assess the test area for potential high voltage hazards and take necessary precautionary steps to assure safety of test personnel b When using an ESD generator as a high voltage power supply as shown Figure 5 30 or Figure 5 31 it is set in the contact discharge mode 66 ECSS E 20 07A Draft 4 April 2008 E Connect the high voltage electrode to the discharge circuit at the node between the spark gap and the capacitor d The discharge circuit length is not larger than what is necessary to place in series the 20 cm long coupling wire the damping resistor the discharge capacitor the spark gap and the current probe NOTE It is important to ensure that the discharge loop is as small as possible for achieving the transient pulse duration objective defined in 5 5 12 4 5 5 12 4b 4 e For calibration the test equipment is configured as shown Figure 5 30 and meeting following provisions l the discharge circuit is not coupled to the EUT 2 choke resistors are near the capacitor 3 the current probe monitoring the primary current from the ESD source is near the damping resistor at the capacitor side 4 the high voltage probe is measuring the voltage across the capacitor grounded at the damping resistor side NOTE The high voltage probe is not meant to measure the voltage during the discharge but the voltage reached before discharge f Test the EU
45. cseeeeeeeeeeeeeeeeeeeeseaeeeeeeseaeeeessaneeeesaanes 20 4 2 12 Shielding excepted wires and Cables cccccseececceeceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeas 21 4 2 13 Wiring including wires and cables Shielding ccccceeesseeeeeeeeeeeeeeeeeeesaees 21 9 VENCA UON cisco E a rr aa Eaa 23 T 2 04 lt A ee ee ee eee eee ee 23 oe C 10 2162 Ieee ee ee ene E eee ee ee 23 5 2 1 Electromagnetic effects verification plan ccceeccecceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeaees 23 5 2 2 Electromagnetic effects verification rePOrt cccseeeccseeeeeeeeeeeseeeeeseeeeeseneeess 23 BIS ESE C OMG OMS serions ner Ar EN E NT E 23 5 3 1 Measurement tolerances cccccccscccssseeceeececeeseeceeseeceeseecseseeesseeesseneesseneeees 23 Do OSS E eee ee ceecaenceeeacaceaeseaacceeacaeaanaeeaouenonencnseccamasancenenecnansesnanasansencnsenanoeaceaces 24 BSS Crona Pa oeer EEEE EEEE EEEE 25 5 3 4 Power source impedance ccccseeccccceeeeeeceececeeeueeeeeseeeeessaeeeeesaeeeesaaseeesaaass 26 5 3 5 General test precautions ccccccceeeecccceeeeseeeeeeeeeeeeeeessseeeeeeesseeeeeeeeseaaeeeeeeeeas 27 5 36 EUT tesi COMMOTION sssrinin AEEA E E 28 537 Operon o EU Tereska A AA 30 5 3 8 Use of measurement equipment cccccseeceeceeeeecceeseeececaueeeeeeeeeeesaaeeesseass 31 D EMISSION OSUN essre EE 32 5 3 10 Susceptibility testing 0000nnnn000nnnnnnnannnnnennnnnnnrnnnnnnsnnnnnensrnrnrennnnrrrn
46. d minimum measurement times specified in Table 5 2 clause 5 3 9 1 4 Repeat 5 5 2 4 c 2 and 5 5 2 4 c 3 for each power lead Measurement Data Oscilloscope l receiver recorder Coax T and bifilar transition Signal generator To power source with Current amplifier Resistor probe Figure 5 5 Conducted emission 30 Hz to 100 kHz measurement system check Measurement receiver Data recorder Current probe To power source Figure 5 6 Conducted emission 30 Hz to 100 kHz measurement setup 39 ECSS E 20 07A Draft 4 April 2008 5 5 3 CE power and signal leads 100 kHz to 100 MHz 5 5 3 1 Purpose This test procedure is used to verify that electromagnetic emissions from the EUT do not exceed the specified requirements for power input leads including returns and for common mode emission 5 5 3 2 Test equipment The test equipment shall be as follows a Measurement receiver b Current probe C Signal generator d Data recording device e Oscilloscope with 50Q input f 50Q power divider 6dB T connector g 50Q coaxial load h Calibration fixture defined in 5 3 8 3 LISN s defined in 5 3 4 j 0 5 5 3 3 Setup The test setup shall be as follows Maintain a basic test setup for the EUT as specified in 5 3 6 and Figure 5 3 b Configure the test setup for the measurement system check as shown in Figure 5 7 C For compliance testing of the EUT l Con
47. ductive composite ground plane the surface resistivity of the actual installation shall be used Composite ground planes shall be electrically bonded to the enclosure with means suitable to the material 5 3 4 Power source impedance a The impedance of power sources providing input power to the EUT shall be controlled by Line Impedance Stabilization Networks LISN s for all measurement LISN s shall not be used on output power leads The LISN s shall be located at the power source end of the exposed length of power leads specified in 5 3 6 6 The LISN circuit shown in Figure 5 2 shall be used NOTE 1 The LISN can be split in several cases one per power lead NOTE 2 The series inductances represent the inductances of the wiring the series resistances represent the resistances of the wiring and of the central protections NOTE3 The 50 QO resistors result in 100 Q at high frequency similar to the characteristic impedance of the line NOTE4 The feed through capacitors provide a short circuit at high frequency and make the LISN symmetrical NOTE5 Connecting the regulation wires of the laboratory supply at the LISN input in order to provide sufficiently low impedance at low frequency is an appropriate method The source impedance is then dominated by the series resistances in the LISN Alternatively a large capacitor between mF and 10 mF will be used If no value is specified x 2 uH and y 0 1 ohm shall be used NOTE T
48. e 5 3 5 3 Overload precautions a Checks shall be performed to assure that an overload condition does not exist NOTE Measurement receivers and transducers are subject to overload especially receivers without preselectors and active transducers b Overload condition shall be corrected NOTE This can be done by instrumentation changes 2 ECSS E 20 07A Draft 4 April 2008 5 3 6 EUT test configurations 5 3 6 1 General The EUT shall be configured as shown in the general test setup of Figure 5 3 and maintained during all testing NOTE For radiated tests it may be desirable to have the LISN outside of the shielded room EUT LISN Power source Access panel Interconnecting cable Power lead Bonding strap Non conductive standoff Grounding plane 2 oS a Figure 5 3 General test setup 5 3 6 2 Bonding of EUT Only the provisions included in the design of the EUT shall be used to bond units 5 3 6 3 Shock and vibration isolators a EUT s shall be secured to mounting bases having shock or vibration isolators if such mounting bases are used in the actual installation b The bonding straps furnished with the mounting base shall be connected to the ground plane C When mounting bases do not have bonding straps bonding straps shall not be used in the test setup 5 3 6 4 Safety grounds When external terminals connector pins or equipment grounding conductors are available for safety ground connect
49. e which produces maximum emissions b During susceptibility testing the EUT shall be placed in its most susceptible operating mode C When the EUT has several available modes including software controlled operational modes the number of modes to be tested for emission and susceptibility shall be such that all circuitry is evaluated NOTE It is expected that the customer defines or agrees operating modes 5 3 7 2 Operating frequencies for tuneable RF equipment Measurements shall be performed with the EUT tuned to not less than three frequencies within each tuning band tuning unit or range of fixed channels consisting of one mid band frequency and a frequency within 5 from each end of each band or range of channels 5 3 7 3 Operating frequencies for spread spectrum equipment Operating frequency requirements for two major types of spread spectrum equipment shall be as follows a frequency hopping measurements are performed with the EUT utilizing a hop set which contains a minimum of 30 of the total possible frequencies and the hop set is divided equally into three segments at the low mid and high end of the EUT operational frequency range b direct sequence measurements are performed with the EUT processing data at the highest possible data transfer rate 30 ECSS E 20 07A Draft 4 April 2008 5 3 7 4 Susceptibility monitoring a The EUT shall be monitored during susceptibility testing for indications of de
50. e EUT enclosure are within the 3 dB beamwidth of the antenna Maintain the placement of electric field sensors as specified in 5 5 11 3 d 1 above 5 5 11 4 Procedures The test procedures shall be as follows a Turn on the measurement equipment and EUT and wait until it is stabilized NOTE It is important at this point to assess the test area for potential RF hazards and take precautionary steps to assure safety of test personnel and fire avoidance b Check and calibrate the measurement system as follows l Procedure when using electric field sensors a b Record the amplitude shown on the electric field sensor display unit due to EUT ambient Reposition the sensor until the level measured in a above is lt 10 of the field strength to be used for testing Procedure when calibrating with the receive antenna a b c d Connect a signal generator to the coaxial cable at the receive antenna connection point antenna removed set the signal source to an output level of 0 dBm at the highest frequency to be used in the present test setup and tune the measurement receiver to the frequency of the signal Source Verify that the output indication is within 3 dB of the applied signal considering all losses from the generator to the measurement receiver and if deviations larger than 3dB are found locate the source of the error and correct the deficiency before proceeding Connect the receive
51. e bundle C Bundles of different categories shall be separated either by a separation distance of 5 cm from the outer circumference or by a metallic screen when they are routed on parallel paths NOTE Overshields or spacecraft walls can be used to fulfil the requirement 21 ECSS E 20 07A Draft 4 April 2008 Wires and cables shall be marked in such a manner that personnel can visually identify the EMC category for each wire or cable 4 2 13 2 Cable shields a Cable shields shall not be used as an intentional current carrying conductor except coaxial cables in radiofrequency circuits and high speed data links using coaxial cables Cable shields other than overshields shall have an insulated sheath to prevent uncontrolled grounding Connectors used to carry shielded wires shall l not use a nonconductive finish 2 provide contact to the equipment housing with a resistance less than 10 mQ through the equipment connector body as shown Figure 4 1 Bonding of cable shields shall be as following l bonding to chassis ground is performed at both ends a through the equipment connector body b using a backshell that provides for circumferential bonding of shields or using a halo ring NOTE No grounding inside the equipment through a connector ground pin in order to prevent any perturbation inside the equipment 2 Connection to electrical reference is performed through dedicated pins NOTE This case typically appe
52. eeeeeeaeeeeeessaeeeees 12 oa PAN OVI et SU GMS e E E E E E 14 4 Regu unrements scr a 16 4 1 General system requirements ccceeeeecececseeeeeeeeeecseaeesseeeeeesseeeseeeeeesssaseeeeeees 16 4 2 Detailed system requirements cccccsscceccsssceeceeseececeueeeeceuseeeseeseeecseneeesneaeeess 16 4 2 1 OVONVIQW ec esccccsecccnetenensetensccneeceuseceuecceseeceueeseuaeseuaeseueeseuseseueeseueeseueeseueeneneess 16 4 2 2 EMC with the launch System ccccccccccsseeeccessseeeceseeeceeeeeeecsaseeeeseeseeessaaeees 16 42 3 LIQNtNING ENVIFONMENE cc ccccceeececceeeeceeececeeececeeueeceeeeseuseessaueessneeeseneesees 17 4 2 4 Spacecraft charging and effects cccccccssssceesseeeeecseeeeeeeeeeeeeesseeeeeesaneesesaaees 17 4 2 5 Spacecraft DC Magnetic EMISSION cccccccessseseeeeeeeeeeeeeeeesaeeeeeeeeseaeeeeeesenaes 18 4 2 6 Radiofrequency Compatibility ccccccccccssececessseeeeeseeeeeeeseeeeeeseeeeesssseeeesaaees 18 4 2 7 Hazards of electromagnetic radiation cccccseececceeeeeeeceeeeeeneeeeeseeeeeesaaees 19 4 2 8 Intrasystem EMC 2 2cccsccdtccseesstcssaesetossacse kinccnbocsnccabacutenedsaumansescntacesscenncskssenccaaeat 19 4 2 9 EMC with ground equipment c ccccccccsssececseeeceeceeeeeeeseeeeeecseeeesesseeeessaeees 19 ECSS E 20 07A Draft E RJ 4 April 2008 Ael TOUNIN oerna RRE EEE 19 4 2 11 Electrical bonding requirements cccc
53. el at 1 kHz and 100 kHz which is at least 6 dB below the emission limit to the current probe NOTE A power amplifier can be necessary at 1 kHz 2 Apply through the current probe a DC current equivalent to the EUT supply current NOTE 1 A DC current is applied for verifying that the current probe will not be saturated by the EUT DC supply current NOTE2 This DC current is applied through the LISN for applying the same impedance through the probe as with the EUT 3 Verify the AC current level as measured with the probe by comparison with voltage across the 1 Q resistor at 1 kHz and the 10 Q resistor at 100 kHz also verify that the current waveform is sinusoidal 38 ECSS E 20 07A Draft 4 April 2008 4 Scan the measurement receiver for each frequency in the same manner as a normal data scan Verify that the data recording device indicates a level within 3 dB of the injected level 5 If readings are obtained which deviate by more than 3 dB locate the source of the error and correct the deficiency prior to proceeding with the testing u Test the EUT by determining the conducted emissions from the EUT input power leads hot line and return and measure the conducted emission separately on each power lead as follows l Turn on the EUT and wait for its stabilization pA Select a lead for testing and clamp the current probe into position A Scan the measurement receiver over the frequency range using the bandwidths an
54. er 1 GHz not applicable Zz 1 GHz to 18 GHz double ridge horn 24 2 by 13 6 cm opening NOTE Above 1 GHz receive antennas may be not used see 5 5 11 3 5 5 11 3b 2 Linearly polarized transmit antennas NOTE The following antennas are commonly used 30 MHz to 200 MHz biconical 137 cm tip to tip 200 MHz to 1 GHz double ridge horn 69 0 by 94 5 cm opening or log periodic 1 GHz to 18 GHz double ridge horn 24 2 by 13 6 cm opening Electric field sensors physically small electrically short Measurement receiver Power meter Directional coupler Attenuator Data recording device LISN defined in 5 3 4 optional 5 5 11 3 Setup The test setup shall be as follows a Maintain a basic test setup for the EUT as shown and specified in 5 3 6 and Figure 5 3 NOTE The LISN should be used For measurement system check use following sensors l Electric field sensors from 30 MHz to 1 GHz 2 Either receive antennas or electric field sensors above 1 GHz NOTE For the electric sensors and receiving antennas to be used see 5 5 11 2 5 5 11 2c and 5 5 11 2 5 5 11 2h Configure test equipment as specified in Figure 5 26 Check the measurement system as follows l Place the electric field sensors 1 m from and directly opposite the transmit antenna as shown Figure 5 27 and a minimum of 30 cm above the ground plane not directly at corners or edges of EUT 2 Place the receive antennas prior to placement of the EUT as shown Figure 5 28
55. erance indicated in its individual specification after being 16 ECSS E 20 07A Draft 4 April 2008 exposed even not operating to the electromagnetic environment from the launcher and launch site NOTE Most of spacecraft equipment is not operating during launch During the launching sequence spacecraft transmitters and receivers platform and payload can be either in OFF or ON state depending on the launch vehicle C The electromagnetic interference safety margin EMISM of safety critical equipment shall be applied to equipment in ON state during prelaunch and launch phase and to EED s 4 2 3 Lightning environment 4 2 3 1 General Protection of the space system against both direct and indirect effects of lightning can be a combination of operational avoidance of the lightning environment and electrical overstress design techniques 4 2 3 2 Requirements to the space system a Assessment of risk on the launch pad inside the protected area for the space system and its equipment against direct and indirect effects of lightning before lift off shall be performed b The spacecraft supplier shall obtain from the launching company the EM environment imposed on the launcher payloads in case of lightning 4 2 4 Spacecraft charging and effects 4 2 4 1 General Mitigation of risks related to spacecraft charging results of a combination of rules and methods preventing voltage build up and so minimizing the occurrence of ESD
56. figure the test setup as shown in Figure 5 8 2 Position the current probe 10 cm from the LISN 5 5 3 4 Procedures The test procedures shall be as follows Turn on the measurement equipment and wait until it is stabilized b If the EMEVP specifies to check the measurement system check it by evaluating the overall measurement system from the current probe to the data output device as follows l Apply a calibrated signal level that is at least 6 dB below the applicable limit at 1 MHz and 10MHz or at a level allowing out of the noise reading on the oscilloscope whatever is greater to the current probe in the jig Zi Apply through the current probe using a second wire a DC current equivalent to the EUT nominal supply current NOTE 1 A DC current is applied for verifying that the current probe will not be saturated by the EUT DC supply current NOTE2 This DC current is applied through the LISN for applying the same impedance through the probe as with the EUT 40 ECSS E 20 07A Draft 4 April 2008 3 Verify the AC current level as measured with the probe by comparison with the voltage on the T derivation 4 Scan the measurement receiver for each frequency in the same manner as a normal data scan and verify that the data recording device indicates a level within 3 dB of the injected level 5 If readings are obtained which deviate by more than 3 dB locate the source of the error and correct the deficiency prior to pro
57. gradation or malfunction NOTE This monitoring is normally accomplished using built in test visual displays aural outputs and other measurements of signal outputs and interfaces b If EUT performance is monitored through installation of special circuitry in the EUT the modifications shall not influence test results 9 3 8 Use of measurement equipment 5 3 8 1 General Any frequency selective measurement receiver can be used for performing the testing described in this standard if the receiver characteristics that is sensitivity selection of bandwidths detector functions dynamic range and frequency of operation meet the constraints specified in this standard and are sufficient to demonstrate compliance with the applicable limits 5 3 8 2 Detector a A peak detector shall be used for all frequency domain emission and susceptibility measurements NOTE This device detects the peak value of the modulation envelope in the receiver pass band Measurement receivers are calibrated in terms of an equivalent root mean square value of a sine wave that produces the same peak value b When measurement devices other than peak detector e g oscilloscopes non selective voltmeters or field strength sensors are used for susceptibility testing correction factors shall be determined and applied for test signals to adjust the reading to equivalent RMS values under the peak of the modulation envelope 5 3 8 3 Calibration fixture jig
58. he test equipment as shown Figure 5 20 2 Place the injection and monitor probes around a cable bundle interfacing an EUT connector 3 Position the monitor probe 5 cm from the connector if the overall length of the connector and backshell does not exceed 5 cm at the overall length of the connector and backshell otherwise l Position the injection probe 5 cm from the monitor probe 5 5 8 4 Procedures The test procedures shall be as follows Turn on the measurement equipment and wait until it is stabilized Calibrate the measurement system by performing the following procedures using the calibration setup l Set the frequency of the generator to 50 kHz and apply the pulse modulation Figure 5 19 2 Increase the applied signal until the oscilloscope indicates the voltage specified by application of clause 4 2 8 3 Verify that both inputs of the oscilloscope voltage monitored on 50 ohms and current monitored by the current probe are consistent within 3 dB This is applicable only if a current probe is used during calibration 4 Record the generator settings 5 Repeat 5 5 8 4 b 2 through 5 5 8 4 b 4 for each measurement frequency Test the EUT by performing the following procedures using the EUT test setup l Turn on the EUT and wait until it is stabilized 2A Select a bundle for testing and clamp the current probes into position a Set the modulated sine generator to a test frequency at low output level b
59. he x and y values respectively the inductance and the resistance inserted in each lead are expected in the EMEVP Magnetic coupling between inductors shall be avoided If the return line is grounded at the power source in the actual installation star distribution the return line of the LISN shall be grounded on the power source side If the return line s of the actual installation is locally grounded chassis return the return line of the LISN need not be provided and the tests shall be performed with the return s tied to case The LISN impedance shall be measured at least annually under the following conditions 26 ECSS E 20 07A Draft 4 April 2008 l the impedance measured between the power output lead on the EUT side of the LISN and the metal enclosure of the LISN 2 an unterminated power input terminal on the power source side of the LISN To Power FE Metal Source 470nF enclosure to 10uF x uH y mQ Regulation wires To EUT Optional 1 to 10mF x uH y mQ 470nF 100 kQ Bonding stud onding stud E to 10uF FR A R R a E ee Figure 5 2 Line impedance stabilization network schematic 5 3 5 General test precautions 5 3 5 1 Safety Clause 4 2 7 shall apply for tests involving high electromagnetic power or high voltage test equipment 5 3 5 2 Excess personnel and equipment Only the equipment and the personnel used to perform the test shall be present in the test area or enclosur
60. ing amplitude gives better results than a sine wave modulated by exponentials or ramp functions 2 Measurement after deperm on the six semi axes at the reference distances Perm l EUT not operating application of a perm field of 300 uT on each XYZ axis 2 Measurement after perm on the six semi axes at the reference distances Stray field EUT operating measurement on the six semi axes at the reference distances Final deperm repeat 5 5 5 3 b 5 5 5 4 Data presentation For DC magnetic field emission data shall be presented as follows superseding clauses 5 3 9 4 5 3 9 4a through 5 3 9 4 5 3 9 41 a For each measurement distance for each of the 6 semi axes the following induction measurements in uT are plotted in tabular form Bex Bix Bevy Bvy Buz B z For each measurement distance mean inductions for each axis are computed in units of uT and plotted in tabular form using following equations 45 ECSS E 20 07A Draft 4 April 2008 gp oe Bas ap Be Fag _ Bz TB 2 2 f 2 C For each measurement distance r 3 axes magnetic moment components in units of Am are calculated using the following equations and reported M 5r Bx M in units of Am2 r in meters B in uT M 5r By M 5r Bz d Using values of M M and M at both distances r and r values M and Mbp of the magnetic moment are calculated using the following equations and reported M V4M t1 Myr MZ 11 M VM 12 M r2 M
61. internal LISN capacitor at the input power side is protecting the source NOTE With parallel injection the internal inductance is protecting the source so a minimum value is needed as specified in 5 5 9 2 5 5 9 2f 5 5 9 4 Procedures The test procedures shall be as follows Turn on the measurement equipment and wait until it is stabilized b Perform the following procedure using the calibration setup l Adjust the pulse generator for the pulse width and pulse repetition rate 2 Adjust the amplitude of the signal to the level specified in associated limit 3 Verify that the waveform complies with the requirements if not correct accordingly 4 Record the pulse generator amplitude setting C Test the EUT by performing the following procedure using the test setup l Turn on the EUT and wait until it is stabilized 2 Adjust the spike generator to a pulse duration J Apply the test signal to each power lead and increase the generator output level to provide the specified voltage without exceeding the pulsed amplitude setting recorded during calibration 4 Apply repetitive 6 to 10 pulses per second positive spikes to the EUT ungrounded input lines for a period not less than 2 minutes in duration and if the equipment employ gated circuitry trigger the spike to occur within the time frame of the gate 5 Repeat 5 5 9 4 c 4 with negative spikes 6 Monitor the EUT for degradation of performance J If susceptibility is no
62. ions and are used in the actual installation they shall be connected to the ground plane NOTE Arrangement and length are specified in 5 3 6 6 5 3 6 5 Orientation of EUT s a EUT s shall be oriented such that surfaces that produce maximum radiated emissions and respond most readily to radiated signals face the measurement antennas 28 b ECSS E 20 07A Draft 4 April 2008 Bench mounted EUTs comprising interconnecting cables shall be located 10 2 cm from the front edge of the ground plane 5 3 6 6 Construction and arrangement of EUT cables 5 3 6 6 1 General a b Electrical cable assemblies shall simulate actual installation and usage NOTE 1 Proper construction techniques such as use of twisted pairs shielding and shield terminations are determinant features NOTE 2 Details on the cable construction used for testing are defined in the EMEVP ECSS E20B annex B and maintained in the EMEVR ECSS E20B annex C Shielded cables or shielded leads including power leads and wire grounds within cables shall be used only if they have been specified in installation requirements 5 3 6 6 2 Interconnecting leads and cables a Individual leads shall be grouped into cables in the same manner as in the actual installation Up to 10 m interconnecting cable lengths in the setup shall be the same as in the actual installation If a cable is longer than 10 m in the actual installation the cable length in the
63. ive load that draws the same rated current as the EUT 5 3 3 Ground plane 5 3 3 1 General a If the actual installation is known the EUT shall be installed on a ground plane that simulates the actual installation b If the actual installation is unknown or multiple installations are expected then the EUT shall be installed on a metallic ground plane C Ground planes shall be 2 m or larger in area with the smaller side no less than 75 cm d When a ground plane is not present in the actual EUT installation the EUT shall be placed on a non conductive table NOTE In such a case test methods are specific and are likely to differ from the ones in the present standard 5 3 3 2 Metallic ground plane a When the EUT is installed on a metallic ground plane the ground plane shall have a DC surface resistance not larger than 0 1 mQ per square 25 ECSS E 20 07A Draft 4 April 2008 The DC resistance between metallic ground planes and the shielded enclosure shall be 2 5 mQ or less The metallic ground planes shall be electrically bonded to the floor or wall of the basic shielded room structure at least once every 1 m The metallic bond straps shall be solid and maintain a five to one ratio or less in length to width Metallic ground planes used outside a shielded enclosure shall extend at least 1 5 m beyond the test setup boundary in each direction 5 3 3 3 Composite ground plane a When the EUT is installed on a con
64. l b Absence of passive intermodulation products shall be verified in accordance with ECSS E 20B clause 7 4 5 4 9 Grounding The system level electrical grounding and isolation shall be verified by isolation and continuity tests at system assembly NOTE The grounding and isolation design is documented by the system level grounding diagram including EGSE 36 ECSS E 20 07A Draft 4 April 2008 5 4 10 Electrical bonding a Except for bonding used only for charging control the bonding resistances shall be measured using a 4 wires method under a pulsed DC current of 1A b Except for bonding used only for charging control the probes shall be reversed and re measured to detect possible non linearities across the bonded junction NOTE See clause 5 4 55 4 5b 5 4 11 Wiring and shielding Wiring category and cable shields shall be verified by review of design and inspection 5 5 Equipment and subsystem level test procedures 5 5 1 General Test procedures are specified in clauses 5 5 2 through 5 5 12 for verifying emission and susceptibility requirements at subsystem or equipment level Table 5 3 gives the correspondence between procedures and recommended limits defined in Annex A Table 5 3 Correspondence between test procedures and limits Informative limit Tiie oftest orocedire Verification Annex P Section 5 CE on power leads differential mode 30 Hz to 100 kHz 1 part CE on power leads differential mode 100 k
65. llows l Determine the test setup boundary of the EUT and associated cabling for use in positioning of antennas 2 Use the physical reference points on the antennas shown in Figure 5 14 for measuring heights of the antennas and distances of the antennas from the test setup boundary as follows a Position antennas 1 m from the front edge of the test setup boundary for all setups b Position antennas above the floor ground plane c Ensure that no part of any antenna is closer than 1 m from the walls and 0 5 m from the ceiling of the shielded enclosure 2 Determine the antenna positions as follows a For testing below 200 MHz j For setups with the side edges of the boundary 3 m or less one position with the antenna centred with respect to the side edges of the boundary For setups with the side edges of the boundary greater than 3 m N antenna positions at spacing as shown in Figure 5 15 where N is the edge to edge boundary distance in metres divided by 3 and rounding up to an integer b For testing from 200 MHz up to 1 GHz place the antenna in such a number of positions that the entire width of each EUT enclosure and the first 35 cm of cables and leads interfacing with the EUT enclosure are within the 3 dB beamwidth of the antenna c For testing at 1 GHz and above place the antenna in such a number of positions that the entire width of each EUT enclosure and the first 7cm of cables and leads interfacing with
66. m Structural elements antenna and RF reference grounds power and signal returns shields and cable shields safety grounds EGSE grounds are considered 4 2 10 2 Requirements A system level grounding diagram shall be established including the EGSE b A ground reference shall be identified for each power signal or RF source or receiver C An upper value of common mode voltage shall be specified considering l power quality requirements defined in ECSS E 20B clause 5 7 2 2 type of detectors and sensitivity 3 characteristics of analogue signal monitor receiver circuit in accordance with ECSS E 50 14A clause 5 2 2 2 d 4 characteristics of bilevel signal monitor receiver circuit in accordance with ECSS E 50 14A clause 6 1 2 2 2 d 19 ECSS E 20 07A Draft 4 April 2008 5 hazards due to fault currents internal to the space vehicle or between the space vehicle and its EGSE When power and signal share common paths wire or structure the magnitude of ground impedance shall be limited over the affected signal spectrum NOTE Non exclusive techniques for reducing the impedance are decrease of common path length decrease of wire and ground impedance filters on common paths 4 2 11 Electrical bonding requirements 4 2 11 1 General Bonding requirements are a mean for fulfilling grounding requirements NOTE Bonding for charging control is specified in ECSS E20 06 4 2 11 2 Normative provisions a A vehicle b
67. nnnnrreennnne 33 5 3 11 Calibration of measuring EQUIPMENT cccccccceeeeeeeeeeeeeeeeeeeeeeeaaeeeeeessaaeeeees 35 e E IEW E E E E 35 cA GEN a E eee eee eee 35 5 4 2 Safety margin demonstration for critical or EED circuits ccceceseeeeeeeeees 35 5 4 3 EMC with the launch system ccceeecceccseeceeceeseeecceeeeeeseaeeeeseaeeesseaeeeesseaes 35 AA IOI ee caeecasntncscateesaateineetereieteisnetteterousseroronanes 36 5 4 5 Spacecraft and static charging ccccccccsseeeeceeceeeeeeeeeseeeeeeeeeeseeeeeeeeseaaeeeeeeeeas 36 5 4 6 Spacecraft DC magnetic field EMISSION cccccccceeeeeeeeeeeeeeeeeeeeeeseaeeeeeeeeeas 36 5 4 7 Intra system electromagnetic compatibility ccccecccceeceseeeeceeeeseeeeseeeeseees 36 5 4 8 Radiofrequency COMpalibility ccccccccsssececcsseeecceeeseecseeseeeeseseesseeaeeeeessess 36 ok Feo ONAN japeeteeeanenmenete eet R te ean ee eRe eee eee eee 36 5 4 10 Electrical bonding ccccceeeceeceeeeeeeceeeeeecceueceeeaeeeeeeseaeeeessaueeeesaeeeeesaaeeeeesaees 37 5 4 11 Wiring and shielding cceecccccseeeceeceeeeeeceeeeeesseeeeeessaeeeeseaaeeeeseaeeeesaaeeeeessegs 37 5 5 Equipment and subsystem level test ProC CUIeS cccsecccseeeeseeeeeeeeeeeaeeeeees 37 SoN 8 gt 62 eee eee eee ne eee ee ae eee ere ee eee ee eee ee eee eee ee eee eee eee 37 ECSS E 20 07A Draft 4 April 2008 5 5 2 CE power leads differential
68. ns l Diameter 4 cm 2 Number of turns 51 3 Wire 7 41 Litz wire 7 strands N 41 AWG 4 Shielding electrostatic 5 Correction Factor manufacturer s data for factors to convert measurement receiver readings to decibels above one picotesla dBpT e Measurement receiver f Calibration fixture coaxial transmission line with 50Q characteristic impedance coaxial connections on both ends and space for a current probe around the centre g Current probe h LISN 5 5 10 3 Setup The test setup shall be as follows Maintain a basic test setup for the EUT as specified in Figure 5 3 and 5 3 6 b Check the measurement system by configuring the measurement equipment the radiating loop and the loop sensor as shown in Figure 5 24 C Test the EUT by configuring the test setup as shown in Figure 5 25 5 5 10 4 Procedures The test procedures shall be as follows a Turn on the measurement equipment and wait until it is stabilized b Perform the following procedure using the calibration setup for verification of levels 58 ECSS E 20 07A Draft 4 April 2008 l Set the signal source to a frequency of 1 kHz and adjust the output to provide a magnetic flux density of 110 dBpT as determined by the reading obtained on measurement receiver A and the relationship given in 5 5 10 2 5 5 10 2c 4 2 Measure the voltage output from the loop sensor using measurement receiver B 3 Verify that the output on measurement receiver B i
69. nsor output readings for equivalent peak detection of modulated waveforms E diagrams or photographs showing actual equipment setup and the associated dimensions 63 ECSS E 20 07A Draft ELEY 4 April 2008 Test setup boundary Electric field Ai a a a I 1 5m Antenna Shielded enclosure Signal RF amplifier Electric field generator peer displav EGSE Figure 5 26 Test equipment configuration 64 ECSS E 20 07A Draft 4 April 2008 Test setup boundary N electric field sensor positions I Electric field Electric field Electric field i sensor enor N antenna positions AV Antenn Antenna x N m x N m x 2N x 2N x m edge to edge boundary distance Shielded enclosure Figure 5 27 RS Electric field Multiple test antenna positions Connected for Test setup boundary system check Receive antenna Transmit antenna Signal source Shielded enclosure a l i Connected for RF amplifier Directional i coupler measurement Measurement Power meter ee Figure 5 28 Receive antenna procedure 65 ECSS E 20 07A Draft 4 April 2008 5 5 12 Susceptibility to electrostatic discharges 5 5 12 1 Overview The purpose of this test is to determine the existence of susceptibility to electromagnetic effects of electrostatic discharges 5 5 12 2 Test equipment The test equipment shall be as follows a DC high voltage supply or an ESD generator as specified in IEC 610
70. onding attachment point connected to the vehicle structure shall be provided as a ground reference point at system level An equipment bonding stud connected to the unit housing shall be provided as a ground reference at equipment level Each unit housing shall be bonded to the nearby spacecraft structure from the equipment bonding stud The DC resistance between the equipment bonding stud and the nearby spacecraft structure shall be less than 2 5 mQ The inductance between the equipment bonding stud and the nearby spacecraft structure shall be less than 30 nH NOTE Example of formula for bonding strap inductance calculation commonly used L 200 a Log 2a b 0 5 0 22 b a L inductance in units of nH a strap length in units of m b width plus thickness of the strap in units of m The DC resistance between the unit housing and the vehicle bonding attachment point shall be less than 20 mQ The DC resistance between the unit housing and the vehicle bonding attachment point may be split as shown in 0 Bonds shall be capable to carry the fault currents determined by analysis at system level without fusing burning or arcing If the structure is used as the return current path bonding provisions shall be such that DC and AC voltage drops along power paths comply with clause 4 2 10 2 4 2 10 2c 4 2 11 3 External grounds The functionality of connecting grounding cables for charge equalization shall be provided on space systems
71. or 67 6 ECSS E 20 07A Draft 4 April 2008 Using the high voltage probe check the breakdown voltage value is stable and within 30 from the value to be used for the test Monitor the transient current pulse NOTE A goal is 30A 30ns duration at mid height rise time as short as possible Means for minimizing the rise time are adjusting the damping resistor reducing the size loop checking that both choke resistors are as close as possible to the capacitor and technology of the spark gap nature of gas and shape of electrodes Record the last current and voltage couple displayed with a common time reference Repeat 5 5 12 4 b 4 and 5 5 12 4 b 5 with opposite polarity C Test the EUT as follows l 2 gt 9 9 12 5 Fully power the unit during the complete ESD test Turn on the high voltage generator Establish a pulse discharge at a pulse rate of 1 Hz with a pulse direction of at least 15 positive and 15 negative Record the last primary and secondary current couple displayed with a common time reference Repeat 5 5 12 4 c 3 and 5 5 12 4 c 4 on each bundle interfacing with each electrical connector Data presentation Superseding clause 5 3 10 4 data presentation shall be as follows a Provide tables showing statements of compliance with the requirement and the induced current level for each interface connector b Provide oscilloscope records taken during calibration and EUT testing procedures c
72. oviding a dipole model can be inadequate and replaced by a multiple dipole model or a spherical harmonics model 4 2 5 2 Attitude control system ACS a As part of the EMCCP a magnetic budget shall be maintained providing l Three axes components of the space vehicle magnetic dipole component decreasing with the inverse cube law with distance NOTE Typical values lie in the range 1 Am or less for small spacecraft to much more than 10 Am for large spacecraft 2 If the solar array is rotating in the space vehicle axes separate evaluation for the main body and the solar array 3 When the space vehicle is using a magnetic sensor as part of the ACS evaluation of the magnetic induction at its location NOTE The angular deviation is the basic requirement however the requirement is generally expressed in terms of modification of the natural field strength at the sensor location For LEO spacecraft if the error on each axis is less than 1 uT the modification of the direction is kept less than 20 milliradians b The specified maximum magnetic field value shall comprise the remanent magnetization magnets electro magnets in off state or residual perm up due to hysteresis of soft materials the induced magnetization of soft materials by the geomagnetic field and the momentum of current loops 4 2 6 Radiofrequency compatibility a Spurious emissions requirements at antenna ports shall be specified for RF compatibility pur
73. plied to hot wires The test signal covers the 30 Hz 100 kHz frequency range 75 ECSS E 20 07A Draft 4 April 2008 1 2 0 8 0 6 Voltage Vrms 0 4 0 2 10 100 1 000 10 000 100 000 1 000 000 Frequency Hz Figure A 4 Conducted susceptibility limit frequency domain A 11 CS powerand signal leads common mode 50 kHz to 100 MHz The following levels known to be achievable and already specified in other standards or project specifications are proposed for the susceptibility test on the power and signal leads specified in clause 5 5 8 the common mode level of 3 volts peak to peak or larger is applied the limit of the current induced on the bundle is 3 A peak to peak the test signal is pulse modulated Square wave modulation is a particular case of pulse modulation the duty cycle is depending on the carrier frequency according to Table A 1 The same level is applied to all cables together or to bundles taken separately The common mode induced current on the bundle is reported The test signal covers the 50 kHz 100 MHz frequency range Table A 1 Equipment susceptibility to conducted interference test signal Frequency range Pulse repetition frequency Duty cycle 1 MHz 10 MHz 100 kHz 20 10 MHz 100 MHz 100 kHz 5 76 ECSS E 20 07A Draft E RJ 4 April 2008 A 12 CS power leads short spike transients The following levels known to be achievable and already
74. ports can be limited to following values receivers 34 dBuV transmitters stand by mode 34 dBuV transmitters transmit mode harmonics except the second and third and all spurious emissions 80dB down the level at the fundamental the second and third harmonics 50 10 log P where P is the peak power output or 80 dB whichever is less Equipment with antennas permanently mounted are not in the scope of this clause A 6 DC magnetc field emission A 6 1 General The DC magnetic field emission generated by subsystems equipment and elementary components is limited or characterized for following purposes for establishing the magnetic momentum of the whole space vehicle for establishing the composite DC magnetic field at critical locations The components of the magnetic emission are DC current loops solenoids the permanent field of hard magnetic materials magnets and the induced magnetic moment by the Earth field on soft magnetic materials including hysteresis 72 ECSS E 20 07A Draft 4 April 2008 A 6 2 Characterization Following parameters of magnetic properties can be determined or characterized permanent induction parameters of operating EUT by determination of magnetic induction B in units of uT under magnetic zero field condition induced parameters of not operating EUT by determination of magnetic induction B in units of uT when immerged in a uniform controlled field of 30 uT c
75. pose by the spacecraft supplier b When specifying limits and frequency ranges the following issues shall be included l sensitivity of possible victim receiver subsystems including out of band response 2 no limits apply to transmit frequencies and information carrying modulation bandwidths 3 highest and lowest intentional frequency used by space system receivers 18 ECSS E 20 07A Draft 4 April 2008 4 antenna port attachments gain loss characteristics 4 2 7 Hazards of electromagnetic radiation Assessment of hazards to electromagnetic radiation is a part of the process required in ECSS Q 40 02 clause 6 1 4 2 8 Intrasystem EMC Intrasystem EMC shall be achieved by a allocation of equipment level EMI requirements documented in the EMCCP including l limits on conducted and radiated emission 2 susceptibility thresholds NOTE Recommended data is defined in Annex A for equipment and subsystems b control of conducted and radiated propagation paths methods defined by clauses 4 2 10 to 4 2 13 4 2 9 EMC with ground equipment a The EGSE and MGSE used for spacecraft integration and ground testing shall l not degrade the EMC performance of the spacecraft 2 have no impact on grounding or isolation b The EGSE shall be immune to signals used for spacecraft susceptibility tests 4 2 10 Grounding 4 2 10 1 General As specified in ECSS E20B a controlled ground reference concept is defined for the space syste
76. rch for possible locations of susceptibility without omitting the locations determined in 5 5 10 4 c 2 e while maintaining the loop 5 cm from the EUT surface or connector and verify that susceptibility is not present 9 5 10 5 Data Presentation In addition to 5 3 10 4 data presentation shall provide a Tabular data showing verification of the radiating loop in 5 5 10 4 5 5 10 4b b Tabular data diagrams or photographs showing the locations and test frequencies determined in 5 5 10 4 5 5 10 4c 2 e and 5 5 10 4 5 5 10 4c 2 f 59 ECSS E 20 07A Draft 4 April 2008 Radiating loop Field monitoring loop Current probe inside jig Signal source amp power i Measurement amplifier zon receiver B Measurement receiver A Figure 5 24 Measurement system check configuration of the radiating system Radiating loop Signal source amp power amplifier a i EUT Figure 5 25 Basic test set up 5 5 11 RS electric field 30 MHz to 18 GHz 5 5 11 1 Purpose This test procedure is used to verify the ability of the EUT and associated cabling to withstand electric fields NOTE Additional requirements can apply beyond 18 GHz if SHF or EHF payloads are present These are beyond the scope of the present standard 5 5 11 2 Test equipment The test equipment shall be as follows a Signal generators b Power amplifiers 60 gt th oO pei 0 ECSS E 20 07A Draft 4 April 2008 Receive antennas l und
77. ressed implied or statutory including but not limited to any warranty of merchantability or fitness for a particular purpose or any warranty that the contents of the item are error free In no respect shall ECSS incur any liability for any damages including but not limited to direct indirect special or consequential damages arising out of resulting from or in any way connected to the use of this Standard whether or not based upon warranty contract tort or otherwise whether or not injury was sustained by persons or property or otherwise and whether or not loss was sustained from or arose out of the results of the item or any services that may be provided by ECSS Published by ESA Requirements and Standards Division ESTEC P O Box 299 2200 AG Noordwijk The Netherlands Copyright 2008 by the European Space Agency for the members of ECSS ECSS E 20 07A Draft 4 April 2008 Change log First issue ECSS E 20 07A Draft 4 April 2008 Contents CHAIN GC NOG ere EEEO uses EPEE OSa Ei 3 COMENS ere ae O E meas 4 MOGUC O Dico a a E E rE 8 POCONO Sea E E 9 2 N rMalive FETClCNGCES rernu anasa aA A Ara 10 3 Terms and definitions nnnnnnnnnnnnnnnnunnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn nnmnnn nennen 11 3 1 Terms defined in other Standards ccccccccccescecssseeceseecseseeeeeeeeseneetseneetaneeenens 11 3 2 Terms specific to the present standard cccccceeeceeeeceeeeeeeeesee
78. rush current of an equipment on the power lines can be limited in the time domain with following characteristics in order to limit the voltage transients on the power bus during any nominal change of configuration the rate of change of current is limited to 5 10f A s at switching ON the rate of change of current is lower than 2 10 A s absolute value of rise and fall slopes Specific requirements are usually defined for pulsed radars plasma thrusters power units Limits can also be specified for the following characteristics in order to achieve compatibility with the upstream protections of the spacecraft power subsystem inrush current duration in ms total charge in mC inrush current slope in A us A 4 CEo on powerand signal leads common mode 100 kHz to 100 MHz The conducted emissions on bundles in common mode can be limited with following characteristics limits are in the range extending from 100 kHz to 100 MHz Icg in units of dB referenced to 1 uA dBuA is lower than the curve of Figure A 3 the same limit is defined for all cables taken together or bundle per bundle 71 ECSS E 20 07A Draft 4 April 2008 90 80 70 60 50 40 lt aa o hn ho 3 O 30 20 10 0 100 000 1 000 000 10 000 000 100 000 000 Frequency Hz Figure A 2 Common mode conducted emission A 5 CEonantenna ports Spurious conducted emissions on antenna
79. s shall be terminated at the LISN s in such a manner that the total length of power lead from the EUT electrical connector to the LISN s shall not exceed 2 5 m All power leads shall be supported 5 cm above the ground plane 29 ECSS E 20 07A Draft 4 April 2008 f If the power leads are twisted in the actual installation they shall be twisted up to the LISN s 5 3 6 7 Electrical and mechanical interfaces a Either the actual equipment from the platform installation or loads that simulate the electrical properties impedance grounding balance and so forth present in the actual installation shall terminate electrical input or output interfaces b Signal inputs shall be applied to the electrical interfaces to exercise EUT circuitry EUT with mechanical outputs shall be loaded under expected conditions d When variable electrical or mechanical loading is present in the actual installation testing shall be performed under expected worst case conditions e When active electrical loading such as a test set is used it shall be ensured that the active load meets the ambient requirements of 5 3 2 when connected to the setup and that the active load does not respond to susceptibility signals f Antenna ports on the EUT shall be terminated with shielded matched loads if the RF link is not used during the test 5 3 7 Operation of EUT 5 3 7 1 General a During emission measurements the EUT shall be placed in the operating mod
80. s within 3 dB of the expected value based on the antenna factor and record this value C Test the EUT by performing the following procedures for determination of location and level of susceptibility l Turn on the EUT and wait until it is stabilized 2 Select test frequencies as follows a Locate the loop sensor 5 cm from the EUT face or electrical interface connector being probed and orient the plane of the loop sensor parallel to the EUT faces and parallel to the axis of connectors b Supply the loop with such a current to produce magnetic field strengths at least 10 dB greater than the limit specified by application of clause 4 2 8 but not to exceed 15 A 183 dBpT c Scan the frequency range d If susceptibility is noted select no less than three test frequencies per octave at those frequencies where the maximum indications of susceptibility are present e Reposition the loop successively to a location in each 30 by 30 cm area on each face of the EUT and at each electrical interface connector and repeat 5 5 10 4 c 2 c and 5 5 10 4 c 2 d to determine locations and frequencies of susceptibility f From the total frequency data where susceptibility was noted in 5 5 10 4 c 2 c through 5 5 10 4 c 2 e select three frequencies per octave over the frequency range 3 At each frequency determined in 5 5 10 4 c 2 f apply a current to the radiating loop that corresponds to the specified limit move the loop to sea
81. set up shall be between 10 m and the actual length The cable arrangement shall be such that it satisfies the following conditions l At least the first 2m except for cables that are shorter in the actual installation of each interconnecting cable associated with each enclosure of the EUT are run parallel to the front boundary of the setup 2 Remaining cable lengths are routed to the back of the setup and placed in a zigzagged arrangement When the setup includes more than one cable individual cables shall be separated by 2 cm measured from their outer circumference For bench top setups using ground planes the cable closest to the front boundary shall be placed 10 cm from the front edge of the ground plane All cables shall be supported 5cm above the ground plane except for interconnecting cables between enclosures of the EUT that are higher in the actual installation 5 3 6 6 3 Input power leads a Two metres of input power leads including neutrals and returns shall be routed parallel to the front edge of the setup in the same manner as the interconnecting leads Each input power lead including neutrals and returns shall be connected to a LISN Power leads that are bundled as part of an interconnecting cable in the actual installation shall be configured in the same fashion for the 2 m exposed length and then shall be separated from the bundle and routed to the LISN s After the 2 m exposed length the power lead
82. signal is equal to or larger than the level on Figure A 6 11 ECSS E 20 07A Draft 4 April 2008 s the source is located at 5 cm of any face of the EUT The signal test covers the 30 Hz 100 kHz frequency range 190 180 170 160 H o 150 E 2 140 E 130 120 110 100 10 100 1 000 10 000 100 000 Frequency Hz Figure A 6 Radiated susceptibility limit A 14 RS electric field 30 MHz to 18 GHz The following levels known to be achievable and already specified in other standards or project specifications are proposed for radiated susceptibility test electric field specified in clause 5 5 11 the amplitude of the test signal is equipment in the vicinity of beams outside of the main frame considered as a Faraday cage 10 V m An electric field of more than 10 V m is applied if RF analysis demonstrates that the expected electric field seen in flight by the equipment is larger equipment far from main lobes and secondary lobes outside of the main frame 1 V m equipment inside the main frame 1 V m At RF transmit frequencies the RS level should be tailored up at RF receive frequencies the RS level should be tailored down for receivers an AM or PAM test signal is used both horizontally and vertically polarized fields are used circular polarized fields are not used The signal test covers the 30 MHz 18 GHz frequency range Additional requirements can apply beyond 1
83. specified in other standards or project specifications are proposed for the transient susceptibility test on the power lines specified in clause 5 5 9 a series of positive spikes then a series of opposite spikes superposed on the power voltage shall be applied at any time step the voltage spike amplitude is 100 or 100 of the actual line voltage if the nominal bus voltage is lower than 100 V Figure A 6 50 or 100 of the actual line voltage if the nominal bus voltage is equal or larger than 100 V Level 0 on Figure A 6 represents the DC bus voltage Only the positive spike is represented on Figure A 6 When a negative spike is applied the absolute instantaneous transient voltage goes down to 0 never negative tests are performed with two spike durations the first zero crossing is at T 150 ns and at T 10 us Independent power lines are tested separately Independent means connected to separate power sources 120 100 80 D g 60 gt o 40 2 20 g C 8 0 a 5 a 20 40 60 Normalized time in units of T 150ns or T 10us Figure A 5 CS voltage spike in percentage of test bus voltage A 13 RS magnetc field 30 Hz to 100 kHz The following levels known to be achievable and already specified in other standards or project specifications are proposed for the radiated susceptibility test magnetic field specified in clause 5 5 10 the amplitude of the test
84. sufficient for some applications The multiple moment model or the spherical harmonics model is a precise determination sometimes needed for sensitive payloads Specific characterization methods are implemented for the multiple moment model or the spherical harmonics identification A 6 3 Limit The DC magnetic emission of subsystems or equipments can be limited at a level of 0 2 uT at a distance of 1m from any face of the equipment This limit corresponds to dipole like equipment with a magnetic moment of 1 Am The limitation is achieved through a combination of techniques current loop area minimization and coaxial or twisted cables use non magnetic material use magnetic shields use compensation techniques with magnets 73 E ECSS E 20 07A Draft 4 April 2008 A 7 _ RE low frequency magnetc field From a few hertz to 50 kHz the magnetic field radiated emissions can be measured Measurement can be performed at several distances for characterizing the accuracy of a dipole model If the EUT can be assimilated to a magnetic dipole emission limits are expressed by its magnetic dipole momentum No limit is defined at equipment level The measurement is only for characterization and useful to verify compliance at system level through analysis Techniques for fulfilling EMC requirement at system level are an appropriate grounding network magnetic shields an optimized location of equipments on the space vehicle A 8 _ R
85. t pulse amplitude modulation pulse coded modulation radiated emission radio frequency root mean square radiated susceptibility super high frequency 3 GHz 30 GHz 15 ECSS E 20 07A Draft 4 April 2008 4 Requirements 4 1 General system requirements EMC policy and general system requirements and the spacecraft charging protection program are specified in Clause 6 and Annex A of ECSS E 20A 4 2 Detailed system requirements 4 2 1 Overview This clause 4 2 define the requirements for design and realization at system level They are the basis for definition of activities of the EMC programme to ensure space system level compatibility with minimum impact to programme cost schedule and operational capabilities 4 2 2 EMC with the launch system 4 2 2 1 General General system requirements for EMC with the launch system are defined in ECSS E20B clause 6 3 2 2 4 2 2 2 Detailed system requirements a Overload capability of the spacecraft RF receivers during the pre launch and launch phases with or without fairing shall be demonstrated by the spacecraft supplier NOTE 1 It is expected the electromagnetic environment generated by companion payloads is assessed by the launching company and addressed in the User s Manual NOTE2 A conductive fairing is likely to cause resonances and cavity effects b Spacecraft equipment shall not exhibit any malfunction degradation of performance or deviation beyond the tol
86. t2 NOTE If the EUT is a centred dipolar source then M M3 deperm field 5000 uT s lt 0 03 uT Decrease 1 at switch off B pT Increase 2 5000 uT time Increase t gt 200s Decrease t gt 400 s Figure 5 12 Smooth deperm procedure 5 5 6 R electric field 30 MHz to 18 GHz 5 5 6 1 Purpose This test procedure is used to verify that electric field emissions from the EUT and its associated cabling do not exceed specified requirements 5 5 6 2 Test equipment The test equipment shall be as follows a Measurement receiver 46 9 th oO pei 0 ECSS E 20 07A Draft 4 April 2008 Data recording device Linearly polarized antennas NOTE the following antennas are commonly used 30 MHz to 200 MHz biconical 137 cm tip to tip 200 MHz to 1 GHz double ridge horn 69 0 by 94 5 cm opening or log periodic 1 GHz to 18 GHz double ridge horn 24 2 by 13 6 cm opening Signal generators Stub radiator LISN defined in 5 3 4 optional 5 5 6 3 Setup The test setup shall be as follows a Maintain a basic test setup for the EUT as shown and described in Figure 5 3 and 5 3 6 and ensure that the EUT is oriented such that the surface that produces the maximum radiated emissions is toward the front edge of the test setup boundary NOTE The LISN should be used Check the measurement system by configuring the test equipment as shown in Figure 5 13 Test the EUT antenna positioning as fo
87. ted determine the threshold level in accordance with 5 3 10 3 and verify that it is above the specified requirements 8 Record the peak current as indicated on the oscilloscope 9 Repeat 5 5 9 4 c 2 through 5 5 9 4 c 8 on each power lead 56 ECSS E 20 07A Draft 4 April 2008 Spike generator Series or parallel Oscilloscope Data recorder Differential probe Figure 5 21 CS of power leads transients calibration set up Stimulation and Spike generator monitoring of Series output Power inputs Oscilloscope Data recorder Differential probe Figure 5 22 CS of power leads spike series injection test setup Stimulation and mu Spike generator monitoring of EUT Parallel output innuts Oscilloscope Data recorder Differential probe Figure 5 23 CS of power leads spike parallel injection test setup 57 ECSS E 20 07A Draft 4 April 2008 5 5 10 RS magnetic field 30 Hz to 100 kHz 5 5 10 1 Purpose This test procedure is used to verify the ability of the EUT to withstand radiated magnetic fields 5 5 10 2 Test Equipment The test equipment shall be as follows Signal source b Power amplifier C Radiating loop having the following specifications l Diameter 12 cm 2 Number of turns 20 3 Wire N 12 AWG insulated copper 4 Magnetic flux density 9 5x10 pT A of applied current at a distance of 5 cm from the plane of the loop d Loop sensor having the following specificatio
88. test methods However it is a legitimate demand of equipment manufacturers to ask for EMI limits outside the frame of a specific project Conducted and radiated emission limits and susceptibility limits defined hereafter are recommended for space projects A 2 CEon power leads differential mode 30 Hz to 100 MHz In differential mode on each independent power bus conducted emissions on power leads induced by loads can be limited in the frequency domain under following conditions limits are in the range extending from 30 Hz to 100 MHz a maximum lyg in units of dB referenced to 1 uA is a function of frequency defined on Figure A 1 in the low frequency range the limit ICE in units of dB referenced to 1 uA dBuA is function of the consumption lac in amperes of the equipment on the line see Figure A 2 Les A Ice 80 1 A lt Ige lt 100 A I 80 20 logio Ide Ig gt 100 A I 120 The mode is called differential because measurement are done separately on hot and return wires however it comprises common mode components Independent means connected to separate power sources 70 ECSS E 20 07A Draft 4 April 2008 130 420 100 Aac 110 30A 100 104d 99 3Adc g0 1 Ade 70 60 50 40 30 20 10 Current limit dBA 10 100 1 000 10 000 100 000 1000000 10000000 100000 000 Frequency Hz Figure A 1 Power leads conducted emission A 3 CEon power leads in rush currents The in
89. the EUT enclosure are within the 3 dB beamwidth of the antenna 47 ECSS E 20 07A Draft 4 April 2008 5 5 6 4 Procedures The test procedures shall be as follows Turn on the measurement equipment and wait until it is stabilized b Verify that the ambient requirements specified in 5 3 2 3 are met and take plots of the ambient C Check the measurement system as follows l Using the system check path of Figure 5 13 perform the following evaluation of the overall measurement system from each antenna to the data output device at the highest measurement frequency of the antenna a Apply a calibrated signal level that is at least 6 dB below the limit limit minus antenna factor to the coaxial cable at the antenna connection point b Scan the measurement receiver in the same manner as a normal data scan and verify that the data recording device indicates a level within 3 dB of the injected signal level c If readings are obtained which deviate by more than 3 dB locate the source of the error and correct the deficiency prior to proceeding with the testing PA Using the measurement path of Figure 5 13 perform the following evaluation for each antenna to demonstrate that there is electrical continuity through the antenna a Radiate a signal using an antenna or stub radiator at the highest measurement frequency of each antenna b Tune the measurement receiver to the frequency of the applied signal and verify that
90. ure 5 31 Susceptibility to ESD test equipment configuration Tables Table 5 1 Absorption at normal incidence Table 5 2 Bandwidth and measurement time Table 5 3 Correspondence between test procedures and limits ECSS E 20 07A Draft 4 April 2008 60 64 65 65 68 69 69 25 32 37 ECSS E 20 07A Draft 4 April 2008 Introduction Electromagnetic compatibility of a space system or equipment is the ability to function satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbances to anything in that environment The space system is designed to be compatible with its external natural induced or man made electromagnetic environment Natural components are lightning for launchers the terrestrial magnetic field for space vehicles Spacecraft charging is defined as voltage building up of a space vehicle or spacecraft units when immerged in plasma Electrostatic discharges result from spacecraft charging with possible detrimental effects External man made interference intentional or not are caused by radar or telecommunication beams during ground operations and the launching sequence Intersystem EMC also applies between the launcher and its payload or between space vehicles Intrasystem EMC is defined between all electrical electronic electromagnetic and electromechanical equipment within the space vehicle and by the presence of its self induced electromagnetic environment It

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