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ETTC'2003 - SEE

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At equipment level<br />

EMC TEST PROGRAM<br />

When an equipment has been previously qualified for another project and will be used for a new<br />

program without modification, then only those tests, or parts of tests, for which the equipment has not<br />

yet demonstrated compliance are performed, provided that full visibility of the previous test<br />

specifications and test results is available. When an equipment is modified to meet requirements, then<br />

the degree of re-testing and any additional testing is defined.<br />

The test requirements for units, based on the allowed limits defined in the EMC part of the equipment<br />

environment test requirements, include: conducted emission (sine and transient), conducted<br />

susceptibility (sine and transient), radiated emission, radiated susceptibility and ESD. These tests are<br />

made as early as possible in the program on the first available model that is electrically representative<br />

of the flight unit. Tests on later models are not normally performed unless the equipment design is<br />

changed or EMC modifications have to be made.<br />

At repeater level<br />

The radiated tests are of the "sniff" (radiated emission located at connection/unit level) & "snort"<br />

(radiated susceptibility located at connection/unit level) type, and as such they provide an easy<br />

possibility of tracing the RF level to its source. The tests are performed at the worst case in receive and<br />

transmit bands. These tests are not intended to duplicate, but rather to confirm and complement the<br />

equipment tests already performed in order to check that no RF connection performed on the<br />

communication module during the AIT sequence presents abnormal RF leakage level.<br />

At system level<br />

The purpose is to verify safety margins in conducted and radiated mode, the compatibility with the<br />

launcher & the launch facility and the RF auto-compatibility.<br />

Conducted mode<br />

The aim of these conducted emissions and conducted susceptibility tests is to verify that the different<br />

functional chains of the satellite are mutually compatible for the conducted mode with sufficient safety<br />

margins in all the spacecraft operating modes. It is demonstrated an operating margin of at least:<br />

- Main power buses: 6 dB<br />

- Pyrotechnic devices: 20 dB<br />

Radiated mode<br />

The radiated emissions by the satellite in launch configuration shall be below the limits defined by the<br />

launch authority. These limits are dependant on the launch site and launch vehicle.<br />

The radiated susceptibility test goal is to check that the satellite continues to operate in accordance<br />

with the relevant system performance specification when it is submitted to a narrow-band and/or<br />

broadband electric fields in the launcher site & vehicle frequency range. The field strength is<br />

dependant on the used launcher.<br />

RF auto-compatibility<br />

4

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