DoEEEt, an ALTER Technology project, provides extensive EMI/EMC testing for small satellites. EMI/EMC testing is intended to ensure that no electromagnetic interference will exist between:
- The launcher and the satellite
- The satellite and the GSE
- Different satellites in the same launcher
- Different pieces of equipment with a given satellite
EMI/EMC Test Flow
EMI/EMC testing consists of 5 kinds of tests:
- Radiated emissions: Radiated emissions from the EUT are not more than a given level
- Radiated immunity: The EUT is immune to radiated emissions from the environment
- Conducted emission: Conducted emission is below a given level. In the case of a satellite, this refers to intra-satellite emissions from one subsystem to another.
- Conducted immunity: A given subsystem is immune to emissions from other subsystems.
- Self immunity: All subsystems working simultaneously do not produce interference with each other.
EMI Test: Electromagnetic interference
EMI/EMC testing indicates to engineers whether a device is compatible with its electromagnetic environment and determines whether it will produce electromagnetic interference, or EMI, in real-world situations.
EMC test: Electromagnetic Compatibility test equipment
Electromagnetic Compatibility (EMC) tests are performed in an anechoic chamber for radiated emission/immunity (to avoid reflections) and using grounded planes (for conducted emission/immunity).
An anechoic chamber is a room designed to absorb reflections of either sound or electromagnetic waves completely. They are also often isolated from waves entering their surroundings. This combination means that a person or detector exclusively hears direct sounds (no reverberant), simulating being inside an infinitely large room. Electromagnetic Compatibility (EMC) testing of flight models needs a cleanliness level of ISO 8.
ISO 8 is the least clean cleanroom classification. A cleanroom must have less than 35,200,000 particles/m3 particles > 0.5 µm and 20 HEPA-filtered air changes per hour.
