Test Hat for S-Band TT&C Antennas

The Test Hat for S-Band TT&C Antennas is a piece of ground support equipment (GSE) that enables end-to-end RF testing of the S-Band TT&C antenna and transceiver chain directly on the satellite platform, at any stage of the assembly, integration and test (AIT) campaign. By providing a controlled −29 dB RF coupling between the antenna aperture and the test equipment, it allows the integration team to inject a known RF signal into the TT&C system and verify the complete chain — uplink sensitivity, downlink output power, frequency accuracy and RF chain performance — without placing the satellite in an anechoic chamber.

The S-Band TT&C frequency range covers two distinct functions: telecommand (uplink, typically 2 025–2 110 MHz) and telemetry (downlink, typically 2 200–2 290 MHz). These two sub-bands have slightly different electromagnetic properties, which affect how uniformly the test hat couples signal across the band. The datasheet specifies coupling factor variation below 1 dB in the telecommand band and below 2 dB in the telemetry band — both acceptable for functional RF testing. The tighter specification in the telecommand band reflects its narrower frequency range and its primary role in receiver sensitivity testing.

Yes. The Test Hat for S-Band TT&C Antennas is compatible with the full Anywaves S-Band TT&C antenna family: the standard S-Band TT&C Antenna (LHCP, RHCP or dual-pol), the Compact S-Band TT&C Antenna, and the S-Band Launcher Antenna. All these antennas share the same mechanical interface (4 × M3 unthreaded holes) and the test hat is designed to work with both LHCP and RHCP polarization variants. A single test hat covers the entire product family. Note that a Test Hat compatible version of the antenna is required.

Yes. The Test Hat for S-Band TT&C Antennas is qualified for use in thermal vacuum environments, with low outgassing properties making it safe to keep installed inside a TVAC chamber throughout the test campaign. Its qualification temperature range of −40°C to +70°C covers the standard TVAC test conditions used for satellite AIT. This means the same tool used for RF verification on the assembly bench can remain in place for TVAC, without any removal or reinstallation steps.

The two products share the same design concept — a single-part cylindrical aluminium cavity with absorber lining and RF probe, screwed directly onto the antenna — but are optimised for different frequency ranges and antenna families. The S-Band Test Hat covers 1.98–2.29 GHz (> 310 MHz bandwidth) for TT&C applications, and is compatible with both LHCP and RHCP polarization. The GNSS Test Hat covers 1.16–1.61 GHz (> 450 MHz bandwidth) for navigation applications, and is RHCP only. They are not interchangeable — each test hat is dimensioned and tuned for its specific antenna aperture and frequency range.