Implementation and Performance of a 14/11 GHz, 120 Mbit/s Regenerative Satellite Transponder

This paper describes the implementation and performance of an experimental 14/11 GHz, 120 Mbit/s regenerative satellite transponder designed for possible use in the European Communications Satellite (ECS) System. Quaternary DPSK and CPSK are applied on the uplink and downlink, respectively. Demodulation and modulation are performed directly at RF. Specific components of the regenerative transponder, which are the receive filter, the differential demodulator, the baseband regenerator, the modulator and the output filter, were developed and assembled to a transponder model. Bit-error rate measurements were carried out by use of a test equipment simulating the earth terminals.