The Characterisation of an Experimental Laboratory 30/20 GHz Satellite Repeater for Digital Transmission

The trend for civil communications satellites is for higher capacity, flexibility and increased sophistication. Future systems will make use of the lower millimeter wave bands, with uplink of 30 GHz, downlink 20 GHz and potential bandwidth of 3.5 GHz. In 1975 ESA instigated a program to investigate these future payloads. The activities included system studies, development of critical components, (amplifiers, mixers, oscillators), repeater integration and testing. This paper describes the R.F. measurement made on a single channel double conversion 30/20 GHz breadboard repeater that included the development components. The measurements include gain, noise figure, group delay AM/PM conversion and its characterisation for transmission of a 4 ø PSK digital signal.