A 64/4 GHZ Down Converter for a 60 GHZ Satellite Communicatiton System

An upperside band down converter from 64 to 4 GHz for a 60GHz satellite communication system was developed. This converter is consisting of a single ended mixer, a local oscillator, a directional filter, an image rejection filter, an IF-preamplifier and the power-supply. In order to combine the signal - and local-oscillatorpower, a directional filter was constructed. The transmission loss at 60 GHz is 1.6dB, and the isolation is better than 22dB. The single ended mixer has a conversion loss of 4.8dB at a local oscillator power of 9.4dBm. The stabilized Gunn oscillator was examined theoretically. The theory was verified by measurements on several stabilized oscillators with unloaded quality factor of about 5000-6000 and an output power of 20-40mW. The oscillator of is compensated and a temperature coefficient of about 1×10¿7# is achieved. The noise figure of the entire down converter amounts to NFssB = 10.6dB.