A 12 GHz Downconverter for direct broadcast satellite ground station

This paper describes a 11.7 - 12.2 GHz Downconverter with a noise figure of 3.1 dB and a gain of 56 dB. This antenna mounted unit block-converts to an output band of 270-770 MHz to interface with an existing low-cost receiver produced in high volume for C-band terminals. Double conversion is used to eliminate image and harmonic signals although the converter has only one local oscillator. Some unusual circuit techniques were used to minimize the cost of the Downconverter in production.