2 GHZ MIC Front End Designed for a Microwave Radio Relay Link

A low-noise 2 GHz front end has been developed, consisting of MIC isolator, RF preamplifier, SSB downconverter and conventional IF preamplifier. An overall 3 dB SSB noise figure and 12 % RF bandwidth has been achieved. The RF preamplifier, using a bipolar transistor, exhibits a noise figure of 2.2 dB and has about 15 dB gain. No filter network between RF preamplifier and mixer is needed because a novel single sideband downconverter circuit with 6 dB SSB noise figure is used.