Design of a 100kHz∼20GHz microwave receiver front end module

A 100kHz~20GHz front end module has been proposed for the high performance hand-held spectrum analyzer. The proposed front end module is the key part of the microwave receiver. It takes use of modern microwave hybrid integrated technique and combines switch duplexer, types of filters, local oscillator frequency multiplexer, types of mixers and intermediate frequency amplifier filter together. It has advantages of volume reduction and performance increasement. The frequency-changing principle of the module is described, and then the switch duplexer and types of filters are simulated and analyzed. The module is fabricated and the measurement results is given. The module adopts fundamental mixing method. The noise figure of the front end module is less than 28dB, the input P-1dB compression point is higher than 6dBm, and the image frequency rejection is higher than 65dB. The total size of the module is 238.7mm×107mm×17.3mm. The number of the front end module produced is more than 200. Its fabrication and consistence are well. The average noise level of the hand-held spectrum analyzer with the proposed front end module is better than -140dBm in the whole band.