A new balanced self-oscillating mixer (SOM) with integrated antenna

A new configuration of the balanced self-oscillating up-converter with integrated antenna is proposed and demonstrated at 5.9 GHz. The structure is composed of an IF feed network and two loop oscillators, a three-port 180/spl deg/ slot-coupled microstrip antenna, and a 3 dB power divider. The two oscillators share a common segment providing a path for mutual injection, leading to the synchronization of the oscillation frequency and phase. The IF-to-RF conversion loss is about 7 dB. Also, the antenna successfully suppresses the LO-to-RF power ratio from 24 dB to -0.6 dB.