WIDE-BAND HIGH ISOLATION SUBHARMONICALLY PUMPED RESISTIVE MIXER WITH ACTIVE QUASI-CIRCULATOR

A novel subharmonically pumped resistive mixer (SH- PRM) with a core chip dimension of 0:64 £ 0:65mm 2 is fabri- cated through a standard 0.18"m CMOS process. An impedance- transforming active quasi-circulator is monolithically integrated with an nMOS fleld-efiect transistor (FET) to perform up-converter mix- ing while simultaneously enhancing all port isolation through a broad- band operation. The design analysis of impedance-transforming ac- tive quasi-circulator is also presented for matching between circulator and resistive transistor. As shown in the measured results, the mixer exhibits a 9{14.5dB conversion loss. All port-to-port isolations bet- ter than 16.5dB over a radio frequency (RF) of 10{20GHz can be achieved.