Sige BiCMOS subharmonic Gilbert mixer using lumped-element ratrace couplers

Abstract

A single-ended down-conversion subharmonic miser is implemented using 0.35-mu m SiGe BiCMOS technology. Two lumped-element rat-race couplers are applied to generate differential LO and RF signals. This single-ended rat-race mixer has the conversion gain of 25 dB, -90-dB 2xLO-to-RF isolation and -78-dB 2xLO-to-IF isolation at the RF frequency of 10 GHz. The input return loss is about -10 dB. (c) 2007 Wiley Periodicals, Inc.