10-GHz SiGeBiCMOS sub-harmonic Gilbert mixer using the fully symmetrical and time-delay compensated LO cells

Abstract

A 10-GHz sub-harmonic Gilbert mixer is demonstrated in this paper using the 0.35 mu m SiGe BiCMOS technology. The time-delay when the sub-harmonic LO (Local Oscillator) stage generates subharmonic LO signals is compensated by using fully symmetrical multiplier pairs. High RF-to-IF isolation and sub-harmonic LO Gilbert cell with excellent frequency response can be achieved by the elimination of the time-delay. The SiGe BiCMOS sub-harmonic micromixer exhibits 17 dB conversion gain, -74 dB 2LO-to-RF isolation, IP1dB of -20 dBm, and IIP3 Of -10 dBm. The measured double sideband noise figure is 16 dB from 100-kHz to 100-MHz because the SiGe bipolar device has very low 1/f noise corner.