10-GHz SiGe BiCMOS Sub-Harmonic Gilbert Mixer Using the Fully Symmetrical and Time-Delay Compensated LO Cells

摘要

A 10-GHz sub-harmonic Gilbert mixer is demonstrated in this paper using the 0.35 μm SiGe BiCMOS technology. The time-delay when the sub-harmonic LO (Local Oscillator) stage generates sub-harmonic 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-W-RF isolation, IP_(1dB) of -20 dBm, and IIP_3, of -10dBm. 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.