Differential VCO and frequency tripler using SiGe HBTs for the 24 GHz ISM band

Abstract

A frequency source generator chip was designed and built in a commercial SiGe process for an integrated front-end transceiver operating in the 24 GHz ISM band. It consists of a negative resistance cross-coupled differential VCO, oscillating at 8 GHz with a 150 MHz tuning range, having an output power of 0 dBm and a phase noise of -90 dBc/Hz at 100 kHz offset. The VCO drives a differential amplifier used as a frequency tripler which results in an overall voltage control frequency source operating at a nominal frequency of 23.5 GHz with a 420 MHz tuning range. It has a -10 dBm output power and consumes 180 mW. Its phase noise is -80 dBc/Hz at 100 kHz. The total chip area measures 600 /spl times/ 300 /spl mu/m/sup 2/.