Low power low phase noise 3.9GHz SiGe VCO with data modulation correction loop

Abstract

A 3.9 GHz LC VCO is fabricated using a 0.35 /spl mu/m SiGe BiCMOS process. The VCO is modulated through a modulation port in transmit mode. The VCO utilizes a modulation correction loop to compensate the modulation deviation due to the variation in the tuning circuit. The VCO measured phase noise is -140 dBc at 8 MHz offset, while draining 4 mA from a 2.5 V regulated supply. A 25% tuning range was also measured.