SiGe BiCMOS topologies for low-voltage millimeter-wave voltage controlled oscillators and frequency dividers

BiCMOS topologies for mm-wave voltage-controlled oscillators and frequency dividers are presented. The topologies, based on a MOS-HBT cascode configuration, enable low-voltage operation without compromising speed. A 37-GHz Colpitts VCO with 8% tuning bandwidth is reported with a phase noise of -97 dBc/Hz at a 1-MHz offset. For the first time, experimental evidence confirms that the bias condition for optimal VCO phase noise coincides with the bias point for minimum noise figure. Additionally, frequency division up to 70 GHz is reported, which is believed to be a record for dividers employing n-channel MOSFETs.