Two 300-GHz Wide Tuning Signal Sources in 130-nm SiGe BICMOS Process

Two wide tuning signal sources operating around 300 GHz, with and without a buffer, have been developed in this work based on a 130-nm silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) technology. The 300-GHz signal source, consisting of a Colpitts voltage-controlled oscillator (VCO) followed by a doubler, shows -2.89 dBm output power around 302 GHz, -81.5 dBc/Hz phase noise at 1-MHz offset, 7.98% tuning range, and 0.96% DC-to-RF efficiency. After placing a differential common-emitter amplifer between the VCO and doubler, it exhibits a little higher operating frequency, from 290.8 to 316.6 GHz, and a better -85.1 dBc/Hz phase noise at 1-MHz offset, but with reduced output power of -5.2 dBm and efficiency of 0.33%. The layout size for each oscillator is 524x495 mu m(2) and 524x540 mu m(2), including DC and RF pads.