A 140 GHz common-base cross-coupled VCO with feedback inductor in InP HBT technology

A 140 GHz voltage-controlled Oscillator (VCO) based on InP heterojunction bipolar transistor (HBT) technology is presented in this paper. This VCO is designed by using common-base(CB) cross-coupled topology, in comparison with the conventional common-emitter(CE) cross-coupled topology, the proposed one can provide a higher oscillation frequency. The feedback inductor is proposed and used at the base of CB cross-coupled transistors for the first time to improve its negative resistance, which also simplifies the start-up condition in this work. The oscillation frequency of the VCO is range from 137.4 GHz to 141.2 GHz, and the output RF power is greater than -1 dBm in it's overall frequency range. The size of layout area is 0.31mm². The phase noise of this VCO is -99.91dBc/Hz at 10MHz offset. The cross-coupled transistors pair draws 12.6 mA at 1.45 V supply, and the buffer draws 12.1mA current from a 3V supply.