A 41.8 GHz Drain-to-Source and Gate-to-Source Feedback Colpitts VCO in 40-nm CMOS

A 41.8 GHz low-phase noise drain-to-source and gate-to-source feedback (DS-GS feedback) Colpitts voltage-controlled oscillator (VCO) is presented. In the proposed VCO, a capacitor DS feedback network is adopted in a conventional gm-boosted GS Colpitts structure to further reduce the flicker noise of switching transistors in the conventional gm-boosted GS Colpitts. The proposed VCO is implemented in a 40-nm CMOS, achieving a 41.5-42.1 frequency tuning range and phase noise of -101.3 dBc/Hz at an offset frequency of 1 MHz, while dissipating 13 mA from a 1.0 V supply.