A V-Band Push-Push LC-VCO with Wide Tuning Range and Low Phase Noise Using Series-Shunt Anti-Parallel SiGe HBT Switches

This paper presents a low Phase Noise (PN) and wide tuning range push-push Voltage-Controlled Oscillator (VCO) for V-band applications implemented with silicon-germanium (SiGe) Heterojunction Bipolar Transistor (HBT) switched capacitor bank. A 5-bit binary weighted capacitor bank was implemented using a novel Series-Shunt Anti-Parallel (SSAP) SiGe HBT switch, achieving 40% higher quality factor and 1.5 dB better PN than those of a conventional CMOS capacitor bank. Also, owing to low Cunit and inductance with high Q in the LC-tank, this work achieved a low PN of -105 dBc/Hz at 1 MHz offsets from 50 GHz with 31% Frequency Tuning Range (FTR), covering 47.0 to 64.3 GHz with an average frequency sensitivity of 470 MHz/V for the control voltage (Kvco), and corresponding to a figure-of-merit (FOMT ) of -190.2 dBc/Hz. To the authors’ best knowledge, this is the lowest PN and Kvco of all VCOs at V-band with over 20% FTR.