A PVT-Insensitive Optimal Phase Noise Point Tracking Bias Calibration in Class-C VCO

Abstract

This paper presents a Class-C voltage-controlled oscillator (VCO) with bias voltage calibration that automatically finds the low-phase noise point and achieves robust start-up regardless of PVT variation. This VCO structure also has the bias circuit that compensates for temperature changes even when calibration is not applied. Through these techniques, the problems of robust start-up and vulnerability to PVT variation, which are chronic problems of Class-C VCO, are overcome. The proposed VCO was designed in a 28 nm CMOS process. Simulation results show that this VCO has an operating range from 3.717 to 4.675 GHz, resulting in a frequency tuning range (FTR) of 22.8%. In addition, power consumption was 2.135 mW, phase noise at 1 MHz was -124.1 dBc/Hz, and the figure of merit (FoM) was -192.2 dBc/Hz. The chip area was very small at 0.196 mm2.