A Wideband Low Phase Noise Harmonic Shaping Class-F23 Oscillator in 65 nm CMOS Technology

Abstract

This paper presents a novel wideband low phase-noise harmonic-shaping $\text{Class}-\mathrm{F}_{23}$ voltage-controlled oscillator (VCO). The utilization of a discrete high-quality-factor $(Q)$ multi{###} $LC$ tank in the VCO results in multiple impedance peaks under both differential mode (DM) and common mode (CM), allowing harmonic components to shape the output waveform over the wide tuning range, without the need of manual tuning. As a result, the phase noise performance can be significantly improved. For demonstration, an oscillator is implemented in TSMC 65-nm CMOS. The tuning range of the oscillator is from 6.52 GHz to 8.52 GHz with phase noise (PN) lower than -120.1 dBc/Hz and the figure of merit (FoM) higher than 190.3 dBc/Hz at 1 MHz frequency offset.