A 58.9–73.7-GHz Quadrature Dual-Core Class-F₃,₅ Oscillator With Tail-Assisted Implicit Quintupling

Abstract

We introduce a new class-F3,5 oscillator topology that enables quadrature operation by duplicating a conventional class-F3 oscillator core and electromagnetically coupling the two cores through a pair of additional coils feeding source terminals of the $g_{m}$ transistors. The coupling network enhances the fifth-harmonic component, enabling efficient extraction and quadrature operation across the 58.9–73.7-GHz mm-wave frequency range (22.6%). Fabricated in 22 nm FD-SOI, the class-F3,5 oscillator achieves an average phase noise of –124.4 dBc/Hz at a 10 MHz offset, resulting in 188/195 dB FoM/FoMT.