Analysis and Implementation of an Ultra-Wide Tuning Range CMOS Ring-VCO With Inductor Peaking

A novel ring voltage controlled oscillator (VCO) topology is proposed which uses monolithic inductors as a peaking load. Four design examples have been fabricated and tested to verify the proposed circuit structure. The highest measured oscillation frequency is 25.07 GHz, with a tuning range of more than four octaves, and the active area is 0.0085 mm
²
. The design has the highest combined frequency and tuning range with the best figure of merit (≈ 195) comparable to previously published work.