A Dual-Resonant Mode 10/22-GHz VCO With a Novel Inductive Switching Approach

Abstract

This paper presents a novel dual-band voltage-controlled oscillator (VCO) in a standard 0.18-mu m CMOS technology. With special design in the LC tank, the circuit exhibits two oscillation modes in different frequency bands. The frequency band selection is achieved by a switched coupled inductor with the tunable inductance and quality factor. This VCO can operate in a 10-GHz band with 7.6% tuning range and a 22-GHz band with 8% tuning range, while the core circuit draws a dc current of 8.44 mA from a 1.8-V supply voltage. The figures-of-merit at 10- and 22-GHz bands are -184.63 and -181.81 dBc/Hz, respectively. These performances are comparable with state-of-the-art dual-band LC-VCOs.