Ultra-wideband CMOS voltage-controlled oscillator with reconfigurable tunable inductors

Abstract

An ultra-wideband voltage-controlled oscillator (VCO) is presented. The proposed VCO adopts a series/parallel reconfigurable structure of inductor arrays to double the tuning range of their equivalent inductance. An ultra-wide VCO frequency range from 4.2 to 18.7 GHz was measured, achieving 25% improvement of frequency tuning characteristic and 40% reduction effect in die area.