A quadrature CMOS clapp voltage‐controlled oscillator

Abstract

A new fully integrated, CMOS Clapp quadrature voltagecontrolled oscillator (QVCO) is presented. The QVCO is composed of two differential n-core Clapp VCOs coupled by four pMOSFETs and was implemented in the 0.18-lm CMOS technology with 0.9-V supply voltage. The die area is 0.574 Â 0.866 mm 2 . At the supply voltage of 0.9 V, the total power consumption is 12.2 mW. The free-running frequency of the QVCO is tunable from 7.89 to 9.3 GHz as the tuning voltage is varied from 0 to 2 V. The measured phase noise at 1-MHz frequency offset is À118.65 dBc/Hz at the oscillation frequency of 7.89 GHz, and the figure of merit of the proposed QVCO is about À185.71 dBc/Hz.