Sub-1 V GPS band CMOS voltage-controlled oscillator with 29% tuning range

Abstract

A sub-1 V 1.6 GHz voltage-controlled oscillator (VCO) was designed and fabricated using 0.35 μm CMOS technology. This LC-based VCO can operate at a supply voltage as low as 0.8 V. A top-biased PMOS, with capacitor connected in parallel, is used in order to reduce the noise contribution in the oscillated frequency even at low voltage supply. Moreover, an accumulation MOS varactor is adopted to provide 29% wider tuning frequency range compared with a diode varactor under same full tuning voltage. With a 0.8 V supply, this 1.6 GHz top-biased A-MOS VCO consumes 9 mW, included output buffer, with a measured phase noise of ?109.3 dBc/Hz @ 600 kHz offset.