0.8 V GPS band CMOS VCO with 29% Tuning Range

This paper presents the design and measurement results of a sub-1 V, wide-tuning range, monolithic voltage-controlled oscillator (VCO). The LC cross-coupled VCO can operate at a supply voltage at 0.8 V. The top-biased PMOS, with capacitor connected in parallel, is used in order to decrease the noise contribution in the oscillated frequency even at a low voltage supply. Moreover, an accumulation MOS varactor (Andreani and Mattisson, 2000) is adopted to provide 29 % wide tuning frequency range. With a 0.8 V supply, the 1.6 GHz A-MOS VCO consumes 11.26 mA, included VCO and output buffer, with a measured phase noise of -109.3 dBc/Hz @ 600 kHz offset