A 8.18 GHz ~12.57 GHz Digitally Controlled Quadrature VCO in 90 nm CMOS Process for X Band Applications

This paper proposes a digitally controlled Quadrature voltage-controlled oscillator (QVCO) having a tuning scope of S. 1S~12.57 GHz, mainly applicable for X band frequency implementations in 90 nm CMOS process. 4-bits MOS varactor based digitally controlling scheme has been employed, which outputs 16 separate frequencies. Phase noise @ lMHz offset varies from -122.47dBc/Hz to -99dBc/Hz, and the output power alters from 9.92 dBm to 7.99 dBm. The Maximum Figure of merit is -190.40dBc/Hz for 8.18 GHz frequency, and the DC power consumption is 10.75 mW. We have also done process corner analysis, temperature sweep analysis, and Monte Carlo simulation of the proposed design for perfect justification. Finally, a fair comparison has also been shown in tabular format for basic performance parameters.