Analysis and Design of a Wide-Tuning-Range VCO With Quadrature Outputs

Abstract

A quadrature voltage-controlled oscillator (QVCO) with a wide tuning range is proposed and implemented in the TSMC 0.18- mum CMOS process. The said QVCO uses a cross-coupled structure and a current-reuse technology to produce the quadrature signal and to save power consumption and area, respectively. Based on our measurement, the phase noise with 1-MHz offset from the carrier frequency of 3.6 GHz is - 114 dBc/Hz and the proposed QVCO has a wide-band tuning range of 3.6-4.9 GHz. Also, the maximal phase error and power imbalance are less than 5 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">deg</sup> and 1.5 dB, respectively, and the power consumption is 8 mW at 2-V power supply voltage.