10 GHz quadrature-phase voltage controlled oscillator and prescaler

In this paper, a 10 GHz quadrature phase LC-VCO with a novel ring-array based injection-locked prescaler is presented. Fabricated in a 0.18 /spl mu/m digital CMOS process, output frequency of VCO ranges from 10.03-9.35 GHz, and the prescaler performs divide-by 8 operation with locking range of 1 GHz. The measured phase noise from a 9.395 GHz carrier is -120 dBc/Hz at 5 MHz offset. Operating under a single 1.8 V supply, the VCO and prescaler respectively consume 21.6 mW and 12.6 mW only. Chip size are 1682.8 /spl mu/m /spl times/ 647.8 /spl mu/m.