Fully integrated 10 GHz CMOS VCO

Abstract

A differential voltage-controlled oscillator has been designed to operate in the 10 GHz band using a 0.25 µm CMOS process and low Q integrated inductors. The low gain and low Q problems of the components are overcome by the deployment of the cascode configuration with negative conductance generation to enhance the loop gain and Q value. PMOS varactors are used for varying the oscillating frequency from 9.7 to 11.4 GHz. The phase noise at 400 kHz offset is from –101 dB/Hz at the low frequency end to –87 dB/Hz at the high frequency end.