Wide tuning band quadrature VCO

摘要

A CMOS quadrature VCO has been designed in a 0.35μm CMOS process. Using a combination of switched binary-weighted capacitors and standard varactors, this VCO achieves a 59% tuning range with a control voltage ranging from −0.25 to 0.75 V. The phase-noise varies within the tuning range from −131.3 dBc/Hz to −121.2 dBc/Hz at 1 MHz frequency offset. The circuit consumes only 9.37 mW at 2.71GHz and 12.5mW at 1.8GHz.