2022 Volume 19 Issue 8 Pages 20220100
This letter presents a linear K-band voltage-controlled oscillator (VCO) with a Gilbert frequency multiplier. Three pairs of varactors form a varactor compensation topology to broaden the linear frequency range and improve the VCO linearity. The varactors are tuned by two control voltages so that the frequency can be tuned in a wide range continuously. A Gilbert cell-based frequency multiplier is implemented to achieve the desired frequency with low phase noise. Fabricated in 0.13μm CMOS technology, the total area of the proposed VCO is approximately 0.28mm2. This VCO achieves a tuning range of 21.4 to 25GHz (15.5%), and a linear tuning range between 0.5V to 1.8V control voltage, the mismatch of the VCO gain is only 9.1% in the linear tuning range. The output phase noise reaches -75.13dBc/Hz at 100kHz offset frequency and -108.53dBc/Hz at 1MHz offset frequency from the 24.2GHz carrier frequency, respectively.
