Design of Class C VCO with Frequency Tripler for 17.8 – 19.19 GHz

In this paper, a voltage-controlled oscillator is provided by a triple frequency. Second harmonic frequency (2fo) is used directly for mixing with the frequency f0. The VCO consists of a detector and a comparator to shift LC-VCO bias condition from initial Class-AB start-up to steady class-C low current oscillation. The frequency of the VCO from 5.93 to 6.39 GHz has shown that the frequency tripling to 17.8 GHz - 19.19 GHz. This work has been simulated in a standard 0.18µm CMOS process. The simulated VCO achieves a phase noise of -114.7 dBc/Hz at 1 MHz offset and -135.1 dBc/Hz at 10 MHz offset from the 17.8 GHz carrier that Monte Carlo and corners analysis confirmed the obtained values. Circuit layout area is 443 × 547.47 , while the power consumption is 13.4 mw from a 1V supply.