Abstract
This article analyzes the 2nd-order harmonic power generation with power level boosted by fundamental and 3rd order harmonic based on the Krummenacher-Vittoz (EKV) models. The optimal waveforms of fundamental and 3rd-order harmonic are derived for maximizing the 2nd-order harmonic power. Adopting this method, a class-F frequency doubler in a 55-nm bulk CMOS technology is designed, fabricated, and measured. The doubler prototype achieves a 3-dB operation bandwidth of 112-125 GHz, a maximum output power (POUT) of 7.8 dBm, a maximum conversion gain (CG) of -0.46 dB, a maximum efficiency of 6.8% with dc power consumption of 88 mW, and a core area of only 0.13 mm2. To the best of our knowledge, the proposed class-F doubler achieves the highest POUT among similar CMOS works and is comparable to those in advanced SiGe technologies.