An 8.3% Efficiency 96–134 GHz CMOS Frequency Doubler Using Distributed Amplifier and Nonlinear Transmission Line

Abstract

This paper presents a wideband (96-134GHz) frequency doubler with a distributed amplifier and a nonlinear transmission line. The proposed doubler achieves wide bandwidth thanks to the transmission line structure. The distributed amplifier not only boosts conversion gain by amplifying the second harmonic from the nonlinear transmission line, but also generates the second harmonic by itself. Optimizing the distributed amplifier gate voltage achieves the maximum conversion gain. The designed prototype is realized in standard 28-nm CMOS with core area of 0.72\times 0.27\ \text{mm}^{2}$. It achieves 33% instantaneous 3-dB bandwidth of 96-134 GHz with measured peak conversion gain of -6.2 dB and conversion efficiency of 8.3% at output frequency of 118 GHz. It consumes 12 mW dc power from a 1-V power supply.