Compact V band frequency doubler with true balanced differential output

Abstract

This paper presents a compact V band Gilbert cell based frequency doubler that generates a truly balanced differential output signal. By analyzing the mechanism causing the imbalanced output in a Gilbert cell based frequency doubler, a Gilbert cell based doubler with a common-mode rejection transformer is designed for V band applications in a 0.13μm SiGe:C HBT process. The doubler delivers about 0.3dBm power at 65GHz, with a 3-dB bandwidth of 20GHz from 55 to 75 GHz, and a power consumption of 50 mW. The measured amplitude imbalance is +0.3/-0.2 dB in the 15GHz bandwidth from 60 to 75GHz.