Optimally Matched 189-232 GHz 6.8 dBm Output Power CMOS Frequency Doubler

This paper presents the design and measurements of a 215-252 GHz 40 nm bulk CMOS frequency doubler with a 6.8 dBm deliverable peak output power and a conversion gain of 11.8 dB. The designed chip is composed of a 28.5 dB gain 6-stages 110 GHz power amplifier, an optimized push-push doubler biased in class-C configuration, and an output impedance matching network. A numerical method had been applied here for designing each implemented matching network achieving the optimum matching while maintaining the minimum insertion loss as well. The presented design shows the highest output power among the other sub-THz-designed CMOS counterparts. The design occupies an area of 0.795 mm2 and shows a total DC power dissipation of 262 mW and DC-RF efficiency of 1.87%.