125-GHz Diode Frequency Doubler in 0.13-$\mu{\hbox {m}}$ CMOS

The first mm-wave Schottky diode frequency doubler fabricated in CMOS is demonstrated. The doubler built in 130-nm CMOS uses a balanced topology with two shunt Schottky barrier diodes, and exhibits ~ 10-dB conversion loss as well as -1.5-dBm output power at 125 GHz. The input matching is better than -10 dB from 61 to 66 GHz. The rejection of fundamental signal at output is greater than 12 dB for input frequency from 61 to 66 GHz. The doubler can generate signals up to 140 GHz.