A broad-band active frequency doubler operating up to 120 GHz

A broad-band monolithic integrated active frequency doubler operating in DC-120 GHz frequency range is presented and compared with several previous versions. The circuit is fabricated in a self-aligned InP DHBT process. Circuit measurements show sinusoidal output waveform at 120 GHz. For -8 dBm input power, the doubler has a maximum conversion gain of -0.25 dB at 50 GHz due to a peaking inductor on the doubler output.