Millimetre-wave InP/InGaAs photo-HBT and its application to a double-stage cascode optoelectronic mixer

We present an ultra-high-speed InP/InGaAs bipolar phototransistor (HPT) with a record optical gain cut-off frequency of 110 GHz and an HPT/HBT two-stage cascode upconverting mixer with a conversion gain of 17 dB at 28 GHz, that is also the highest reported for monolithically integrated optoelectronic mixers.