Ka-band power performance of InP/InGaAs/InP double heterojunction bipolar transistors

We report for the first time the Ka-band power performance of InP/InGaAs/InP DHBTs. A 2×10 μm² common-emitter transistor delivered a continuous wave (CW) output power of 19.1 mW (1.91 W/mm power density), an associated gain of 5.3 dB, and a power-added efficiency (PAE) of 35.5% at 30 GHz. The maximum output power density was 2.34 W/mm and the peak associated gain was 6.6 dB. Under common-base operation, the maximum associated gain increased to 15.2 dB, but the maximum output power density and peak PAE dropped to 1.91 W/mm and 24.5%, respectively, at the same frequency.