A 200mW D-band Power Amplifier with 17.8% PAE in 250-nm InP HBT Technology

We report a compact and high efficiency D-band power amplifier in 250nm InP HBT technology. A compact and low loss 8:1 transmission line power combiner is demonstrated. The three-stage power amplifier combines 8 capacitively linearized common-base power cells. The amplifier has 23dBm peak power with 17.8% power added efficiency (PAE) and 16.5dB associated large-signal gain at 131GHz. At 131GHz, the small-signal gain is 21.9dB. The small-signal 3dB-bandwidth is 125.8-145.8GHz. Over the 127-151GHz bandwidth, the saturated output power is greater than 22.3dBm with greater than 15% associated PAE. The amplifier occupies 1.34mm ² die area and consumes 1.1W DC power. To the authors' knowledge, this result demonstrates a record PAE.