Broadband PA Architectures with Asymmetrical Combining and Stacked PA cells across 50-70 GHz and 64-110 GHz in 250 nm InP

High-efficiency and broadband power amplifiers are (PAs) key to enabling the next-generation of millimeter-Wave systems and multi-functional communication, sensing and imaging arrays. Due to the low ft/fmax, low breakdown voltages and low gain in silicon devices at frequencies at mmWave frequencies, InP HBTs have been a promising candidate to enable high-efficiency, high power and broadband transmitter front-ends for compact arrays above 50 GHz. In this paper, we present two broadband PA architectures covering 50-70 GHz, and 64-110 GHz in 250 nm InP HBT enabled through asymmetrical power combining architectures with stacked PA cells. The PAs generate more than 20 dBm of peak power in either of the bands, with peak output collector efficiency (ηout) exceeding 40%, total collector efficiency (η) exceeding 30% and peak PAE >23 % for both bands. This work presents one of the highest bandwidth and highest efficiency PAs with peak power greater than 20 dBm.