A 220GHz solid-state power amplifier MMIC with 26.8dB S21 gain, and 55.5mW Pout at 17.0dB compressed gain

A 220GHz solid-state power amplifier MMIC is presented, simultaneously demonstrating 55.5mW output power P_out at 17.0dB compressed gain (1.12mW P_in). The maximum saturated P_out is 60mW at 14.0dB compressed gain (2.36mW P_in). This 3-stage, 4-cell amplifier has 26.8dB S₂₁ gain at 220GHz, with 3-dB small-signal bandwidth from at least 210GHz to 235GHz. P_DC is 3.38W. Amplifier cells were fabricated from a 250nm InP HBT technology, jointly with a substrate-shielded, thin-film microstrip wiring environment using BCB. The 55-60mW P_out is achieved by combining four amplifier cascode cells. The use of three gain stages significantly relaxes the RF source power requirements, where only 1.12mW P_in is needed to achieve 55.5mW P_out, and 2.36mW P_in to achieve 60mW fully saturated P_out. This represents at least 5-6dB gain improvement to state-of-the-art for 220GHz SSPAs when operated at similar output powers. Over 20GHz bandwidth, at least 50mW P_out is observed from 205-225GHz.