Indium-Phosphide Transistors: A Review of Current State and Suitability for Commercial > 100-GHz Wireless Communication Systems

Carriers are currently introducing 5G wireless systems at sub-6, 28, 38, 57–71, and 71–86 GHz. As 5G is commercially deployed, research into the next-generation communication systems (6G), expected to be 100–340 GHz, is beginning. Power-efficient systems operating at such high frequencies require RF front ends with transistor RF figures of merit (FOMs) such as transit frequency ${f}_{\tau}$ and maximum oscillation frequency ${f}_{\max}$ in excess of 500 GHz. Indium-phosphide (InP) heterojunction bipolar transistors (HBTs) and high-electron mobility transistors (HEMTs) are promising technologies for these extreme frequency applications.