Breakdown in millimeter-wave power InP HEMTs: a comparison with PHEMTs

In spite of their superior transport characteristics, InP HEMTs deliver lower output power than GaAs PHEMTs in the millimeter-wave regime. However, the superior power-added efficiency of InP HEMTs when compared with PHEMTs, makes this technology attractive for many applications. The reason for the lower power output of InP HEMTs is their relatively small off- and on-state breakdown voltage (BV). The authors review the state of knowledge regarding the physics of BV in InP HEMTs placing it in contrast with PHEMTs. They also discuss strategies for improving BV and the power output of InP HEMTs.