Suitability of InP DHBTs in ET/APT Systems

Abstract

InP DHBTs are receiving a great deal of attention for its potential in the yet, undefined, 5G systems. In this paper, "waterfall" curves are evaluated for InP DHBTs at 900MHz and show that it can provide an improvement in PAE at low voltages (10% better than GaAs or SiGe HBTs). RF Knee MAG/MSG metrics at 5.4GHz and 15.4 GHz as compared to GaAs HBTs were also measured. These measurements indicate in some bias regions, InP can provide a large advantage in RF Gain compared to GaAs. These results demonstrate that InP DHBTs have significant potential for envelope tracking (ET) and average power tracking (APT) at conventional frequencies (<;6GHz) as well as for 5G wireless systems from 0.4- 40GHz. To the authors' knowledge, InP DHBT data in this context has not been previously reported in the literature.