Simplified analytical model and high power characteristics of InGaP/GaAs HBTs at X-band

Abstract

Simplified large-signal analysis and high power characterization of InGaP/GaAs heterojunction bipolar transistors (HBTs) at X-band are reported. The simplified analytical model suggested in this work allows a first order prediction of the power performance trends as functions of device physical parameters. The solution to nonlinear equations governing the large signal behavior of the transistor is found by an iterative approach. The impact of different large signal parameters on the power performance of HBTs has been analyzed. Under class B operation, a 10-finger 2 x 20 mu m(2) HBT at V-CE = 10 V achieves a maximum output power of 1.08 W (5.4 W/mm) with power-added efficiency of 44%.