Large signal pulsed RF and DC load pull characterization of high voltage 10W GaAs-GaInP HBTs

This paper presents an on-wafer set up for the characterization of high voltage (26V) power HBTs under simultaneous large pulsed RF signal and pulsed DC test conditions. Both RF power profiles and DC current/voltage profiles are measured thanks to the use of a pulsed VNA (for RF) and a sampling scope (for DC). Typically the pulse width range is (300 ns - 300 ms) and a 10% duty cycle is applied. RF power performances and DC consumption of the transistors under test are recorded at different time positions within the pulse width This enables to investigate the effects of transient thermal aspects on RF power characteristics. S Band Measurements of 10 Watt (20 finger 2*70mm/sup 2/ GaAs-GaInP HBTs from Thales; TRT and UMS foundry) with specific gold radiator are reported in this paper.