Microwave Performance of GaAs PBT's Fabricated from MO–CVD Wafers

Microwave performance of GaAs PBT's fabricated from MO-CVD wafers is presented. Fabricated transistors operate as a mixed mode of pentode and triode. The transconductance of devices with active areas of 15 µm long by 50 µm wide is about 100 mS, corresponding to 35 mS/mm per equivalent gate width. The frequency at unity current gain ( f T) and the maximum frequency of oscillation (f max) are determined to be 7.5 GHz and 18 GHz, respectively, from s-parameter measurement.