DESIGN AND CHARACTERIZATION OF ALGAAS INGAAS/GAAS-BASED DOUBLE-HETEROJUNCTION PHEMT DEVICE/

We report on the design and characterization of pseudomorphic high-ele ctron-mobility transistors for linear power applications. Compared to a conventional single heterojunction, the double-heterojunction PHEMT shows a flat transconductance of > 200 mS/mm over a wide gate bias swi ng. A high breakdown voltage of 15 V was measured. A flat cutoff frequ ency (f(T)) of > 15 GHz over a wide gate and drain bias region was ach ieved. A maximum oscillation frequency (f(max)) of > 75 GHz was obtain ed. (C) 1998 John Wiley & Sons, Inc.