SINGLE-VOLTAGE-SUPPLY HIGHLY EFFICIENT E D DUAL-GATE PSEUDOMORPHIC DOUBLE-HETERO HEMTS WITH PLATINUM BURIED GATES/

Highly efficient enhance/depletion (E/D) dual-gate HEMT's for use in h igh-power linear amplifiers with a single biasing supply are demonstra ted. These devices include platinum buried gates to realize a single b iasing supply. A double-hetero structure and a GaAs/InGaAs/GaAs superl attice channel were adopted to obtain a good linearity and a large gai n. An E/D dual-gate field effect transistors (FET) structure is also a dopted to improve the gain and efficiency. High output power of 24 dBm , high power gain of 24 dB, and high power-added-efficiency of 36% for the gate width of 4-mm sample were obtained under conditions with a 1 .5-GHz Japan Personal Digital Cellular (PDC) standard and with a +3.5 V single biasing supply.