Single-voltage-supply highly efficient E/D dual-gate pseudomorphic double-hetero HEMT's with platinum buried gates

Highly efficient enhance/depletion (E/D) dual-gate HEMT's for use in high-power linear amplifiers with a single biasing supply are demonstrated. These devices include platinum buried gates to realize a single biasing supply. A double-heterostructure and a GaAs/InGaAs/GaAs superlattice channel were adopted to obtain a good linearity and a large gain. An E/D dual-gate field effect transistors (FET) structure is also adopted to improve the gain and efficiency. High output power of 24 dBm, high power gain of 24 dB, and high power-added-efficiency of 46% 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.