56W SiC MESFET transistors with > 50% PAE for L-band applications

Abstract

Packaged 30mm SiC MESFET transistors were demonstrated with peak power density of 1.9W/mm and power-added-efficiency (PAE) of 53%. The target application of these devices is L-band communication. Discrete devices with gate dimension of 2 /spl times/ 400 /spl mu/m show a saturation current density of 320mA/mm and an extrinsic transconductance of 25mS/mm. The cut-off and maximum oscillation frequency of these devices was 12GHz and 17GHz, respectively. Large periphery devices with 10W CW output power rating exhibit stable electrical performance over a period of 1100hrs, with less than /spl plusmn/10% drift in drain-source current under continuous DC stress.