215W pulsed class A UHF power amplification based on SiC bipolar technology

Abstract

4H-SiC BJTs with multiple finger structure were designed and fabricated. Large devices with 0.52 mm/sup 2/ active area show DC gain around 18. A class A power amplifier is designed at 450 MHz using a single cell large device. Matching at the input is done with a parallel capacitor and a transmission line. The device is biased at V/sub CE/=180 V and pulsed with 0.1 % duty cycle to avoid self-heating. A maximum output power of 215 W is achieved with a power gain of 7.5 dB, corresponding to a power density of 4.3 W/mm normalized to emitter finger length.