Design of a GaN-based high gain X-Band power amplifier

Abstract

RF power amplifiers remain a vital element of space, airborne, and radar applications. Modern systems require high power and gain while maintaining high efficiency. However, obtaining these features with a compact design brings challenges. Monolithic Microwave Integrated Circuits (MMIC) provide flexibility and enhanced performance while operating at higher frequencies. Among other transistor technologies, GaN on SiC based high electron mobility transistors (HEMTs) provide extraordinary performance with high power density, thermal conductivity, and high band gap. In this thesis, we present a three-stage X-Band MMIC power amplifier (PA) based on NANOTAM 250 nm GaN-on-SiC process technology. The characterization steps of the transistors are discussed to extract process parameters for the design. The amplifier is designed on the Keysight ADS environment. The design is realized on a 3-inch GaN-on-SiC wafer. In the 8.5–10.5 GHz frequency band, measurements show that the PA achieves a 40 dB small signal gain, PAE higher than 40%, and average 20 W output power under 28 V, 100 mA/mm pulsed biasing conditions at room temperature. The MMIC occupies 10.26 mm2 area and has 1.96 W/mm2 power density.