A High Efficiency, Ka-Band, GaN-on-SiC MMIC with Low Compression

The demand for more bandwidth is creating more commercial applications for the Ka-band. Satellite communications, point-to-point communications, 5G, and military radar are all applications that use or plan to use the Ka-band. The high power density and high breakdown voltage of GaN-on-SiC make it of particular interest for power amplifiers. Wolfspeed has developed a leading 150 nm, GaN-on-SiC process using an optically defined, i-line gate. The purpose of this work is to demonstrate the capabilities of this process by designing a 3-stage, 28 V, Ka-band, power amplifier MMIC. Most GaN power amplifiers start compressing well before saturated power is achieved. This MMIC power amplifier displays high efficiency, low quiescent bias, and low gain compression representing an improvement in the state of the art.