A High Efficiency MMIC X-band GaN Power Amplifier

This paper describes the design methodology and the On-Wafer (OW) measurement results of two broadband two stages MMIC High Power Amplifiers (HPAs) operating in the 812 GHz bandwidth. A Balanced HPA (BA-HPA) and a SingleEnded HPA (SE-HPA) are considered, they are fabricated on 150 nm HEMT Gallium Nitride on Silicon Carbide technology (AlGaN/GaN on SiC) called GH15 from UMS. The main aim of this realization was the achievement of a high Output Power associated with a very high Power Added Efficiency. To obtain a good compromise between output power and power added efficiency, a multi harmonic tuning approach of load and source impedances has been applied. In addition, particular attention was given to the way of drawing the matching network layouts to minimize the coupling effect between different elements. The On-Wafer measured power results under pulsed wave signal of the BA-HPA demonstrate a maximum output power (POUT) higher than 15 W (42 dBm) with 52% Power Added Efficiency (PAE) and 22 dB of insertion gain (GI) in the 8-12 GHz bandwidth. Moreover, in the same previous bandwidth, the SEHPA reaches a maximum POUT equal to 43 dBm associated with54% PAE and 23 dB GI. To our knowledge, these results are one of the best in terms of PAE performances and frequency bandwidth trade-offs.