A linear high efficiency doherty amplifier with 40 dBm saturated output power using GaN on SiC HEMT devices

This paper describes the design of a linear high efficiency Doherty power amplifier using TriQuint´s 2nd generation Gallium Nitride (GaN) on Silicon Carbide (SiC) T1G6001032-SM. The device was designed for an operating frequency of 3.6 GHz with a 40 dBm saturated output power, and achieves a power added efficiency (PAE) of 60.5% and 52.5% with 6 dB power backed-off (PBO). Advanced Design Systems (ADS) simulation software, in conjunction with Modelithic´s active and passive device models, were used throughout the design process and are evaluated against measured results. The use of these device models demonstrates a successful first-pass design, putting less dependence on empirical load-pull analysis, thereby decreasing design-cycle time to market.