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.