GaN power transistors in narrow and wide bandwidth applications

An active load-pull based investigation was conducted into the achievable performance of a 10 W gallium nitride (GaN) HEMT whilst operating in both narrow and wide bandwidth applications. It was found that a minimum efficiency of 40% was obtained over a broad bandwidth whilst delivering a constant output power of 10 W with the device biased in a class-AB mode. Conversely, in a narrow-band, high efficiency inverse class-F mode very high performance in terms of output power (12 W) and efficiency (81% PAE) has been measured. This has demonstrated the significant benefits in terms of the versatility of GaN devices for current and future PA applications.