High efficiency 20 W GaN Doherty power amplifier for 1.5 GHz and 1.8 GHz microcell base station applications

The application of GaN devices for high power amplifiers is rapidly growing and changing the base station market. This paper presents two different symmetrical Doherty amplifier solutions using two of the same wideband 10 W GaN discrete transistors for 1500 MHz and 1865 MHz microcell base station applications. During the Doherty amplifier tuning process, both designs utilize a sliding load to provide a quick way to verify the maximum power and efficiency locations prior to making physical board modifications. The performance of the Doherty power amplifier designs at 1500 MHz and 1865 MHz demonstrate high gain, efficiency and linearity for the continuing development of microcell and picocell applications.