Implementation of a current-mode class-S RF power amplifier with GaN HEMTs for LTE-Advanced

In this work, a current-mode class-S RF power amplifier demonstrator working around 1 GHz has been designed and implemented following a partitioning design approach. Based on this approach, the entire class-S system has been systematically divided into several sub-modules; each sub-module is then separately designed, fabricated, and characterized. The unique advantages of this specialized design technique for implementing such complicated RF PA circuits have been presented. To our best knowledge, modulated signal with 80 MHz modulation bandwidth has been for the first time applied to test a class-S PA in the GHz range. Finally, the operating principles of the current-mode class-S power amplifier have been proven by the designed demonstrator with GaN HEMTs and key design considerations have been pointed out.