Design of Broadband High-Efficiency GaN Power Amplifiers

We discuss the broadband design of high-efficiency GaN power amplifiers (PAs) using continuous modes. A Machine Learning approach to the full EM-based optimization of a hybrid design is first outlined and demonstrated experimentally. We then consider the challenges of achieving high efficiency in a broadband integrated PA, including the features of GaN transistors that facilitate broadband operation. It is shown that proper sizing of transistor can lead to an optimum load resistance close to 50O, thereby extending the bandwidth of the output matching network of the PA in an integrated environment. We present techniques to realize the continuous- mode operation in an integrated GaN PA, with low loss and compact chip size. Finally, we show predicted results for the integrated GaN PA implementation.