Load Tuning Assisted Discrete-Level Supply Modulation Using BST and GaN Devices for Highly Efficient Power Amplifiers
The combination of supply modulation and load tuning using highly efficient GaN components and very linear thin-film barium-strontium-titanate varactors constitutes an agile and reconfigurable platform that allows optimized broadband operation for high peak-to-average power ratio (PAPR) signals. The flexible hardware developed in this work shows that the PAEavg of a 60 MHz wide 11.9 dB PAPR signal is improved by 4 percentage points using load tuning and further 10 percentage points by supply modulation. The improved PAE values were obtained while maintaining linearity. The power amplifier including output matching network is a very compact realization inside a modified RF transistor package.