RF MEMS variable matching networks for multi-band and multi-mode GaN power amplifiers

This work presents Radio-Frequency Microelectromechanical-System (RF MEMS) based tunable matching networks for a multi-band Gallium Nitride (GaN) power amplifier application. In the frequency range from 3.5 GHz to 8.5 GHz a return loss of 5 dB to 10 dB was measured for the input network, matching impedances close to the border of the smith chart. For the output matching network return loss of 10 dB to 20 dB and insertion loss of 1.3 dB to 2 dB were measured. The matching networks can tune the power amplifier to four different operating frequencies, as well as changing the transistor´s mode of operation from maximum delivered output power to maximum Power Added Efficiency (PAE), while keeping the operating frequency constant.