Characterization of broadband Monolithic Gallium Nitride distributed power amplifier using thermal imaging technique

A thermal imaging technique is used to characterize a Monolithic Gallium Nitride distributed power amplifier under DC and RF drive conditions. The temperature difference among the active cells (transistors) in distributed power amplifier is observed under RF drive conditions. It is believed that this non-uniform performance of individual cells in broadband distributed power amplifier results in its lower efficiency and lower power output comparing to narrowed band design. The experimentally observed results match with the results of large signal simulation. The technique can be used to optimize the distributed power amplifier design in the future.