Design methodology of high-efficiency contiguous mode harmonically tuned power amplifiers

This paper presents a design methodology for high-efficiency broadband power amplifiers (PAs). The continuous class-F PA operation is extended to a contiguous set of voltage/current waveforms providing a design area for targeted drain efficiency of greater than 78.5%. The proposed methodology relaxes the design constraints by utilizing a different set of voltage waveforms in extracting the impedance design space while ensuring that the device operates below the limit of breakdown. As such, the proposed methodology provides device reliability under the broadband operation. For the experimental validation, Cree 10-W gallium nitride (GaN) transistor is used. The PA outputs more than 10W power with power added efficiency (PAE) greater than 75% with a peak PAE of 85%. This performance is achieved over the frequency band 550 to 950 MHz.