Class-J RF power amplifier with wideband harmonic suppression

This work outlines a design approach used for achieving highly efficient power amplification over a wide bandwidth, given narrowband passive harmonic load-pull results at a single center frequency. Specific considerations have been given to harmonic suppression concerns which are addressed by appropriate choice of matching network topology. The method is justified by amplifier fabrication using a commercially available 10W GaN HEMT transistor and achieving an efficiency of at least 60% over a 15% bandwidth from 2.3-2.7GHz. Output power between 10-12W was delivered across the band, centered at 2.5GHz. Harmonic suppression of at least -41dBc and -39dBc was obtained across the second and third harmonic bands respectively, largely removing the dependency on post-filtering.