Continuous class BJ power amplifier with DGS output matching

This paper presents the design, implementation, and experimental evaluation of a high efficiency continuous Class BJ mode power amplifier, using a compact defected ground structure (DGS) to provide the necessary output matching and harmonic termination for broadband operation. Detailed consideration has been given to the DGS microstrip line impedance and corresponding equalization network, in order to achieve the required fundamental and harmonic matching. The method is demonstrated through design and realization of an amplifier using a commercially available 10W GaN HEMT transistor that achieves efficiencies above 70% over a 600MHz bandwidth with an output power of at least 40 dBm.