A Novel Two Stage Broadband Doherty Power Amplifier for Wireless Applications
Broadband and highly efficient amplifiers are of great interest in modern wireless communication systems. In this paper, we present a novel two stage broadband Doherty power amplifier (DPA) which is able to maintain high efficiency at saturated output power and at backoff output power levels over a wide bandwidth. The amplifier uses a novel and simple approach to achieve bandwidth enhancement and at the same time uses a driver amplifier. We employ Klopfenstein taper to deliver wide bandwidth. The measurement results show that the proposed broadband two stage DPA is able to deliver 31% 35% drain efficiency at 6 dB output power backoff while at the saturation it achieves 40% 55% drain efficiency over the designed bandwidth of 1.5 to 2.6 GHz. The amplifier can deliver above 35 dBm output power with substantial gain of around 20 dB. The proposed DPA is a promising candidate for wideband and high gain requirements in modern wireless systems.
IEEE Microwave and Wireless Components Letters