Design of a Three-Way Doherty Power Amplifier for Base-Station Applications
The Doherty Power Amplifier (DPA) is used in a base station for mobile system (W-CDMA and 3G) because of its high efficiency. This paper presents the design and operation behavior of three-way Doherty amplifier. The amplifier is designed in the configuration with two quarter-wave impedance transformers in the output combining circuit and with GaAsFET device in carrier and peaking amplifies. The class AB power amplifier used in the configuration of the carrier amplifier. The class C is used in the configuration of the peaking amplifiers. The results obtained shows that three-way DPA can be used in wide-band spectrum. The amplifier works at 2.14GHz and has very good power added efficiency (PAE %), gain and output power at Output Back-Off regions (OBO) (-6dBm, -9.54dBm and -12dBm) below maximum output power compared with classical DPA and conventional power amplifier type class AB.