Dual-band microwave power amplifier design using GaN transistors

This paper presents the design and the applications of dual-band microwave power amplifiers using GaN transistors. First, a dual-band power amplifier using dual-band transmission line (TL) impedance matching networks, which can simultaneously match two different complex impedances to 50 Ω at two uncorrelated frequencies, is introduced. Secondly, design of a dual-band GaN based Doherty power amplifier (DPA) is presented in this paper. The dual-band DPA is based on a simplified DPA structure and wideband matching networks. The simplified DPA structure eliminates the 35 Ω quarter wavelength impedance inverters used in the conventional DPAs by matching the output impedances of the carrier and peak amplifiers of the DPA to other values (e.g. 100 Ω).