A quadband concurrent linear/efficient power amplifier for multiband wireless applications

In this paper, a design for a quadband linear/efficient class-AB power amplifier, with an output power exceeding 10-watts in all four bands is presented. The designed power amplifier - based on a GaN HEMT- provides a power added efficiency over 47% in all four bands. Source/load-pull simulations are used for optimum matching at each band; quadband stub-based matching is used for input matching whilst LC broadband matching, based on equiripple approximation, is used for output matching. Drain biasing is implemented using an efficient high impedance quarter wave open stubs (QWOS) precisely located at appropriate positions along transmission line, which furthermore provide low insertion loss at the operating frequency bands. Fractional bandwidths of 88, 15, 13.3 & 16.4% are reported in the operation bands of 900, 1600, 1900 & 2450 MHz, respectively.