Analytical Dual-Band Matching Approach for Concurrent High-Efficiency Power Amplifiers

In this brief, a dual-band complex impedance transformer is proposed and applied to design a concurrent high-efficiency power amplifier (PA) with a widely spaced frequency. The transmission line parameters of the PA, including dual-band harmonic control network, and dual-band fundamental matching network, are obtained using the derived analytical design formula, which avoids the time-consuming numerical optimization. In addition, the proposed transformer can reduce the probability to use the transmission line with extremely high or low impedance. Simulation and measurement verified that the fabricated dual-band PA achieves the peak power-added efficiency (PAE) of 78.8% and 73.1% with the output power of 42.5 and 40.2 dBm at 0.88 and 2.4 GHz, respectively.