Investigation of High-Efficiency Parallel-Circuit Class-EF Power Amplifiers With Arbitrary Duty Cycles

摘要

In this article, a parallel-circuit class-EF power amplifier with a shunt quarter-wave transmission-line for driving signals with arbitrary duty cycles is proposed and investigated. At the particular condition of duty cycle = 1/3, the values of the elements in the output network, as well as, some critical design parameters are analyzed and optimized. This leads to a series of significant improvements in the peak drain voltage (V-max), the maximum operating frequency (f(max)), and the power output capability (c(p)). Furthermore, in order to verify the advantage of the proposed new amplifier and its feasibility in realistic situations, a proof-of-concept circuit is designed and fabricated. Finally, at the operating frequency of 3.59 GHz, excellent performance has been achieved with the power-added efficiency of 79.9% and output power of 40.7 dBm.