Power combining techniques into unbalanced loads for Class-E and inverse Class-E amplifiers

A power combining strategy for class-E and inverse class-E amplifiers operating at high frequencies such that they can operate into unbalanced loads is proposed. This power combining method is particularly important for the inverse class-E amplifier configuration whose single-stage topology is naturally limited for small-to-medium power applications. Design examples for the power combining synthesis of classical class-E and then inverse class-E amplifiers with specification 3 V 1.5 W 2.5 GHz are given. For this specification, it is shown that a three-branch combiner has a natural 50 output impedance. The resulting circuits are simulated within agilent advanced design systems environment with good agreement to theoretical prediction. Further the performance of the proposed circuits when operated in a linear amplification using nonlinear components transmitter configuration whereby two-branch amplifiers are driven with constant amplitude conjugate input phase signals is investigated.