Wide bandwidth, high efficiency switch-mode power amplifiers.

摘要

A detailed investigation of switch-mode RF power amplifiers with regard to power, efficiency and bandwidth is presented. Ideal Class F and Inverse F waveform analysis with the inclusion of on-state resistance is described. Basic equations are derived that allow comparisons of the two classes with different operating conditions. A simulation method using large-signal device models for comparing transistor technologies, device scaling or class of operation is described.;Extreme performance sensitivity to harmonic input terminations is observed with GaN HEMT transistors, and this behavior is analyzed. The drop in performance is found to be caused by input waveform distortion induced by non-linear input capacitance and is related to the class of amplifier. A method of predicting which harmonic impedance causes the greatest loss of performance and estimating the loss is demonstrated.;Wideband performance of Class F, Inverse F and Class E is analyzed. An extension to the Class F waveform solution using reactive components at the first and second harmonic is discovered. The benefits of this reactively matched Class F are explored. This leads to very wideband Class J amplifiers that have a reduced sensitivity to the harmonic input match and operate at higher frequencies than their Class F counterparts.