Inverse Class‐E power amplifier with broadband capability at different switch‐off duty ratio

Abstract

The paper explores the investigation of an inverse Class‐E amplifier featuring a series output filter across various switch‐off duty ratios D. Analysis of different duty ratios as a design parameter reveals their impact on peak switch voltage, output power capability, and maximum operating frequency. Notably, it is demonstrated that adjusting the D ratio affects these parameters, with specific emphasis on achieving a maximum normalized switch voltage lower than 2 and an output power capability exceeding 0.1 for D = 0.7. Furthermore, the paper considers both parasitic shunt capacitance and series inductor in the load network, a departure from previous works that solely focused on the series inductor. The proposed circuit is highlighted for its ease of implementation compared with conventional reactance compensation circuits employing parallel resonant circuits, which are challenging to form directly. An innovative approach is introduced to showcase the broadband performance of the inverse Class‐E amplifier. The measured drain efficiency and output power versus input power at 430 MHz are 82% and 45.3 dBm, respectively. A similar performance can be achieved within the frequency range of 380–600 MHz by proper tuning at saturated power. The measurement results demonstrate a maximum high power‐added efficiency (PAE) of 79% and drain efficiency of 82% within this frequency range, accompanied by a gain exceeding 12.0 dB and output power surpassing 44 dBm.