Design of a broadband and high-efficiency power amplifier based on a new symmetrical triangular resonant filter

This letter introduces a design methodology for a broadband high-efficiency power amplifier (PA) that incorporates a new symmetrical triangular low-pass filter with Embedded Radial Stub. To extend the design space, a resistive-reactive series of continuous inverse modes (Res.-Rea. SCIMs) theory is employed. The proposed filter, which serves as the output matching network of the PA, is constructed with dual-triangular symmetric (DTS) microstrip lines and a radial stub, which are interconnected by microstrip lines. By combining a DTS filter and a radial stub, a new filter with improved performance has been proposed. The new filter achieves low passband loss, high out-of-band rejection, and narrow transition bandwidth. These characteristics are well utilized in the inverse Class-F power amplifier, resulting in excellent performance. It is applied to the output matching circuit to realize a broadband high-efficiency PA. To validate the effectiveness of the proposed structure, a PA prototype is designed and fabricated with a 10-W GaN HEMT device. Measurement results demonstrate a bandwidth from 0.6 GHz to 1.4 GHz, with a drain efficiency (DE) of 66.3%-73.3%, a gain of 9.53-12.17 dB, and an output power of 39.53-42. 17 dBm.