A High‐Efficiency Doherty Power Amplifier Based on Harmonic Suppression Power Divider and Broadband Filtering Matching Structure

ABSTRACT This article presents the design of a wideband and high‐efficiency Doherty power amplifier with integrated filtering characteristics. A T‐shaped microstrip line is adopted for the power divider. In the subsequent matching network, a coupled microstrip line filtering structure was innovatively adopted. To enhance out‐of‐band suppression, the filtering structure is terminated with cascaded microstrip lines, thereby maintaining high efficiency while extending the bandwidth. Within the frequency range of 1.6–1.95 GHz, the proposed amplifier achieves a large signal gain of 8–10.6 dB and a saturated output power of 42.1–43.7 dBm. The drain efficiencies at 6 dB output power back‐off and at saturation are 46.6%–58.2% and 58%–77.7%, respectively. The adjacent channel leakage ratio of 80 MHz‐5G‐NR signal at center frequency after pre‐distortion reaches ‐45.8/‐46 dBc, which satisfies the relevant requirements of communication systems.