volume | PIER Journals

Abstract

This paper addresses the challenge of inter-band interference suppression in Dual-Band Power Amplifier (DBPA) by proposing a high-isolation dual-band power amplifier design integrated with a Ring-Coupled Bandstop Filter (RCBSF). Through a ring-coupled structure of main transmission lines and coupled branches, combined with the collaborative tuning of λ/4 open stubs and coupling capacitor, the design achieves low-loss transmission in the dual-frequency passbands of 1.5 GHz and 2.1 GHz, forms a suppression band of ≥ 20 dB in the 1.6-2.0 GHz range, and realizes deep suppression of > 40 dB for second/third harmonics. The RCBSF is embedded into the output matching network of the power amplifier to form a dual-band power amplifier. Measured results show that the power-added efficiencies (PAEs) of the amplifier at 1.5 GHz and 2.1 GHz are 58% and 60%, respectively, with output powers of 38 dBm and 37 dBm, and gains of 15 dB and 14 dB, respectively. In non-target frequency bands, the PAE approaches 0%, and a suppression greater than 40 dB is achieved, verifying that the filter's high selectivity and compact layout enhance the performance of the dual-band power amplifier. This design achieves efficient power transmission and strong interference isolation, providing a cost-effective solution for multi-band communication systems.

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Dr. Jingchang Nan

Dr. Hai Jiang

Dr. Wenjin Liu