Design and Optimization of Dual-Band Branch-Line Coupler with Stepped-Impedance-Stub for 5G Applications

摘要

This paper presents a design optimization of a dual-band branch-line coupler with stepped-impedance-stub lines. This coupler operates over 5G NR frequency bands n5 and n2, developed by 3GPP for the 5G (fifth generation) mobile network, and these two bands are centered at 0.85 GHz and 1.9 GHz respectively. To achieve the design specifications an adjusted Tuning Space Mapping method is used. This method of optimization moves the hardship of optimization from high-fidelity electromagnetic models to low-fidelity tuning models. The simulated and measured results of this enhanced coupler show good dual-band performance at the two bands.