A Dual-Passband Frequency Selective Surface for 5G Communication

In this letter, a new frequency selective surface is proposed, which is mainly applied to 5G communication. The equivalent circuit method is used to provide assistance for structural design. This structure can generate dual-frequency passbands and achieve double resonant frequencies 28.1 and 39.5 GHz. It acquires large enough bandwidths to cover 27.5-28.35 and 38.6-40 GHz, which are bands of 5G communication. In addition, this structure is a multi-layer structure composed of one metallic layer and two dielectric layers, and its unit size is 0.56λ × 0.56λ, where λ is the wavelength corresponding to the first resonant frequency. Simulated results show that this structure has excellent filtering properties with respect to polarization stability as well as angular stability. Finally, the prototype of this structure is fabricated. The measured results and simulated results have consistent filtering characteristics within the tolerance of error.