Frequency selective surface filters with high-quality factors based on a Fano resonance

In this work, we propose a design method of the narrow passband filter with a high Q -factor based on a Fano resonance. A single -layer metallic frequency selective surface (FSS) with a simple structure is first designed according to this idea, but the result is not satisfying since the filter transmittance will significantly decrease with the increase of the Q -factor due to the presence of an inherent ohmic damping. Further, to improve the design, a ceramic -based FSS filter based on the similar mechanism is proposed, and the requirements of the ultrahigh Q -factors can be met owing to the high permittivity and low loss tangent of microwave ceramics. The design strategy proposed in this paper may have a promising potential in modern wireless communication and related fields. (c) 2024 Optica Publishing Group