Design and Experiment of Wideband Filters Based on Double-Layered Square-Loop Arrays in the F-Band

Abstract

We present a wideband metamaterial (MM) filter based on a metal-dielectric-metal (MDM) structure. The proposed structure consists of a quartz dielectric substrate and two metallic square-loop arrays, which were deposited on both surfaces of the substrate. The performance of the proposed design was numerically simulated by considering the angle of incidence. The surface current and electric field distributions were calculated for the two resonant frequencies to examine the intrinsic mechanism of the proposed filter. The transmittance of the structure for various oblique angles of incidence was also analyzed. It is generally challenging to completely align the two metallic layers due to limitations in the manufacturing process. Hence, the influence of periodic misalignment on wave propagation was studied. Furthermore, a prototype of the proposed structure was fabricated and the transmission spectra were measured. Simulation and experimental results reveal that our proposed filter can achieve wideband transmission in the F-band. This work is valuable for the design of broadband filters in millimeter and terahertz waves.