Reflective frequency selective surface based on low-permittivity dielectric metamaterials

In this letter, the design of reflective frequency selective surface (RFSS) using low-permittivity dielectrics is proposed based on effective medium theory. The effective medium approach is based on quasi-static extension of the Maxwell-Garnett model. Unlike conventional RFSSs, such RFSS is composed of low-permittivity dielectrics rather than high-permittivity or metallic materials. By drilling periodic hole arrays in multi-layer continuum dielectric plates, strong electric and magnetic resonances are introduced to produce drastic changes in effective parameters, leading to impedance mismatch and band-stop response. The band-stop response can be tailored by adjusting the size and spacing of the unit cell. As an example, an RFSS with rectangular hole element is demonstrated at K-band. The mechanism is analyzed by presenting the effective electromagnetic parameters and dynamic field distributions. A prototype was fabricated and measured. Excellent agreements between measured and simulated results were obtained. The method can also be used to design RFSS in THz and optical frequencies. (C) 2015 AIP Publishing LLC.