Liquid Crystal Based Reconfigurable Frequency Selective Surface for ISM Applications

This paper presents a liquid crystal (LC) based reconfigurable dual-band band-stop frequency selective surface (FSS) working in Industrial Scientific Medical (ISM) bands. With the help of dielectric anisotropy of LC materials, the proposed FSS can be continuously adjusted under external electric fields. The LC cell is sandwiched between two metallic layers, and each metallic layer consists of two square loops. This FSS can steadily block both TE and TM polarized waves in ISM bands with the incident angle varies from 0° to 30°. The attenuation could reach 20 dB. It can effectively verify the superiority of LC materials in the field of reconfigurable microwave devices.