Design and analysis of em shielding frequency selective surface for x and ku bands application

Abstract

Frequency Selective Surfaces (FSSs) have metallic patches or apertures geometries and are printed on the substrate. They provide reflection characteristics or transmission characteristics in the desired frequency range for desired applications. FSSs are used for multiple applications, such as radomes, dichroic sub reflectors, reflect array lenses, RFID tags, Radar Cross Section (RCS), Electromagnetic shielding, polarizer, stealth, antenna gain enhancement, collision avoidance etc., Depending upon the applications the design of the FSS demanding the polarization characteristics, angular stability characteristics, miniaturization, and bandwidth response. For particular applications, FSS design is suitable in angular and polarization independent operation for various incident electromagnetic waves. FSS is majorly used for the frequency bands of X and Ku-bands, because in this field the FSS design has a lot of real time applications and has made specific target to be investigated. For X-band, radar plays a major role and is used to identify the objects. Such as ships, aircrafts, weather formation, motor vehicles etc. Ku-band plays a major role in satellite communication especially for satellite television for editing and broadcasting the program. The first part of this thesis discusses the design of broadband frequency selective surface. The design of single layer and single frequency FSS for X-band applications is proposed. The unit cell design is made from modified swastika geometry and provides polarization independency with its symmetrical unit cell structure. The overall size of the proposed design is 0.069and#955; x 0.069and#955;, where and#955;, represents free space wavelength corresponds to the operating frequency of 10.2 GHz. The proposed FSS is printed on the FR4 substrate with thickness of 0.8mm and it exhibits stop band response at center frequency of 10.2 GHz. It also offers broadband response with a bandwidth of newline4.0 GHz in 10 dB insertion loss. The proposed FSS provides stable frequency response for various angles of inc