Frequency Selective Surfaces with Cross-shaped Aperture Elements

In modern microwave and terahertz technology, one of the most hot topic areas of using frequency selective surfaces is frequency filtering of electromagnetic signals. Such structures make it possible to reduce the weight and dimension parameters of the radio equipment, which is especially important for onboard systems of aviation and space technology operating under harsh environment, which imposes high-reliability requirements on the units and components of these systems. One of the trends in the development of filtering devices of various types and different element bases has recently become the design of broadband and ultra-wideband, as well as narrowband and ultra-narrowband systems.

Freestanding frequency selective surfaces with cross-shaped aperture elements are investigated numerically and experimentally in the present chapter. Transmission characteristics of such two-dimensional periodic structures as a function of sizes are analyzed using numerical methods.Employing the conjugate-gradient method narrowband filters have been developed and optimized. The results of measurements carried out in the present study agree well with the obtained theoretical data.