Design of a multiband, dynamic reconfigurable band-stop frequency selective surface for WIFI/5G applications

Frequency selective surfaces are defined as structures that reflect or transmit electromagnetic waves in certain frequency bands. These surfaces are usually formed by periodic arrangement of metallic or dielectric elements. The use of such surfaces is of great importance in modern telecommunications, radar and defence technologies. However, the fixed frequency characteristics of conventional frequency selective surfaces can be limiting in applications with dynamic and variable frequency requirements. In this context, frequency-adjustable frequency selective surfaces stand out with the ability to operate in different frequency bands. In this thesis, a multiband, polarisation stable dynamic reconfigurable band stop frequency selective surface for Wi-Fi and 5G applications has been designed using CST Studio Suite software. In the FSS design, PIN diodes are used to dynamically switch between frequency bands. When the results were analysed, a unique FSS was designed which can dynamically switch between 2.4 GHz, 3.5 GHz and 5.8 GHz frequency bands for three different states, has TE and TM polarisation stability and angular stability up to 60 degrees. In addition, the simulation results of the designed FSY were compared with the measurement results and the equivalent circuit model and found to be compatible.