A Polarization-Insensitive Switchable Filter using Meandered AFSS for WiFi/WiMAX Applications

This paper presents a polarization-independent switchable bandstop filter using active frequency selective surface (AFSS). The proposed structure comprises of two mutually orthogonal patches of copper printed on the opposite faces of an FR4 substrate, thereby resulting in a polarization-insensitive topology. The metallic patches are meandered for compactness. Single p-i-n diode is mounted on each side of the geometry for switching the bandstop filter response between 2.12 GHz (under forward bias) and 3.15 GHz (under reverse bias). Parallel biasing configuration is employed for remotely controlling the diode components. The frequency responses along with several parametric variations are studied in Ansys HFSS simulation software. The proposed AFSS geometry can be used for various potential applications, including LTE and WLAN/WiMAX.