WiMAX, WLAN, and X-Band Filtering Mechanism: Simple-Structured Triple-Band Frequency Selective Surface

A single-substrate-layer frequency selective surface (FSS) with a 1.6 mm thick FR4 substrate is proposed for triple-band-stop filtering applications. The proposed design includes simple conductive elements on both sides of the substrate. A square loop is located on the top side, while on the backside, another square loop being combined with two folded arms is embedded. Wise inclusion of the conductive elements with proper dimensions stimulated a three-band operation in 3.2-3.7, 4.1-6, and 8-12.1 GHz. WiMAX, WLAN, and X-band are covered within the mentioned frequency bands, respectively. As a figure of merit, for the presented band-stop FSS structure, stable frequency response is obtained against different angles of TE and TM polarizations. Moreover, experimental results obtained from the fabricated prototype are in close agreement with simulation studies confirming the FSS outperformance in real-world applications. Single substrate layer structure, small size, simple conductive elements, and coverage of in-service frequency bands are some of the advantages of the proposed FSS.