An FSS Structure Based on Apollonius Circles with Stable Resonance Frequency for WLAN Applications

In this study, the fractal structure of the Apollonius Circle previously used for array antenna structures is modified and used as a stable resonance element on frequency selective surfaces (FSS) operating at the WLAN band. The proposed structure designed using a low-cost Taconic-RF35 substrate resonates at 5 GHz and has a bandwidth of 3.52 GHz. The performance of the design is simulated using CST Microwave Studio in terms of surface current on the proposed structure and the dependence of the FSS resonant frequency on the angle of the incident plane wave. From the result, the FSS design provides stable performance as a band stop filter at different angles ranging from 0˚ to 55˚ in TE and TM modes.