A two-sided frequency selective surface (FSS) is proposed to shield two bands of the mobile frequencies (EGSM-900 and DCS-1800). The FSS consists of an array of square concentric-rings cells printed on both sides of the substrate to offer better shielding of the two mobile frequencies. The CST Microwave suit is used for the simulations. The equivalent circuit model for the two-sided FSS is analysed and the transmission frequency in terms of the two stop frequencies is estimated. The obtained shielding is better than 40 dB across the two bands. The proposed FSS can be used to reduce mobile radiation or to isolate halls from nearby mobile base stations. The bandwidth of the FSS cell can be increased by using ring pairs of unequal sizes on the two sides of the substrate.

A dual stopband frequency selective surface (FSS) for shielding two bands of the mobile frequencies is proposed. The designed FSS consists of periodic cells of concentric rings to prevent transmission of the two mobile frequencies of EGSM-900 and DCS-1800. The designed FSS is simulated in CST Microwave suit. The equivalent circuit for the two rings is analyzed, and an estimate for the frequency of the transmission in terms of the two stop frequencies is derived. The results show a stable response with various polarization angles. The obtained insertion loss is more than 30 dB across the two bands. This FSS can be used to isolate halls or reduce undesired radiation from nearby mobile base stations.