A Novel Compact Dual-Band Frequency Selective Surface for GSM Shielding by Utilizing a 2.5-Dimensional Structure

Based on 2.5-dimensional (2.5-D) structure, a novel compact dual-band frequency selective surface for GSM shielding is proposed in this letter. The unit cell geometry is designed by knitting double square-loop elements in 2.5-D which realizes the compact dual band-stop characteristics successfully. The size of proposed 2.5-D frequency selective surfaces (FSS) cell is only 0.072 λ0, where λ0 corresponds to free-space wavelength of the lower resonance frequency. The 2.5-D FSS is modeled and simulated by Microwave CST STUDIO SUITE. The simulation result shows that the FSS offers band-stop response at 900 and 1790 MHz with shielding effectiveness of 41.9 dB and 49.2 dB, respectively. Furthermore, the 2.5-D FSS performs a good angle-stability under both TE and TM polarizations. Hence, the designed 2.5-D FSS can be used for GSM shielding effectively. A prototype of proposed 2.5-D FSS is fabricated. The measurement result proves the satisfactory consistency with the simulation results.