Here, a multi-stopband frequency selective surface (FSS), covering commercial frequency bands CDMA, GSM-900, GSM-1800, LTE-2200 MHz, Wi-Fi, and Bluetooth for mobile communication applications has been proposed employing a pair of concentric square ring patches as a unit cell. Possibilities of annular ring patch type FSS are explored first. Finally, the design comes up with a compact square ring patch type single layer FSS. It is also explored that by increasing the width of the inner ring, operating bandwidth can be enhanced to cover closely spaced commercial frequency bands in a single band. Thereby the mutual coupling between the closely spaced resonators for multiple bands can be minimized. The proposed design is flexible enough to tune the desired resonance frequency by changing the length of the individual ring resonators. The design concept has been formulated using linear polynomial regression (LPR) techniques and validated through proper measurement of the fabricated prototype. This FSS can be used as a mobile back cover to protect mobile users from harmful radiations.
2. Barton, J. H., C. R. Garcia, E. A. Berry, R. Salas, and R. C. Rumpf, "3-D printed all-dielectric frequency selective surface with large bandwidth and field of view," IEEE Trans. Antennas Propag., Vol. 63, 1032-1039, 2015.
3. Lalbakhsh, A., M. U. Afzal, K. P. Esselle, and S. L. Smith, "Wideband near-field correction of a fabry-perot resonator antenna," IEEE Trans. Antennas Propag., Vol. 67, 1975-1980, 2019.
4. Afzal, M. U., A. Lalbakhsh, and K. P. Esselle, "Electromagnetic-wave beam-scanning antenna using near-field rotatable graded-dielectric plates," Journal of Applied Physics, Vol. 124, 234901-234911, 2018.
5. Mackay, A., B. Sanz-Izquierdo, and E. A. Parker, "Evolution of frequency selective surfaces," Forum for Electromagnetic Research Methods and Application Technologies (FERMAT), Vol. 2, 1-7, 2014.
6. Nair, R. U. and R. M. Jha, "Electromagnetic design and performance analysis of airborne radomes: Trends and perspectives antenna applications corner," Antennas Propag. Mag., Vol. 56, No. 4, 276-298, 2014.
7. Luukkonen, O., F. Costa, C. R. Simovski, A. Monorchio, and S. A. Tretyakov, "A thin electromagnetic absorber for wide incidence angles and both polarizations," IEEE Trans. Antennas Propag., Vol. 57, No. 10, 3119-3125, Oct. 2009.
8. Zahirjoozdani, M., M. Khalajamirhosseini, and A. Abdolali, "Wideband radar cross-section reduction of patch array antenna with miniaturized hexagonal loop frequency selective surface," Electron. Lett., Vol. 52, No. 9, 767-768, 2016.
9. Hiranandani, M. A., A. B. Yakovlev, and A. A. Kishk, "Artificial magnetic conductors realised by frequency-selective surfaces on a grounded dielectric slab for antenna applications," IEE Proceedings - Microwaves, Antennas and Propagation, Vol. 153, 487-493, 2006.
10. Lalbakhsh, A., M. U. Afzal, K. P. Esselle, S. L. Smith, and B. A. Zeb, "Single-dielectric wideband partially reflecting surface with variable reflection components for realization of a compact high-gain resonant cavity antenna," IEEE Trans. Antennas Propag., Vol. 67, 1916-1921, 2019.
11. Lalbakhsh, A., M. U. Afzal, and K. P. Esselle, "Multiobjective particle swarm optimization to design a time-delay equalizer metasurface for an electromagnetic band-gap resonator antenna," IEEE Antennas and Wireless Propag. Lett., Vol. 16, 912-915, 2017.
12. Zhu, D. Z., P. L. Werner, and D. H. Werner, "Design and optimization of 3-D frequency-selective surfaces based on a multiobjective lazy ant colony optimization algorithm," IEEE Trans. Antennas Propag., Vol. 65, 7137-7149, 2017.
13. Lalbakhsh, A., M. U. Afzal, K. P. Esselle, and B. A. Zeb, "Multi-objective particle swarm optimization for the realization of a low profile bandpass frequency selective surface," International Symposium on Antennas and Propagation (ISAP), Hobart, TAS, Australia, Nov. 9-12, 2015.
14. Yan, M., S. Qu, J. Wang, and H. Zhou, "A miniaturized dual-band FSS with stable resonant frequencies of 2.4 GHz/5 GHz for WLAN applications," IEEE Antennas and Wireless Propag. Lett., Vol. 13, 895-898, 2014.
15. Rahmati, B. and H. R. Hassani, "Multiband metallic frequency selective surface with wide range of band ratio," IEEE Trans. Antennas Propag., Vol. 63, 3747-3753, 2015.
16. Döken, B. and M. Kartal, "Easily optimizable dual-band frequency selective surface design," IEEE Antennas and Wireless Propag. Lett., Vol. 16, 2979-2982, 2017.
17. Dai, X.-W. and T. Zhou, "Dual-band reflect array with crossed-dipole elements for GSM and LTE applications," AEU - International Journal of Electronics and Communications, Vol. 70, 605-610, 2016.
18. Bagci, F., C. Mulazimoglu, S. Can, E. Karakaya, A. Egemen Yilmaz, and B. Akaoglu, "A glass based dual band frequency selective surface for protecting systems against WLAN signals," AEU - International Journal of Electronics and Communications, Vol. 82, 426-434, 2017.
19. Bashiri, M., C. Ghobadi, J. Nourinia, and M. Majidzadeh, "WiMAX, WLAN, and X-band filtering mechanism: Simple-structured triple-band frequency selective surface," IEEE Antennas and Wireless Propag. Lett., Vol. 16, 3245-3248, 2017.
20. Kartal, M., J. J. Golezani, and B. Doken, "A triple band frequency selective surface design for GSM systems by utilizing a novel synthetic resonator," IEEE Trans. Antennas Propag., Vol. 65, 2724-2727, 2017.
21. Yang, L. and L. Guizhen, "The research on biological effects of mobile phone radiation to human body," Proceedings of 2008 Asia-Pacific Microwave Conference, 1-4, Macau, China, 2008.
22. Yaning, L., "Review on the investigation of the mechanism of the biological effects of the electromagnetic radiation," Basic Medical Sciences and Clinics, Vol. 20, No. 1, 21-23, 2000.
23. Da, R. and H. Yoo, "Application of a compact electromagnetic bandgap array in a phone case for suppression of mobile phone radiation exposure," IEEE Transactions on Microwave Theory and Techniques, Vol. 66, 2363-2372, 2018.
24. Natarajan, R., M. Kanagasabai, S. Baisakhiya, R. Sivasamy, S. Palaniswamy, and J. K. Pakkathillam, "A compact frequency selective surface with stable response for WLAN applications," IEEE Antennas and Wireless Propag. Lett., Vol. 12, 718-720, 2013.
25. Wu, T. K., Frequency Selective Surface and Grid Array: Wiley series in Microwave and Optical Engineering, New York, Jul. 1995.
26. Chatterjee, S. and A. S. Hadi, Regression Analysis by Example, John Wiley & Sons, New Jersey, 2006.