A New 3D Frequency-Selective Structure for 5G Communication

Abstract

Background: In this paper, a new frequency-selective structure (FSS) for 3 to 4 GHz frequency band of fifth generation (5G) is proposed as a result of an analytical mode-matching method. background: Nowadays, frequency-selective structures (FSSs) have been more attractive for researchers for their different applications, such as reducing the electromagnetic interference in communication systems, reducing radar cross-section, antennas mutual coupling reduction, security of wireless networks, energy harvesting , wearable sensing FSS, and electromagnetic absorbers in a wide frequency band. One of the other applications of the FSSs is as covers that pass the specific frequencies of the 5G communication system and reflect the wave of WLAN frequencies in 2 and 5 GHz bands. Methods: A new periodic structure with stepped rods is designed using a closed-form equation derived by the analytical mode-matching method. Performance of the structure is simulated by different numerical packages. Results: The analytical and simulation results demonstrate that the designed structure transmits incident waves in 3.4 to 3.9 GHz frequency range with return loss lower than 10 dB and insertion loss of about 0.5 dB. The structure reflects the frequencies out of this range, especially wireless local area network (WLAN) 5 GHz, which is adjacent to this band. Furthermore, the performance of the proposed structure is independent of the TE and TM polarization of the incident wave and relative to the angle of the incident wave up to 60 degrees from perpendicular to the FSS surface, it has minor variations of about 8% in the transmitted frequency bandwidth. In addition, the average value of maximum field enhancement factor (MFEF) as the ratio of maximum field magnitude on the FSS surface to the magnitude of the incident field, used for assessing power handling capability of the structure, is about 4.5. Conclusion: Therefore, these features make the proposed structure suitable for 5G communication and high power systems.