DESIGN OF MICROSTRIP DUAL-BAND BANDPASS FILTER FOR SUB-6 GHZ 5G MOBILE COMMUNICATIONS

(Received: 7-Jul.-2023, Revised: 12-Aug.-2023 , Accepted: 2-Sep.-2023)

Authors Rachida Boufouss, Abdellah Najid,

Keywords #5G #Bandpass filter #Dual-band #Stepped-impedance resonators #Sub-6 GHz

Abstract In this paper, a microstrip bandpass filter for dual-band sub-6 GHz 5G mobile communications is designed. The two first resonance frequencies of the stepped-impedance resonator are used as the operating frequencies of the two passbands. Furthermore, the stepped-impedance resonator is folded to form an open-loop stepped-impedance resonator for compactness. This form of the resonator generates a second transmission zero in the upper stopband, which improves the out-of-band rejection. A 50 Ω tapped-line input/output is used to feed the filter. The proposed structure is designed, analyzed and manufactured and the measured results are found to be in good agreement with the simulation results. From the measured results, it is found that the proposed filter achieved a return loss of 21.5 dB and 28.3 dB, an insertion loss of 0.4 dB and 1.7 dB and a bandwidth of 12.5% and 10.81% at 3.61 GHz and 5.55 GHz, respectively. In addition, the proposed filter has a compact size, which makes it suitable for sub-6 GHz 5G mobile communications.

References

[1] A. Osseiran et al., "Scenarios for 5G Mobile and Wireless Communications: The Vision of the METIS Project," IEEE Communications Magazine, vol. 52, no. 5, pp. 26–35, May 2014.

[2] X. Zhang, Y. Li, W. Wang and W. Shen, "Ultra-wideband 8-port MIMO Antenna Array for 5G Metal-frame Smartphones," IEEE Access, vol. 7, pp. 72273–72282, 2019.

[3] L. Liu, Q. Fu, F. Liang and S. Zhao, "Dual-band Filter Based on Air-filled SIW Cavity for 5G Application," Microwave and Optical Technology Letters, vol. 61, no. 11, pp. 2599–2606, Nov. 2019.

[4] D. Tharani, R. K. Barik, Q. S. Cheng, K. Selvajyothi and S. S. Karthikeyan, "Compact Dual-band SIW Filters Loaded with Double Ring D-shaped Resonators for Sub-6 GHz Applications," Journal of Electromagnetic Waves and Applications, vol. 35, no. 7, pp. 923–936, May 2021.

[5] W. Huang, L. Li, L. Li and J. Dong, "A Compact CPW Bandpass Filter Based on Spiral-shaped DGSs for 5G Frequency Band," Progress In Electromagnetics Research Letters, vol. 94, pp. 27–34, 2020.

[6] C. Karpuz, P. O. Ozdemir, H. Senol, A. Cengiz, H. H. Balik, and A. Gorur, "A Novel Concept in Design of Microwave Planar Dual Band Filter Having the Controllable Closed/Isolated Bands by Using the Simple Vias and the Slow Wave Effect for 5G/IoT Applications," Proc. of the 2021 IEEE 51st European Microwave Conf. (EuMC), London, United Kingdom, pp. 385–388, Apr. 2022.

[7] H. Zhang, K. Ma, W. Zhang and N. Yan, "A Novel Self-packaged DBBPF with Multiple TZs for 5G Sub-6 GHz Applications," Microwave and Optical Technology Letters, vol. 65, no. 1, pp. 62–68, 2023.

[8] Z. Xu, Y. Wu, Q. Dong and W. Wang, "Miniaturized Dual-band Filter Using Dual-mode Dielectric Waveguide Resonator," IEEE Microwave and Wireless Components Letters, vol. 32, no. 12, pp. 1411–1414, 2022.

[9] W.-L. Hsu, P.-Y. Lyu and S.-F. Chang, "Design of a Miniature Dual-band Bandpass Filter with Inter-locked Stepped-impedance Resonators for 5G New Radio Access Technology," Int. Journal of Microwave and Wireless Technologies, vol. 12, no. 8, pp. 733–737, Oct. 2020.

[10] A. Kapoor, P. Kumar and R. Mishra, "Analysis and Design of a Passive Spatial Filter for Sub-6 GHz 5G Communication Systems," Journal of Computational Electronics, vol. 20, no. 5, pp. 1900–1915, Oct. 2021.

[11] Y. Zhang, K. Ma and X. Chen, "A Compact Low-cost Dual-band Bandpass Filter with Enhanced Suppression Using Substrate Integrates Suspended Line Technology," Microwave and Optical Technology Letters, vol. 64, no. 2, pp. 276–282, 2022.

[12] D. Yang and Y. Dong, "Miniaturized Multilayer Surface-mountable 5G Filter Based on Shielded Spiral Resonator," IEEE Trans. on Circuits and Systems II: Express Briefs, vol. 69, no. 8, pp. 3366–3370, 2022.

[13] M. Riaz, B. S. Virdee, P. Shukla, K. Ouazzane, M. Onadim and S. Salekzamankhani, "Quasi-elliptic Dual-band Planar BPF with High-selectivity and High Inter-band Isolation for 5G Communications Systems,"Microwave and Optical Technology Letters, vol. 62, no. 4, pp. 1509–1515, Apr. 2020.

[14] J.-S. Hong, Microstrip Filters for RF/Microwave Applications, 2nd Edn., DOI: 10.1002/0471221619, John Wiley & Sons, Inc., Hoboken, N.J: Wiley, 2011.

[15] W. Zhang, K. Ma, H. Zhang and H. Fu, "Design of a Compact SISL BPF with SEMCP for 5G Sub- 6 GHz Bands," IEEE Microwave and Wireless Components Letters, vol. 30, no. 12, pp. 1121–1124, Dec. 2020.

[16] N. Praveena and N. Gunavathi, "High Selectivity SIW Cavity Bandpass Filter Loaded CSRR with Perturbing Vias for Sub-6 GHz Applications," Progress In Electromagnetics Research Letters, vol. 109, pp. 103–110, 2023.