volume | PIER Journals

Abstract

A new technique to reduce the mutual coupling between closely-spaced, single-layered patch antenna elements is presented. The proposed design comprises an integrated novel decoupling structure to generate an out-of-phase decoupling signal to effectively lower the coupling between the elements. In addition, coplanar L-probes and interdigital filter shaped slits on the ground plane are incorporated to further improve the isolation. The realized isolation level is about 28 dB at the frequency of operation. This is a significant achievement for a single-layered low-profile structure, wherein the center-to-center element spacing is only around 0.25λ₀, and more importantly, no shorting vias are used.

1. Larsson, E. G., O. Edfors, F. Tufvesson, and T. L. Marzetta, "Massive MIMO for next generation wireless systems," IEEE Comm. Magz., Vol. 52, No. 2, 186-195, Feb. 2014.
doi:10.1109/MCOM.2014.6736761

2. Yang, L., M. Fan, F. Chen, J. She, and Z. Feng, "A novel compact electromagnetic-bandgap (EBG) structure and its applications for microwave circuits," IEEE Trans. Microw. Theory Tech., Vol. 53, No. 1, 183-190, Jan. 2005.
doi:10.1109/TMTT.2004.839322

3. Yang, F. and Y. R. Samii, "Microstrip antennas integrated with electromagnetic band-gap EBG structures: A low mutual coupling design for array applications," IEEE Trans. Antennas Propag., Vol. 51, No. 10, 2936-2946, Oct. 2003.
doi:10.1109/TAP.2003.817983

4. Farahani, H. S., M. Veysi, M. Kamyab, and A. Tadjalli, "Mutual coupling reduction in patch antenna arrays using a UC-EBG superstrate," IEEE Antennas Wireless Propag. Lett., Vol. 9, 57-59, 2010.
doi:10.1109/LAWP.2010.2042565

5. Yang, X., Y. Liu, Y. Xu, and S. Gong, "Isolation enhancement in patch antenna array with fractal UC-EBG structure and cross slot," IEEE Antennas Wireless Propag. Lett., Vol. 16, 2175-2178, 2017.
doi:10.1109/LAWP.2017.2703170

6. Alibakhshikenari, M., M. Khalily, B. S. Virdee, C. H. See, R. A. Abd-Alhameed, and E. Limiti, "Mutual coupling suppression between two closely placed microstrip patches using EM-band gap metamaterial fractal loading," IEEE Access, Vol. 7, 23606-23614, 2019.
doi:10.1109/ACCESS.2019.2899326

7. Liu, Y., X. Yang, Y. Jia, and Y. J. Guo, "A low correlation and mutual coupling MIMO antenna," IEEE Access, Vol. 7, 127384-127392, 2019.
doi:10.1109/ACCESS.2019.2939270

8. Karimian, R., A. Kesavan, M. Nedil, and T. A. Denidni, "Low-mutual-coupling 60-GHz MIMO antenna system with frequency selective surface wall," IEEE Antennas Wireless Propag. Lett., Vol. 16, 373-376, 2017.
doi:10.1109/LAWP.2016.2578179

9. Qamar, Z., L. Riaz, M. Chongcheawchamnan, S. A. Khan, and M. F. Shafique, "Slot combined complementary split ring resonators for mutual coupling suppression in microstrip phased arrays," IET Microw., Antennas Propag., Vol. 8, No. 15, 1261-1267, Sep. 2014.
doi:10.1049/iet-map.2013.0541

10. Habashi, A., J. Nourinia, and C. Ghobadi, "Mutual coupling reduction between very closely spaced patch antennas using low-profile folded split-ring resonators (FSRRs)," IEEE Antennas Wireless Propag. Lett., Vol. 10, 862-865, 2011.
doi:10.1109/LAWP.2011.2165931

11. Gao, D., Z.-X. Cao, S.-D. Fu, X. Quan, and P. Chen, "A novel slot-array defected ground structure for decoupling microstrip antenna array," IEEE Trans. Antennas Propag., Vol. 68, No. 10, 7027-7038, Oct. 2020.
doi:10.1109/TAP.2020.2992881

12. Dey, S., S. Dey, and S. K. Koul, "Isolation improvement of MIMO antenna using novel EBG and hair-pin shaped DGS at 5G millimeter wave band," IEEE Access, Vol. 9, 162820-162834, 2021.
doi:10.1109/ACCESS.2021.3133324

13. Qian, B., X. Chen, and A. A. Kishk, "Decoupling of microstrip antennas with defected ground structure using the common/differential mode theory," IEEE Antennas Wireless Propag. Lett., Vol. 20, No. 5, 828-832, May 2021.
doi:10.1109/LAWP.2021.3064972

14. Govindarajulu, S. R., A. Jenkel, R. Hokayem, and E. A. Alwan, "Mutual coupling suppression in antenna arrays using meandered open stub filtering technique," IEEE Open Jrn. Antennas Propag., Vol. 1, 379-386, 2020.
doi:10.1109/OJAP.2020.3010153

15. Askarian, A., J. Yao, Z. Lu, and K. Wu, "Surface-wave control technique for mutual coupling mitigation in array antenna," IEEE Microw. Wireless Compon. Lett., Vol. 32, No. 6, 623-626, Jun. 2022.
doi:10.1109/LMWC.2021.3139196

16. Pei, T., L. Zhu, J. Wang, and W. Wu, "A low-profile decoupling structure for mutual coupling suppression in MIMO patch antenna," IEEE Trans. Antennas Propag., Vol. 69, No. 10, 6145-6153, Oct. 2021.
doi:10.1109/TAP.2021.3098565

17. Cheng, Y., X. Ding, W. Shao, and B. Wang, "Reduction of mutual coupling between patch antennas using a polarization-conversion isolator," IEEE Antennas Wireless Propag. Lett., Vol. 16, 1257-1260, 2017.
doi:10.1109/LAWP.2016.2631621

18. Farsi, S., H. Aliakbarian, D. Schreurs, B. Nauwelaers, and G. A. E. Vandenbosch, "Mutual coupling reduction between planar antennas by using a simple microstrip U-section," IEEE Antennas Wireless Propag. Lett., Vol. 11, 1501-1503, 2012.
doi:10.1109/LAWP.2012.2232274

19. Vishvaksenan, K. S., K. Mithra, R. Kalaiarasan, and K. S. Raj, "Mutual coupling reduction in microstrip patch antenna arrays using parallel coupled-line resonators," IEEE Antennas Wireless Propag. Lett., Vol. 16, 2146-2149, 2017.
doi:10.1109/LAWP.2017.2700521

20. Meng, H. and K.-L. Wu, "An LC decoupling network for two antennas working at low frequencies," IEEE Trans. Microw. Theory Tech., Vol. 65, No. 7, 2321-2329, Jul. 2017.
doi:10.1109/TMTT.2017.2658562

21. Zhang, Y. M. and S. Zhang, "A novel aperture-loaded decoupling concept for patch antenna arrays," IEEE Trans. Microw. Theory Tech., Vol. 69, No. 9, 4272-4283, Sept. 2021.
doi:10.1109/TMTT.2021.3085904

22. Lau, B. K. and J. B. Andersen, "Simple and efficient decoupling of compact arrays with parasitic scatterers," IEEE Trans. Antennas Propag., Vol. 60, No. 2, 464-472, Feb. 2012.
doi:10.1109/TAP.2011.2173440

23. Zhao, L. and K. Wu, "A decoupling technique for four-element symmetric arrays with reactively loaded dummy elements," IEEE Trans. Antennas Propag., Vol. 62, No. 8, 4416-4421, Aug. 2014.
doi:10.1109/TAP.2014.2326425

24. Zhai, G., Z. N. Chen, and X. Qing, "Mutual coupling reduction of a closely spaced four-element MIMO antenna system using discrete mushrooms," IEEE Trans. Microw. Theory Tech., Vol. 64, No. 10, 3060-3067, Oct. 2016.
doi:10.1109/TMTT.2016.2604314

25. Zaker, R. and A. Kheirdoost, "Bandwidth and isolation improvement of highly coupled printed array antenna using multiple shorting posts," IEEE Trans. Antennas Propag., Vol. 69, No. 11, 7987-7992, Nov. 2021.
doi:10.1109/TAP.2021.3076662

26. Yang, W., L. Chen, S. Pan, W. Che, and Q. Xue, "Novel decoupling method based on coupling energy cancellation and its application in 5G dual-polarized high-isolation antenna array," IEEE Trans. Antennas Propag., Vol. 70, No. 4, 2686-2697, Apr. 2022.
doi:10.1109/TAP.2021.3137170

27. Liu, N.-W., L. Zhu, Z.-X. Liu, M. Li, G. Fu, and Y. Liu, "A novel low-profile circularly polarized diversity patch antenna with extremely small spacing, reduced size, and low mutual coupling," IEEE Trans. Antennas Propag., Vol. 70, No. 1, 135-144, Jan. 2022.
doi:10.1109/TAP.2021.3111344

28. Sufian, M. A., N. Hussain, H. Askari, S. G. Park, K. S. Shin, and N. Kim, "Isolation enhancement of a metasurface-based MIMO antenna using slots and shorting pins," IEEE Access, Vol. 9, 73533-73543, 2021.
doi:10.1109/ACCESS.2021.3079965

29. Luan, H., C. Chen, W. Chen, L. Zhou, H. Zhang, and Z. Zhang, "Mutual coupling reduction of closely E/H-plane coupled antennas through metasurfaces," IEEE Antennas Wireless Propag. Lett., Vol. 18, No. 10, 1996-2000, Oct. 2019.
doi:10.1109/LAWP.2019.2936096

30. Sun, L., Y. Li, Z. Zhang, and H. Wang, "Antenna decoupling by common and differential modes cancellation," IEEE Trans. Antennas Propag., Vol. 69, No. 2, 672-682, Feb. 2021.
doi:10.1109/TAP.2020.3009427

31. Sun, L., Y. Li, and Z. Zhang, "Decoupling between extremely closely spaced patch antennas by mode cancellation method," IEEE Trans. Antennas Propag., Vol. 69, No. 6, 3074-3083, Jun. 2021.
doi:10.1109/TAP.2020.3030922

32. Lai, Q. X., Y. M. Pan, S. Y. Zheng, and W. J. Yang, "Mutual coupling reduction in MIMO microstrip patch array using TM₁₀ and TM₀₂ modes," IEEE Trans. Antennas Propag., Vol. 69, No. 11, 7562-7571, Nov. 2021.
doi:10.1109/TAP.2021.3090520

33. Radavaram, S. and M. Pour, "A wideband coplanar L-strip fed rectangular patch antenna," IEEE Antennas Wireless Propag. Lett., Vol. 20, No. 9, 1779-1783, 2021.
doi:10.1109/LAWP.2021.3096958

34. Pozar, D. M., "Microwave network analysis," Microwave Engineering, 4th Edition, Wiley, Hoboken, NJ, USA, 2012.

35., High Frequency Structure Simulator (HFSS), ANSYS, Canonsburg, PA, USA, 2022 R1.

36. Ludwig, A., "Mutual coupling, gain and directivity of an array of two identical antennas," IEEE Trans. Antennas Propag., Vol. 24, No. 6, 837-841, Nov. 1976.
doi:10.1109/TAP.1976.1141440

Dr. Sai Radavaram

Professor Maria Pour