volume | PIER Journals

Abstract

The proposed symmetric quad circular radiator antenna with a semicircular etched-slot DGS was designed and fabricated on an FR4 substrate of size 50 × 50 × 1.6 mm³. The antenna provides impedance bandwidths of 2.24-2.94 GHz, 3.84-3.98 GHz, and 4.92-5.06 GHz, with resonant frequencies observed at 2.44 GHz (-40.3 dB), 2.86 GHz (-17.9 dB), 3.92 GHz (-14.9 dB), and 4.98 GHz (-10.6 dB). These operating bands make the antenna suitable for WLAN, ISM, and other sub-6 GHz wireless communication systems. The antenna also achieves a realized gain above 5 dB at the operating frequencies, indicating stable radiation characteristics. The diversity performance was evaluated using standard metrics. The ECC remains below 0.5, which lies within the acceptable range for diversity operation. In addition, the diversity gain varies between 9.88 and 10.02 dB, while the channel capacity loss stays below 0.6 bits/s/Hz across the frequency range. A compact symmetric quad circular radiator antenna incorporating a three-segment semi-circular bridge along with a semicircular etched-slot mdefected ground structure (DGS) is presented for multi-band wireless communication applications. These results confirm that the proposed antenna provides reliable radiation and diversity performance for practical wireless communication applications.

1. Rekha, S. and G. Shine Let, "Design and SAR analysis of wearable UWB MIMO antenna with enhanced isolation using a parasitic structure," Iranian Journal of Science and Technology, Transactions of Electrical Engineering, Vol. 46, No. 2, 291-301, 2022.
doi:10.1007/s40998-022-00482-9 Google Scholar

2. Yin, Wenfei, Shaoxiang Chen, Junjie Chang, Chunhua Li, and Salam K. Khamas, "CPW fed compact UWB 4-element MIMO antenna with high isolation," Sensors, Vol. 21, No. 8, 2688, 2021.
doi:10.3390/s21082688 Google Scholar

3. Potti, Devisowjanya, Yarasi Tusharika, Mohammed Gulam Nabi Alsath, Savarimuthu Kirubaveni, Malathi Kanagasabai, Radha Sankararajan, Santosh Narendhiran, and P. Balaji Bhargav, "A novel optically transparent UWB antenna for automotive MIMO communications," IEEE Transactions on Antennas and Propagation, Vol. 69, No. 7, 3821-3828, 2021.
doi:10.1109/tap.2020.3044383 Google Scholar

4. Khan, Aqeel Ahmed, Syed Aftab Naqvi, Muhammad Saeed Khan, and Bilal Ijaz, "Quad port miniaturized MIMO antenna for UWB 11 GHz and 13 GHz frequency bands," AEU --- International Journal of Electronics and Communications, Vol. 131, 153618, 2021.
doi:10.1016/j.aeue.2021.153618 Google Scholar

5. Upadhyaya, Trushit, Vishal Sorathiya, Samah Al-Shathri, Walid El-Shafai, Upesh Patel, Killol Vishnuprasad Pandya, and Ammar Armghan, "Quad-port MIMO antenna with high isolation characteristics for sub 6-GHz 5G NR communication," Scientific Reports, Vol. 13, No. 1, 19088, 2023.
doi:10.1038/s41598-023-46413-4 Google Scholar

6. Khan, Ijaz, Xiaozhi Qi, Yizhi Shao, Kuang Zhang, Chaoyun Song, Mian Muhammad Kamal, and Qun Wu, "Hybrid technique-based circularly polarized MIMO antenna with low mutual coupling for millimeter-wave communications," Optics Express, Vol. 33, No. 8, 17782-17801, 2025.
doi:10.1364/oe.554905 Google Scholar

7. Althuwayb, Ayman A., "Low-interacted multiple antenna systems based on metasurface-inspired isolation approach for MIMO applications," Arabian Journal for Science and Engineering, Vol. 47, No. 3, 2629-2638, 2022.
doi:10.1007/s13369-021-05720-6 Google Scholar

8. Raza, Muhammad Usman, Kai Zhang, Zenebe Melesew Yetneberk, and Sen Yan, "Four-port circularly polarized antenna array with enhanced isolation and polarization conversion using metasurface for 5G communications," Optics Express, Vol. 32, No. 25, 45315-45329, 2024.
doi:10.1364/oe.543723 Google Scholar

9. Lee, Jaehyun, Hogyeom Kim, and Jungsuek Oh, "Large-aperture metamaterial lens antenna for multi-layer MIMO transmission for 6G," IEEE Access, Vol. 10, 20486-20495, 2022.
doi:10.1109/access.2022.3150037 Google Scholar

10. Yousef, Basma M., Allam M. Ameen, Arpan Desai, Heng-Tung Hsu, Vigneswaran Dhasarathan, and Ahmed A. Ibrahim, "Defected ground structure-based wideband circularly polarized 4-port MIMO antenna for future Wi-Fi 6E applications," AEU --- International Journal of Electronics and Communications, Vol. 170, 154815, 2023.
doi:10.1016/j.aeue.2023.154815 Google Scholar

11. Tiwari, Rakesh N., Ragannagari Thirumalaiah, Vykuntam Rakesh Naidu, Golla Sreenivasulu, Prabhakar Singh, and S. Rajasekaran, "Compact dual band 4-port MIMO antenna for 5G sub-6 GHz/N38/N41/N90 and WLAN frequency bands," AEU --- International Journal of Electronics and Communications, Vol. 171, 154919, 2023.
doi:10.1016/j.aeue.2023.154919 Google Scholar

12. Tulum, Mehmet Akif, Ahmet Serdar Turk, and Peyman Mahouti, "Data driven surrogate modeling of phase array antennas using deep learning for millimetric band applications," IEEE Access, Vol. 11, 114415-114423, 2023.
doi:10.1109/access.2023.3324733 Google Scholar

13. Zahid, Muhammad, Qammar Ali, Nirman Bhowmike, Devi Prasanth Bolla, Sultan Shoaib, and Yasar Amin, "Dual-band MIMO antenna for n79 and sub-7 GHz smartphone applications," Electronics, Vol. 13, No. 14, 2724, 2024.
doi:10.3390/electronics13142724 Google Scholar

14. Hu, Kexin, Yi Zhou, Suresh K. Sitaraman, and Manos M. Tentzeris, "Additively manufactured flexible on-package phased array antennas for 5G/mmWave wearable and conformal digital twin and massive MIMO applications," Scientific Reports, Vol. 13, No. 1, 12515, 2023.
doi:10.1038/s41598-023-39476-w Google Scholar

15. Desai, Arpan, Trushit Upadhyaya, Merih Palandoken, and Cem Gocen, "Dual band transparent antenna for wireless MIMO system applications," Microwave and Optical Technology Letters, Vol. 61, No. 7, 1845-1856, 2019.
doi:10.1002/mop.31825 Google Scholar

16. Khan, Shahid, Safdar Nawaz Khan Marwat, Muhammad Amir Khan, Salman Ahmed, Neelam Gohar, Mohammad Ehsanul Alim, Abeer D. Algarni, and Hela Elmannai, "A self-decoupling technique to realize dense packing of antenna elements in MIMO arrays for wideband sub-6 GHz communication systems," Sensors, Vol. 23, No. 2, 654, 2023.
doi:10.3390/s23020654 Google Scholar

17. Fang, Yixiang, Yongtao Jia, Jia-Qi Zhu, Ying Liu, and Jiadai An, "Self-decoupling, shared-aperture, eight-antenna MIMO array with MIMO-SAR reduction," IEEE Transactions on Antennas and Propagation, Vol. 72, No. 2, 1905-1910, 2024.
doi:10.1109/tap.2023.3339223 Google Scholar

18. Kulkarni, Neeta, Rajin M. Linus, and Nilesh Bhaskarrao Bahadure, "A small wideband inverted L-shaped flexible antenna for sub-6 GHz 5G applications," AEU --- International Journal of Electronics and Communications, Vol. 159, 154479, 2023.
doi:10.1016/j.aeue.2022.154479 Google Scholar

19. Ameen, Allam M., Mohamed I. Ahmed, Hala Elsadek, and Wagdy R. Anis, "Design of 4-direction MIMO Vivaldi antenna system for vehicles communication in 5G applications," Journal of Electromagnetic Waves and Applications, Vol. 36, No. 14, 2027-2040, 2022.
doi:10.1080/09205071.2022.2054046 Google Scholar

20. Babu, K. Vasu, Pasumarthi Srinivasa Rao, B. Chandrababu Naik, and B. Ravi Kumar, "Compact dual-band design and analysis of half-circular U-shape MIMO radiator for wireless applications," Microsystem Technologies, Vol. 29, No. 4, 501-514, 2023.
doi:10.1007/s00542-022-05359-9 Google Scholar

21. Menath, Anagha, Vijay Kumar, Avinash Chandra, and Rajkishor Kumar, "Multi band miniaturized 2 × 2 MIMO antenna for sub-6-GHz applications," IEEE Access, Vol. 14, 13948-13956, 2026.
doi:10.1109/access.2026.3656660 Google Scholar

22. Hemalatha, T. and Bappadittya Roy, "Low-profile CO-CSRR and EBG loaded tri-quarter circular patch EWB MIMO antenna with multiple notch bands," IEEE Open Journal of Antennas and Propagation, Vol. 5, No. 3, 634-643, 2024.
doi:10.1109/ojap.2024.3377695 Google Scholar

23. Das, Gouree Shankar, Bijay Bikash Chamuah, Yatish Beria, Partha Protim Kalita, and Akash Buragohain, "Compact four elements sub-6 GHz MIMO antenna for 5G applications," Materials Today: Proceedings, 2023.
doi:10.1016/j.matpr.2023.06.344 Google Scholar

24. Ramal, Purushothaman Janaki, Syed Nawab Syed Althaf, Kannan Vishnulakshmi, Palaniselvan Sundaravadivel, and Rajeshkumar Dhandapani, "A compact wide-band circular slot quad-port MIMO antenna for 5G wireless applications," Progress In Electromagnetics Research Letters, Vol. 120, 65-71, 2024.
doi:10.2528/pierl24040301 Google Scholar

25. Kolte, Jyoti C., Ashwini Kumar, and Payal Bansal, "Designing MIMO antenna with high isolation decoupling structure," Progress In Electromagnetics Research B, Vol. 113, 37-50, 2025.
doi:10.2528/pierb25040102 Google Scholar

Dr. Prasanth Kumar Jujjarapu

Dr. Nallamothu Suneetha

Dr. Padavala Akhendra Kumar

Dr. Akondi Narayana Kiran

Dr. Bokkisam Venkata Sai Sailaja