volume | PIER Journals

Abstract

This paper presents a compact printed ultra-wideband (UWB) monopole antenna employing a coupling structure and a short stub for broadband impedance matching and antenna miniaturization. The proposed antenna is fabricated on an FR-4 substrate with dimensions of 24 × 14 × 1.6 mm³ and fully covers the FCC-defined UWB from 3.1 to 10.6 GHz, achieving a VSWR of ≤ 2. The coupling structure introduces additional capacitive loading, while the short stub provides effective inductive compensation. This enables stable, broadband operation despite significant size reduction. Experimental results demonstrate quasi-omnidirectional radiation characteristics over the entire operating band. In addition to frequency-domain evaluation, time-domain performance is investigated using two identical antennas arranged in face-to-face and side-by-side configurations. The measured correlation coefficients exceed 0.94 in both configurations, and the group delay remains nearly constant at approximately 0.3 ns across the UWB. This indicates high waveform fidelity. These results confirm that the proposed antenna is well-suited for compact UWB communication systems requiring both broadband and time-domain stability.

1. Xu, Huilin and Liuqing Yang, "Ultra-wideband technology: Yesterday, today, and tomorrow," 2008 IEEE Radio and Wireless Symposium, 715-718, Orlando, FL, USA, 2008.
doi:10.1109/RWS.2008.4463592

2. Win, Moe Z., Davide Dardari, Andreas F. Molisch, Werner Wiesbeck, and Jinyun Zhang, "History and applications of UWB," Proceedings of the IEEE, Vol. 97, No. 2, 198-204, Feb. 2009.
doi:10.1109/JPROC.2008.2008762 Google Scholar

3. Pyndiah, Ramesh, "An overview of UWB technology," 2006 IET Seminar on Practical Applications for Wireless Networks, 65-80, Paris, France, 2006.

4. Kiminami, K., Hirata, and Shiozawa, "Double-sided printed bow-tie antenna for UWB communications," IEEE Antennas and Wireless Propagation Letters, Vol. 3, 152-153, 2004.
doi:10.1109/lawp.2004.832126 Google Scholar

5. Liang, Jianxin, C. C. Chiau, Xiaodong Chen, and C. G. Parini, "Study of a printed circular disc monopole antenna for UWB systems," IEEE Transactions on Antennas and Propagation, Vol. 53, No. 11, 3500-3504, Nov. 2005.
doi:10.1109/tap.2005.858598 Google Scholar

6. Agrawall, N. P., G. Kumar, and K. P. Ray, "Wide-band planar monopole antennas," IEEE Transactions on Antennas and Propagation, Vol. 46, No. 2, 294-295, Feb. 1998.
doi:10.1109/8.660976 Google Scholar

7. Evans, J. A. and M. J. Amunann, "Planar trapezoidal and pentagonal monopoles with impedance bandwidths in excess of 10:1," IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010), Vol. 3, 1558-1561, Orlando, FL, USA, Jul. 1999.
doi:10.1109/APS.1999.788241

8. Taniguchi, T. and T. Kobayashi, "An omnidirectional and low-VSWR antenna for the FCC-approved UWB frequency band," IEEE Antennas and Propagation Society International Symposium. Digest. Held in conjunction with: USNC/CNC/URSI North American Radio Sci. Meeting (Cat. No.03CH37450), Vol. 3, 460-463, Columbus, OH, USA, Jun. 2003.
doi:10.1109/APS.2003.1219885

9. Su, Saou-Wen, Kin-Lu Wong, and Chia-Lun Tang, "Ultra-wideband square planar monopole antenna for IEEE 802.16a operation in the 2-11-GHz band," Microwave and Optical Technology Letters, Vol. 42, No. 6, 463-466, Jul. 2004.
doi:10.1002/mop.20337 Google Scholar

10. Antonino-Daviu, E., M. Cabedo-Fabrés, M. Ferrando-Bataller, and A. Valero-Nogueira, "Wideband double-fed planar monopole antennas," Electronics Letters, Vol. 39, No. 23, 1635-1636, Nov. 2003.
doi:10.1049/el:20031087 Google Scholar

11. Wong, Kin-Lu, Chih-Hsien Wu, and Saou-Wen Su, "Ultrawide-band square planar metal-plate monopole antenna with a trident-shaped feeding strip," IEEE Transactions on Antennas and Propagation, Vol. 53, No. 4, 1262-1269, Apr. 2005.
doi:10.1109/tap.2005.844430 Google Scholar

12. Srifi, Mohamed Nabil, Symon K. Podilchak, Mohamed Essaaidi, and Yahia M. M. Antar, "Planar circular disc monopole antennas using compact impedance matching networks for ultra-wideband (UWB) applications," 2009 Asia Pacific Microwave Conference, 782-785, Singapore, Dec. 2009.
doi:10.1109/APMC.2009.5384265

13. Koshiji, Fukuro, Shunsuke Itaya, Yusuke Akiyama, and Kohji Koshiji, "Proposal and investigation of miniaturizing unbalanced dipole antenna for ultra wideband radio," Journal of the Japan Institute of Electronics Packaging, Vol. 15, No. 7, 526-533, 2012.
doi:10.5104/jiep.15.526 Google Scholar

14. Abbosh, A. M., "Miniaturization of planar ultrawideband antenna via corrugation," IEEE Antennas and Wireless Propagation Letters, Vol. 7, 685-688, 2008.
doi:10.1109/lawp.2008.2009323 Google Scholar

15. Sadat, S., M. Fardis, F. Geran, G. Dadashzadeh, N. Hojjat, and M. Roshandel, "A compact microstrip square-ring slot antenna for UWB applications," 2006 IEEE Antennas and Propagation Society International Symposium, 4629-4632, Albuquerque, NM, USA, Jul. 2006.
doi:10.1109/APS.2006.1711670

16. Azim, Rezaul, Mohammad Tariqul Islam, and Norbahiah Misran, "Compact tapered-shape slot antenna for UWB applications," IEEE Antennas and Wireless Propagation Letters, Vol. 10, 1190-1193, Oct. 2011.
doi:10.1109/lawp.2011.2172181 Google Scholar

17. Chen, Dong and Chong-Hu Cheng, "A novel compact ultra-wideband (UWB) wide slot antenna with via holes," Progress In Electromagnetics Research, Vol. 94, 343-349, 2009.
doi:10.2528/pier09062306 Google Scholar

18. Nikolaou, Symeon and Muhammad Ali Babar Abbasi, "Miniaturization of UWB antennas on organic material," International Journal of Antennas and Propagation, Vol. 2016, No. 1, 5949254, 2016.
doi:10.1155/2016/5949254 Google Scholar

19. Kempanna, Subhash Bodaguru, Rajashekhar C. Biradar, Tanweer Ali, Vikash Kumar Jhunjhunwala, Sarun Soman, and Sameena Pathan, "A compact slotted UWB antenna based on characteristics mode theory for wireless applications," Designs, Vol. 7, No. 6, 141, Dec. 2023.
doi:10.3390/designs7060141 Google Scholar

20. Park, Seungyong and Kyung-Young Jung, "Novel compact UWB planar monopole antenna using a ribbon-shaped slot," IEEE Access, Vol. 10, 61951-61959, Jun. 2022.
doi:10.1109/access.2022.3182443 Google Scholar

21. Lin, Han, Zhongyuan Lu, Zhonggen Wang, and Weidong Mu, "A compact UWB monopole antenna with triple band notches," Micromachines, Vol. 14, No. 3, 518, 2023.
doi:10.3390/mi14030518 Google Scholar

22. Heo, Hyuk, Myeong-Jun Kang, Seoungyong Park, Jisu Lee, Longyue Qu, and Kyung-Young Jung, "Design of a UWB circularly-polarized planar monopole antenna using characteristic mode analysis," Scientific Reports, Vol. 14, No. 1, 26236, 2024.
doi:10.1038/s41598-024-78131-w Google Scholar

23. Tsegaye, Assefa, Xian-Qi Lin, Hao Liu, and Hassan Sani Abubakar, "A compact monopole wideband antenna based on DGS," Electronics, Vol. 14, No. 12, 2311, 2025.
doi:10.3390/electronics14122311 Google Scholar

24. Xiang, Zhen, Zhonggen Wang, Chenlu Li, and Rui You, "Design of UWB monopole antenna with ring structure based on characteristic mode theory," Progress In Electromagnetics Research C, Vol. 158, 225-234, 2025.
doi:10.2528/PIERC25060317 Google Scholar

25. Jansri, Chalee, Chuwong Phongcharoenpanich, and Suthasinee Lamultree, "A printed circular monopole antenna with slot and modified ground plane for UWB applications," 2018 15th International Conference on Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology (ECTI-CON), 564-567, Chiang Rai, Thailand, 2018.
doi:10.1109/ECTICon.2018.8620058

26. Anveshkumar, N. and A. S. Gandhi, "Design and performance analysis of a modified circular planar monopole UWB antenna," 2017 8th International Conference on Computing, Communication and Networking Technologies (ICCCNT), 1-5, Delhi, India, 2017.
doi:10.1109/ICCCNT.2017.8203970

27. Guo, Qianqian, Jingwei Zhang, Yuchao Wang, and Chaoyun Song, "Investigation of graphene film-based circular monopole antenna for UWB applications," 2019 Computing, Communications and IoT Applications (ComComAp), 361-364, Shenzhen, China, 2019.
doi:10.1109/ComComAp46287.2019.9018834

28. Takemura, Nobuyasu and Syunta Ichikawa, "Broadbanding of printed bell-shaped monopole antenna by using short stub for UWB applications," Progress In Electromagnetics Research C, Vol. 78, 57-67, 2017.
doi:10.2528/pierc17060702 Google Scholar

29. Takemura, Nobuyasu, "Design and experimental evaluation of a compact half-shaped printed-monopole antenna with short stub for UWB systems," Progress In Electromagnetics Research C, Vol. 165, 1-10, 2026.
doi:10.2528/pierc25102603 Google Scholar

30. Takemura, Nobuyasu, "Design and experimental evaluation of a miniaturized printed UWB monopole antenna employing a coupling and stub structure," 2026 IEEE International Workshop on Antenna Technology (iWAT), 1-2, Liverpool, United Kingdom, Mar. 2026.
doi:10.1109/iWAT66946.2026.11501889

31. Pele, I., A. Chousseaud, and S. Toutain, "Simultaneous modeling of impedance and radiation pattern antenna for UWB pulse modulation," 2004 IEEE Antennas and Propagation Society Symposium, Vol. 2, 1871-1874, Monterey, CA, USA, Jun. 2004.
doi:10.1109/APS.2004.1330566

Prof. Nobuyasu Takemura