A novel flexible printed monopole antenna with a windmill-shaped fractal design, which is fed by co-planar waveguide (CPW) is presented in this manuscript for ultra-wideband (UWB) applications. By integrating a modified windmill-shape fractal into the conventional irregular hexagonal-patch, the antenna achieves a significantly wider impedance bandwidth extending up to 156.6% across the frequency band of 1.37-11.25 GHz. Additionally, increasing the number of the windmill-shaped fractals leads to the emergence of further resonances. The overall dimensions of the designed antenna are 50 × 70 × 0.2 mm3, and it boasts an impressive bandwidth-dimension ratio (BDR) of 4457, showcasing exceptional efficiency in utilizing its compact size. The maximum gain reaches 4.8 dBi, while the radiation efficiency attains an impressive 98%. The modified windmill-shape fractal antenna design leverages the multifractal concept, providing monopole antennas with enhanced flexibility in controlling resonances and bandwidth. This manuscript offers a comprehensive presentation and discussion of the process used to improve the impedance bandwidth, shedding light on the antenna's exceptional performance and capabilities.
2. Sharma, N. and S. S. Bhatia, "Stubs and slits loaded partial ground plane inspired novel hexagonal ring-shaped fractal antenna for 5G/LTE/RFID/GSM/Bluetooth/WLAN/WiMAX wireless applications: Design and measurement," Progress In Electromagnetics Research C, Vol. 112, 99-111, 2021.
3. Ouf, E. G. E., M. A. E. Abo-Elhassan, A. E. Farahat, K. F. A. Hussein, and S. Mohassieb, "High performance two-arm antenna for super wideband operation," Progress In Electromagnetics Research C, Vol. 125, 105-115, 2022.
4. Mandelbrot, B. B., Fractals: Form, Chance and Dimension, W. H. Freeman, 1977, ISBN 0-7167-0473-0.
5. Anguera, J., A. And´ujar, J. Jayasinghe, V. V. S. S. S. Chakravarthy, P. S. R. Chowdary, J. L. Pijoan, T. Ali, and C. Cattani, "Fractal antennas: An historical perspective," Fractal and Fract., Vol. 4, 3, 2020.
6. Marzouk, M., Y. Rhazi, I. H. Nejdi, F.-E. Zerrad, M. Saih, S. Ahmad, A. Ghaffar, and M. Hussein, "Ultra-wideband compact fractal antenna for WiMAX, WLAN, C and X band applications," Sensors, Vol. 23, 4254, 2023.
7. Khan, M. A., U. Rafique, H. S¸. Savci, A. N. Nordin, S. H. Kiani, and S. M. Abbas, "Ultrawideband pentagonal fractal antenna with stable radiation characteristics for microwave imaging applications," Electronics, Vol. 11, 2061, 2022.
8. Saleem, I., U. Rafique, S. Agarwal, H. S. Savci, S. M. Abbas, and S. Mukhopadhyay, "Ultrawideband fractal ring antenna for biomedical applications," International Journal of Antennas and Propagation, Vol. 2023, Article ID 5515263, 9 pages, 2023.
9. Kaur, N., J. Singh, and M. Kumar, "Hexagonal ring-shaped dual band antenna using staircase fractal geometry for wireless applications," Wireless Pers. Commun., Vol. 113, 2067-2078, 2020.
10. Reha, A., A. El Amri, O. Benhmammouch, A. O. Said, A. El Ouadih, and M. Bouchouirbat, "CPW-fed H-tree fractal antenna for WLAN, WIMAX, RFID, C-band, HiperLAN, and UWB applications," Int. J. Microw. Wirel. Technol., Vol. 8, 327-334, 2016.
11. Daniel, R. S. and R. Selvaraj, "A low-profile split ring monopole antenna loaded with hexagonal split ring resonator for RFID applications," Progress In Electromagnetics Research M, Vol. 92, 169-179, 2020.
12. Regulagadda, N. R. and U. V. R. Kumari, "A multiband flexible wideband CPW wearable slot antenna for biomedical and IoT applications," Progress In Electromagnetics Research C, Vol. 135, 131-144, 2023.
13. Amsaveni, A. and M. Bharathi, "Design and implementation of H-shaped fractal antenna for UWB applications," 2021 International Conference on Advancements in Electrical, Electronics, Communication, Computing and Automation (ICAECA), 1-5, Coimbatore, India, 2021.
14. Muthu, R. C. and R. B. Rani, "Asymmetric CPW-fed hexagonal monopole antenna with Boomerang-shaped fractals for ultra-wideband applications," Frequenz, Vol. 76, No. 9–10, 555-568, 2022.
15. Sediq, H. T., J. Nourinia, C. Ghobadi, and B. Mohammadi, "A novel shaped ultrawideband fractal antenna for medical purposes," Biomedical Signal Processing and Control, Vol. 80, Part 2, 2023.
16. Sun, Y., T. I. Yuk, and S. W. Cheung, "Design of a textile ultra-wideband antenna with stable performance for body-centric wireless communications," IET Microw. Antennas Propag., Vol. 8, 1363, 2014.
17. Zou, Q. and S. Jiang, "A compact flexible fractal ultra-wideband antenna with band notch characteristic," Microwave and Optical Technology Letters, Vol. 63, No. 3, 895-901, 2021.
18. Awan, W. A., N. Hussain, and T. T. Le, "Ultra-thin flexible fractal antenna for 2.45 GHz application with wideband harmonic rejection," AEU — International Journal of Electronics and Communications, Vol. 110, 2019.
19. Fahmy, W. M., A. E. Farahat, K. F. A. Hussein, and A. A. Ammar, "High Q-factor bandstop filter based on CPW resonator broadside-coupled to CPW through-line," Progress In Electromagnetics Research B, Vol. 86, 121-138, 2020.
20. Fahmy, W. M., A. E. Farahat, K. F. A. Hussein, and A. A. Ammar, Dual-band bandpass filter optimized for high Q-factor,” Appl. Comput. Electromagn. Soc. J. (ACES), Vol. 36, 398-410, 2021.