Abstract
The conventional tapered slot Vivaldi antenna is well known for its ultra-wide band characteristics with low directivity. To improve the directivity of the conventional Vivaldi antenna, a four-slot Vivaldi antenna (FSVA) is proposed here to operate in the frequency range of 2–11 GHz. For feeding the FSVA, a binomial three-section V-shaped even mode power divider with progressing T-junctions is also designed and tested here, which is then integrated with the antenna. The proposed antenna prototype is designed and fabricated on a 1-mm thick FR-4 substrate (ɛr=4.3, tanδ=0.025), and the return loss and radiation characteristics are investigated in the anechoic environment. The measured result shows a good agreement with the numerical simulation performed using the EM Simulator i. e. CST MWS-2015. It is found that the directivity of FSVA is approximately doubled as compared to that of the conventional Vivaldi antenna having the same dimensions. From the application point of view, the fabricated antenna is used to image various metallic objects hidden inside the sand using a vector network analyzer and associated RF components. The obtained 2D microwave images of the test media successfully show that the hidden objects can effectively be located and detected using the proposed FSVA in conjunction with a simple imaging scheme.
References
[1] P. J. Gibson, “The Vivaldi aerial,” in 9th IEEE European Microwave Conf., Brighton, UK, pp. 101–105, 1979, Sep. 17–20.10.1109/EUMA.1979.332681Search in Google Scholar
[2] M. Bhaskar, E. Johari, Z. Akhter, and M. J. Akhtar, “Design of anisotropic zero-index metamaterial loaded tapered slot Vivaldi antenna for microwave imaging,” in IEEE Antennas and Propagation Society Int. Symp. (APS-URSI), Memphis, Tennessee, pp. 1594–1595, 2014, July 6–11.10.1109/APS.2014.6905123Search in Google Scholar
[3] S. H. He, “An improved Vivaldi antenna for vehicular wireless communication systems,” IEEE Antennas Wirel. Propag. Lett., vol. 13, pp. 1505–1508, 2014.10.1109/LAWP.2014.2343215Search in Google Scholar
[4] E. W. Reid, L. O. Balbuena, A. Ghadiri, and K. Moez, “A 324-element Vivaldi antenna array for radio astronomy instrumentation,” IEEE Trans. Instrum. Meas., vol. 61, pp. 241–250, 2012.10.1109/TIM.2011.2159414Search in Google Scholar
[5] J. Shin and D. H. Schaubert, “A parameter study of stripline-fed Vivaldi notch-antenna arrays,” IEEE Trans. Antennas Propag., vol. 47, pp. 879–886, 1999.10.1109/8.774151Search in Google Scholar
[6] D. H. Schaubert, S. Kasturi, A. O. Boryssenko, and W. M. Elsallal, “Vivaldi antenna arrays for wide bandwidth and electronic scanning,” in 2nd European Conf. Antennas and Propagation (EuCAP), Edinburgh, Scotland, pp. 1–6, 2007, Nov. 11–16.10.1049/ic.2007.1334Search in Google Scholar
[7] R. Kazemi and A. E. Fathy, “16-element Vivaldi antenna array fed by a single ridge substrate integrated waveguide with over 75% bandwidth,” in IEEE MTT-S Int. Microwave Conf. (IMS), Tampa, Florida, pp. 1–4, 2014, June 1–6.10.1109/MWSYM.2014.6848385Search in Google Scholar
[8] M. Bhaskar, E. Johari, Z. Akhter, and M. J. Akhtar, “Gain enhancement of the Vivaldi antenna with band notch characteristics using zero-index metamaterial,” Microw. Opt. Technol. Lett. (MOTL), vol. 58, pp. 233–238, 2016.10.1002/mop.29534Search in Google Scholar
[9] Z. Bin and T. J. Cui, “Directivity enhancement to Vivaldi antennas using compactly anisotropic zero-index metamaterials,” IEEE Antennas Wirel. Propag. Lett., vol. 10, pp. 326–329, 2011.10.1109/LAWP.2011.2142170Search in Google Scholar
[10] P. Kumar, Z. Akhter, A. K. Jha, and M. J. Akhtar, “Directivity enhancement of double slot Vivaldi antenna using anisotropic zero-index metamaterials,” in IEEE Antennas and Propagation Society Int. Symp. (APS-URSI), Vancouver, British Columbia, Canada, pp. 2333–2334, 2015, July 19–24.10.1109/APS.2015.7305555Search in Google Scholar
[11] A. Dhouibi, S. N. Burokur, A. Lustrac, and A. Priou, “X-band metamaterial-based Luneburg lens antenna,” in IEEE Int. Symp. Antennas and Propagation Society (APS-URSI), Orlando, Florida, 2013, July 7–13.10.1109/APS.2013.6711306Search in Google Scholar
[12] A. Elsherbiniet, C. Zhang, S. Lin, M. Kuhn, A. Kamel, A. E. Fathy, and H. Elhennawy. “UWB antipodal Vivaldi antennas with protruded dielectric rods for higher gain, symmetric patterns and minimal phase center variations,” in IEEE Int. Symp. Antennas and Propagation Society (APS-URSI), Honolulu, Hawaii, pp. 1973–1976, 2007, June 9–15.10.1109/APS.2007.4395909Search in Google Scholar
[13] A. M. Oliveira De, M. B. Perotoni, S. T. Kofuji, and J. F. Justo, “A palm tree antipodal Vivaldi antenna with exponential slot edge for improved radiation pattern,” IEEE Antennas Wirel. Propag. Lett., vol. 14, pp. 1334–1337, 2015.10.1109/LAWP.2015.2404875Search in Google Scholar
[14] Y. W. Wang, G. M. Wang, and B. F. Zong, “Directivity improvement of Vivaldi antenna using double-slot structure,” IEEE Antennas Wirel. Propag. Lett., vol. 12, pp. 1380–1383, 2013.10.1109/LAWP.2013.2285182Search in Google Scholar
[15] K. S. Yngvesson, T. L. Korzeniowski, Y. S. Kim, E. L. Kollberg, and J. F. Johansson, “The tapered slot antenna-A new integrated element for millimeter-wave applications,” IEEE Trans. Microwave Theory Tech., vol. 37, pp. 365–374, 1984.10.1109/22.20062Search in Google Scholar
[16] E. Gazit, “Improved design of the Vivaldi antenna,” Proc. Inst. Elect. Eng., vol. 135, pp. 89–92, 1988.10.1049/ip-h-2.1988.0020Search in Google Scholar
[17] D. H. Schaubert, J. A. Aas, M. E. Cooley, and N. E. Buris, “Moment method analysis of infinite stripline-fed tapered slot antenna arrays with a ground plane,” IEEE Trans. Antennas Propag., vol. 42, pp. 1161–1166, 1994.10.1109/8.310008Search in Google Scholar
[18] M. J. Povinelli, “Experimental design and performance of end-fire and conformal flared slot (notch) antennas and application to phased arrays: an overview of development,” in Proc. Antenna Application Symp., Allerton Park/Monticello, Illinois, 1988.Search in Google Scholar
[19] R. M. Barret, “Microwave printed circuits-a historical survey,” IRE Trans. Microwave Theory Tech., vol. 3, pp. 1–9, 1955.10.1109/TMTT.1955.1124910Search in Google Scholar
[20] A. Sardi, J. Zbitou, A. Errkik, L. E. Abdellaoui, A. Tajmouati, and M. Latrach, “A novel design of a low cost wideband Wilkinson power divider,” Int. J. Electr. Comput. Energetic Electron. Commun. Eng., vol. 9, pp. 68–71, 2015.Search in Google Scholar
[21] D. M. Pozar, Microwave Engineering, 3rd ed. New Delhi: John Wiley & Sons, 2008.Search in Google Scholar
[22] Z. Akhter and M. J. Akhtar, “Time domain microwave technique for dielectric imaging of multi-layered media,” J. Electromagn. Waves App., vol. 29, pp. 386–401, 2015.10.1080/09205071.2014.997840Search in Google Scholar
[23] Z. Akhter, B. N. Abhijith, and M. J. Akhtar, “Hemisphere lens-loaded Vivaldi antenna for time domain microwave imaging of concealed objects,” J. Electromagn. Waves App., vol. 30, pp. 1183–1197, 2016.10.1080/09205071.2016.1186574Search in Google Scholar
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