A Broadband High Gain Tapered Slot Antenna for Underwater Communication in Microwave Band

A broadband high gain Tapered slot antenna array for under water communication is presented in this paper. The procedure to design the unit element antenna is followed by applying a linear tapered array-slot structure to the conventional Vivaldi antenna; hence the bandwidth, gain and radiation efficiency of the antenna are improved. The proposed antenna array is designed on the low-cost FR4 epoxy substrate material with value of dielectric constant εr=4.4\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varepsilon _r= 4.4$$\end{document}, and loss tangent δ=0.02\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\delta = 0.02$$\end{document}. The reduction of the feed line width and location adjustment is used to expand the impedance bandwidth of the proposed antenna. Moreover, the single antenna element is expanded to 1×2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$1\times 2$$\end{document}, 1×4\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$1\times 4$$\end{document} and 2×4\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$2\times 4$$\end{document} to form an antenna array respectively. The dimensions of the developed array antenna are satisfying the proper impedance matching. The simulated reflection coefficient results confirm that the proposed antenna array achieves an impedance bandwidth of above 55% obtained at 10 dB return loss, the peak realized gain of 10.75 dBi and radiation efficiency of more than 90%. The measured results show a good agreement and hence making the designed antenna array appropriate to work in the underwater communication band.