The design of broadband omnidirectional horizontally polarized dipole antennas with branch lines

Abstract

In this article, a broadband omnidirectional horizontally polarized dipole antenna with branch lines is proposed. The proposed antenna consists of a dipole element with T‐shaped branch lines arranged in a circle in four directions on one microstrip substrate; power is supplied through an integrated balun. To check the broadband characteristics of this antenna, its radiation characteristics were examined while changing the width of the feed line, the distance between the dipole antenna and the branch line, the length of the branch line, and the distance between branch lines. As a result, the return loss in a structure with no branch line was −10 dB or less in the 16% band of 1.7–2 GHz, but in the structure with branch lines, it was −15 dB or less in the 38% band of the PCS/IMT/WLAN (1.7–2.5 GHz), which is broader by about 500 MHz than in a conventional antenna. The gain of the proposed antenna was atleast 1 dBi in the band used. The proposed antenna has a thin profile, as it consists of a single substrate. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2901–2905, 2015

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“…The antenna gain is enhanced by a thicker air-layer substrate and the ratio (P. L. Teng, C. L. Tang, and K. L. Wong 2001), ( Zhang, P.-F., S.-Z. Liu, and S. Zhao, 2015) and (Park, J.-S. and H.-K. Choi, 2015). The right-hand Circular Polarized operation is generated for the antenna geometry shown in figure 3.…”

A broadband horizontally polarised omnidirectional antenna with stable radiation patterns

“…In the existing literatures, varieties of HPOAs have been proposed for wireless communication system. Such as classical Alford antenna in [5] and its modified type in [6], Square loop antennas composed of four printed dipoles in [7, 8], circular loop antennas composed of printed dipoles in [9, 10], and circular loop antenna designed by using tightly coupling method in [11]. Conventional Alford and modified Alford antennas are proposed in [5, 6].…”

“…Their rotationally non‐uniform current flows are difficult to achieve a uniform omnidirectional radiation patterns in the azimuth plane, and their bandwidths are only about 25%. To achieve uniform radiation pattern in the azimuth plane, a series of new types of HPOA are introduced in [7–10]. In [7], the horizontally polarised antenna achieves an impedance of 31%.…”

“…To achieve uniform radiation pattern in the azimuth plane, a series of new types of HPOA are introduced in [7–10]. In [7], the horizontally polarised antenna achieves an impedance of 31%. The impedance bandwidths of the antennas in [8, 9] are about 45%, but they are not wide enough for most wireless communication systems.…”

A Simple Dual-Wideband Magneto-Electric Dipole Directional Antenna

“…Hence these antennas should operate in 0.806 ∼ 0.96 GHz and 1.71 ∼ 2.69 GHz bands, and display omnidirectional or directional radiation performance for practical application consideration. Recently, various wide bandwidth omnidirectional antennas have been proposed in [1][2][3][4][5]. The literatures about dual-wideband directional antennas are relatively few.…”