Compact High Gain Omnidirectional Horizontally Polarized Antenna Array Utilizing an Aperture With Uniform Field Distribution

Abstract

A compact high gain omnidirectional horizontally polarized (OHP) antenna array is proposed in this communication. The theoretical calculations prove that a slender aperture with uniform field distribution can achieve OHP radiation with high directivity. The rectangular patch antenna operating in TM10 mode is employed to obtain an element with the specific field distribution. To extend the electrical length of the aperture, the element is elongated, and four collinear elements are integrated as an array without any redundant structures. Benefitted from the reasonable electric field distribution and concise configuration, the aperture efficiency is significantly improved. Therefore, the proposed antenna can achieve high gain OHP radiation in a compact size. The overall dimension of the antenna array is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4.62\lambda \times 0.22\lambda \times 0.07\lambda $ </tex-math></inline-formula> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula> is the free space wavelength at the center frequency). Measured results verify that the impedance bandwidth of the array covers 5.46–6.13 GHz with a relative bandwidth of 11.6%, a maximum realized gain of 11 dBi, and good omnidirectional characteristics with a gain variation of less than 3 dB in the entire operating bandwidth.