Wideband Horizontally Polarized Omnidirectional Antenna With a Conical Beam for Millimeter-Wave Applications

Abstract

A wideband millimeter-wave (MMW) horizontally polarized omnidirectional antenna with a conical beam is proposed in this paper. The proposed antenna is composed of a radiating circular loop, six arc strips, a one-to-six radial waveguide power divider, and a conical reflector. The radiating circular loop consists of six arc dipoles with curved terminals. The wideband six-way radial waveguide power divider is employed to feed the six arc dipoles, and the wideband performance is achieved by combing the TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">010</sub> mode and the TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">020</sub> mode of the circular cavity. Six arc strips are utilized as directors to improve the omnidirectional performance at the higher frequency band. The conical reflector is designed to improve the radiation gain and obtain a conical beam in the vertical plane without affecting the horizontal plane omnidirectional performance. A prototype is fabricated and measured. The simulation and measured results show that the proposed antenna can achieve a −10 dB impedance bandwidth of 22.9% with stable radiation patterns in the band of 39–49.3 GHz. Owing to the attractive wide bandwidth, good omnidirectional performance, and ease of fabrication, the proposed antenna is a good choice for the forthcoming fifth generation MMW wireless communication systems, especially for the indoor ceiling antenna networking applications.