Compact Vertically Polarized Omnidirectional Ultra-Wideband Antenna and its Band-Notched Filtering Application

Yaohui Zhang,Yonghong Zhang,Zhongqian Niu,Yong Fan,Daotong Li

doi:10.1109/access.2019.2930620

Yaohui Zhang, Yonghong Zhang + Show 3 more

Open Access

https://doi.org/10.1109/access.2019.2930620

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Abstract

This paper first proposes a 3D printed, compact, low-profile, ultra-wideband (UWB) antenna with vertically polarized omnidirectional radiation characteristics. The antenna is composed of one triangular feeding structure, one triangular shorted structure, a common capacitive top hat, and two parasitic metallic pins. Compared with traditional UWB antennas with symmetrical configuration, the proposed UWB antenna is a three-dimensional version of inverted “F”with asymmetrical structure. The proposed antenna can realize compact aperture and low profile (0.19λ L × 0.19λ L × 0.06λ L , where λ L is the free-space wavelength of the lowest operating frequency). Two parasitic pins are utilized to enhance the omnidirectionality of the antenna in the azimuth plane. The impedance bandwidth is greater than 10:1 (2.96-30 GHz) for VSWR <; 3, and the bandwidth with horizontal radiation pattern ripple better than ±5 dB is more than 4.9:1 (2.96-14.5 GHz). Second, this UWB design is modified to realize dual bands with a deep band-notch by adding a split gap inside the antenna. The proposed band-notched antenna is designed with the bandwidth of 2.4-2.5 and 5-10 GHz for VSWR <; 2 with good horizontal radiation pattern omnidirectionality, which can be used for 2.4/5 GHz WLAN applications. The prototypes of the proposed UWB and band-notched antennas are fabricated by metallic 3D printing, and the simulated and measured results meet well.

Highlights

Because the ultra-wideband (UWB) antennas can radiate efficiently over large frequency bands and demonstrate consistent radiation characteristics in the whole operating frequency band, they have been applied in various fields, such as the wireless communications, sensing, radar systems and microwave imaging
We firstly propose a 3D printed, compact, low-profile, UWB antenna with monopole-like radiation characteristics
Without changing other parameter values, the proposed band-notched antenna can realize the bandwidth of 2.4-2.5 and 5-10 GHz for VSWR < 2 with good omnidirectional performance, which can be used for 2.4/5 GHz WLAN applications

Summary

Introduction

Because the ultra-wideband (UWB) antennas can radiate efficiently over large frequency bands and demonstrate consistent radiation characteristics in the whole operating frequency band, they have been applied in various fields, such as the wireless communications, sensing, radar systems and microwave imaging. In some low-frequency applications, such as the military communications at HF, VHF and UHF bands, UWB antennas with monopole-like radiation patterns, namely the vertically polarized omnidirectional radiation patterns, are required. The works [2]–[5] utilize conical monopole to realize vertically polarized omnidirectional patterns for ease of design and fabrication. The body-of-revolution (BoR) monopole antenna with specified radiation objectives and size constraints is designed using algorithm and optimization in [6].

Methods

Findings

Conclusion