A Low-Cost Light-Weight Ultrawideband Wide-Angle Scanning Tightly Coupled Dipole Array Loaded With Multilayer Metallic Strips

Zhiguo Jiang,Bing-Zhong Wang,Shaoqiu Xiao

doi:10.1109/access.2021.3054658

Abstract

This article presents a new ultrawideband wide-angle scanning tightly coupled dipole array loaded with multilayer metallic strips. The loaded multilayer metallic strips, which is composed of several narrow strips with different lengths, are used to equivalent the metal patch which has a specific shape. It can help achieve smoother impedance transform from the dipole to the free space. An equivalent circuit model (ECM) of the unit cell is proposed to help analyze and design the tightly coupled dipole array. Thanks to the loaded multilayer metallic strips, the array can be fed by a simple feeding structure, avoiding a matching network located below the ground plane. Also, all components of the proposed array are printed on a single dielectric substrate, resulting in a low-cost and light-weight array. The proposed tightly coupled dipole array can achieve 6.2:1 bandwidth with voltage stand wave ratio (VSWR) <; 3 while scanning to ±60° in all planes. The total profile of the array is 0.13 wavelength at 1.4 GHz. Finally, an 8×8 prototype is fabricated and measured. The measured results prove the feasibility of the design.

Highlights

Ultrawideband wide-scan array can cover wide range in ultra-wide bandwidth, making it have important implications for the high-resolution imaging system [1] and multifunctional communication system [2]
Compared with the state-of-the-art wideband array, the proposed array has two advantages: 1) all the components are printed on a single dielectric substrate, resulting in a low-cost and light-weight array; and 2) all the components are placed above the ground plane, avoiding an impedance transform structure located below the ground plane
We found that the results calculated by equivalent circuit are agree well with the full wave simulation, proving the validity of the equivalent circuit model

Summary

INTRODUCTION

Ultrawideband wide-scan array can cover wide range in ultra-wide bandwidth, making it have important implications for the high-resolution imaging system [1] and multifunctional communication system [2]. The original tightly coupled dipole array needs an external 180◦ hybrids or balun to avoid common-mode resonance, resulting in a high-cost feeding structure. The stepped stripline can be horizontally placed on the ground plane, it increases the difficulty of the assembly [12] Another effective method to avoid the external balun is using shorting vias or capacitively-loaded vias to remove the common-mode resonance out of the operating band [13], [14]. Compared with the state-of-the-art wideband array, the proposed array has two advantages: 1) all the components are printed on a single dielectric substrate, resulting in a low-cost and light-weight array; and 2) all the components are placed above the ground plane, avoiding an impedance transform structure located below the ground plane.

THE ANALYSIS OF THE BASIC ELEMENT

CONCLUSION