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

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 $8\times 8$ prototype is fabricated and measured. The measured results prove the feasibility of the design.