Conical Conformal Tightly Coupled Dipole Arrays Co-Designed With Low-Scattering Characteristics

Abstract

Conformal designs and scattering reduction have long been significant challenges to ultrawideband phased arrays. In this work, a conical conformal tightly coupled dipole array (TCDA) with low-scattering characteristics is developed. The design procedure from a planar antenna element to a two-dimensional (2-D) conformal finite array is presented in detail. In this design, a novel structure of conformal resistive strips is used as a cover layer for the radiating dipoles to control scattering, and its ability to control scattering is insensitive to variations in the dimensions of the designed conformal array. To achieve a wide scanning range and reduce scattering in a wide band, a metasurface composed of full-split rings is employed as the superstrate. The final designed array achieves a 3:1 impedance bandwidth for scanning up to ±60° in two principal planes. Moreover, scattering is reduced by more than 10 dB throughout the entire operating band. Finally, an array prototype is fabricated and measured. Measured results are in good agreement with the simulated results, thus demonstrating the effectiveness of the proposed array.