Modular All-Metal Ultrawideband Cylindrical Array for Multifunction Operation
John T. Logan, W. Mark Dorsey, John A. Valenzi
Abstract
Legacy cylindrical phased array systems are constrained to narrowband operation due to antenna element limitations amid a growing need to support advanced multifunctional platform requirements. In this article, a notch-based all-metal ultrawideband (UWB) antenna element suitable for cylindrical arrays is introduced. The proposed element is designed to operate over 2.75–10 GHz while being highly amenable to a cylindrical architecture via modularized assembly of compact scalable column facets. The primary enabling technical innovations are: 1) a new shunt-loaded stepped-impedance (SI) gap design scheme to improve low-frequency performance without increasing profile and 2) the design of a tongue-and-groove azimuthal crosswall that precisely conforms to the wedge-shaped unit cell for simple yet robust cylinder assembly. For a proof-of-concept demonstration, a 120° sector array is built having a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$12^{\prime \prime }$ </tex-math></inline-formula> outer diameter and 21 columns—each comprising eight single-polarized elements (168 total feed points). Measurements are presented for active phase-mode impedance and embedded element patterns of a central element, demonstrating good agreement with full-wave simulations.