Leaky-wave-based design of all-metal corrugated radially periodic antennas

This article presents the study and design of periodically corrugated all-metal structures, a class of compact, low-profile antennas suited for space and aeronautic applications. Leaky-wave theory is employed to guide their design and optimization. A method-of-moments (MoM) solver is used to characterize the dispersion of different unit cells (UCs), providing new insights into their modal behavior. By studying the dispersion, the radiation performance is predicted and significantly improved with respect to the state of the art. Highly directional, compact, and robust 2-D radially periodic leaky-wave antennas (LWAs) are proposed and validated through full-wave simulations. Broadside gain-bandwidth tradeoff is improved by suppressing the open stopbands (OSBs) of the original UCs via geometric asymmetries and, for the first time, by jointly tapering the phase and attenuation constants of the leaky mode. Using a figure of merit, all proposed antennas are shown to significantly outperform the state of the art for all-metal 2-D corrugated antennas, clearly demonstrating the advantages of the leaky-wave approach.