radar antenna

摘要

A radar or other microwave antenna comprises at least one antenna element, a feed structure for the element extending to the antenna element substantially normally thereto through a dielectric substrate, and characterized in that the dielectric substrate is anisotropic whereby to reduce unwanted common-mode currents in the feed structure. The anisotropy may be provided by elongate conductive elements distributed through the dielectric substrate and aligned with their longitudinal axes parallel to the feed structure.