Variable focus microwave antenna

Abstract

Concentric shapes (e.g., discs and rings), are nested and displaced from a central plate. The discs are individually positioned by means of mechanical or electro-mechanical actuators such that the over-all result approximates a spherical surface reflector antenna having an adjustable radius of curvature, with the radii of curvature being equivalent to the focal length of the antenna. Another innovation includes reducing the dimensional positioning of the various discs by a modulo of the wavelength of the operating frequency of the antenna, thus reducing the throw accommodation of the actuators to only one wavelength. Each of the discs and the central plate are designed to have substantially the same area, as a nominal configuration. The accuracy of the approximation is improved as the number of discs is increased; however, very acceptable performance is obtained with as few as ten discs when compared to a perfect spherical surface.

Dependencies are inferred from the claim text.