A limited-scan antenna comprised of a microwave lens and phased-array feed /

Limited-scan antennas are finding increasing use in satellite communications and airport approach radars. Earlier attempts to achieve limited scan involved the use of parabolic lenses, zoning, and movable or dual-focus feeds. In the method described here, the main beam is scanned electronically by using a circular-arc phased array. The microwave lens is designed so that its back face satisfies the scanning condition. The beam is focused by shaping the front face of the lens to meet the required focusing condition and by varying the phase propagation of the lens. Two of the lenses studied were dielectric-loaded. A waveguide lens designed to scan in one dimension yielded experimental results that were good agreement with the theoretical predictions. Representative plots, and computer-generated farfield patterns of two topographically unique cases, are given."Microwave Physics Laboratory Project 4600.""ADA016405 (from http://www.dtic.mil).""2 May 1975."Includes bibliographical references (page 35).Limited-scan antennas are finding increasing use in satellite communications and airport approach radars. Earlier attempts to achieve limited scan involved the use of parabolic lenses, zoning, and movable or dual-focus feeds. In the method described here, the main beam is scanned electronically by using a circular-arc phased array. The microwave lens is designed so that its back face satisfies the scanning condition. The beam is focused by shaping the front face of the lens to meet the required focusing condition and by varying the phase propagation of the lens. Two of the lenses studied were dielectric-loaded. A waveguide lens designed to scan in one dimension yielded experimental results that were good agreement with the theoretical predictions. Representative plots, and computer-generated farfield patterns of two topographically unique cases, are given.Mode of access: Internet