Abstract: A bootlace microwave lens antenna has orthogonal delay lines for reducing adratic phase errors to improve focusing capability. The collector and radiator elements consist of mutually orthogonal pairs of subelements with one of the subelements oriented radially and the other oriented tangentially on the respective collector and radiator surfaces. Individual delay lines interconnect corresponding radial and tangential subelements on each surface thus allowing for phase corrections in the axial planes parallel to and perpendicular to the plane of scan by the introduction of an appropriate phase delay in each delay line.

Abstract: A scannable antenna having a radiating array of antenna elements correspondingly coupled, through equal line lengths, to a more closely spaced array of antenna elements positioned in a space coupling region. A feed array of antenna elements, with spacings substantially equal to the spacing in the radiating array and substantially of the same physical size as the more closely spaced array, is positioned in the space coupling region in close proximity, no more than a wave length away, to the more closely spaced array. The feed array is coupled to a distribution network which provides desired phase and amplitude aperture distributions.

Abstract: The novel multi-beam multi-lens antenna of the present invention provides multi-beam coverage over a hemisphere or greater three-dimensional spatial coverage region. In its simplest configuration, the antenna comprises two microwave lenses whose design is integrated to minimize path length errors and aberrations for beams over a 360.degree. azimuth coverage range. The antenna comprises a 3-D focal ring bootlace first microwave lens that is a figure of revolution and a non-planar dome second microwave lens which provides the refractive properties necessary to obtain the hemispheric coverage while providing additional degrees of freedom necessary to reduce errors and aberrations of the lens system to within acceptable levels. Both lenses are time delay lenses to effect broadband operation and are circularly symmetric. This symmetry results in antenna performance that is invariant with azimuth beam position.

Abstract: A feed system for scanning focal plane antenna systems with which a variable focal spot illumination may be achieved within the focal region of a primary antenna over a limited scanning sector is disclosed. An array of collector elements positioned to receive radiation from a scannable feed antenna is coupled to an array of radiator elements positioned in the focal region of the primary antenna, the positioning of the radiator and collector elements are such that the focal spot illumination is caused to vary with the scan angle of the antenna.