Abstract: An antenna comprised of a plurality of identical subarrays each having N antenna elements. The antenna elements of a core of subarrays all contribute outputs which are used for forming sum and difference beams. A peripheral area surrounding the core has subarrays which have a lesser number of antenna elements which participate in the signal processing operation to derive the sum and difference beams. The antenna elements of each subarray are combined in a manifold having one output, for the peripheral subarrays, and three outputs for the core subarrays. The manifold outputs are provided to various digital receivers which process the manifold signals with predetermined weighting functions. A digital beamformer processes the digital receiver outputs to derive the sum and difference beams which are used by a radar processor for tracking targets.

Abstract: A phased array antenna consisting of like multi-element tiles whose elements are located so as to produce an irregular array when the tiles have mutually different orientations, e.g., random. The resulting irregular array reduces the effective translational period of the array elements, which in turn ameliorates grating lobes even for wide (one wavelength) effective element spacings. An antenna so designed can maintain low peak sidelobes at far higher frequencies than a conventional translational-periodic phased array antenna of the same element density.

Abstract: A radar electronic scan apparatus 10 employs an array of transmit/receive phase-shift modules 14 with a plurality of ferrite phase-shift subarrays 16. Each ferrite phase-shift subarray has a pair of phase-shift ferrite substrates 32A and 32B mounted on a support with each substrate having four phase taps for connection to radiators of the electronic scan apparatus.

Abstract: RF manifolding for a radar antenna which allows tight spacing of Phase Control Modules (PCMs) is disclosed. The manifolding consists of ridged branch manifold waveguides to which ridged cross waveguide sections are installed. Each branch manifold waveguide of the present invention has ridges on one broad wall, coupling slots on another broad wall, and a plurality of cross waveguides connected on the side having the coupling slots. The cross waveguides are likewise provided with ridges on one broad wall, which are oriented at right angles to the ridges of the branch manifold waveguide, and have coupling slots on the opposite broad wall which correspond to the coupling slots of the branch manifold waveguide. The PCMs are mounted on the end of each cross waveguide, parallel to the ridges thereof.