Abstract: A directive antenna feed arrangement providing for multiple selectable beam locations and with the ability to provide multiple and independently locatable nulls in specific angular directions in the sidelobe structure of the radiation pattern. An antenna having a plurality of independent antenna elements linearly deployed is coupled to a beam-forming network such as a Rotman lens feed. Main beam directivity is controlled by selection of the Rotman lens ports corresponding to the desired beam direction. Other angles corresponding to the directions of unwanted signals, especially those received on the major sidelobes, are effectively nulled by a phasing network discretely connected to the Rotman lens port at the appropriate angle, the phase control receive signals being mixed with the main beam signal energy. Angle tracking and beam-steering circuits are depicted and described for control of the main beam angle and positioning of the nulls generated.

Abstract: A polarization-agile radar array employing at least one linear array having a periodic first meander line and a second meander line which is a close-spaced, mirror image of the first such line, these lines being separately driven so that when they are fed with equal amplitude and phase, the polarization will be in a first plane and when driven in anti-phase, orthogonal polarization is achieved. The meander lines extend in the same plane which is parallel to a ground from which it is spaced. Intermediate polarization angles are achieved by intermediate phase and amplitude relationships of the drive, equal amplitude and phase quadrature exitation providing circular polarization. A series of generally parallel, conductive vanes is affixed to the ground plane to compensate for the reactance of longitudinal sections of the meander line longitudinal feeder (connecting) sections as the wave passes therethrough when its polarization is essentially parallel to those feeder lines.

Abstract: An annular rotary antenna feed coupler especially for around-the-mast use, as on shipboard. A housing in the general shape of a cylinder with a central axial opening essentially concentric with the axial center line of the housing contains a circumferential distribution of a number of fixed axially elongated, conductive loops each with a feed port. Radially spaced therefrom, a second, group of elongated conductive loops circumferentially distributed about a circle of different radius as compared to the aforementioned fixed loops is rotatably mounted. A corresponding plurality of ports, one for each rotating loop, is also provided, and input and output combiner/divider devices, one for the fixed and another for the rotating sub-assemblies serve to combine all ports into a single fixed and a single rotating port. Mechanically, the rotating combiner/divider rotates with the antenna array with which it operates.

Abstract: An integrated planar antenna array comprising at least two separate interleaved arrays separately controllable and responding to separate frequency bands. Both arrays operate with substantially the same phase center and substantially within the same effective aperture. The first array or subarray comprises spaced linear, slotted-waveguide arrays and the second subarray includes a meander line occupying the space between each of the waveguides of the first array. Scan systems are shown for independent operation of the two arrays. An alternative for the second subarray is shown in the form of slotted, square-coaxial, linear arrays in the spaces between the waveguides of the first subarray.

Abstract: An annular rotary RF coupler for installation about a vertical support structure, particularly the mast of a ship. Two annular troughs are regularly divided in circumferential increments providing a cellular structure of individual waveguide cross-sections. A lower annulus remains fixed, the individual waveguide sections therein being fed from a power-divided, equal-phase, feed configuration. The oppositely facing upper annulus rotates with respect to the lower one about a common mechanical center of rotation of a mechanically rotating antenna system. Connection to the rotating waveguide sections may be through power combiner/divider means, or individual subarrays may be discretely connected to one or more waveguide sections in the rotating annulus. For power tapering across an antenna array aperture, the waveguide section dimensions in the circumferential direction within the rotating annulus are appropriately tailored.

Abstract: This relates to dual band waveguide radiating element for an antenna. A pair of adjacent rear wall excited waveguide elements have a slot in the common wall between them. This slot contains an excitation element so that the structure operates as a ridge waveguide. The rear wall excitation is at the higher of the two frequencies, e.g. S band, while the ridge waveguide operates at the lower frequency, e.g. L band.