Trw Limited

Northrop Grumman Systems Corporation

Brent T Toland

Te-Kao Wu

Ronald Y Chan

L Dwight Gilger

David L Brundrett

Andrew Lee Roberts

Dan R Johnson

Vrage Minassian

Youn H Choung

Shinobu J Hamada

Rork S Brown

James S Hamada

Robert L Hart

Kwok-Kee Chan

Kenneth A Hummer

Alon S Barlevy

William M Hughes

An antenna array ( ) comprises a plurality of antenna elements ( ) creating a plurality of radio frequency waves. The central portion ( ) of opposed edges of the waves are guided with conductive material. The waves are isolated from each other by non-conductive (cir or dielectric) spaces ( ). The waves are guided by tapered surfaces ( ) having a predetermined thickness and emitted through a mouth having a mouth length (M). The ratio of the predetermined thickness to the mouth length is increased until there is no substantial increase in the high frequency limit of the array.

Wideband antenna with tapered surfaces

A satellite antenna system employing a dual-band feed horn and dual-band beam forming network. The feed horn provides a common aperture for both satellite uplink and downlink communications signal. The feed horn includes corrugations on an inside surface defining two sets of alternating channels having different depths to create circularly symmetric beams for the uplink and downlink signals. The antenna system includes at least one reflector, where the reflector shape, position, and the configuration of the feed horn, is determined so that the mainlobe of the lower frequency downlink feed signal illuminates the entire reflector, and the mainlobe of the higher frequency uplink feed signal illuminates an inner portion of the reflector. The first sidelobes of the higher frequency feed signal illuminate the outer portion of the reflector so that the uplink and downlink antenna signals have the same beamwidth, and thus cover the same cell size on the Earth.

Dual-band equal-beam reflector antenna system

Wideband matching surface for dielectric lens and/or radomes and/or absorbers

A deployable phased-array-of-reflectors antenna includes individual reflectors and feed arrays. Each feed array is disposed above a corresponding individual reflector. The individual reflector antennas are preferably disposed adjacent to one another (e.g., on a hexagonal lattice) to form a phased array antenna using the individual reflectors antennas as elements. Phase and amplitude control electronics are coupled to each reflector antenna to provide steering for the signal energy coupled between the reflectors and the feed arrays. Switching electronics are coupled to the feed arrays and selectively activate and deactivate beam forming clusters of feeds in the feed arrays. A method for generating a steerable antenna pattern couples signal energy through a beamforming section to form steered signal energy. Next, the method couples the steered signal energy between a phased array of reflector antennas. The method selectively activates a first feed cluster for a first reflector, a second feed cluster for a second reflector, and so on, until feed clusters are activated in all of the reflectors in the array. The method then couples the steered signal energy between the first and second feed clusters. The method subsequently activates and deactivates the feed clusters to reduce the impact of grating lobes in the total antenna pattern, or when a particular cluster attenuation has been reached.

Deployable phased array of reflectors and method of operation

A frequency selective medium that is adapted to receive an incident electromagnetic radiation at an angle of incidence of about 45.degree. has two arrays of conductive elements on opposite parallel surfaces (20, 22) of a dielectric substrate. In one embodiment, the conductive elements are cross-dipoles (6) each having a horizontal dipole (10) and a vertical dipole (8) of different lengths and widths. In another embodiment, the conductive elements comprise a plurality of conductive gridded rectangular loops (40). The frequency selective medium allows incident waves that are within a passband of transmit frequencies to transmit through the medium, and reflects waves at frequencies within a stopband adjacent the passband. In other embodiments, meanderline polarizers (28) are added to cross-dipole and gridded rectangular loop frequency selective media to circularly or dual-linearly polarize incident linearly polarized waves.

Dual polarization frequency selective medium for diplexing two close

An omnidirectional isotropic antenna employing a tubular waveguide 12, a dielectric insert 18 which includes a lens 20 and a depending stem 22. The lens 20 is an elliptoid generated by rotating an elliptoid form about the longitudinal axis 42 of the tubular waveguide 12 with its foci 40 aligned with the longitudinal axis 42 and its major axis 38 lying in a zone of rotation 43 intersecting the horizontal plane 44 that is normal to the axis 42 and containing the foci 40. The stem 22 has integrally formed a polarizing element 36, and an impedance to matching element 21. There is provided a passband filter 50 and a modified tubular waveguide 60 that provides node differences for the RF signals.

Omnidirectional isotropic antenna

A beam waveguide type dual reflector (3, 4) type antenna, referred to as a Cassegrain antenna, is constructed with a beam waveguide (5, 6, 9, 11, 13, 15), having three axes of rotation (X1, Y1, & Z1), the first (X1) and second axes (Y1) of rotation being perpendicular to each other and the second (Y1) and third (Z1) axes of rotation being perpendicular to each other and with the spacing between the first (X1) and third (Z1) axes being constant to achieve a greater field of view, while retaining the capability of handling simultaneously cross polarized microwave signals. Actuator singularities, defining forbidden regions, singularity associated with rotation about the first and second axes are avoided by switching to rotation about the first and third axes as the singularity is approached by the antenna, permitting the antenna to move through that singularity region.

Three axis beam waveguide antenna

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Manhattan Beach, CA, United States of America

Brent T Toland