Westinghouse Electric Corporation

Northrop Grumman Systems Corporation

United States of America As Represented by the Secretary of the Air Force

USA As Represented by Secretary of the Navy

Steven N Stitzer

Harry Goldie

John D Adam

Deborah P Partlow

Daniel C Buck

Alex E Bailey

Andrew J Piloto

Philip S Carter, Jr

Tapan K Gupta

Michael R Daniel

Gerald I Klein

Carl E Nothnick

Salvador H Talisa

Ronnie L Starling

Herbert Jefferson Henderson

William B Yablon

Sumantrai D Patel

John Chino

Andrea Curbean

Jose Armando Coronado

Daniel Bobowicz

Norman E Thurlow

Harry Goldie, Deceased

Carol J Painter

Robert G Schmier

Terry L Reeve

Timothy M Fertiq

Jeffrey J Dickstein

Lawrence J Hunter

Dennis A Grube

James D Woermbke

A phased array includes a first plurality of radiators having a first polarization and a second plurality of radiators having a second polarization, different from said first polarization. The phased array is constructed such that radiating patterns of the first and second plurality of radiators are congruent. The radiators are constructed so that they radiating apertures thereof can occupy virtually the same space, i.e., the spacing of the radiating elements is less than a wavelength. Other features provided allow this compactness to be achieved. Impedance matching features are integrated into the radiators themselves. The elevation assemblies of the radiators are mated together, and then are coupled across to their respective azimuth assemblies. Two azimuth assemblies for either type of polarization may be provided when monopulse operation is required. Assemblies for both polarizations transmit sequentially, but receive simultaneously, thus allowing a complete polarization matrix to be collected with two pulse transmissions.

Dual polarized electronically scanned antenna

The present invention provides for a low power receiver protector and stepped attenuator for conditioning a received input signal within a microwave receiver front end. The low power receiver protector includes a detector for generating a surge signal in response to the received input signal exceeding a predetermined threshold, a delay line for delaying the received input signal for fixed duration, and a limiter for reducing the voltage of the received input signal in response to the generation of the surge signal. The stepped attenuator includes a plurality of cells each having an attenuation transmission path which includes an attenuator for providing a predetermined amount of attenuation of the received input signal. Each attenuation transmission path, bypass transmission path and delay line comprise a high temperature superconductor to provide minimal loss and reduced size.

High temperature superconducting low power receiver protector/clutter

A planar phase shifter having plural layers of ferrite forming a closed magnetic toroidal path and including internal layers of dielectric material of a relatively high dielectric constant and underlying layers of dielectric material having a relatively low dielectric constant. A stripline to slot line transition is also formed at least at one end of the device. All of the elements are formed over a ground plane and have either metallized external sidewalls or a set of metallized vias running through the outer wall portions over its length.

Planar ferrite toroid microwave phase shifter

A microwave transition consisting of a stripline member coupled to a pair of slot lines deposited on the outer surfaces of a pair of contiguous dielectric rib members. The stripline and one slot line on one of the rib members cross each other at right angles on parallel planes forming an energy coupling junction. One end of both slot lines comprise slot line regions which are either smooth tapered or stepped out to the full width of the dielectric ribs so as to couple RF energy to the normal fields in a twin toroid phase shifter which in one embodiment the toroids extend past the cross-over junction while in the second embodiment two additional dielectric layers are contiguously applied to the outside surfaces of the dielectric rib members containing the slot lines for matching the electric fields in the slots to the toroids. The outer surfaces of the transition including the twin toroids are metallized and fitted into a metal sleeve which provides support for the composite structure.

Stripline transition for twin toroid phase shifter

A planar phase shifter formed of multiple layers of a ferrite. Selected layers of the ferrite are patterned with a conductor and the multiple layers of magnetic dielectric and conductor are cofired. The phase shifter is fabricated by first obtaining ferrite powder. Then, layers of the ferrite are made, preferably by tape casting. Next the ferrite layers are metallized by applying selected amounts of conductive metals in a selected pattern upon the tape. Selected numbers of vias are placed through selected layers of tape and conductive metal is placed in the vias to provide vertical connections through the layers. The tape layers are then stacked in a predetermined order and are laminated. The laminated stack of layers is then fired to a temperature of approximately 800.degree. C. to 1000.degree. C., sintering the laminated layers into one integrated structure.

Planar phase shifters using low coercive force and fast switching,

In the present invention the upper edge of the frequency response of the magnetostatic wave (MSW) filter is sharpened. A band limiting element (BLE) is coupled to the MSW filter, preferably in the filter element output. In one embodiment the BLE absorbs signals above a certain frequency in the upper band edge of the MSW. In another embodiment, the BLE reinforces the output response.

Magnetostatic wave (MSW) filter with sharp upper cut-off frequency and

A frequency selective limiting device is described incorporating a planar ferrite member and at least one signal-carrying conductor positioned thereon. A conductor is located on the ferrite member to confine a portion of an RF magnetic field produced by the microwave signals within the ferrite member. In one embodiment of the invention, the conductor comprises coplanar ground planes positioned adjacent to the signal-carrying conductor, thereby forming a coplanar waveguide. Alternatively a pair of coplanar conductors may form a slot line. In another embodiment a second ferrite member is positioned in confronting relationship with the first ferrite member carrying the conductors.

Coplanar waveguide frequency selective limiter

A frequency selective limiting device is described incorporating a plurality of individual attenuating units spaced apart from one another in substantially parallel relation and positioned between a pair of ground planes. Each individual attenuating unit is interposed between a pair of magnetic strips. In one embodiment of the invention, each individual attenuating unit includes a microstrip conductor positioned between a dielectric substrate layer and a layer of ferrite material. In an alternate embodiment of the invention, each individual attenuating unit includes a microstrip conductor positioned between a pair of planar ferrite members, the pair of ferrite members and microstrip conductor being mechanically supported by a dielectrical substrate layer. In both embodiments of the invention, adjacent attenuating units are serially connected by microstrip jumpers to provide a flow path for microwave signals passed through the limiting device. The plurality of ferrite members in association with the plurality of magnetic strips are operable to attenuate by a predetermined level a microwave signal above a preselected threshold power level passed through the limiting device.

Frequency selective limiting device

The signal-to-noise enhancer can be used in frequency memory loops to prevent loop capture by noise. If a frequency selective limiter is incorporated in the loop, more than one signal can be stored simultaneously because the limiter prevents the loop amplifier from saturating. At present, the limiter must be a separate device. The frequency selective signal-to-noise enhancer/limiter apparatus comprises an enhancer apparatus and a limiter apparatus on a single substrate, using a single pair of magnets to bias both units.

Frequency selective signal-to-noise enhancer/limiter apparatus

A microwave duplexer apparatus utilizing a frequency selective limiter unit in conjunction with a microwave circulator to direct RF energy from a transmitter to an antenna and from an antenna to a receiver in a single antenna duplex communication system. gi

Full duplex communication system apparatus using frequency selective

A microwave circuit network which combines a number of signal-to-noise enhancers of the magnetostatic wave excitation type, utilizing ferrite material, to extend the signal-to-noise enhancement frequency bandwidth beyond that which is offered individually by any one of the enhancers being combined while reducing substantially any signal interaction between the signal-to-noise enhancement operations thereof is disclosed.

Broadband circuit for microwave S/N enhancers

A coaxial line, wide dynamic range, ferrite limiter having optimal frequency selectivity for microwave frequencies is provided by a stepped ferrite rod with disks of varying volumes and dielectric constants controlling the operating frequency and threshold level for each step segment.

Stepped-rod ferrite microwave limiter having wide dynamic range and

Two sectoral radial resonators coupled at their centers of radii by a strip transmission line and doubly loaded with opposing ferrimagnetic spheres between the said strip transmission line and the ground planes provides a frequency selective power limiter.

Frequency selective ferrimagnetic power limiter

An improved microwave device for filtering and power limiting is described incorporating a yttrium-iron-garnet (YIG) sphere and a transmission line wherein coupling between the YIG sphere and the transmission line is enhanced by placing the YIG sphere in a groove in a ground plane under the transmission line. The current induced in the groove of the ground plane results in enhanced coupling.

Enhanced coupling in ferrimagnetic microwave devices

A ferrimagnetic sphere that is biased to the subsidiary resonance mode and placed within a microwave slotted resonant structure functions as a frequency selective microwave power limiter. When the power level of a signal at the input port exceeds a threshold level, the device prevents the power level at the output port from increasing further. A weak signal present simultaneously passes with relatively little attenuation if it is slightly offset in frequency.

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Ellicott City, MD, United States of America

Steven N Stitzer