David E Crouch

US Patent:

6411174, Jun 25, 2002

Filed:

Jun 14, 2000

Appl. No.:

09/593201

Inventors:

David D. Crouch - Corona CA
Vincent Giancola - Chino CA
Kenneth W. Brown - Yucaipa CA

Assignee:

Raytheon Company - Lexington MA

International Classification:

H01P 512

US Classification:

333125, 333137

Abstract:

A compact four-way waveguide power divider ( ). The inventive power divider ( ) includes an input waveguide ( ) that terminates at a junction with two adjacent waveguides on opposite sides of the input waveguide. On the opposite side of the junction is a conducting wall into which is built an inductive septum ( ). The inductive septum ( ) serves to partially match the input impedance of the structure. Second and third inductive septums ( and ) are also built into the output arms of the power divider ( ). The purpose of the second and third septums ( and ) is twofold. In addition to partially matching the power dividers input impedance, the positions of the second and third septums ( and ) can be adjusted to equalize the power division between the output arms. Hence, the waves exiting the four output arms of the power divider have highly equalized amplitudes and phases. Further, the phases at the output ports are equalized by adjusting the lengths of the output arms.

US Patent:

6522226, Feb 18, 2003

Filed:

Jun 26, 2001

Appl. No.:

09/892093

Inventors:

David D. Crouch - Corona CA
Kenneth W. Brown - Yucaipa CA
William E. Dolash - Monclair CA

Assignee:

Raytheon Company - Lexington MA

International Classification:

H01P 108

US Classification:

333252, 333251

Abstract:

A millimeter-wave window is constructed from a high conductivity metal plate. The metallic plate is made transparent over a range of frequencies by perforating it with a periodic array of slots. In one embodiment, the millimeter-wave window is used in a gyrotron as the output window. In such a case, one suitable periodic array of slots comprises an equilateral triangular array of slots for operation at 95 GHz. By proper choice of the hole spacing and diameter, the window can be made transparent at any desired frequency. In addition to being transparent, however, the window must also be vacuum tight, as the pressure inside a gyrotron is on the order of 10 torr. The present invention solves this problem by covering the surface of the window with a thin layer of a suitable dielectric material, such as fused quartz.

US Patent:

6580561, Jun 17, 2003

Filed:

Aug 23, 2001

Appl. No.:

09/938116

Inventors:

David D. Crouch - Corona CA
William E. Dolash - Montclair CA

Assignee:

Raytheon Company - Lexington MA

International Classification:

G02B 2710

US Classification:

359618, 359629, 359636, 359196

Abstract:

A variable beamsplitter ( ) for use with quasi-optical millimeter-wave beams. The beamsplitter ( ) consists of a circular metal plate ( ) into which a periodic array ( ) of rectangular slots is cut. The plate ( ) is arranged so that the incident millimeter-wave beam is incident at an angle of 45Â relative to the surface of the plate ( ). The polarization of the incident beam is parallel to the surface of the plate ( ). When the orientation of the plate ( ) is such that the electric field is perpendicular to the slots (i. e. , the electric field is directed across the narrow dimension of the slots), the plate ( ) transmits nearly 100% of the incident power. If the plate is rotated about its axis by 90Â (while maintaining a 45Â angle between the incident beam and the plate) so that the incident electric field is parallel to the slots, then the plate ( ) transmits 0% and reflects nearly 100% of the incident power at an angle of 90Â relative to the incident beam. By varying the angle of rotation between 0Â and 90Â, both the reflected and transmitted power can be varied continuously between 0% and 100% of the incident power.

US Patent:

6693605, Feb 17, 2004

Filed:

Aug 30, 2002

Appl. No.:

10/231937

Inventors:

David D. Crouch - Corona CA
Alan A. Rattray - Alta Loma CA

Assignee:

Raytheon Company - Waltham MA

International Classification:

H01Q 1524

US Classification:

343909

Abstract:

A wave plate ( ) formed of a perforated metallic plate of a particular thickness (L) has circular holes ( ) that induce a change in the polarization of an electromagnetic wave passing through the holes in the plate. By choosing the proper hole diameter, the hole spacing in orthogonal directions, and the plate thickness, the desired relative phase shift is achieved with maximum transmission and minimal reflection. Two or more axially-aligned wave plates form a variable wave plate system. By changing the relative rotational positions of the wave plates, the polarization of the electromagnetic wave passing through the system can be selectively varied.

US Patent:

6768468, Jul 27, 2004

Filed:

Sep 27, 2001

Appl. No.:

09/965206

Inventors:

David D. Crouch - Corona CA
William E. Dolash - Montclair CA

Assignee:

Raytheon Company - Waltham MA

International Classification:

H01Q 1908

US Classification:

343753, 343909

Abstract:

A flat metal plate ( ) has a plurality of holes ( ) that have a property that changes across the surface of the plate so that the flat plate ( ) mimics the behavior of a curved wavefront transformer. The changing property can include a dimension, such as radius or depth, such that the holes ( ) near the center of the plate ( ) are smaller, for example, than the holes ( ) further away from the center of the plate ( ). The size of each hole ( ) is a function of the local phase change imparted on an electromagnetic wave of a particular wavelength or frequency that hits the hole ( ), plus the propagation phase change that occurs in the reflected wave exiting the hole ( ) as it travels the distance between the hole ( ) and the focal point.

US Patent:

6864857, Mar 8, 2005

Filed:

Jan 10, 2002

Appl. No.:

10/044691

Inventors:

David D. Crouch - Corona CA, US
William E. Dolash - Montclair CA, US

Assignee:

Raytheon Company - Waltham MA

International Classification:

H01Q015/14

US Classification:

343912, 343909

Abstract:

An optically transparent dielectric reflector () that reflects an incident millimeter-wave beam at a design frequency. The reflector () includes layers of different optically transparent dielectric materials. The thickness of the individual layers is chosen so that the transmitted waves cancel almost completely in the forward direction, yielding a high degree of transmission loss and substantial reflection. In the preferred embodiment, the invention is comprised of alternating layers of optical sapphire and air. In the best mode, there are seven sapphire layers, with outer sapphire layers () having a nominal thickness of 70. 8 mils, inner sapphire layers () with a nominal thickness of 30. 4 mils, and air layers have a nominal thickness of 32. 0 mils Vented metal spacers () are used to maintain optimal thickness of air layers.

US Patent:

7019640, Mar 28, 2006

Filed:

May 19, 2003

Appl. No.:

10/440944

Inventors:

David J. Canich - Upland CA, US
David D. Crouch - Corona CA, US
James R. Gallivan - Pomona CA, US
Robert E. Karlson - Mission Viego CA, US
Keith G. Kato - Alta Loma CA, US
David R. Sar - Corona CA, US
Philip D. Starbuck - Redlands CA, US

Assignee:

Raytheon Company - Waltham MA

International Classification:

G08B 1/00

US Classification:

340531, 34053913, 34053926, 3405681, 3406861, 34082549, 34082569, 34082572

Abstract:

A system and method for monitoring a cargo container. The novel system () includes a sensor module () mounted in each target area () and a central monitoring system (). Each sensor module () includes one or more sensors () and a transceiver () for transmitting data from the sensors to the central monitoring system (). The central monitoring system () includes a transceiver () for receiving the data from all sensor modules () and a local master processor () for processing and analyzing the data. In the preferred embodiment, each transceiver () is capable of receiving and retransmitting signals of other sensor modules to relay signals of a particular sensor module () in a daisy chain fashion to and from the central monitoring system ().

US Patent:

7209080, Apr 24, 2007

Filed:

Jul 1, 2004

Appl. No.:

10/883093

Inventors:

David D. Crouch - Corona CA, US
Michael Sotelo - Chino CA, US
William E. Dolash - Montclair CA, US

Assignee:

Raytheon Co. - Waltham MA

International Classification:

H01Q 1/38
H01Q 13/10

US Classification:

343700MS, 343770

Abstract:

A system and method for combining and radiating electromagnetic energy. The invention includes a novel antenna comprising a first dielectric substrate having opposite first and second surfaces, a patch of conducting material disposed on the first surface, a ground plane of conducting material disposed on the second surface, and at least three input ports, each input coupled to the patch at a feed point. The feed points are positioned to minimize the total power reflected from each input port. In an illustrative embodiment, the feed points are equally distributed around a circle having the same center as the patch and having a radius chosen to minimize the reflections at each input. In accordance with the novel method of the present invention, the outputs of multiple sources are combined in the antenna itself, by coupling the sources directly to the antenna.