Refracting Means And Radio Wave Energy Filters (e.g., Lenses And Polarizers) Patents (Class 343/909)
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Patent number: 6774862Abstract: A multibeam antenna apparatus is disclosed. The multibeam antenna apparatus includes a main reflector (1), a sub-reflector (2), a focused beam feeder (3), a primary radiator array (5) having a plurality of primary radiators (5a), and a lens array (10) having a plurality of wavefront transformation lenses (10a) corresponding to the plurality of primary radiators (5a), respectively. The lens array (10) can be placed in the vicinity of a front end of the primary radiator array (5). As an alternative, the lens array (10) is placed in an electric wave propagation range of the focused beam feeder (3) where multiple beams which constitute a multibeam are spatially isolated from one another in terms of electric power. Thus the multibeam antenna apparatus can prevent an error from occurring in the orientation of each beam.Type: GrantFiled: November 4, 2002Date of Patent: August 10, 2004Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Tomohiro Mizuno, Hiroyuki Satou, Izuru Naitou, Soichi Matsumoto
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Patent number: 6774867Abstract: An artificial magnetic conductor is resonant at multiple resonance frequencies. The artificial magnetic conductor is characterized by an effective media model which includes a first layer and a second layer. Each layer has a layer tensor permittivity and a layer tensor permeability having non-zero elements on the main tensor diagonal only.Type: GrantFiled: December 23, 2002Date of Patent: August 10, 2004Assignee: E-Tenna CorporationInventors: Rodolfo E. Diaz, William E. McKinzie, III
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Patent number: 6774861Abstract: A dual band high efficiency hybrid offset reflector antenna system (10) that includes a low frequency antenna (12, 16) including a paraboloidal main offset reflector (12) for reflecting a low frequency signal, as well as a high frequency antenna (12, 14, 18) including both the main offset reflector (12) and a hyperboloidal subreflector (14) for reflecting a high frequency signal discrete from the low frequency signal. The hyperboloidal subreflector (14) includes a frequency selective surface (33) that passes the low frequency signal reflected by the paraboloidal main offset reflector (12) with low subreflector diffraction loss, and that is highly reflective at the high frequency. Offset beam squint pointing error can be eliminated because the high and low frequency bands have separate feed focal locations (30a, 30b).Type: GrantFiled: June 19, 2002Date of Patent: August 10, 2004Assignee: Northrop Grumman CorporationInventors: Youn H. Choung, George H. Simkins
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Patent number: 6768476Abstract: An antenna consisting of a thin strip bent-wire monopole disposed on an artificial magnetic conductor (AMC) is loaded at the end opposite to the feed point with a distributed or lumped capacitance to achieve an electrically small antenna for use in handheld wireless devices. The capacitive load reduces the length of the antenna to smaller than one-quarter of a wavelength at a given frequency of operation without suffering a substantial loss of efficiency. This results in an easier integration into portable devices, greater radiation efficiency than other loaded antenna approaches and longer battery life in portable devices, and lower cost than use of a chip inductor.Type: GrantFiled: December 5, 2002Date of Patent: July 27, 2004Assignee: Etenna CorporationInventors: James D. Lilly, William E. McKinzie, III, David T. Auckland, Andrew Humen, Jr.
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Patent number: 6768051Abstract: Microstructured materials which can be tuned to a particular range of r.f. frequencies to display particular magnetic permeabilities have been proposed. A typical material is made of an array of capacitive elements e.g. spirals or rolls of conducting material on a non-conducting substrate. These materials can be used as screening material which is effective for the particular band of frequencies to which it is tuned. In one example, the rolls 2 to 5 are orientated normal to the face of the screen 1, which reflects or absorbs the magnetic vector of electromagnetic radiation impinging normal onto the reflector face.Type: GrantFiled: January 28, 2003Date of Patent: July 27, 2004Assignee: Marconi Optical Components LimitedInventors: Michael Charles Keogh Wiltshire, Ian Robert Young
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Patent number: 6768468Abstract: A flat metal plate (20) has a plurality of holes (50) that have a property that changes across the surface of the plate so that the flat plate (20) mimics the behavior of a curved wavefront transformer. The changing property can include a dimension, such as radius or depth, such that the holes (50) near the center of the plate (20) are smaller, for example, than the holes (50) further away from the center of the plate (20). The size of each hole (50) is a function of the local phase change imparted on an electromagnetic wave of a particular wavelength or frequency that hits the hole (50), plus the propagation phase change that occurs in the reflected wave exiting the hole (50) as it travels the distance between the hole (50) and the focal point.Type: GrantFiled: September 27, 2001Date of Patent: July 27, 2004Assignee: Raytheon CompanyInventors: David D. Crouch, William E. Dolash
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Publication number: 20040140945Abstract: By configuring a high impedance frequency selective surface (HZ-FSS) structure for the appropriate values of surface impedance (surface resistance and surface reactance), a high frequency artificial ferrite metamaterial can be synthesized with almost any desired value of real and imaginary permeability. Materials with these properties have not previously been physically realizable at frequencies above 1 GHz.Type: ApplicationFiled: January 12, 2004Publication date: July 22, 2004Inventors: Douglas H. Werner, Douglas J. Kern
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Patent number: 6759993Abstract: Dual polarisation antenna having low side lobes, useful in a satellite radio communication system. The antenna includes a reflector assembly (12) illuminated by a feed source (11). The reflector assembly (12) includes a front reflector (15) that reflects two electromagnetic waves orthogonally polarized and each at a different frequency, an auxiliary reflector (16) that reflects one of the orthogonally polarized electromagnetic waves, and a deflecting surface (13) that totally diffracts the orthogonally polarized electromagnetic wave that passes through the auxiliary reflector (16).Type: GrantFiled: March 20, 2002Date of Patent: July 6, 2004Assignee: AlcatelInventors: Thierry Judasz, Jean-Francois David, Jean-Marc Bassaler, Jacques Maurel
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Publication number: 20040119658Abstract: Briefly, in accordance with an embodiment of the invention, a frequency selective surface (FSS) structure and a method is provided. The FSS structure may include a first conductive plate over a first surface of a substrate. The FSS structure may further include a first printed inductor over the first surface of the substrate and coupled to the first conductive plate. The method may include forming a frequency selective surface by patterning a first conductive material over a surface of a substrate to form a printed inductor.Type: ApplicationFiled: December 24, 2002Publication date: June 24, 2004Inventor: Alan E. Waltho
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Patent number: 6747607Abstract: Disclosed herein is an arrangement for shielding electronic sensors from undesired microwave or millimeter wave radiation. In this arrangement, reflective element is disposed in the sensor path to intercept incoming signals. The reflective element has a pluraity of adjacent parallel ridges therein having sloped faces angled for reflecting incoming desired infrared radiation onto the sensor. The width of the ridges are selected so that desired signals will be reflected by the sloped ridge faces but undesired microwave or millimeter radiation will be reflected by the overall major surface of the mirror. Accordingly, undesired microwave or millimeter radiation will be reflected away from the sensor by the overall front major surface thereby preventing the sensor from being damaged.Type: GrantFiled: February 12, 1988Date of Patent: June 8, 2004Assignee: The Directv Group, Inc.Inventors: Wilfried O. Eckhardt, Weldon S. Williamson
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Patent number: 6747608Abstract: A high performance multi-band antenna reflector having low sidelobe and cross polarization levels, and a superior carrier-to-interference ratio has two concentric zones (12, 14 in a first embodiment and 102, 104 in a second embodiment). In the first embodiment, the outer concentric zone (14) is a frequency selective absorber (20) made of a metallic pattern (22) dimensioned to reflect signals in one frequency band and absorb signals in a second frequency band. In the second embodiment, the outer concentric zone (104) is a frequency selective surface (106) that reflects signals in one frequency band and passes signals in a second frequency bands. Resistance cards (122) overlay the top and bottom sides of the junction between the frequency selective surface (106) and a reflective layer (110) on an inner surface (112) of the central concentric zone (102).Type: GrantFiled: April 3, 2003Date of Patent: June 8, 2004Assignee: Northrop Grumman CorporationInventor: Te-Kao Wu
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Publication number: 20040100418Abstract: The present invention provides a dual antenna system where a first antenna element has a metallic surface with openings that are resonant at frequencies other than the operating frequency of a second antenna element. The openings are sized such that the metallic components are relatively transparent at and near resonant frequencies of those openings. According to the present invention, the resonant frequencies of the openings may be the transmitting or receiving frequencies of the second antenna element, or of nearby antennas.Type: ApplicationFiled: November 22, 2002Publication date: May 27, 2004Inventors: Timothy E. Best, Peter C. Strickland
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Patent number: 6727787Abstract: A device for manipulating microwave radiation includes a substrate that defines the shape of a surface for reflecting microwave radiation. The device also includes a metal fitting. The fitting conforms to the defined shape, and provides the surface that reflects microwave radiation.Type: GrantFiled: December 21, 2001Date of Patent: April 27, 2004Assignee: The Charles Stark Draper Laboratory, Inc.Inventors: Thomas M. Worth, Kaplesh Kumar
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Patent number: 6727863Abstract: The present invention relates to planar materials having bandgap properties. The materials are formed by depositing conductive fractal patterns on a non-conducting substrate. The bandgap location(s) are defined by parameters including the number of fractal levels, and the dimension of the fractal mother element. The bandgaps can also be actively controlled by injecting current into the conducting pattern.Type: GrantFiled: October 26, 2001Date of Patent: April 27, 2004Assignee: The Hong Kong University of Science and TechnologyInventors: Weijia Wen, Ping Sheng, Che Ting Chan, Weikun Ge, Lei Zhou, Jensen Li
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Publication number: 20040075617Abstract: A low profile, wide band gap antenna having a high impedance surface, the high impedance surface including a conductive plane and an array of conductive elements spaced from the conductive plane by a distance which is no greater than 10% of a wavelength of an operating frequency of the antenna structure. The conductive plane has an opening therein which is driven by an antenna driving element adjacent the opening in the conductive plane.Type: ApplicationFiled: September 16, 2003Publication date: April 22, 2004Applicant: HRL LABORATORIES, LLC.Inventors: Jonathan J. Lynch, Daniel F. Sievenpiper
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Patent number: 6720931Abstract: A beam scanning plane antenna is formed by stacking, in order, a system connecting portion, a Rotman lens portion, and a beam scanning antenna portion. The system connecting portion is formed by stacking, in order, a fourth grounding conductor, a sixth dielectric, a connecting substrate and a fifth dielectric. The Rotman lens portion is formed by stacking, in order, a third grounding conductor, a fourth dielectric, a Rotman lens substrate and a third dielectric. The beam scanning antenna portion is formed by stacking, in order, a second grounding conductor, a second dielectric, a power feeding substrate, a first dielectric and a first grounding conductor. A plurality of antenna groups that each include an irradiating element, a power feeding line and a first connecting portion, are formed on the power feeding substrate. The Rotman lens substrate includes a Rotman lens pattern, a second connecting portion and a third connecting portion.Type: GrantFiled: October 16, 2002Date of Patent: April 13, 2004Assignee: Hitachi Chemical Co., Ltd.Inventors: Takao Michisaka, Masahiko Ohta, Hisayoshi Mizugaki, Kiichi Kanamaru
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Patent number: 6720936Abstract: An adaptive antenna system (20) includes a programmable reflection surface (22), a controller (24) in communication wit the programmable reflection surface (22), and a feeder element (26) outwardly spaced from a receiving side (28) of the programmable reflection surface (22). The controller (24) is operable to write a pattern (34) of reflective (36) and absorptive (42) regions into the programmable reflection surface (22) in accordance with a frequency and a direction of a received or transmitted electromagnetic wave (32). The controller (24) is further operable to write patterns (68, 80) into the programmable reflection surface (22) to dynamically adjust adaptive antenna system (20) to changing frequencies and directions of transmitted and received electromagnetic waves.Type: GrantFiled: May 9, 2002Date of Patent: April 13, 2004Assignee: BBNT Solutions LLCInventors: Richard M. Koolish, Brig Barnum Elliott
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Patent number: 6721103Abstract: A dielectric lens including a plurality of wedges being formed from a dielectric material, each of the plurality of wedges being substantially identical and orange-slice shaped and including two planar surfaces separated by an angular width, and each of the plurality of wedges having a plurality of gaps for altering an effective permittivity of the dielectric lens, wherein the plurality of wedges form the dielectric lens by connecting the plurality of wedges along the planar surfaces such that each of the planar surfaces intersect along a common line.Type: GrantFiled: September 30, 2002Date of Patent: April 13, 2004Assignee: EMS Technologies Canada Ltd.Inventor: Peter C. Strickland
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Publication number: 20040066340Abstract: A multi layered high impedance structure presents a high impedance to multiple frequency signals, with a different frequency for each layer. Each layer comprises a dielectric substrate, and an array of radiating elements such as parallel conductive strips or conductive patches on the substrate's top surface, with a conductive layer on the bottom surface of the bottommost layer. The radiating elements of succeeding layers are vertically aligned with conductive vias extending through the substrates to connect the radiating elements to the ground plane. Each layer presents as a series of parallel resonant L-C circuits to an E field at a particular signal frequency, resulting in a high impedance surface at that frequency. The new structure can be used as the substrate for a microstrip patch antenna to provide an optimal electrical distance between the resonator and backplane at multiple frequencies.Type: ApplicationFiled: September 26, 2003Publication date: April 8, 2004Applicant: Rockwell Technologies, LLCInventors: Jonathan Bruce Hacker, Moonil Kim, John A. Higgins
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Patent number: 6703979Abstract: A grating comprising a plurality of substantially parallel members having a conducting surface of depth L, separated by a dielectric layer gap, and having of pitch &lgr;g and where L>16&lgr;g. The members are preferably metallic or comprise metallic foil covered plastic. The gap may be filled wholly or partially with dielectric material including liquid crystal whose refractive index can be controlled by suitable application of voltage across the gap.Type: GrantFiled: September 6, 2002Date of Patent: March 9, 2004Assignee: QinetiQ LimitedInventors: John R Sambles, Christopher R Lawrence
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Patent number: 6703981Abstract: One or more electrochromic surfaces (11) (formed on rigid or flexible carrier surfaces) are used in various ways with one or more radio frequency energy radiating elements (10) and/or guiding elements (91 and 120) to lend selective reflectivity to achieve greater resultant control over directionality, gain, phase, and/or shape of the radiated energy.Type: GrantFiled: June 5, 2002Date of Patent: March 9, 2004Assignee: Motorola, Inc.Inventors: William Meitzler, Paul Vonallmen
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Publication number: 20040041741Abstract: An antenna comprising: (a) semi-conductor means (1) having upper and lower surfaces; the upper and lower surfaces having a pattern of electrically conducting regions; (b) first generating means (9, 10) for generating conducting plasma filaments of charged carrier between the upper and lower conducting regions; (c) radio frequency feed means (8) to selected ones of the conducting plasma filaments in order to couple radio frequency energy to or from the semi-conductor means; and (d) second generating means for selectively generating a pattern of conductive filaments between the surfaces of the semi-conductor means in order to reflect and thereby to focus an electromagnetic wavefront incident upon an edge of the semi-conductor means to at least one radio frequency feed point within the semi-conductor means; and the antenna being planar dielectric lens antenna with controlled conductive elements forming a direction antenna for the reception or transmission of a beam frequency energy in the plane of the semi-conduType: ApplicationFiled: December 20, 2002Publication date: March 4, 2004Inventor: David Hayes
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Patent number: 6693605Abstract: A wave plate (10) formed of a perforated metallic plate of a particular thickness (L) has circular holes (12) 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.Type: GrantFiled: August 30, 2002Date of Patent: February 17, 2004Assignee: Raytheon CompanyInventors: David D. Crouch, Alan A. Rattray
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Publication number: 20040021607Abstract: A multisource antenna includes at least two excitation sources and for spatially channeling energy picked up/radiated by the excitation sources and providing for frequency decoupling between the bands respectively corresponding to the waves received/transmitted by the sources. The sources are arranged on a ground plane to interleave radiating apertures at the level of the spatial and frequency selective arrangements.Type: ApplicationFiled: July 28, 2003Publication date: February 5, 2004Applicant: ALCATELInventor: Herve Legay
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Publication number: 20040017331Abstract: A radio frequency reconfigurable lens is provided. In particular, a lens comprising at least two opposed frequency selective surface sheets is provided. A relative phase shift may be imparted to an incident radio frequency wave by varying the distance between at least some of the unit cells of a first of the FSS sheets and adjacent unit cells on a second of the FSS sheets. In order to provide a desired phase taper across the width of a lens, and/or to provide different phase shift amounts, pairs of FSS surfaces having controllable columns or rows can be cascaded together. According to an additional aspect of the present invention, radio frequency waves can be scanned by cascading multiple tunable stages. The present invention also provides a radio frequency shutter.Type: ApplicationFiled: July 29, 2002Publication date: January 29, 2004Applicant: Ball Aerospace and Technologies Corp.Inventors: Thomas M. Crawford, P. Keith Kelly, Farzin Lalezari, Theresa C. Boone
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Patent number: 6680711Abstract: An antenna system includes a feedhorn, main reflector, sub-reflector, and frequency selective member. The sub-reflector includes an axially symmetrical reflecting surface. The frequency selective member includes an axially non-symmetrical reflecting surface. The frequency selective member transmits signals having a first frequency from the feedhorn to the sub-reflector. These signals are symmetrically reflected by the sub-reflector to the main reflector. The frequency selective member reflects signals having a second frequency from the main reflector to the feedhorn. These signals are reflected at a small conical angle by the frequency selective member to the feedhorn. In this way, the present transmit/receive system provides coincident transmit and receive signals with only conically scanned receive signals.Type: GrantFiled: July 9, 2002Date of Patent: January 20, 2004Assignee: The Boeing CompanyInventors: Glen J. Desargant, Albert L. Bien
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Publication number: 20040008145Abstract: A spatial filtering surface includes a dielectric substrate and a plurality of spaced, geometrically configured, resonant elements positioned on the dielectric substrate. The resonant elements form concentric rings that each attenuate any electromagnetic radiation passing therethrough a different amount wherein a spatial filter transform is imparted for tapering the magnitude and phase of a produced aperture field.Type: ApplicationFiled: July 11, 2002Publication date: January 15, 2004Applicant: Harris CorporationInventors: William D. Killen, Heriberto Delgado
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Publication number: 20040008148Abstract: A method and system for shaped beam and multiple frequency use having a shaped main reflector, two feeds having separate and distinct frequency bands, a first shaped sub-reflector having a frequency selective surface and a second shaped sub-reflector. The first shaped sub-reflector has the electrical property of reflecting one frequency band and passing another. A second desired frequency band from the second feed passes through the tuned FSS surface of the first sub-reflector and reflects off the second sub-reflector towards the main reflector.Type: ApplicationFiled: July 10, 2002Publication date: January 15, 2004Inventors: Albert E. Lyerly, Parthasarathy Ramanujam
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Patent number: 6670932Abstract: An artificial magnetic conductor includes a frequency selective surface having a frequency dependent permeability &mgr;1z in a direction normal to the frequency dependent surface, a conductive ground plane, and a rodded media disposed between the frequency selective surface and the conductive ground plane.Type: GrantFiled: November 1, 2000Date of Patent: December 30, 2003Assignee: E-Tenna CorporationInventors: Rodolfo E. Diaz, William E. McKinzie, III
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Patent number: 6670928Abstract: An active electronic scan microwave reflector, capable of being illuminated by a microwave source to form an antenna. The reflector includes a set of elementary cells arranged side by side on a surface, each cell including a phase-shifting microwave circuit and a conductor plate arranged substantially parallel to the microwave circuit, the phase-shifting circuit including at least two half-phase-shifters. One half-phase-shifter includes at least a dielectric support, at least two electrically conductive wires substantially parallel to a given direction, arranged on the support and bearing at least a two-state semiconductor element, the conductors being substantially normal to the wires, and two conductor zones arranged towards the periphery of the cell, substantially parallel to the control conductors.Type: GrantFiled: May 28, 2002Date of Patent: December 30, 2003Assignee: ThalesInventors: Claude Chekroun, Jean-Paul Largent
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Patent number: 6670921Abstract: A flexible antenna array comprises a plurality of layers of thin metal and a flexible insulating medium arranged as a sandwich of layers. Each layer of the sandwich is patterned as needed to define: (i) antenna segments patterned in one of the metal layers, (ii) an array of metallic top elements formed in a layer spaced from the the antenna segments, the array of metallic top elements being patterned in another metal layer, (iii) a metallic ground plane formed in a layer spaced from the array of metallic top elements, the metallic ground plane having been formed from still another metal layer, and (iv) inductive elements coupling each of the top elements in the array of metallic top elements with said ground plan. An array of remotely controlled switches are provided for coupling selected ones of said antenna segments together.Type: GrantFiled: July 13, 2001Date of Patent: December 30, 2003Assignees: HRL Laboratories, LLC, Raytheon CompanyInventors: Daniel F. Sievenpiper, Adele E. Schmitz, James H. Schaffner, Gregory L. Tangonan, Tsung-Yuan Hsu, Robert Y. Loo, Robert S. Miles
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Publication number: 20030231142Abstract: A multi-band artificial magnetic conductor (AMC) is described in an electrically small antenna for use in handheld wireless devices and base station antenna applications. The multi-band AMC contains a ground plane, two or more frequency selected surfaces (FSS) having periodic conductive patches disposed on opposing surfaces and a dielectric layer sandwiched between the surfaces, and dielectric layers between the FSS layers and between the lower FSS layer and the ground plane. Various parameters of the dual band AMC are chosen such that the AMC has non-harmonically related resonant frequencies within two or more different frequency bands.Type: ApplicationFiled: June 14, 2002Publication date: December 18, 2003Inventors: William E. McKinzie, Shawn D. Rogers
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Publication number: 20030227417Abstract: An apparatus and method to twist the field polarization of an electromagnetic wave over a desired frequency band is described. In one embodiment, a transmission twister rotates the polarization of a linearly-polarized incident field to produce a transmitted field. In one embodiment, the transmission twister includes a resonant polarization-twisting array between two linearly-polarized arrays. In one embodiment, the transmission twister rotates the polarization by 90 degrees. In one embodiment, the transmission twister produces low reflection of a desired incident polarization. In one embodiment, the transmission twister has a transmission coefficient (with respect to the desired incident field polarization and a correspondingly rotated transmitted field polarization) close to unity.Type: ApplicationFiled: January 17, 2003Publication date: December 11, 2003Inventors: Errol K. English, Ethan C. Saladin
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Publication number: 20030218576Abstract: System and method for improving the interference resistance of an radio frequency (RF) antenna system through passive prescreening of the RF energy incident upon the antenna. The invention physically partitions the RF environment into two or more sectors with respect to the direction of arrival of incident energy. The power level of the RF frequencies of interest incident upon each sector is determined such that whenever the power level exceeds a given threshold, the received signal from energy incident on that sector is modified.Type: ApplicationFiled: September 5, 2002Publication date: November 27, 2003Inventors: Cordell Fox, Kevin Wing, Robert A. Murphy, David C. Priester
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Publication number: 20030214456Abstract: A method for designing a multiple layer frequency selective surface structure. An overall response for the structure is specified. The desired response may be modeled as a filter response. Parameters for each of the layers making up the structure that provide the overall response are determined based on the polarization modes between the layers being decoupled. To provide for decoupling, the individual layers are rotated with respect to each other. The overall response of the structure is then calculated and compared to the desired response. Adjustments are made in the parameters of each layer until the calculated response is equal or nearly equal to the desired response.Type: ApplicationFiled: March 6, 2003Publication date: November 20, 2003Applicant: HRL LABORATORIES, LLCInventors: Jonathan J. Lynch, Joseph S. Colburn
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Publication number: 20030214439Abstract: A low cross-polarization microstrip patch array antenna includes a microstrip patch array, an antenna substrate, a ground plane and a polarizer. The polarizer mounts over the array and includes a low dielectric spacer, a thin polarizer substrate mounted on the spacer and a plurality of uniformly spaced, thin, conductive strips on the polarizer substrate. The strips extend perpendicular to the direction of desired radiation and parallel to the direction of undesired radiation.Type: ApplicationFiled: May 20, 2002Publication date: November 20, 2003Inventor: Donald A. Huebner
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Publication number: 20030214451Abstract: A multibeam antenna apparatus is disclosed. The multibeam antenna apparatus includes a main reflector (1), a sub-reflector (2), a focused beam feeder (3), a primary radiator array (5) having a plurality of primary radiators (5a), and a lens array (10) having a plurality of wavefront transformation lenses (10a) corresponding to the plurality of primary radiators (5a), respectively. The lens array (10) can be placed in the vicinity of a front end of the primary radiator array (5). As an alternative, the lens array (10) is placed in an electric wave propagation range of the focused beam feeder (3) where multiple beams which constitute a multibeam are spatially isolated from one another in terms of electric power. Thus the multibeam antenna apparatus can prevent an error from occurring in the orientation of each beam.Type: ApplicationFiled: November 4, 2002Publication date: November 20, 2003Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventors: Tomohiro Mizuno, Hiroyuki Satou, Izuru Naitou, Soichi Matsumoto
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Publication number: 20030214457Abstract: An antenna apparatus such that a dielectric strip and a dielectric resonator are provided for form a primary vertical radiator, another dielectric strip is provided which is coupled to the dielectric strip to form a directional coupler, and a radiation beam is tilted by changing the relative position of the primary radiator with respect to the dielectric lens by displacing the primary vertical radiator in the direction coupler.Type: ApplicationFiled: March 12, 2003Publication date: November 20, 2003Applicant: Murata Manufacturing Co., Ltd.Inventors: Yohei Ishikawa, Toru Tanizaki, Fuminori Nakamura, Ikuo Takakuwa
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Publication number: 20030197658Abstract: An antenna consisting of a thin strip bent-wire monopole disposed on an artificial magnetic conductor (AMC) is loaded at the end opposite to the feed point with a distributed or lumped capacitance to achieve an electrically small antenna for use in handheld wireless devices. The capacitive load reduces the length of the antenna to smaller than one-quarter of a wavelength at a given frequency of operation without suffering a substantial loss of efficiency. This results in an easier integration into portable devices, greater radiation efficiency than other loaded antenna approaches and longer battery life in portable devices, and lower cost than use of a chip inductor.Type: ApplicationFiled: December 5, 2002Publication date: October 23, 2003Inventors: James D. Lilly, William E. McKinzie, David T. Auckland, Andrew Humen
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Patent number: 6633744Abstract: A ground-based antenna for use with a satellite communications (SATCOM) system that reduces interference from geosynchronous earth orbit (GEO) satellites. Because GEO satellites that provide coverage of the continental United States (CONUS) are uniformly separated along an equatorial arc around the earth, the GEO satellites are approximately uniformly separated in sine space when viewed from a ground terminal located within CONUS over typical communications frequency bands, such as the Ka band (29-39 GHz) and the Ku band (10-15 GHz). The invention can reduce interference by providing an uniformly illuminated rectangular aperture, in which the horizontal dimension is chosen so when the aperture is normal to a transmission axis between the antenna and the Nth satellite of a SATCOM systems, the nulls of the antenna radiation pattern align with the N±1, N±2, N±3, . . . satellites.Type: GrantFiled: October 12, 1999Date of Patent: October 14, 2003Assignee: EMS Technologies, Inc.Inventor: James M. Howell
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Publication number: 20030184497Abstract: An antenna employs cylindrical Fresnel zone plate (CFZP) construction in combination with a reflective ground plate and a sectorial reflector to enhance antenna gain, while lowering assembly cost and improving antenna placement flexibility. By forming a surface of symmetry for the antenna, the ground plate allows the antenna to mimic the operation of a symmetrical CFZP antenna using only half the nominal number of Fresnel elements. Further, the sectorial reflector restricts radiated emissions over a desired sector angle, minimizing radiation in undesirable directions, such as toward mounting walls or other nearby surfaces that would cause unwanted signal reflections, such as might aggravate multipath signal phenomenon.Type: ApplicationFiled: August 8, 2002Publication date: October 2, 2003Inventors: Chunfei Ye, Erping Li
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Patent number: 6628242Abstract: A multi layered high impedance structure presents a high impedance to multiple frequency signals, with a different frequency for each layer. Each layer comprises a dielectric substrate, and an array of radiating elements such as parallel conductive strips or conductive patches on the substrate's top surface with a conductive layer on the bottom surface of the bottommost layer. The radiating elements of succeeding layers are vertically aligned with conductive vias extending through the substrates to connect the radiating elements to the ground plane. Each layer presents as a series of parallel resonant L-C circuits to an E field at a particular signal frequency, resulting in a high impedance surface at that frequency. The new structure can be used as the substrate for a microstrip patch antenna to provide an optimal electrical distance between the resonator and backplane at multiple frequencies.Type: GrantFiled: August 23, 2000Date of Patent: September 30, 2003Assignee: Innovative Technology Licensing, LLCInventors: Jonathan Bruce Hacker, Moonil Kim, John A. Higgins
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Patent number: 6621461Abstract: A method for broadcasting, a signal, and an antenna system are disclosed. The antenna system comprises a feed horn and a reflector. The feed horn provides a radio frequency (RF) signal. The reflector is aligned with the feed horn and is illuminated by the feed horn, and comprises a reflective grid. The reflective grid lines are substantially parallel as viewed from a geographic location of a desired output beam from the antenna system. A method in accordance with the present invention comprises illuminating a reflector with an RF signal emanating from a feed horn, the feed horn being substantially located at a focal point of the reflector, wherein the reflector comprises a reflective grid, and reflecting the RF signal with the reflective grid, wherein lines of the reflective grid are substantially parallel as viewed from a geographic location of a desired output beam from the antenna system.Type: GrantFiled: August 9, 2000Date of Patent: September 16, 2003Assignee: Hughes Electronics CorporationInventors: Parthasarathy Ramanujam, Brian M. Park, Paul E. Guillaume, Cameron Massey
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Publication number: 20030164803Abstract: A high performance multi-band antenna reflector having low sidelobe and cross polarization levels, and a superior carrier-to-interference ratio has two concentric zones (12, 14 in a first embodiment and 102, 104 in a second embodiment). In the first embodiment, the outer concentric zone (14) is a frequency selective absorber (20) made of a metallic pattern (22) dimensioned to reflect signals in one frequency band and absorb signals in a second frequency band. In the second embodiment, the outer concentric zone (104) is a frequency selective surface (106) that reflects signals in one frequency band and passes signals in a second frequency bands. Resistance cards (122) overlay the top and bottom sides of the junction between the frequency selective surface (106) and a reflective layer (110) on an inner surface (112) of the central concentric zone (102).Type: ApplicationFiled: April 3, 2003Publication date: September 4, 2003Inventor: Te-Kao Wu
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Patent number: 6608607Abstract: A high performance multi-band antenna reflector having low sidelobe and cross polarization levels, and a superior carrier-to-interference ratio has two concentric zones (12, 14 in a first embodiment and 102, 104 in a second embodiment). In the first embodiment, the outer concentric zone (14) is a frequency selective absorber (20) made of a metallic pattern (22) dimensioned to reflect signals in one frequency band and absorb signals in a second frequency band. In the second embodiment, the outer concentric zone (104) is a frequency selective surface (106) that reflects signals in one frequency band and passes signals in a second frequency bands. Resistance cards (122) overlay the top and bottom sides of the junction between the frequency selective surface (106) and a reflective layer (110) on an inner surface (112) of the central concentric zone (102).Type: GrantFiled: November 27, 2001Date of Patent: August 19, 2003Assignee: Northrop Grumman CorporationInventor: Te-Kao Wu
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Patent number: 6606076Abstract: A reflective panel for deflecting electromagnetic waves comprised of a resistive material varying in resistivity across the panel; a center portion on the panel, having a predetermined resistivity; a periphery portion on the panel having a higher resistivity than the center portion; and wherein the center portion of the panel is adapted to reflect the electromagnetic waves and wherein the periphery portion is adapted to minimize diffractions.Type: GrantFiled: February 28, 2001Date of Patent: August 12, 2003Assignee: The Ohio State UniversityInventors: Walter D. Burnside, David Steinberger, Chiwei Chuang
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Patent number: 6606077Abstract: A multi-beam antenna comprises an electromagnetic lens, at least one first antenna feed element, at least one second antenna feed element, and a selective element located between first and second portions of the electromagnetic lens with which the respective antenna feed elements respectively cooperate. The transmissivity and reflectivity of the selective element are responsive to an electromagnetic wave property, e.g. frequency or polarization. A first electromagnetic wave in cooperation with the at least one first antenna feed element and having a first value of the electromagnetic wave property is substantially transmitted through the selective element so as to propagate in both the first and second portions of the electromagnetic lens. A second electromagnetic wave in cooperation with the at least one second antenna feed element and having a second value of the electromagnetic wave property is substantially reflected by the selective element.Type: GrantFiled: July 23, 2002Date of Patent: August 12, 2003Assignee: Automotive Systems Laboratory, Inc.Inventors: James P. Ebling, Gabriel Rebeiz
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Publication number: 20030142036Abstract: A frequency selective surface includes a pattern of electromagnetic material formed on a substrate suspendable over a ground plane for reflecting or transmitting electromagnetic waves at one or more particular frequencies. The frequency selective surface may include one or more meandering line inductors and/or one or more interdigitated capacitors formed within the pattern of electromagnetic materials for adjusting the frequencies at which the electromagnetic waves are reflected or transmitted. The frequency selective surface may also or instead include one or more inductors and/or one or more capacitors arranged in series within the pattern of electromagnetic materials to adjust the frequencies at which the electromagnetic waves are reflected or transmitted. In addition, the pattern of electromagnetic materials may be formed within the substrate in such a manner that the frequencies at which the electromagnetic waves are reflected or transmitted are tunable.Type: ApplicationFiled: November 27, 2002Publication date: July 31, 2003Inventors: Michael John Wilhelm, Douglas H. Werner, Pingjuan L. Werner, Jeffrey S. Daniels, Lance D. Swann, William L. Warren
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Publication number: 20030137457Abstract: A direct current (DC) inductive shorted patch antenna includes a direct current inductive (DCL) frequency selective surface (FSS) forming the radiating element, a ground plane, a feed, and a radio frequency (RF) short to the ground plane positioned between the feed and the radiating element.Type: ApplicationFiled: September 12, 2002Publication date: July 24, 2003Applicant: e-tenna CorporationInventors: William E. McKinzie, Greg S. Mendolia, John Dutton
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Patent number: 6597327Abstract: A reconfigurable adaptive wideband antenna includes a reconfigurable conductive substrate for dynamic reconfigurablility of the frequency, polarization, bandwidth, number of beams and their spatial directions, and the shape of the radiation pattern. The antenna is configured as a reflect array antenna having a single broadband feed. Reflective elements are electronically painted on the reconfigurable conductive surface using plasma injection of carriers in high-resistivity semiconductors.Type: GrantFiled: January 26, 2001Date of Patent: July 22, 2003Assignee: Sarnoff CorporationInventors: Sridhar Kanamaluru, Aly E. Fathy, Ayre Rosen