Patents Assigned to EMS Technologies
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Patent number: 6407716Abstract: The present invention provides a dichroic surface with a pointed resonator cross grid pattern that offers enhanced bandwidth and a sharper response between frequency bands. The dichroic surface is fabricated as a self-adhesive decal, conforming the dichroic surface to the surface of the reflector antenna.Type: GrantFiled: April 19, 2001Date of Patent: June 18, 2002Assignee: EMS Technologies Canada, Ltd.Inventors: Peter C. Strickland, Timothy E. Best
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Patent number: 6396453Abstract: A multimode horn used to feed an antenna includes a generally conical wall for transmitting and/or receiving an electromagnetic signal there through. The wall flares radially outwardly from a throat section to an aperture and defines an internal surface having a plurality of discontinuities formed thereon and made out of electrically conductive material. The geometry of the discontinuities are configured and sized for altering the higher order mode content of the signal to achieve a balance between a plurality of performance parameters of the antenna over at least one pre-determined frequency range of the signal. The discontinuities are selected from the group consisting of local smooth profile, step, corrugation and choke.Type: GrantFiled: April 13, 2001Date of Patent: May 28, 2002Assignee: EMS Technologies Canada, Ltd.Inventors: Eric Amyotte, Martin Gimersky, Aping Liang, Chuck Mok, Ralph Pokuls
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Patent number: 6396448Abstract: An antenna comprising a feed for delivering electromagnetic energy to a rotatable combination of a dielectric lens and a reflective surface. The combination of the dielectric lens and the reflective surface is placed proximate to and in front of an energy feed, such as a horn, to support the scanning of an antenna beam in response to rotation of the lens/reflective surface assembly. The lens typically comprises a dielectric material and the reflective surface can comprise a thin layer of material operable to reflect electromagnetic energy. For example, the lens can comprise a half-cylinder shape of dielectric material and the reflective surface can be applied to the flat portion of the half-cylindrical lens. Alternatively, the antenna can comprise two or more electromagnetic feeds and a cylindrical lens of dielectric material including a centrally-embedded, two-sided reflective surface.Type: GrantFiled: August 15, 2000Date of Patent: May 28, 2002Assignee: EMS Technologies, Inc.Inventors: Kurt Alan Zimmerman, John Elliott Wann, Robert Alan Freeman, Donald Nelson Black, Jr., James Charles Marsik
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Patent number: 6392600Abstract: A compact antenna system can generate RF radiation fields having increased beamwidths and bandwidths. The antenna system can include one or more patch radiators separated from each other by an air dielectric and by relatively small spacer elements. The lower patch radiators can be mounted to a printed circuit board that can include an RF feed network and a ground plane which defines a plurality of symmetrically, shaped slots. The slots within the ground plane of the printed circuit board can be excited by stubs that are part of the feed network of the printed circuit board. The slots, in turn, can establish a transverse magnetic mode of RF radiation in a cavity which is disposed adjacent to the ground plane of the printed circuit board and a ground plane of the antenna system. The feed network of the printed circuit board can be aligned with portions of the cavity such that the portions of the cavity function as a heat sink for absorbing or receiving thermal energy produced by the feed network.Type: GrantFiled: February 16, 2001Date of Patent: May 21, 2002Assignee: EMS Technologies, Inc.Inventors: James C. Carson, James K. Tillery, Sara Phillips
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Publication number: 20020050955Abstract: An antenna assembly comprising a radiating element which passively receives a signal fed by a vertically-stacked pair of asymmetrically-shaped, conductive cone elements mounted below the radiating element. The cone elements are centrally fed by a coaxial cable input at a common junction formed the apex of each cone element. This antenna assembly provides a low-profile antenna to transmit and receive radio frequency (RF) energy with high gain and desirable antenna patterns for data transmission in an in-building, wireless local area network. The antenna assembly can be mounted in a standard ceiling or wall-mounted enclosure, with the low-profile antenna extending beneath the surface of a conductive enclosure cover that serves as the ground plane for the antenna element. This configuration achieves high antenna gain with a downtilt-beam, omnidirectional radiation pattern, which is highly desirable in an in-building wireless local area network (WLAN) application.Type: ApplicationFiled: October 17, 2001Publication date: May 2, 2002Applicant: EMS Technologies, Inc.Inventors: Peter C. Strickland, Kurt Alan Zimmerman, John Elliott Wann, Thomas Steven Taylor
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Patent number: 6369766Abstract: An antenna assembly comprising a radiating element which passively receives a signal fed by a vertically-stacked pair of asymmetrically-shaped, conductive cone elements mounted below the radiating element. The cone elements are centrally fed by a coaxial cable input at a common junction formed the apex of each cone element. This antenna assembly provides a low-profile antenna to transmit and receive radio frequency (RF) energy with high gain and desirable antenna patterns for data transmission in an in-building, wireless local area network. The antenna assembly can be mounted in a standard ceiling or wall-mounted enclosure, with the low-profile antenna extending beneath the surface of a conductive enclosure cover that serves as the ground plane for the antenna element. This configuration achieves high antenna gain with a downtilt-beam, omnidirectional radiation pattern, which is highly desirable in an in-building wireless local area network (WLAN) application.Type: GrantFiled: December 14, 1999Date of Patent: April 9, 2002Assignee: EMS Technologies, Inc.Inventors: Peter C. Strickland, Kurt Alan Zimmerman, John Elliott Wann, Thomas Steven Taylor
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Patent number: 6232928Abstract: Antenna mounting bracket assembly having a spine, an upper bracket, a lower bracket and a cam bracket for mounting an antenna on a support structure, such as a vertical pole and for providing adjustment of the antenna's downwards tilt position. The spine provides for the proper spacing and rotational alignment between the upper and lower ends of the accompanying antenna. The cam bracket can allow either analog or digital adjustment of the downwards tilt position of the antenna. The assembly can allow for the installation of the antenna upon the support structure by a single technician.Type: GrantFiled: February 3, 2000Date of Patent: May 15, 2001Assignee: EMS Technologies, Inc.Inventors: Kurt A. Zimmerman, James W. Maxwell
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Patent number: 6211840Abstract: An antenna comprising at least one dipole, the dipole comprising a pair of arms drooping relative to a plane orthogonal to a central axis, end portions of the arms being bent back toward the central axis. In one form of the invention the arms are bent back toward the central axis in at least one plane which is parallel to the central axis, and in another form of the invention the dipole arms are bent in the same rotational direction out of a pland which includes the central axis.Type: GrantFiled: October 16, 1998Date of Patent: April 3, 2001Assignee: EMS Technologies Canada, Ltd.Inventors: Peter John Wood, Peter C. Strickland, Senglee Foo, Timothy Edward Best
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Patent number: 6208304Abstract: An aircraft mounted antenna system comprising a plurality of linear blade antenna arrays mounted on an upper portion of an aircraft fuselage. The blade arrays are symmetrically placed on the fuselage about a plane vertically bisecting the upper portion of the fuselage. The placement of the blade arrays is such that large scanning angle gain losses are minimized as the blade arrays on one side of the fuselage hand off the satellite tracking, acquisition, and communication to the blade arrays on the other side of the fuselage as the scanning angle increases.Type: GrantFiled: May 10, 1999Date of Patent: March 27, 2001Assignee: EMS Technologies Canada, Ltd.Inventor: Peter C. Strickland
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Patent number: 6181298Abstract: An improved top fed quadrafilar helical antenna that provides circular polarization with near uniform gain over the upper hemisphere. The antenna comprises a pair of crossed printed circuit boards with two feed lines and two horizontal arms per board and four piecewise linear conductors. Each arm is connected to a feed line and to the end of a conductor that is piecewise linearly attached to the edges of the crossed printed circuit boards.Type: GrantFiled: August 19, 1999Date of Patent: January 30, 2001Assignee: EMS Technologies Canada, Ltd.Inventor: Peter C. Strickland
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Patent number: 6127985Abstract: A waveguide-implemented antenna comprising a planar array of waveguide slot radiators for communicating electromagnetic signals exhibiting simultaneous dual polarization states. The antenna can consist of parallel ridged waveguides having rectangular or "T"-shaped ridged cross sections. The ridged walls of each parallel ridged waveguide contain a linear array of input slots for receiving (transmitting) electromagnetic signals having a first polarization state from (to) the parallel ridged waveguides and for transmitting (receiving) those signals into (from) a corresponding array of cavity sections. The cavity sections comprise a short section of uniform waveguide with a thickness of much less than a wavelength in the propagation direction. The cavity sections feed to output slots which are rotated relative to the input slots; such that the output slots exhibit a second polarization state, which they radiate (receive) to (from) free space.Type: GrantFiled: March 1, 1999Date of Patent: October 3, 2000Assignee: EMS Technologies, Inc.Inventor: Michael G. Guler
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Patent number: 6072437Abstract: Varying the azimuth and elevation beam patterns for an antenna. For a horn-type antenna implemented by a parallel-plate waveguide structure, an input port can accept an electromagnetic signal and an output slot can transmit the electromagnetic signal. An azimuth lens can be placed proximate to the output slot for adjusting the antenna beam pattern within the azimuth plane. The azimuth lens comprises two or more lens elements, each typically having a cylindrical shape and comprising a dielectric material, which support the generation of discrete beams in the azimuth plane in response to the electromagnetic signal output by the output slot. These discrete beams can sum in-phase to form a composite beam having a shape or pattern generally defined by the characteristics of the azimuth lens elements. Specifically, this composite beam has a pattern within the azimuth plane defined by the size and shape of the azimuth lens elements and the spacing between these elements.Type: GrantFiled: June 29, 1998Date of Patent: June 6, 2000Assignee: EMS Technologies, Inc.Inventors: Kurt A. Zimmerman, James M. Howell, James P. Montgomery
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Patent number: 6069590Abstract: An antenna having feedback elements for improving the isolation characteristic of the antenna by generating a feedback signal that operates to cancel an undesired leakage signal coupling from an input port to an output port of the antenna system. The antenna can include a distribution network for electrically coupling the electromagnetic signals from and to radiating elements and a radome structure for protecting both the radiating elements and the distribution network from exposure to the operating environment of the antenna. The radome structure can include feedback elements for electrically cooperating with the radiating elements of the antenna system. Electromagnetic signals transmitted by the radiating elements can be coupled to the feedback elements, which results in the feedback elements resonating at the frequency of the transmitted electromagnetic signals. These resonating feedback elements can generate a feedback signal that, in turn, is received by the radiating elements.Type: GrantFiled: February 20, 1998Date of Patent: May 30, 2000Assignee: EMS Technologies, Inc.Inventors: James Ernest Thompson, Jr., Po Than
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Patent number: 6067053Abstract: A planar array antenna having radiating elements characterized by dual simultaneous polarization states and having substantially rotationally symmetric radiation patterns. A distribution network, which is connected to each dual polarized radiator, communicates the electromagnetic signals from and to each radiating element. A ground plane is positioned generally parallel to and spaced apart from the radiating elements by a predetermined distance. The conductive surface of the ground plane operates to image the radiating elements over a wide coverage area, thereby enabling a radiation pattern within an azimuth plane of the antenna to be independent of any quantity of radiating elements. Side walls, placed on each side of the array of radiators, can operate in tandem with the ground plane, to reduce the half-power beamwidth in the azimuth plane for a selected radiator design.Type: GrantFiled: October 18, 1996Date of Patent: May 23, 2000Assignee: EMS Technologies, Inc.Inventors: Donald L. Runyon, James E. Thompson, Jr., James C. Carson
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Patent number: 6028562Abstract: A waveguide-implemented antenna comprising a planar array of waveguide slot radiators for communicating electromagnetic signals exhibiting simultaneous dual polarization states. The antenna can consist of parallel waveguides of rectangular or ridged cross section. The broadwalls of each parallel waveguide contain a linear array of input slots for receiving (transmitting) electromagnetic signals having a first polarization state from (to) the parallel waveguide and for transmitting (receiving) those signals into (from) an array of cavity sections. The cavity sections comprise a short section of uniform waveguide with a length of much less than a wavelength in the propagation direction. The cavity sections feed to output slots which are rotated relative to the input slots; such that the output slots exhibit a second polarization state, which they radiate (receive) to (from) free space.Type: GrantFiled: July 31, 1997Date of Patent: February 22, 2000Assignee: EMS Technologies, Inc.Inventors: Michael G. Guler, James P. Montgomery
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Patent number: 6011520Abstract: A geodesic slotted cylindrical (GSC) antenna having a shaped elevation pattern and a narrow or shaped azimuth beam that can be scanned 360.degree. in the azimuth plane. The azimuth radiation pattern of the GSC antenna can be reconfigured through the use of interchangeable beam forming feed networks. The GSC antenna comprises a parallel plate waveguide formed by spaced-apart inner and outer cylinders constructed from conductive material. Radiation occurs from a stack of circumferential slots in the outer cylinder. By varying the slot spacing with the azimuth angle, the elevation pattern can be altered as a function of the azimuth angle. The GSC antenna can be excited by a number of equally spaced probes on a circle at the base of the cylinders. The feed radius is typically smaller than the outer cylinder's radius to minimize the number of active components and to minimize the number of spurious ray paths that can wrap around inside the cylinder's parallel plate region.Type: GrantFiled: February 18, 1998Date of Patent: January 4, 2000Assignee: EMS Technologies, Inc.Inventors: James M. Howell, Thomas E. Sharon
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Patent number: 6005884Abstract: A data communications system characterized by the combination of a base station connected to a plurality of repeaters for communicating with remote terminals in response to outgoing data from a host computer and for communicating with the host computer in response to incoming data from the remote terminals. Each repeater is assigned a coverage area with in a predetermined communications area to support data communications with the remote terminals located within its coverage area. In response to incoming data, a repeater conducts a signal amplification operation and outputs amplified incoming data to the base station via a first communications link. The base station processes the amplified incoming data and, in turn, generates processed incoming data for distribution to the host computer via a second communications link.Type: GrantFiled: November 6, 1995Date of Patent: December 21, 1999Assignee: EMS Technologies, Inc.Inventors: Joel Powell Cook, Randolph Raymond Beebe, Thomas Edward Sharon
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Patent number: 5986526Abstract: An adjustable RF microwave tuning post for use in an RF cavity is disclosed. It is comprised of a flexible integrally-formed hollow tuning post disposed in the RF cavity. A drive shaft extending internally of the tuning post is provided to vary the dimensions of the tuning post. The drive shaft is connected to the tuning post at the top end thereof and connected at the other end of the drive shaft to an adjusting nut. The tuning post is made flexible by the use of bellows, which in a preferred embodiment of the invention is located along the side walls thereof.Type: GrantFiled: March 3, 1997Date of Patent: November 16, 1999Assignee: EMS Technologies Canada, Ltd.Inventors: Josef Kopal, Gerard Senechal, Andre Bouvrette, Jean-Michel Levesque, Kanti Patel, Christopher Yong, Yves Patenaude, Alexander Csaki, Yvan Cote, Gerard Carrier, Serge Samson
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Patent number: 5973310Abstract: A method of processing an electromagnetic signal received and contained completely within the bounds of a two dimensional signal detection array, is comprised of (a) determining a position of the signal in a large window on the detector array, (b) reducing the dimensions of the window by a predetermined ratio with the position of the signal at the center thereof, (c) locating the position of the signal in the reduced size window (d) repeating steps (b) and (c) until the window is a predetermined number of pixels in size, and (e) continuously monitoring the presence and location of the signal.Type: GrantFiled: December 10, 1997Date of Patent: October 26, 1999Assignee: EMS Technologies Canada, Ltd.Inventor: Wolfram Lunscher
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Patent number: 5966102Abstract: A planar array antenna having radiating elements characterized by dual simultaneous polarization states and having substantially rotationally symmetric radiation patterns. A distribution network, which is connected to each dual polarized radiator, communicates the electromagnetic signals from and to each radiating element. A ground plane is positioned generally parallel to and spaced apart from the radiating elements by a predetermined distance. The conductive surface of the ground plane operates to image the radiating elements over a wide coverage area, thereby enabling a radiation pattern within an azimuth plane of the antenna to be independent of any quantity of radiating elements. A central polarization control network (PCN), which is connected to the distribution network, can control the polarization states of the received signals distributed via the distribution network by the radiating elements.Type: GrantFiled: December 14, 1995Date of Patent: October 12, 1999Assignee: EMS Technologies, Inc.Inventor: Donald L. Runyon