Patents Assigned to EMS Technologies, INc.
  • Patent number: 6072437
    Abstract: 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: Grant
    Filed: June 29, 1998
    Date of Patent: June 6, 2000
    Assignee: EMS Technologies, Inc.
    Inventors: Kurt A. Zimmerman, James M. Howell, James P. Montgomery
  • Patent number: 6069590
    Abstract: 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: Grant
    Filed: February 20, 1998
    Date of Patent: May 30, 2000
    Assignee: EMS Technologies, Inc.
    Inventors: James Ernest Thompson, Jr., Po Than
  • Patent number: 6067053
    Abstract: 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: Grant
    Filed: October 18, 1996
    Date of Patent: May 23, 2000
    Assignee: EMS Technologies, Inc.
    Inventors: Donald L. Runyon, James E. Thompson, Jr., James C. Carson
  • Patent number: 6028562
    Abstract: 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: Grant
    Filed: July 31, 1997
    Date of Patent: February 22, 2000
    Assignee: EMS Technologies, Inc.
    Inventors: Michael G. Guler, James P. Montgomery
  • Patent number: 6011520
    Abstract: 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: Grant
    Filed: February 18, 1998
    Date of Patent: January 4, 2000
    Assignee: EMS Technologies, Inc.
    Inventors: James M. Howell, Thomas E. Sharon
  • Patent number: 6005884
    Abstract: 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: Grant
    Filed: November 6, 1995
    Date of Patent: December 21, 1999
    Assignee: EMS Technologies, Inc.
    Inventors: Joel Powell Cook, Randolph Raymond Beebe, Thomas Edward Sharon
  • Patent number: 5966102
    Abstract: 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: Grant
    Filed: December 14, 1995
    Date of Patent: October 12, 1999
    Assignee: EMS Technologies, Inc.
    Inventor: Donald L. Runyon
  • Patent number: 5955998
    Abstract: A ferrite scanning line source is formed of a ferrite toroid and one or more dielectric slabs mounted to a side of the toroid. A signal propagating through the waveguide is phase shifted by the magnetization of the toroid. The further down the toroid the signal propagates the greater the phase shift that is applied to the signal. Radiators or coupling ports are formed by slots cut in a wall of the waveguide. The phase of the signal radiating from each slot in the line source is shifted from the signals emanating from the preceding and following slot in the line source. By properly locating the slots along the line source, a composite beam formed by the energy radiating from each slot may be titled (scanned) to a desired direction. In addition, the amount of phase shift applied to the signal by the waveguide depends on the magnetic state of the phase shifter.
    Type: Grant
    Filed: January 5, 1996
    Date of Patent: September 21, 1999
    Assignee: EMS Technologies, Inc.
    Inventors: Roger G. Roberts, Wyman L. Williams, Jeff M. Alexander
  • Patent number: 5757329
    Abstract: The antenna includes an antenna body, comprising a conductive material, having a cavity surrounded by intersecting wall segments. The wall segments include a rear plate and a face plate having a planar array of longitudinal slots, and both plates are positioned in spaced-apart parallel planes. The antenna further includes a center wall, centrally placed between the face plate and the rear plate, to form within the cavity a parallel pair of waveguide channels. The center bar has a center bar opening extending longitudinally along a portion of the center bar, thereby separating the center bar portion into first and second center bar segments. A guidance hole is aligned with an edge of the center bar and extends through the first center bar segment and at least a portion of the second center bar segment. A probe distributes radio frequency (RF) energy in substantially equal phase and amplitude to the waveguide channels via the center bar opening.
    Type: Grant
    Filed: December 29, 1995
    Date of Patent: May 26, 1998
    Assignee: EMS Technologies, Inc.
    Inventors: John C. Hoover, Steven F. Hering
  • Patent number: 5757246
    Abstract: A method and apparatus for suppressing the generation of passive intermodulation within passive devices. A dielectric sheet comprising dielectric material is placed between first and second conductive elements of the passive device. The second conductive element is then mounted to the first conductive element, thereby "sandwiching" the dielectric sheet between the first and second conductive elements. In this manner, a direct contact connection can not be formed at the junction of the first conductive element and the second conductive element. This absence of a continuous direct contact minimizes the opportunity for passive intermodulation products to be generated at this junction of the passive device.
    Type: Grant
    Filed: February 27, 1995
    Date of Patent: May 26, 1998
    Assignee: EMS Technologies, Inc.
    Inventor: Eric Norman Johnson
  • Patent number: 5726666
    Abstract: An antenna comprising a waveguide component and a probe assembly, coupled to the antenna assembly, for distributing radio frequency (RF) energy to slots positioned on at least one of the broad walls of the waveguide component. The probe assembly can be positioned at the approximate center point of the waveguide component to present a desired impedance to the waveguide cavity and to distribute RF energy of substantially equal amplitude and phase to each section of the waveguide cavity. The probe assembly includes a post, connected to one or both of the rear and front walls, and a probe pin. The post, which is typically positioned within the center of the waveguide cavity, comprises (1) a post cavity located within and extending along at least a portion of the post, and (2) a post slot having an opening located along the post and traversing the post cavity.
    Type: Grant
    Filed: April 2, 1996
    Date of Patent: March 10, 1998
    Assignee: EMS Technologies, Inc.
    Inventors: John C. Hoover, David J. Kiesling
  • Patent number: 5677796
    Abstract: An improved spherical gradient lens and a method of fabricating same. A uniform sphere of a material such as high density irradiated polystyrene or a methylpentene copolymer in the polyolefin family having a uniform relative dielectric constant is provided. A plurality of radially extending holes are formed therein, for example by drilling, the holes having a predetermined cross sectional geometry along axes extending radially from the center of the sphere. The geometry of holes is selected to control the resultant local density of material, and thus the relative dielectric constant as a function of distance from the center of the sphere. Hole diameters are chosen so as to be small compared to the shortest wavelength of interest with which the lens will be used.
    Type: Grant
    Filed: August 25, 1995
    Date of Patent: October 14, 1997
    Assignee: EMS Technologies, Inc.
    Inventors: Kurt A. Zimmerman, Donald L. Runyon
  • Patent number: 5302958
    Abstract: A low loss, fast switching, electronically tunable filter circuit which is microstrip compatible is obtained through the use of a resonant ring structure having two couplers, a low noise amplifier and a variable phase shifter. The tunable filter may advantageously be used in the receive channel of a transmit/receive module for phased arrays wherein the resonant frequency of the ring can be tuned anywhere in the operating frequency range so as to increase the dynamic range of the receiver.
    Type: Grant
    Filed: August 14, 1992
    Date of Patent: April 12, 1994
    Assignee: EMS Technologies, Inc.
    Inventors: Roger G. Roberts, Paul R. Cox