Patents by Inventor Edward Hirshfield

Edward Hirshfield has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6301476
    Abstract: A method for use in a satellite communications system (20) of a type that has at least one satellite (22) having forward and reverse beams each comprised of sub-beams for relaying user communications between a ground station (24) and user terminals (30). In a first embodiment forward and reverse antenna systems are separately optimized for their intended applications without regard for maintaining congruence between antenna beam sub-beams at the surface of the earth.
    Type: Grant
    Filed: August 7, 2000
    Date of Patent: October 9, 2001
    Assignee: Globalstar L.P.
    Inventors: Paul A Monte, Edward Hirshfield
  • Patent number: 6101385
    Abstract: A method for use in a satellite communications system (20) of a type that has at least one satellite (22) having forward and reverse beams each comprised of sub-beams for relaying user communications between a ground station (24) and user terminals (30). In a first embodiment forward and reverse antenna systems are separately optimized for their intended applications without regard for maintaining congruence between antenna beam sub-beams at the surface of the earth.
    Type: Grant
    Filed: October 9, 1997
    Date of Patent: August 8, 2000
    Assignee: Globalstar L.P.
    Inventors: Paul A Monte, Edward Hirshfield
  • Patent number: 5909191
    Abstract: An antenna element and beamforming network (10) preferably comprises a plurality of radiators (12), a plurality of band pass filters (14) and a plurality of test couplers (16). Each radiator (12) is coupled to a dedicated MMIC (18). The output of MMICs (18) are coupled to a power stripline combiner (20) to provide a single output. Each of MMICs (18) is independently controllable to shape the antenna beams as desired for producing nulls in pattern coverage. The output of stripline combiner (20) may also be coupled through an output test coupler (46) to a jammer detector and correlator (24). In one embodiment, radiators (12) are horns that include filters (14). The output of each horn is coupled to the input of its dedicated MMIC (18). In another embodiment, radiators (12) are a patch array coupled together by a stripline combiner. The output of the stripline combiner is coupled by band pass filter (14) to the input of the respective MMICs (18).
    Type: Grant
    Filed: October 1, 1997
    Date of Patent: June 1, 1999
    Assignee: Space Systems/Loral, Inc.
    Inventors: Edward Hirshfield, Evert C. Nygren, Ernesto A. Balderrama, George S. Cohen
  • Patent number: 5623269
    Abstract: A communications satellite payload provides for efficient communications between user devices, such as hand held cellular telephones, and terrestrial gateways that may be connected to world-wide public telephone and telegraph (PTTs) networks. The satellite payload simultaneously supports a plurality of independent antenna beams, for example 12 or 16 beams, on both the uplink and downlink for user devices employing full duplex communications. The satellite payload furthermore supports an identical number of full duplex channels between a terrestrial gateway and the satellite. The communications satellite payload is carried by one satellite of a plurality of such satellites in a low earth orbit (LEO) constellation to provide worldwide communications. Downlink beam forming occurs prior to final amplification of transmitted signals, thereby reducing losses within the beam forming equipment.
    Type: Grant
    Filed: February 2, 1995
    Date of Patent: April 22, 1997
    Assignee: Space Systems/Loral, Inc.
    Inventors: Edward Hirshfield, Chich-Hsing A. Tsao
  • Patent number: 5581268
    Abstract: An antenna structure (10) that includes a plurality of transmit linear elements (22a-22d) arranged parallel to one another and a plurality of receive linear elements (24a-24d) also arranged parallel to one another. Individual ones of the plurality of transmit linear elements are spaced apart from one another and have one of the plurality of receive linear elements disposed therebetween. A width of each of the plurality of transmit linear elements and the plurality of receive linear elements varies periodically along a length of the linear element, thereby also periodically impedance modulating each element. Furthermore, a narrowest width portion of a transmit linear element is disposed adjacent to a widest width portion of an adjacently disposed receive linear element, and vice versa, thereby minimizing coupling between the elements.
    Type: Grant
    Filed: August 3, 1995
    Date of Patent: December 3, 1996
    Assignee: Globalstar L.P.
    Inventor: Edward Hirshfield
  • Patent number: 5548292
    Abstract: A communications satellite payload provides for efficient communications between user devices, such as hand held cellular telephones, and terrestrial gateways that may be connected to world-wide public telephone and telegraph (PTTs) networks. The satellite payload simultaneously supports a plurality of independent antenna beams, for example 12 or 16 beams, on both the uplink and downlink for user devices employing full duplex communications. The satellite payload furthermore supports an identical number of full duplex channels between a terrestrial gateway and the satellite. The communications satellite payload is carried by one satellite of a plurality of such satellites in a low earth orbit (LEO) constellation to provide world-wide communications. Downlink beam forming occurs prior to final amplification of transmitted signals, thereby reducing losses within the beam forming equipment.
    Type: Grant
    Filed: February 2, 1995
    Date of Patent: August 20, 1996
    Assignee: Space Systems/Loral
    Inventors: Edward Hirshfield, Chich-Hsing A. Tsao
  • Patent number: 5504493
    Abstract: A phase array transmitting antenna system, including a plurality of radiating elements, each radiating element is capable of transmitting radiation. One or more constant phase and amplitude amplifiers are affixed to the radiating element in the array, wherein each radiating element is capable of producing radiation of a substantially uniform phase as the other radiating elements in the array, but distinct amplitudes according to patterns which simplify implementation.
    Type: Grant
    Filed: May 9, 1995
    Date of Patent: April 2, 1996
    Assignee: Globalstar L.P.
    Inventor: Edward Hirshfield
  • Patent number: 5422647
    Abstract: A communications satellite payload provides for efficient communications between user devices, such as hand held cellular telephones, and terrestrial gateways that may be connected to world-wide public telephone and telegraph (PTTs) networks. The satellite payload simultaneously supports a plurality of independent antenna beams, for example 12 or 16 beams, on both the uplink and downlink for user devices employing full duplex communications. The satellite payload furthermore supports an identical number of full duplex channels between a terrestrial gateway and the satellite. The communications satellite payload is carried by one satellite of a plurality of such satellites in a low earth orbit (LEO) constellation to provide worldwide communications. Downlink beam forming occurs prior to final amplification of transmitted signals, thereby reducing losses within the beam forming equipment.
    Type: Grant
    Filed: May 7, 1993
    Date of Patent: June 6, 1995
    Assignee: Space Systems/Loral, Inc.
    Inventors: Edward Hirshfield, Chich-Hsing A. Tsao
  • Patent number: 5283587
    Abstract: An active transmit phased array antenna system for generating multiple independent simultaneous antenna beams to illuminate desired regions while not illuminating other regions. The size shape of the regions is a function of the size and number of elements populating the array and the number of beams is a function of the number of beam forming networks feeding the array. All the elements of the array are operated at the same amplitude level and beam shapes and directions are determined by the phase settings. The active transmit phased array antenna includes a plurality of antenna elements disposed in a hexiform configuration. Each antenna element is identical and includes a radiating horn capable of radiating in each of two orthogonal polarizations. The horn is fed by a multi-pole bandpass filter means whose function is to pass energy in the desired band and reject energy at other frequencies. The filter means is coupled into an air dielectric cavity mounted on substrate.
    Type: Grant
    Filed: November 30, 1992
    Date of Patent: February 1, 1994
    Assignee: Space Systems/Loral
    Inventors: Edward Hirshfield, Edgar W. Matthews, Jr., Howard H. Luh