Edward Te Hirshfield

US Patent:

55044930, Apr 2, 1996

Filed:

May 9, 1995

Appl. No.:

8/437931

Inventors:

Edward Hirshfield - Cupertino CA

Assignee:

Globalstar L.P. - San Jose CA

International Classification:

H01Q 322
H01Q 324
H01Q 326

US Classification:

342372

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.

US Patent:

55482929, Aug 20, 1996

Filed:

Feb 2, 1995

Appl. No.:

8/383211

Inventors:

Edward Hirshfield - Cupertino CA
Chich-Hsing A. Tsao - Saratoga CA

Assignee:

Space Systems/Loral - Palo Alto CA

International Classification:

H04B 7185
H01G 322

US Classification:

342324

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. A multi-element phased array of receiving antennas and a multi-element phased array of transmitting antennas is also disclosed, wherein each element of each phased array is utilized for each individual one of a plurality of received or transmitted beams.

US Patent:

55812686, Dec 3, 1996

Filed:

Aug 3, 1995

Appl. No.:

8/509754

Inventors:

Edward Hirshfield - Cupertino CA

Assignee:

Globalstar L.P. - San Jose CA

International Classification:

H01Q 138
H01Q 2300

US Classification:

343853

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. The transmit amplifiers (16a, 16b) and the receive amplifiers (30a, 30b) are located at opposite ends of an antenna stalk body (36) such that the transmit amplifiers and receive amplifiers are intimately associated with their respective antenna elements, thereby further minimizing losses. Also, because the transmit amplifiers may generate considerable heat, the construction technique thermally isolates the lower power receive amplifiers from the higher power transmit amplifiers.

US Patent:

52835871, Feb 1, 1994

Filed:

Nov 30, 1992

Appl. No.:

7/983123

Inventors:

Edward Hirshfield - Cupertino CA
Edgar W. Matthews - Mountain View CA
Howard H. Luh - Sunnyvale CA

Assignee:

Space Systems/Loral - Palo Alto CA

International Classification:

H01Q 322
H01Q 324
H01Q 326

US Classification:

342372

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.

US Patent:

54226473, Jun 6, 1995

Filed:

May 7, 1993

Appl. No.:

8/060207

Inventors:

Edward Hirshfield - Cupertino CA
Chich-Hsing A. Tsao - Saratoga CA

Assignee:

Space Systems/Loral, Inc. - Palo Alto CA

International Classification:

H04B 7185
H01Q 322

US Classification:

342354

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. A multi-element phased array of receiving antennas and a multi-element phased array of transmitting antennas is also disclosed, wherein each element of each phased array is utilized for each individual one of a plurality of received or transmitted beams.

US Patent:

59091916, Jun 1, 1999

Filed:

Oct 1, 1997

Appl. No.:

8/942704

Inventors:

Edward Hirshfield - Cupertino CA
Evert C. Nygren - Los Altos CA
Ernesto A. Balderrama - Milpitas CA
George S. Cohen - Palo Alto CA

Assignee:

Space Systems/Loral, Inc. - Palo Alto CA

International Classification:

G01S 740

US Classification:

342174

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).

US Patent:

61013854, Aug 8, 2000

Filed:

Oct 9, 1997

Appl. No.:

8/947931

Inventors:

Paul A Monte - San Jose CA
Edward Hirshfield - Cupertino CA

Assignee:

Globalstar L.P. - San Jose CA

International Classification:

H04Q 736

US Classification:

455427

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. In a second embodiment a method optimizes signal flow between the ground station and the user terminals and includes the steps of: (a) determining user terminal RF signal conditions within the sub-beams of at least one of the forward and reverse beams; and (b) in response to the determined RF signal conditions, re-allocating sub-beams of at least one of the forward and reverse beams such that the totality of the sub-beams of the forward beam are non-congruent with the totality of the sub-beams of the reverse beam, at the surface of the earth, while maintaining the forward beam substantially congruent with the reverse beam, at the surface of the earth. The step of determining includes a step of maintaining a database that stores a map of the sub-beams. In one embodiment of this invention the steps of determining and maintaining are executed at the ground station, while in another embodiment the steps of determining and maintaining are executed on-board the satellite.

US Patent:

63014769, Oct 9, 2001

Filed:

Aug 7, 2000

Appl. No.:

9/633694

Inventors:

Paul A Monte - San Jose CA
Edward Hirshfield - Cupertino CA

Assignee:

Globalstar L.P. - San Jose CA

International Classification:

H04Q 720

US Classification:

455427

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. In a second embodiment a method optimizes signal flow between the ground station and the user terminals and includes the steps of: (a) determining user terminal RF signal conditions within the sub-beams of at least one of the forward and reverse beams; and (b) in response to the determined RF signal conditions, re-allocating sub-beams of at least one of the forward and reverse beams such that the totality of the sub-beams of the forward beam are non-congruent with the totality of the sub-beams of the reverse beam, at the surface of the earth, while maintaining the forward beam substantially congruent with the reverse beam, at the surface of the earth. The step of determining includes a step of maintaining a database that stores a map of the sub-beams. In one embodiment of this invention the steps of determining and maintaining are executed at the ground station, while in another embodiment the steps of determining and maintaining are executed on-board the satellite.