James Milton Howell

US Patent:

6704543, Mar 9, 2004

Filed:

May 23, 2000

Appl. No.:

09/576475

Inventors:

Thomas E. Sharon - Duluth GA
Thomas S. Taylor - Atlanta GA
William R. Hafner - Alpharetta GA
Steven H. Rigg - Norcross GA
James M. Howell - Woodstock GA

Assignee:

EMS Technologies, Inc. - Norcross GA

International Classification:

H04B 7185

US Classification:

455 121, 455 131, 455427, 455429

Abstract:

A satellite communications system having ground user terminals, hubs, and a geosynchronous satellite. The satellite generates a network of spot beam coverage areas on the earth. A hub and at least one ground terminal are located in each of at least two spot beams. A first user terminal transmits an uplink signal according to a first signal protocol to the hub through the satellite. A second user terminal receives a downlink signal according to a second signal protocol through the downlink spot beam from the hub through the satellite. The hub may be located in the same spot beam coverage area as the first or the second user terminal or may be located in an altogether different spot beam coverage area. Through selective frequency and/or polarization routing on board the satellite, a hub located within a âparentâ beam can communicate with user terminals within the parent beam at a specified frequency and polarization, and can communicate with users in other âdependentâ beams on a different frequency and/or polarization. This routing allocates the total available bandwidth between parent and dependent beams.

US Patent:

20040166801, Aug 26, 2004

Filed:

Nov 12, 2003

Appl. No.:

10/706326

Inventors:

Thomas Sharon - Duluth GA, US
Thomas Taylor - Atlanta GA, US
William Hafner - Alpharetta GA, US
Steven Rigg - Norcross GA, US
James Howell - Woodstock GA, US
Thomas Glynn - Annapolis MD, US
Dennis Kershner - Ellicott City MD, US

Assignee:

EMS Technologies, Inc. - Norcross GA

International Classification:

H04B007/185
H04Q007/20

US Classification:

455/012100, 455/427000

Abstract:

A satellite communications system having ground user terminals, hubs, and a geosynchronous satellite. The satellite generates a network of spot beam coverage areas on the earth. A hub and at least one ground terminal are located in each of at least two spot beams. A first user terminal transmits an uplink signal according to a first signal protocol to the hub through the satellite. A second user terminal receives a downlink signal according to a second signal protocol through the downlink spot beam from the hub through the satellite. The hub may be located in the same spot beam coverage area as the first or the second user terminal or may be located in an altogether different spot beam coverage area. Through selective frequency and/or polarization routing on board the satellite, a hub located within a “parent” beam can communicate with user terminals within the parent beam at a specified frequency and polarization, and can communicate with users in other “dependent” beams on a different frequency and/or polarization. This routing allocates the total available bandwidth between parent and dependent beams. The system enables asynchronous communications between each hub and the satellite to maximize frequency re-use and the overall capacity of the system.

US Patent:

60724374, Jun 6, 2000

Filed:

Jun 29, 1998

Appl. No.:

9/106833

Inventors:

Kurt A. Zimmerman - Atlanta GA
James M. Howell - Woodstock GA
James P. Montgomery - Roswell GA

Assignee:

EMS Technologies, Inc. - Norcross GA

International Classification:

H01Q 1906

US Classification:

343753

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. In addition, the horn-antenna can include an elevation lens that can rotate within the internal parallel-plate structure of the horn-type antenna to vary the beam pattern within the elevation plane.