Method and system for providing satellite coverage using fixed spot beams and scanned spot beams

• US 6,272,317 B1
• Filed: 09/23/1998
• Issued: 08/07/2001
• Est. Priority Date: 06/02/1997
• Status: Expired due to Term

• Current Assignee: Hughes Electronics Corporation (AT&T, Inc.)
• Original Assignee: Hughes Electronics Corporation (AT&T, Inc.)
• Inventors: Anselmo, Carl S., Sullivan, Daniel P., Houston, Sam W.
• Primary Examiner(s): Bost, Dwayne
• Assistant Examiner(s): Trinh, Sonny
• Application Number:
  US09/159,332
• Time in Patent Office: 1,049 Days
• Field of Search: 455/427, 455/12.1, 455/13.2, 455/98, 455/429, 455/63, 455/13.1, 342/354, 342/154, 342/356
• US Class Current: 455/13.1
• CPC Class Codes: H04B 7/18521 Systems of inter linked satellites, i.e. inter satellite service for optical links between satellites H04B10/118
• CPC Class Codes: H04B 7/18578 Satellite systems for providing broadband data service to individual earth stations for selecting H04W; provisions for broadband connection, H04Q11/0478

Abstract

A satellite-based communications system operating at high data rates includes a plurality of communications satellites each having an uplink and a downlink antenna for receiving and transmitting a plurality of spot beams which may be fixed or scanned. The fixed beams may be directed to areas of high satellite use. The scanned beams may be rapidly scanned between areas of use insufficient to support a dedicated beam. The scanned beam allows potentially nearly ubiquitous coverage by using high frequency beams. To rapidly scan, beam forming networks have a plurality of phase coefficients that may be changed so that the angle of the beam may change. A controller coupled to the beam forming network may be used to change the phase coefficients in response to beam inputs such as the desired beam and configurations of the other beams on the satellite.

Claims

1. A satellite comprising:

a plurality of beam inputs;

an uplink antenna having a plurality of antenna receiving elements and a first reflector positioned adjacent to said plurality of antenna receiving elements;

a receive beam forming network coupled to said plurality of antenna receiving elements, said receiving beam forming network having a plurality of tunable receiving beam forming elements, each of said tunable receiving beam forming elements coupled to one of said antenna receiving elements and each of said tunable receiving beam forming elements having a receiving phase coefficient;

a downlink antenna having a plurality of antenna transmitting elements and a second reflector positioned adjacent to said plurality of antenna transmitting elements;

a transmitting beam forming network coupled to said plurality of antenna transmitting elements, said transmitting beam forming network having a plurality of tunable transmitting beam forming elements, each of said tunable transmitting beam forming elements coupled to one of said antenna transmitting elements and each of said tunable transmitting beam forming elements having a transmitting phase coefficient;

a controller coupled to said transmitting beam forming network, said receiving beam forming network and said beam forming inputs, said controller calculating and adjusting said transmitting and receiving phase coefficients in response to said beam forming inputs, said controller selecting either fixed spot coverage area or a scanned spot coverage by generating respective uplink spot beams and uplink scanned spot beams or by generating respective downlink spot beams and downlink scanned spot beams for each of the receiving and transmitting antenna elements,

said first reflector directing both said uplink spot beams and said uplink scanned spot beams and said second reflector directing both said downlink spot beams and said downlink scanned spot beams.

2. A satellite as recited in claim 1 wherein said transmitting tunable beam forming network comprises a transmitting amplitude coefficient.

3. A satellite as recited in claim 2 wherein said beam input comprises a side lobe level input.

4. A satellite as recited in claim 3 wherein said transmitting amplitude coefficient is adjusted in response to said antenna side lobe level.

5. A satellite as recited in claim 1 wherein said receiving tunable beam forming network comprises a receiving amplitude coefficient.

6. A satellite as recited in claim 1 further comprising a transmitting power divider coupled to said transmitting beam forming network and a receiving power divider coupled to said receiving beam forming network.

7. A satellite as recited in claim 6 further comprising plurality of a low noise amplifiers coupled between each of said receiving elements and said receiving power divider.

8. A satellite as recited in claim 6 further comprising a solid state amplifier coupled to said transmitting beam forming elements.

9. A satellite as recited in claim 1 wherein said controller comprises a beam-forming processor.

10. A satellite as recited in claim 1 wherein said beam input comprises current beam position, antenna beam width and beam sharing requests.

11. A system for providing high frequency data communications in a satellite-based communications network, the system comprising:

a plurality of communications satellites each having an uplink antenna and a downlink antenna capable of receiving and transmitting a plurality of signals utilizing a plurality of beams having fixed spot beams and scanned spot beams to a plurality of spot coverage areas and a plurality of scanned spot areas respectively at a predetermined range of frequencies, the plurality of satellites each further having receiving and transmitting beam forming networks coupled to the uplink and downlink antennas respectively, said uplink antenna having a continuous array of reconfigurable receiving antenna elements and said downlink antenna having a continuous array of reconfigurable transmitting antenna elements; and

a controller located on said satellite coupled to each of said transmitting and receiving beam forming networks, said controller selecting either fixed spot coverage area or a scanned spot coverage by generating respective uplink spot beams and uplink scanned spot beams or by generating respective downlink spot beams and downlink scanned spot beams for each of the reconfigurable receiving and transmitting antenna elements; and

a first reflector positioned adjacent to said first plurality of receiving elements and a second reflector positioned adjacent to said plurality of transmitting elements,

said first reflector directing both said uplink spot beams and said uplink scanned spot beams and said second reflector directing both said downlink spot beams and said downlink scanned spot beams.

12. A satellite comprising:

an uplink antenna having a plurality of antenna receiving elements arranged in a first continuous array, each of said receiving elements being reconfigurable to form receiving fixed spot beams and receiving scanned spot beams;

a receive beam forming network coupled to said plurality of antenna receiving elements, said receiving beam forming network coupled to said plurality of antenna receiving elements for configuring said antenna receiving elements into said receiving fixed spot beams and said receiving scanned spot beams;

a downlink antenna having a plurality of antenna transmitting elements arranged in a second continuous array, each of said transmitting elements being reconfigurable to form transmitting fixed spot beams and transmitting scanned spot beams; and

a transmitting beam forming network coupled to said plurality of antenna transmitting elements, said transmitting beam forming network coupled to said plurality of antenna transmitting elements for configuring said antenna transmitting elements into said transmitting fixed spot beams and said transmitting scanned spot beams.