Portable satellite phone having directional antenna for direct link to satellite

• US 5,949,369 A
• Filed: 12/30/1996
• Issued: 09/07/1999
• Est. Priority Date: 12/30/1996
• Status: Expired due to Term

• Current Assignee: Rakuten, Inc. (Rakuten Group, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Bradley, James Frederick, Cooper, Paul W.
• Primary Examiner(s): OEN, WILLIAM L
• Application Number:
  US08/774,456
• Time in Patent Office: 981 Days
• Field of Search: 343/702, 343/790, 343/792, 343/878, 343/883, 343/757, 343/725, 342/56, 342/74, 342/75, 342/76, 342/77, 342/359, 342/367
• US Class Current: 342/352
• CPC Class Codes: H01Q 1/242 specially adapted for hand-held use
• CPC Class Codes: H01Q 1/245 with means for shaping the antenna pattern, e.g. in order to protect user against rf exposure
• CPC Class Codes: H04B 1/3833 Hand-held transceivers
• CPC Class Codes: H04B 7/18571 for satellites; for fixed or mobile stations

Abstract

A portable satellite phone is integrated into a communication system. The portable satellite phone forms a highly directed beam toward a satellite and adaptively maintains a beam to track the satellite as the portable satellite phone and/or the satellite moves relative to each other. A communication system based on the portable satellite phones may link a portable satellite phone with either another portable satellite phone or a ground based communication system connected to conventional telephone stations. The portable satellite phone includes a steering information detector or both a steering information detector and a proximity detector. The steering information detector has a bearing sensor, an attitude sensor and GPS signal receivers for position detection. The portable satellite phone also includes a database that contains the positional information of all potential communication satellites. The proximity detector detects objects that may interfere with the antenna beam. The proximity detector includes infrared sensors, sonar detectors, motion detectors and optical devices to determine a range and bearing of objects that may interfere with the antenna beam. When an object may be harmed or interfere with the antenna beam, an alarm may be activated to warn the user and/or the object of potential harm from the electromagnetic energy transmitted by the directed antenna.

Claims

1. A portable terminal, comprising:

a directional antenna; and

an antenna controller coupled to the directional antenna, wherein the antenna controller forms an antenna beam of the directional antenna and determines a direction of the antenna beam based on information generated by the portable terminal to allow the portable terminal to electromagnetically communicate with the satellite.

2. The portable terminal of claim 1, wherein the antenna controller directs the antenna beam of the directional antenna in the direction determined by the antenna controller to communicate with the satellite.

3. The portable terminal of claim 1, further comprising:

a steering information-determining device, wherein the steering information-determining device generates steering information including a position, a bearing and an attitude of the portable terminal.

4. The portable terminal of claim 3, wherein the steering information-determining device comprises:

a Global Positioning System signal receiver that receives Global Positioning System signals; and

steering information sensors that include at least one of a compass, a gyroscope, a plumb line and an attitude sensor.

5. The portable terminal of claim 3, wherein the antenna controller maintains the antenna beam of the directional antenna toward the satellite based on a position of the satellite and the steering information of the portable terminal generated by the steering information-determining device.

6. The portable terminal of claim 5, further comprising a database, wherein the antenna controller determines the position of the satellite based on at least one of data retrieved from the database and position data received from the satellite.

7. The portable terminal of claim 6, further comprising a clock, wherein the antenna controller determines the position of the satellite by generating orbital information based on the retrieved data and the clock.

8. The portable terminal of claim 5, wherein the antenna controller transitions from communicating with the satellite to communicating with another satellite by one of snapping the antenna beam and bridging the antenna beam.

9. The portable terminal of claim 8, wherein the antenna controller snaps the antenna beam from the satellite to the another satellite at a time determined by one of the antenna controller and a synchronization signal from the satellite.

10. The portable terminal of claim 8, wherein the antenna controller broadens the antenna beam to communicate with the satellite and the another satellite simultaneously, the antenna controller reforming the broadened antenna beam to direct the antenna beam toward the another satellite at a time determined by at least one of the antenna controller, the satellite and the another satellite.

11. The portable terminal of claim 1, further comprising:

a proximity detector, wherein the antenna controller adjusts one of a shape of the antenna beam, a direction of the antenna beam and a power of the antenna beam based on the output of the proximity detector.

12. The portable terminal of claim 11, wherein the antenna controller reduces a power transmitted by the antenna beam when the proximity detector detects an object within a predetermined distance from at least one of the antenna beam and the portable terminal.

13. The portable terminal of claim 11, wherein the antenna controller outputs an alarm when the proximity detector detects the object within a predetermined distance from a path of the antenna beam.

14. The portable terminal of claim 1, further comprising:

a database; and

a Global Positioning System signal receiver that receives Global Positioning System signals, wherein the antenna controller determines an elevation angle of the satellite based on a position of the satellite and a position of the portable terminal, the position of the satellite being determined based on data in the database and the position of the portable terminal being determined based on the Global Positioning System signals, the antenna controller forming a fan beam at the determined elevation angle, the fan beam being directed at the satellite if the portable terminal is maintained at a preset attitude and a bearing generally facing the satellite.

15. The portable terminal of claim 14, wherein the preset attitude is vertical.

16. The portable terminal of claim 1, wherein the satellite is one of a geostationary earth orbit satellite, a medium altitude earth orbit satellite, a low altitude earth orbit satellite, an intermediate circular orbit satellite and a geo-helio synchronous orbit satellite.

17. The portable terminal of claim 1, wherein the directional antenna is a phased array antenna.

18. The portable terminal of claim 17, wherein the phased array antenna is one of a planar phased array antenna and a volumetric phased array antenna.

19. A method for operating a portable terminal, comprising:

forming an antenna beam of a directional antenna; and

determining a direction of the antenna beam based on information generated by a portable terminal to allow the portable terminal to electromagnetically communicate with a satellite.

20. The method of claim 19, further comprising directing the antenna beam in the direction generated by the determining step.

21. The method of claim 19, further comprising generating steering information that includes a position, a bearing and an attitude of the portable terminal.

22. The method of claim 21, wherein the steering information is generated based on data received from a Global Positioning System signal receiver that receives Global Positioning System signals and steering information sensors that include at least one of a compass, a gyroscope, a plumb line and an attitude sensor.

23. The method of claim 21, further comprising maintaining the antenna beam of the directional antenna toward the satellite based on a position of the satellite and the steering information generated by the portable terminal.

24. The method of claim 23, further comprising determining the position of the satellite based on at least one of data retrieved from a database and position data received from the satellite.

25. The method of claim 24, further comprising generating orbital information based on the retrieved data and a clock, the determining the position of the satellite step determining the position of the satellite based on the orbital information.

26. The method of claim 23, further comprising one of snapping and bridging the antenna beam to transition from communicating with the satellite to communicating with another satellite.

27. The method of claim 26, wherein snapping the antenna beam comprises determining a time to snap the antenna beam from the satellite to the another satellite, the time being determined by one of the antenna controller and receiving a synchronization signal received from the satellite.

28. The method of claim 26, wherein bridging the antenna beam comprises:

broadening the antenna beam to communicate with the satellite and the another satellite simultaneously; and

reforming the broadened antenna beam to direct the antenna beam toward the another satellite at a time determined by at least one of the antenna controller, the satellite and the another satellite.

29. The method of claim 19, further comprising:

generating proximity information of an object; and

adjusting the antenna beam based on the proximity information output by the generating step.

30. The method of claim 29, wherein the adjusting step comprises one of reshaping the antenna beam, changing the direction of the antenna beam and reducing a power of the antenna beam.

31. The method of claim 30, wherein reducing the power step is performed when an object is within a predetermined distance from at least one of the antenna beam and the portable terminal.

32. The method of claim 29, further comprising outputting an alarm when the object is within a predetermined distance from a path of the antenna beam.

33. The method of claim 19, further comprising:

determining an elevation angle of the satellite; and

forming a fan beam at the elevation angle, wherein the elevation angle is determined based on a position of the satellite and a position of the portable terminal, the position of the satellite being determined based on data in a database of the portable terminal and the position of the portable terminal being determined based on Global Positioning System signals, the fan beam being directed at the satellite if the portable terminal is maintained at a preset attitude.

34. The method of claim 33, wherein the preset attitude is vertical.

35. The method of claim 19, wherein the satellite is one of a geostationary earth orbit satellite, a medium altitude earth orbit satellite, a low altitude earth orbit satellite, an intermediate circular orbit satellite and a geo-helio synchronous orbit satellite.

36. The portable terminal of claim 19, wherein the directional antenna is a phased array antenna.

37. The portable terminal of claim 36, wherein the phased array antenna is one of a planar phased array antenna and a volumetric phased array antenna.