Vehicle mounted antenna and methods for transmitting and/or receiving signals

• US 20080309569A1
• Filed: 03/13/2008
• Published: 12/18/2008
• Est. Priority Date: 03/16/2007
• Status: Active Grant

• Current Assignee: Mobile Sat Ltd.
• Original Assignee: Mobile Sat Ltd.
• Inventors: Berejik, Zacharia
• Granted Patent: US 7,911,403 B2
• Time in Patent Office: Days
• US Class Current: 343/761
• CPC Class Codes: H01Q 1/185 by electronic means
• CPC Class Codes: H01Q 1/28 Adaptation for use in or on aircraft, missiles, satellites, or balloons
• CPC Class Codes: H01Q 1/32 Adaptation for use in or on road or rail vehicles
• CPC Class Codes: H01Q 13/0225 of non-circular cross-section H01Q13/0216 takes precedence
• CPC Class Codes: H01Q 13/0258 Orthomode horns orthomode transducers H01P1/161
• CPC Class Codes: H01Q 13/065 provided with a flange or a choke
• CPC Class Codes: H01Q 19/192 with dual offset reflectors
• CPC Class Codes: H01Q 3/08 for varying two co-ordinates of the orientation
• CPC Class Codes: H01Q 3/20 wherein the primary active element is fixed and the reflecting device is movable

Abstract

An antenna for communicating with a satellite from a moving vehicle. The antenna comprises a transmitter for generating a transmission signal, main and sub reflectors, and a waveguide associated with the transmitter for conducting the transmission signal toward the sub reflector. The sub reflector is configured for redirecting the transmission signal toward the main reflector; the main reflector is configured for projecting the redirected transmission signal as an antenna beam toward the satellite.

Claims

1. An antenna for communicating with a satellite from a moving vehicle, comprising:

a transmitter for generating a transmission signal;

main and sub reflectors; and

a waveguide associated with said transmitter for conducting said transmission signal toward said sub reflector;

wherein said sub reflector is configured for redirecting said transmission signal toward said main reflector, said main reflector being configured for projecting said redirected transmission signal as an antenna beam toward the satellite.

2. The antenna of claim 1, wherein said waveguide having a bended passage.

3. The antenna of claim 2, wherein said bended passage having a bending angle of at least 5 degrees.

4. The antenna of claim 1, wherein said waveguide having a feed horn connected to its end, said waveguide being configured for conducting said transmission signal toward said sub reflector via said feed horn.

5. The antenna of claim 4, wherein said main reflector is disposed between said transmitter and said feed horn.

6. The antenna of claim 1, wherein is transmitter being connected to a polarizing element, said waveguide being used for guiding said transmission signal between said polarizing element and said feed horn.

7. The antenna of claim 1, further comprising a calibration track configured for allowing the adjustment of the position of said waveguide in relation to said sub reflector to calibrate said antenna beam.

8. The antenna of claim 6, wherein said polarizing element is a rotating ortho-mode transducer (OMT) configured for associating between said transmitter, a receiver, and said waveguide, said OMT being configured for rotating around the central axis of said waveguide for polarizing said transmission signal.

9. The antenna of claim 8, wherein said rotating OMT allowing a non-orthogonal assembly of said transmission signal and a satellite signal received via said waveguide.

10. The antenna of claim 8, wherein the positioning of said waveguide in relation to said main and sub reflectors is fixed during said rotating.

11. The antenna of claim 8, further comprising first and second rotary joints, said first rotary joint being disposed between said OMT and said waveguide and said second rotary joint being disposed between said OMT and at least one of a down converter, said transmitter, and a low noise block (LNB) downconverter.

12. The antenna of claim 11, wherein at least one of said first and second rotary joints is less than 1 centimeter length.

13. The antenna of claim 11, wherein said first and second rotary joints allows adjusting the polarization of said transmission signal by facilitating the rolling of said polarizing element around the central axis of said waveguide while maintaining said waveguide firmly fixed in relation to said main and sub reflectors.

14. The antenna of claim 1, further comprising an actuating unit configured for adjusting a tilting angle of said main reflector to maintain a line of sight between the moving vehicle and the satellite.

15. The antenna of claim 14, wherein said actuating unit being configured for adjusting said tilting angle during a motion of the moving vehicle.

16. The antenna of claim 14, further comprising a rotational base for supporting said main and sub reflectors and said waveguide on the moving vehicle, said actuating unit being configured for adjusting a rotation angle of said rotational base to maintain a line of sight between the moving vehicle and the satellite.

17. An antenna for communicating with a satellite from a moving vehicle, comprising:

a rotational base configured for being mounted on the moving vehicle;

a main reflector configured for being tilted around a tilting axis located in a proximity to a lower portion of said main reflector;

a feed for emitting a transmission signal; and

a sub reflector configured for redirecting said transmission signal toward said main reflector, said main reflector being configured for projecting said redirected transmission signal as an antenna beam toward the satellite;

wherein said tilting allows the maintaining of a line of sight between said main reflector and the satellite during a motion of said moving vehicle.

18. The antenna of claim 17, wherein said feed and said sub reflector remain substantially stationary in relation to said rotational base during said tilting.

19. The antenna of claim 17, wherein said antenna beam having a main lobe, said tilting allows the tilting of the center of said main lobe in a range of at least 50 degrees in relation to said rotational base without a gain degradation of more than 2 decibels.

20. The antenna of claim 19, wherein said tilting allows the tilting of the center of said main lobe in a range of at least 60 degrees.

21. The antenna of claim 17, wherein said tilting is performed by at least one supporting element, said main reflector and said at least one supporting element being detachably coupled.

22. The antenna of claim 19, wherein said range is between tilting angles of more than 15 degrees in relation to said rotational base.

23. The antenna of claim 17, further comprising a radome having a substantially flat top for covering said main and sub reflectors.

24. The antenna of claim 17, wherein at least one of said sub and main reflectors having a substantially ellipsoidal inner reflective surface profile.

25. The antenna of claim 17, wherein said feed is configured for radiating said sub reflector with a substantially ellipsoidal conical beam to create an ellipsoidal radiation spot on said sub reflector.

26. The antenna of claim 25, wherein said sub reflector is configured for redirecting said ellipsoidal radiation spot toward said main reflector to create an additional ellipsoidal radiation spot thereon, wherein the width-height ratio of said additional ellipsoidal radiation spot is higher than the width-height ratio of said ellipsoidal radiation spot.

27. The antenna of claim 25, wherein said ellipsoidal radiation spot having a width-height ratio of at least 1.6:

1.

28. The antenna of claim 26, wherein said additional ellipsoidal radiation spot is at least 4:

1.

29. The antenna of claim 25, wherein said feed having a pair of opposing ends for creating said substantially ellipsoidal conical beam.

30. The antenna of claim 19, wherein said antenna lobe has a gain selected from a group consisting of at least 30 decibel isotropic (dBi) at 14 Ghz and at least 25 decibel isotropic (dBi) at 11 Ghz.

31. The antenna of claim 17, further comprising a transmitter configured for emitting said transmission signal and a waveguide for conducting said transmission signal toward said feed.

32. A method for transmitting a transmission signal to a satellite, comprising:

providing a transmission signal;

polarizing said transmission signal;

using a waveguide for conducting said polarized transmission signal toward a sub reflector; and

redirecting said conducted polarized transmission signal toward a main reflector to allow the projecting thereof toward the satellite as an antenna beam.

33. A method for receiving a communication signal from a satellite, comprising:

tilting a main reflector of an antenna mounted on a vehicle to allow a reception of the communication signal during a motion of said vehicle;

redirecting the communication signal toward a sub reflector, said sub reflector being positioned in front of a waveguide;

using said waveguide for directing a reflection of the redirected communication signal from said sub reflector toward a polarizing element; and

polarizing the directed reflection to allow the reception of said communication signal from the satellite during said motion.