Beam switching antenna system and method and apparatus for controlling the same

• US 20050057394A1
• Filed: 02/25/2004
• Published: 03/17/2005
• Est. Priority Date: 09/15/2003
• Status: Active Grant

• Current Assignee: LG Telecom Incorporated (LG Corporation)
• Original Assignee: LG Telecom Incorporated (LG Corporation)
• Inventors: Lee, Hyo Jin
• Granted Patent: US 7,274,330 B2
• Time in Patent Office: Days
• US Class Current: 342/374
• CPC Class Codes: H01Q 1/40 Radiating elements coated with or embedded in protective material
• CPC Class Codes: H01Q 19/10 using reflecting surfaces
• CPC Class Codes: H01Q 19/30 the primary active element being centre-fed and substantially straight, e.g. Yagi antenna
• CPC Class Codes: H01Q 19/32 the primary active element being end-fed and elongated
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching
• CPC Class Codes: H01Q 3/44 varying the electric or magnetic characteristics of reflecting, refracting, or diffracting devices associated with the radiating element

Abstract

A beam switching antenna system and method and apparatus for controlling the same is provided, by which optimal antenna characteristics can be maintained according to a peripheral environment, the necessary time and power consumption of searching an optimal beam-direction can be reduced, and electromagnetic waves of a beam generated from an antenna can be minimized. The beam switching antenna system includes an antenna element for transmitting and receiving a beam; a dielectric body surrounding said antenna element; at least one conductive reflector facing a lateral outside of said dielectric body; and a ground switch circuit connected to said at least one conductive reflector. The ground switch circuit includes a reference voltage source generating a reference voltage; a ground line connected to the reference voltage source; an electrical switching device connected between the ground line and the conductive reflector; and a controller for controlling the electrical switching device. The conductive reflector includes an upper conductive reflector having one end connected to one terminal of the electrical switching device; and a lower conductive reflector having one end connected to another terminal of the electrical switching device and the other end connected to the ground line.

Claims

1. A beam switching antenna system comprising:

an antenna element for transmitting and receiving a beam;

a dielectric body surrounding said antenna element;

at least one conductive reflector facing a lateral outside of said dielectric body; and

a ground switch circuit connected to said at least one conductive reflector.

2. The beam switching antenna system of claim 1, wherein said ground switch circuit selectively grounds said at least one conductive reflector.

3. The beam switching antenna system of claim 1, wherein said antenna element is a monopole element having a length of λ

/4, where λ

is the wavelength of a radio wave in air.

4. The beam switching antenna system of claim 3, wherein said dielectric body has a thickness of λ

_d/4, where λ

_d is the wavelength of a radio wave in the dielectric of said dielectric body.

5. The beam switching antenna system of claim 4, wherein the thickness of said dielectric body is determined by the dielectric constant and the area of said dielectric body.

6. The beam switching antenna system of claim 1, said ground switch circuit comprising:

a reference voltage source generating a reference voltage;

a ground line connected to said reference voltage source;

an electrical switching device connected between said ground line and said at least one conductive reflector; and

a controller for controlling said electrical switching device.

7. The beam switching antenna system of claim 6, wherein said ground line has a length of λ

/4, where λ

is a wavelength of a radio wave in air.

8. The beam switching antenna system of claim 6, said at least one conductive reflector comprising:

an upper conductive reflector having one end connected to one terminal of said electrical switching device; and

a lower conductive reflector having one end connected to another terminal of said electrical switching device and the other end connected to said ground line.

9. The beam switching antenna system of claim 8, wherein said upper conductive reflector has a length of λ

/8, where λ

is a wavelength of a radio wave in air.

10. The beam switching antenna system of claim 8, wherein said lower conductive reflector has a length of λ

/16, where λ

is a wavelength of a radio wave in air.

11. The beam switching antenna system of claim 1, wherein said dielectric body has at least three circumferential planar surfaces.

12. The beam switching antenna system of claim 1, installed in at least one of a mobile communication terminal, a base station, and a repeater.

13. A method for controlling a beam switching antenna system including an antenna element for forming a beam, at least one conductive reflector for reflecting the beam, and a ground switch for applying a reference voltage to the at least one conductive reflector, the method comprising steps of:

forming the beam of the antenna element; and

imparting the formed beam with a predetermined beam pattern by controlling the ground switch to apply the reference voltage to the at least one conductive reflector.

14. The method of claim 13, wherein said beam pattern imparting step is performed by selectively closing the ground switch.

15. A method for controlling a beam switching antenna system of a mobile communication terminal, comprising steps of:

forming a beam;

determining whether an earphone is connected to the mobile communication terminal; and

controlling the formed beam to have non-directivity if the earphone is connected to the mobile communication terminal.

16. The method of claim 15, further comprising steps of:

determining an operation mode of the mobile communication terminal; and

controlling the beam to have directivity if it is determined that the mobile communication terminal operates in a traffic mode and to have non-directivity if it is determined that the mobile communication terminal operates in an idle mode.

17. The method of claim 16, further comprising a step of controlling the beam to have directivity if it is determined that the earphone is not connected to the mobile communication terminal and that the mobile communication terminal operates in the traffic mode.

18. The method of claim 16, further comprising a step of controlling the beam to have non-directivity if it is determined that the earphone is not connected to the mobile communication terminal and that the mobile communication terminal operates in the idle mode.

19. The method of claim 16 or claim 17, wherein, if the beam is controlled to have directivity, the beam is directed away from a user of the mobile communication terminal.

20. An apparatus for controlling a beam switching antenna system including an antenna element for forming a beam, at least one conductive reflector for reflecting the beam, and a ground switch for applying a reference voltage to the at least one conductive reflector, the apparatus comprising:

a signal source for supplying the antenna element with a signal to form the beam; and

a controller for controlling the ground switch to apply the reference voltage to the at least one conductive reflector, to thereby imparting the formed beam with a predetermined beam pattern.

21. The apparatus of claim 20, wherein said controller selectively closes the ground switch.

22. The apparatus of claim 20, wherein the beam switching antenna system is installed in a mobile communication terminal.

23. The apparatus of claim 22, further comprising:

an earphone sensing circuit for determining whether an earphone is connected to the mobile communication terminal; and

a mode signal generating circuit for determining an operation mode of the mobile communication terminal.

24. The apparatus of claim 23, wherein said controller controls the beam to have non-directivity if it is determined that the earphone is connected to the mobile communication terminal.

25. The apparatus of claim 23, wherein said controller controls the beam to have directivity if it is determined that the mobile communication terminal operates in a traffic mode and to have non-directivity if it is determined that the mobile communication terminal operates in an idle mode.

26. The apparatus of claim 23, wherein said controller controls the beam to have directivity if it is determined that the earphone is not connected to the mobile communication terminal and that the mobile communication terminal operates in a traffic mode and to have non-directivity if it is determined that the earphone is not connected to the mobile communication terminal and that the mobile communication terminal operates in an idle mode.

27. The apparatus of claim 25 or claim 26, wherein, if said controller controls the beam to have directivity, the beam is directed away from a user of the mobile communication terminal.

28. A method for controlling a beam switching antenna system including an antenna element for forming a beam, at least one conductive reflector for reflecting the beam, and a ground switch for applying a reference voltage to the least one conductive reflector, the method comprising steps of:

selectively configuring the beam switching antenna system for a current-directional beam pattern to receive a first signal and for a non-directional beam pattern to receive a second signal;

comparing the first and second signals; and

controlling, using the ground switch, the beam based on the comparison of the first and second signals.

29. The method of claim 28, wherein said first-and-second signal comparing step is performed by a comparison of a detected reception property of the first and second signals and wherein, if the detected reception property of the first signal is not worse than that of the second signal, the beam is oriented in the current direction.

30. The method of claim 29, further comprising steps of:

selectively configuring the beam switching antenna system for a beam orientation of a direction different from the current direction to receive a third signal, if the detected reception property of the second signal is better than that of the first signal;

comparing the first and third signals; and

controlling the beam based on the comparison of the first and third signals.

31. The method of claim 30, wherein said first-and-third signal comparing step is performed by a comparison of the detected reception property of the first and third signals and wherein, if the detected reception property of the first signal is not worse than that of the third signal, the beam is set to have non-directivity.

32. The method of claim 30, wherein said first-and-third signal comparing step is performed by a comparison of the detected reception property of the first and third signals and wherein, if the detected reception property of the first signal is not worse than that of the third signal, the beam is oriented in the current direction.

33. The method of claim 32, wherein, if the detected reception property of the third signal is better than that of the first signal, the beam is oriented in a direction different from the current direction.

34. The method of any one of claims 29 to 32, wherein the detected reception property is a signal intensity of the received signal.

35. The method of any one of claims 29 to 32, wherein the detected reception property is an error rate of the received signal.

36. The method of claim 28 or 30, employing a predetermined search cycle.

37. The method of claim 36, further comprising steps of:

comparing a signal level of each received signal to a reference signal level; and

executing the predetermined search cycle, if the signal level of the each received signal is not greater than the reference signal level.

38. A method for controlling a beam switching antenna system including an antenna element for forming a beam, at least one conductive reflector for reflecting the beam, and a ground switch for applying a reference voltage to the at least one conductive reflector, the method comprising steps of:

selectively configuring the beam switching antenna system for a non-directional beam pattern to receive a first signal, for a first-directional beam pattern to receive a second signal, and for a second-directional beam pattern to receive a third signal;

comparing the received signals; and

controlling, using the ground switch, the beam based on the comparison of the received signals.

39. The method of claim 38, wherein said comparing step is performed by a comparison of measured intensities of the received signals and wherein the beam is controlled to have a direction corresponding to the received signal having the greatest intensity.

40. The method of claim 38, wherein said comparing step is performed by a comparison of measured error rates of the received signals and wherein the beam is controlled to have a direction corresponding to the received signal having the lowest error rate.

41. An apparatus for controlling a beam switching antenna system including an antenna element for forming a beam, at least one conductive reflector for reflecting the beam, and a ground switch for applying a reference voltage to the at least one conductive reflector, the apparatus comprising:

a controller for comparing first and second signals and for controlling, using the ground switch, the beam based on the comparison of the first and second signals,

wherein the beam switching antenna system is selectively configured for a current-directional beam pattern to receive the first signal and for a non-directional beam pattern to receive the second signal.

42. The apparatus of claim 41, wherein said controller compares a detected reception property of the first and second signals and, if the detected reception property of the first signal is not worse than that of the second signal, sets the oriented direction of the beam to the current direction.

43. The apparatus of claim 42, wherein, if the detected reception property of the second signal is better than that of the first signal, said controller orients the beam in a direction different from the current direction to receive a third signal, compares the first and third signals, and controls the oriented direction of the beam based on the comparison of the first and third signals.

44. The apparatus of claim 43, wherein said controller compares the detected reception property of the first and third signals and, if the detected reception property of the first signal is not worse than that of the third signal, controls the beam to be directed in the current direction.

45. The apparatus of claim 43, wherein, in a handoff condition, said controller forms an omni-directional beam.

46. The apparatus of claim 44, wherein, if the detected reception property of the third signal is better than that of the first signal, said controller sets the oriented direction of the beam to a direction different from the current direction.

47. The apparatus of any one of claims 42 to 46, wherein the detected reception property is a signal intensity of the received signal.

48. The apparatus of any one of claims 42 to 46, wherein the detected reception property is an error rate of the received signal.

49. The apparatus of claim 41, wherein said controller sets a search time for periodically executing respective processes for beam formation, signal reception, and beam pattern control.

50. The apparatus of claim 41, wherein said controller compares a predetermined reference signal level to a signal level of each received signal and, if the signal level of the each received signal is not greater than the reference signal level, repeats an execution of respective processes for beam formation, signal reception, and beam pattern control.

51. The apparatus of claim 41, wherein the beam is oriented by controlling, using the ground switch, an application of the reference voltage to the at least one conductive reflector.

52. An apparatus for controlling a beam switching antenna system including an antenna element for forming a beam, at least one conductive reflector for reflecting the beam, and a ground switch for applying a reference voltage to the at least one conductive reflector, the apparatus comprising:

a controller for comparing received signals and for controlling, using the ground switch, the beam based on the comparison of the received signals,

wherein the beam switching antenna system is selectively configured for a non-directional beam pattern to receive a first signal, for a first-directional beam pattern to receive a second signal, and for a second-directional beam pattern to receive a third signal.

53. The apparatus of claim 52, wherein said controller compares measured intensities of the received signals and controls the beam to have a direction corresponding to the received signal having the greatest intensity.

54. The apparatus of claim 52, wherein said controller compares measured error rates of the received signals and controls the beam to have a direction corresponding to the received signal having the lowest error rate.