Antenna control apparatus, antenna control program, and antenna control system

• US 10,177,823 B2
• Filed: 09/05/2016
• Issued: 01/08/2019
• Est. Priority Date: 03/22/2016
• Status: Active Grant

• Current Assignee: Nippon Telegraph and Telephone Corporation
• Original Assignee: Nippon Telegraph and Telephone Corporation
• Inventors: Sasaki, Ai-ichiro, Hirata, Akihiko, Morisawa, Fumiharu, Oka, Souichi, Kagami, Osamu
• Primary Examiner(s): Trandai, Cindy
• Application Number:
  US15/541,243
• Publication Number:
  US 20180109296A1
• Time in Patent Office: 855 Days
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 3/01 varying the shape of the antenna or antenna system
• CPC Class Codes: H01Q 3/02 using mechanical movement of antenna or antenna system as a whole
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 7/08 Ferrite rod or like elongated core
• CPC Class Codes: H04B 5/263 Multiple coils at either side
• CPC Class Codes: H04B 5/70 specially adapted for specific purposes
• CPC Class Codes: H04B 7/04 using two or more spaced independent antennas
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04W 16/20 for indoor coverage or short range network deployment
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication
• CPC Class Codes: H04W 52/0206 in access points, e.g. base stations access point devices per se H04W88/08
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Provided is an antenna control technique for forming the boundary of a communication area at a desired location. An antenna parameter control apparatus 2 calculates an antenna parameter in a case of feeding electric currents with an equal intensity in mutually reverse directions to two antennas 1A, 1B which generate a magnetic field. The antenna parameter control apparatus 2 includes an input parameter acquisition unit 21 that acquires input parameters for calculating the antenna parameter; and a parameter calculation unit 22 that calculates an inter-center distance d between the antennas 1A, 1B as the antenna parameter based on the input parameters.

Claims

1. An antenna control apparatus that controls an inter-center distance between two antennas, the antenna control apparatus comprising:

an input parameter acquisition unit that acquires, as input parameters, a distance from the two antennas to a boundary of a communication area formed by the antennas, and a lower limit value of an attenuation rate of a magnetic field intensity at the boundary of the communication area; and

a calculation unit that calculates, based on the distance to the boundary of the communication area and the lower limit value of the attenuation rate of the magnetic field intensity, the inter-center distance between the antennas such that the attenuation rate of the magnetic field intensity equal to the lower limit value is obtained at the boundary of the communication area and the intensity of the electric currents flowing through the antennas is minimized, wherein

the antennas are fed with the electric currents with an equal intensity in mutually reverse directions and

the calculation unit calculates the inter-center distance in accordance with the following formula;

2. The antenna control apparatus according to claim 1, wherein

the input parameter acquisition unit acquires the magnetic field intensity required at the boundary of the communication area,

based on the distance to the boundary of the communication area, the magnetic field intensity, and the lower limit value of the attenuation rate of the magnetic field intensity, the calculation unit calculates the minimum intensity of the electric currents such that the magnetic field intensity and the attenuation rate of the magnetic field intensity equal to the lower limit value are obtained at the boundary of the communication area.

3. The antenna control apparatus according to claim 2, wherein

the calculation unit calculates the minimum intensity of the electric currents in accordance with the following formula:

4. The antenna control apparatus according to claim 1, wherein

the input parameter acquisition unit acquires an upper limit value of the inter-center distance,

the calculation unit calculates the minimum intensity of the electric currents based on the distance to the boundary of the communication area, the magnetic field intensity required at the boundary of the communication area, and the upper limit value of the inter-center distance, such that the magnetic field intensity required at the boundary of the communication area is obtained at the boundary of the communication area with the inter-center distance set equal to the upper limit value.

5. The antenna control apparatus according to claim 4, wherein

the calculation unit calculates the minimum intensity of the electric currents in accordance with the following formula:

6. The antenna control apparatus according to claim 1, further comprising a control unit that controls the two antennas based on the inter-center distance between the antennas calculated by the calculation unit.

7. An antenna control apparatus that controls an inter-center distance between two antennas, the antenna control apparatus comprising:

an input parameter acquisition unit that acquires, as input parameters, a distance from the two antennas to a boundary of a communication area formed by the antennas, a distance from the antennas to a location farther than the boundary of the communication area, a magnetic field intensity required at the boundary of the communication area, and an upper limit value of the magnetic field intensity at the location farther than the boundary of the communication area; and

a calculation unit that calculates, based on the distances, the magnetic field intensity, and the upper limit value, the inter-center distance between the antennas and the minimum intensity of the electric currents such that the magnetic field intensity required at the boundary of the communication area is obtained at the boundary of the communication area, the magnetic field intensity equal to the upper limit value is obtained at the location farther than the boundary of the communication area, and the electric currents flowing through the antennas are minimized, wherein

the antennas are fed with the electric currents with an equal intensity in mutually reverse directions and

the calculation unit obtains the inter-center distance and the minimum intensity of the electric currents as solutions of the following formula;

8. The antenna control apparatus according to claim 7, wherein

the input parameter acquisition unit acquires an upper limit value of the inter-center distance,

the calculation unit calculates the minimum intensity of the electric currents based on the distance to the boundary of the communication area, the magnetic field intensity required at the boundary of the communication area, and the upper limit value of the inter-center distance, such that the magnetic field intensity required at the boundary of the communication area is obtained at the boundary of the communication area with the inter-center distance set equal to the upper limit value.

9. The antenna control apparatus according to claim 8, wherein

the calculation unit calculates the minimum intensity of the electric currents in accordance with the following formula:

10. The antenna control apparatus according to claim 7, further comprising a control unit that controls the two antennas based on the inter-center distance between the antennas calculated by the calculation unit.

11. A non-transitory computer readable medium storing an antenna control program that controls an inter-center distance between two antennas and causes a computer to execute a process comprising:

acquiring, as input parameters, a distance from the two antennas to a boundary of a communication area formed by the antennas, and a lower limit value of an attenuation rate of a magnetic field intensity at the boundary of the communication area; and

calculating, based on the distance to the boundary of the communication area and the lower limit value of the attenuation rate of the magnetic field intensity, the inter-center distance between the antennas such that the attenuation rate of the magnetic field intensity equal to the lower limit value is obtained at the boundary of the communication area and the intensity of electric currents flowing through the antennas is minimized, wherein

the antennas are fed with the electric currents with an equal intensity in mutually reverse directions and

the inter-center distance is calculated in accordance with the following formula;

12. An antenna control system comprising:

the antenna control apparatus that controls an inter-center distance between two antennas and

the two antennas fed with electric currents with an equal intensity in mutually reverse directions, wherein

the antennas control apparatus comprising;

an input parameter acquisition unit that acquires, as input parameters, a distance from the two antennas to a boundary of a communication area formed by the antennas, and a lower limit value of an attenuation rate of a magnetic field intensity at the boundary of the communication area; and

a calculation unit that calculates, based on the distance to the boundary of the communication area and the lower limit value of the attenuation rate of the magnetic field intensity, the inter-center distance between the antennas such that the attenuation rate of the magnetic field intensity equal to the lower limit value is obtained at the boundary of the communication area and the intensity of the electric currents flowing through the antennas is minimized, wherein

the calculation unit calculates the inter-center distance in accordance with the following formula

13. The antenna control system according to claim 12, wherein the two antennas are loop antennas or bar antennas.

14. The antenna control system according to claim 12, wherein the two antennas are connected in series.