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

Patent metadata

Field	Value
Publication number	US-10177823-B2
Application number	US-201615541243-A
Country	US
Kind code	B2
Filing date	Sep 5, 2016
Priority date	Mar 22, 2016
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

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 1 A, 1 B 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 1 A, 1 B as the antenna parameter based on the input parameters.

First claim

The invention claimed is:

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:

d
opt
′

=

d
⁡

(

Z
C

,

A
min

)

=

2
⁢

⁢

Z
C

·

80
-

A
min

20
+

A
min

,

where d′ opt denotes the inter-center distance, Z C denotes the distance to the boundary of the communication area, and A min denotes the lower limit value of the attenuation rate of the magnetic field intensity.

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:

I
opt
′

=

I
⁡

(

Z
C

,

H
C

,

A
min

)

=

2
⁢
π

3

·

10

(

H
C

-
120

)

/
20

·

Z
C
3

S
eff

·

20
+

A
min

80
-

A
min

·

(

100

20
+

A
min

)

5
/
2

,

where I′ opt denotes the minimum intensity of the electric currents, Z C denotes the distance to

Assignees

• Nippon Telegraph & Telephone

Inventors

• Sasaki Ai-Ichiro
• Hirata Akihiko
• Morisawa Fumiharu
• Oka Souichi
• Kagami Osamu

Classifications

• H04W16/20

  for indoor coverage or short range network deployment · CPC title

• H01Q3/01

  varying the shape of the antenna or antenna system · CPC title

• H01Q3/02

  using mechanical movement of antenna or antenna system as a whole · CPC title

• H04W4/80

  Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication · CPC title

• H01Q7/08

  Ferrite rod or like elongated core · CPC title