Nippon Telegraph and Telephone Corporation

Souichi Oka

Ai-ichiro Sasaki

Akihiko Hirata

Osamu Kagami

Fumiharu Morisawa

Ai-Ichiro Sasaki

A loop antenna array capable of forming a clear boundary of a communication area is provided. The loop antenna array includes three loop antennas, in which a direction of a current flowing through the loop antenna arranged in the middle and a direction of a current flowing through each of the loop antennas arranged on both sides of the loop antenna arranged in the middle are opposite from each other, and the sum of magnetic moments of the three loop antennas is zero.

Loop antenna array

A loop antenna array that can form a linear and clear communication area boundary is provided. The loop antenna array includes two loop antennas. Currents flow through the loop antennas in opposite directions from each other. In other words, viewing in a direction passing through each of the loop antennas, at a timing when a positive voltage is applied to a signal terminal of an alternating-current source, a clockwise current flows through one loop antenna while a counterclockwise current flows through the other loop antenna. Conversely, at a timing when a negative voltage is applied to the signal terminal of the alternating-current source, a counterclockwise current flows through one loop antenna while a clockwise current flows through the other loop antenna.

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

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Atsugi, Japan

Souichi Oka