Abstract: Provided is a loop antenna array that can easily create a magnetic field distribution which enables the boundary of a communication area to be clearly set. 2n loop antennae are provided adjacently to one another, where n is a natural number. The directions of currents in adjacent ones of the loop antennae are opposite to each other. For example, in a loop antenna array, two loop antennae are disposed adjacently to each other on an insulator substrate. First feed points energize one loop antenna and second feed points energize the other loop antenna.

Abstract: Provided is a loop antenna which can contribute to an increase of an area of a radio system using a magnetic field. The loop antenna includes a main loop 1 which is an open loop connected to a signal source 5 or a reception circuit; and an amplification loop 2 which is a closed loop having the same shape as the main loop 1. The main loop 1 and the amplification loop 2 are arranged on a same surface of a flat substrate formed of an insulator. A first capacitance is connected to the main loop 1, and a second capacitance is connected to the amplification loop.

Abstract: A main loop is an open loop that is wound on a bar-shaped rod formed of a magnetic body or an insulation body and that has terminals T and T that couple a signal source or a receiving circuit to the main loop. The number of turns is 1 or more. An amplifying loop is wound on a part of the rod that is different from the part on which the main loop is wound. The main loop and the amplifying loop are thus spaced from each other. The amplifying loop is a closed loop including no terminals. The number of turns is 1 or more. The number of turns may be the same as or different from the number of turns of the main loop.

Abstract: A main loop is an open loop that is wound on a bar-shaped rod formed of a magnetic body or an insulation body and that has terminals T and T that couple a signal source or a receiving circuit to the main loop. The number of turns is 1 or more. An amplifying loop is wound on a part of the rod that is different from the part on which the main loop is wound. The main loop and the amplifying loop are thus spaced from each other. The amplifying loop is a closed loop including no terminals. The number of turns is 1 or more. The number of turns may be the same as or different from the number of turns of the main loop.

Abstract: Provided is a loop antenna which can contribute to an increase of an area of a radio system using a magnetic field. The loop antenna includes a main loop 1 which is an open loop connected to a signal source 5 or a reception circuit; and an amplification loop 2 which is a closed loop having the same shape as the main loop 1. The main loop 1 and the amplification loop 2 are arranged on a same surface of a flat substrate formed of an insulator. A first capacitance is connected to the main loop 1, and a second capacitance is connected to the amplification loop.

Abstract: Provided is a loop antenna array that can easily create a magnetic field distribution which enables the boundary of a communication area to be clearly set. 2n loop antennae are provided adjacently to one another, where n is a natural number. The directions of currents in adjacent ones of the loop antennae are opposite to each other. For example, in a loop antenna array, two loop antennae are disposed adjacently to each other on an insulator substrate. First feed points energize one loop antenna and second feed points energize the other loop antenna.