Small antenna and calculation apparatus

A small antenna comprising:

• a first element that includes a wire and a wide conductor;
• and
• a second element that is arranged to face the wire of the first element with sandwiching a dielectric body, and includes a conductor provided by a wire, wherein:
• a connecting portion between the wire of the first element and the wide conductor has a power feeding point, and an end portion of the second element has a power feeding point;
• a part of the wire of each of the first element and the second element has an inductance shape with three or more bending structures or an inductance shape with a spiral structure;
• a first resonance mode, in which a current direction of current flowing through the first element is same as a current direction of current flowing through the second element, has a first resonant frequency;
• a second resonance mode, in which the current direction of current flowing through the first element is opposite to the current direction of current flowing through the second element, has a second resonant frequency;
• and
• a length from each power feeding point to the inductance shape is determined to hold the first resonant frequency of the first resonance mode within a range from a frequency slightly higher than the second resonant frequency of the second resonance mode to a high anti-resonant frequency of the second resonance mode, or a range from a frequency slightly lower than the second resonant frequency of the second resonance mode to a low anti-resonant frequency of the second resonance mode.

A calculation apparatus for designing a small antenna, which includes:

• a first element that has a pair of conductors provided by a wire, one end portion of each of the pair of conductors being a power feeding point;
• and a second element that is arranged to face the first element with sandwiching a dielectric body, and has a conductor provided by a wire, wherein:
• a part of the wire of each of the first element and the second element has an inductance shape with three or more bending structures or an inductance shape with a spiral structure;
• a first resonance mode, in which a current direction of current flowing through the first element is same as a current direction of current flowing through the second element, has a first resonant frequency;
• a second resonance mode, in which the current direction of current flowing through the first element is opposite to the current direction of current flowing through the second element, has a second resonant frequency;
• and
• the calculation apparatus receives the first resonant frequency and the second resonant frequency, and calculates one of an admittance, an impedance, a reflection coefficient, and a return loss of the small antenna.

A calculation apparatus for designing a small antenna, which includes:

• a first element that has a wire and a wide conductor;
• and a second element that is arranged to face the wire of the first element with sandwiching a dielectric body, and has a conductor provided by a wire, a connecting portion between the wire of the first element and the wide conductor having a power feeding point, and an end portion of the second element having a power feeding point, wherein:
• a part of the wire of each of the first element and the second element has an inductance shape with three or more bending structures or an inductance shape with a spiral structure;
• a first resonance mode, in which a current direction of current flowing through the first element is same as a current direction of current flowing through the second element, has a first resonant frequency;
• a second resonance mode, in which the current direction of current flowing through the first element is opposite to the current direction of current flowing through the second element, has a second resonant frequency;
• and
• the calculation apparatus receives the first resonant frequency and the second resonant frequency, and calculates one of an admittance, an impedance, a reflection coefficient, and a return loss of the small antenna.

A calculation apparatus for designing a small antenna, which includes:

• a first element that has a pair of conductors provided by a wire, one end portion of each of the pair of conductors being a power feeding point;
• and a second element that is arranged to face the first element with sandwiching a dielectric body, and has a conductor provided by a wire, wherein:
• a part of the wire of each of the first element and the second element has an inductance shape with three or more bending structures or an inductance shape with a spiral structure;
• and
• the calculation apparatus receives one resonant frequency of the first element and the second element, and calculates one of an other resonant frequency of the first element and the second element and an antenna shape.

A calculation apparatus for designing a small antenna, which includes:

• a first element that has a wire and a wide conductor;
• and a second element that is arranged to face the wire of the first element with sandwiching a dielectric body, and includes a conductor provided by a wire, a connecting portion between the wire of the first element and the wide conductor having a power feeding point, and an end portion of the second element having a power feeding point, wherein:
• a part of the wire of each of the first element and the second element has an inductance shape with three or more bending structures or an inductance shape with a spiral structure;
• and
• the calculation apparatus receives one resonant frequency of the first element and the second element, and calculates one of an other resonant frequency of the first element and the second element and an antenna shape.

A small antenna comprising:

• a first element that includes a pair of conductors provided by a wire, one end portion of each of the pair of conductors being a power feeding point;
• and
• a second element that is arranged to face the first element with sandwiching a dielectric body, and includes a conductor provided by a wire, wherein:
• a part of the wire of each of the first element and the second element has an inductance shape with three or more bending structures or an inductance shape with a spiral structure;
• a length from a center of each of the first element and the second element to the inductance shape is determined to separate a first resonant frequency of a first resonance mode, in which a current direction of current flowing through the first element is same as a current direction of current flowing through the second element, from a second resonant frequency of a second resonance mode, in which the current direction of current flowing through the first element is opposite to the current direction of current flowing through the second element;
• and
• a width of at least a part of each wire other than the inductance shape of the first element or the second element is configured to be wider than a width of the inductance shape.