Antenna device and communication apparatus including the same

1. An antenna device comprising:

a metal portion which has a surface; and

an antenna which includes a core and a coil section wound around the core and including one coil having one end connected to an input terminal and another end connected to an output terminal without another coil between the one coil and the input terminal and the one coil and the output terminal, the coil section provided above the surface of the metal portion and having an opening portion, the core including a first edge and a second edge which is opposite the first edge,

wherein a surface of the coil section in which the opening portion is formed is approximately perpendicular to the surface of the metal portion,

the antenna is disposed in the vicinity of a first edge of the metal portion, the first edge of the core is disposed in the vicinity of the first edge of the metal portion and the second edge of the core faces a second edge of the metal portion, a first distance between the first edge of the core and the first edge of the metal portion being shorter than a second distance between the second edge of the core and the second edge of the metal portion, and

the antenna is spaced from the metal portion by a distance which is greater than the thickness of the core in a direction perpendicular to the surface of the metal portion.

2. The antenna device according to claim 1 , wherein the metal portion has an approximately rectilinear edge, and wherein the surface in which the opening portion is formed is approximately parallel to the approximately rectilinear edge of the metal portion.

3. The antenna device according to claim 1 , wherein the coil section includes a first opening portion and a second opening portion, the first opening portion being directed to a center side of the metal portion and the second opening portion being directed to an external side of the metal portion.

4. The antenna device according to claim 3 , wherein the first opening portion is disposed directly above the surface of the metal portion.

5. The antenna device according to claim 3 , wherein the first edge of the core is disposed directly above the first edge of the metal portion.

6. The antenna device according to claim 4 , wherein the second edge of the core is disposed a third distance from the first edge of the metal portion and the third distance is greater than the first distance.

7. The antenna device according to claim 4 , wherein the second opening portion is disposed directly above the surface of the metal portion.

8. An antenna device comprising:

a metal portion which has a surface and an approximately rectilinear edge; and

an antenna which includes a core and a coil section wound around the core and including one coil having one end connected to an input terminal and another end connected to an output terminal without another coil between the one coil and the input terminal and the one coil and the output terminal, the coil section provided above the surface of the metal portion and having an opening portion, the core including a first edge and a second edge which is opposite to the first edge,

wherein a surface of the coil section in which the opening portion is formed is approximately perpendicular to the surface of the metal portion,

the surface in which the opening portion is formed is approximately parallel to the approximately rectilinear edge of the metal portion,

the antenna is disposed in the vicinity of a first edge of the metal portion, the first edge of the core is disposed in the vicinity of the first edge of the metal portion and the second edge of the core faces a second edge of the metal portion, a first distance between the first edge of the core and the first edge of the metal portion being shorter than a second distance between the second edge of the core and the second edge of the metal portion, and

the antenna is spaced from the metal portion by a distance which is greater than the thickness of the core in a direction perpendicular to the surface of the metal portion.

9. The antenna device according to claim 3 , wherein the coil section is bent to be approximately parallel to a surface in which the first opening portion is formed and a surface in which the second opening portion is formed, between the surface in which the first opening portion is formed and the surface in which the second opening portion is formed,

wherein the surface in which the first opening portion is formed is approximately perpendicular to the surface of the metal portion, and

wherein the second opening portion is disposed outside the surface of the metal portion.

10. The antenna device according to claim 9 , wherein the surface in which the second opening portion is formed is approximately horizontal to the surface of the metal portion.

11. The antenna device according to claim 9 , wherein the second opening portion is disposed below the surface of the metal portion.

12. A communication apparatus, comprising:

a metal portion which has a surface;

an antenna which includes a core and a coil section wound around the core and including one coil having one end connected to an input terminal and another end connected to an output terminal without another coil between the one coil and the input terminal and the one coil and the output terminal, the coil section provided above the surface of the metal portion and has a pair of opening portions, the core including a first edge and a second edge which is opposite to the first edge; and

a casing which accommodates the metal portion and the antenna and has a main communication surface through which communication is mainly performed,

wherein a surface of the coil section in which at least one of the pair of opening portions is formed is approximately perpendicular to the surface of the metal portion,

wherein the antenna is disposed in the vicinity of a first edge of the metal portion, the first edge of the core is disposed in the vicinity of the first edge of the metal portion and the second edge of the core faces a second edge of the metal portion, a first distance between the first edge of the core and the first edge of the metal portion being shorter than a second distance between the second edge of the core and the second edge of the metal portion,

wherein the pair of opening portions of the coil section is disposed so that a first opening portion thereof is directed to a center side of the metal portion and a second opening portion thereof is directed to an external side of the metal portion, and

wherein the coil section is disposed on the casing, and

the antenna is spaced from the metal portion by a distance which is greater than the thickness of the core in a direction perpendicular to the surface of the metal portion.

13. A communication apparatus comprising:

a metal portion which has a surface;

an antenna which includes a core and a coil section wound around the core and including one coil having one end connected to an input terminal and another end connected to an output terminal without another coil between the one coil and the input terminal and the one coil and the output terminal, the coil section provided above the surface of the metal portion and has a pair of opening portions, the core including a first edge and a second edge which is opposite to the first edge; and

a casing which accommodates the metal portion and the coil section and has a main communication surface through which communication is mainly performed,

wherein a surface of the coil section in which at least of one of the pair of opening portions is formed is approximately perpendicular to the surface of the metal portion,

wherein the antenna is disposed in the vicinity of a first edge of the metal portion, the first edge of the core is disposed in the vicinity of the first edge of the metal portion and the second edge of the core faces a second edge of the metal portion, a first distance between the first edge of the core and the first edge of the metal portion being shorter than a second distance between the second edge of the core and the second edge of the metal portion,

wherein the pair of opening portions of the coil section is disposed so that a first opening portion thereof is directed to a center side of the metal portion and a second opening portion thereof is directed to an external side of the metal portion,

wherein the coil section is disposed above the metal portion on a side opposite to the main communication surface, and

the antenna is spaced from the metal portion by a distance which is greater than the thickness of the core in a direction perpendicular to the surface of the metal portion.

14. The antenna device according to claim 1 , wherein when an outermost edge of the metal portion and an outermost edge of the coil section are aligned and a lateral distance between the outermost edge of the metal portion and the outermost edge of the coil section is zero and the lateral distance between the outermost edge of the metal portion and the outermost edge of the coil section ranges from minus a lateral length of the coil section from zero to plus the lateral length of the coil section from zero.

15. The antenna device according to claim 8 , wherein when an outermost edge of the metal portion and an outermost edge of the coil section are aligned a lateral distance between the outermost edge of the metal portion and the outermost edge of the coil section is zero and the lateral distance between the outermost edge of the metal portion and the outermost edge of the coil section ranges from minus a lateral length of the coil section from zero to plus the lateral length of the coil section from zero.

16. The communication apparatus according to claim 12 , wherein when an outermost edge of the metal portion and an outermost edge of the coil section are aligned a lateral distance between the outermost edge of the metal portion and the outermost edge of the coil section is zero and the lateral distance between the outermost edge of the metal portion and the outermost edge of the coil section ranges from minus a lateral length of the coil section from zero to plus the lateral length of the coil section from zero.

17. The communication apparatus according to claim 13 , wherein when an outermost edge of the metal portion and an outermost edge of the coil section are aligned a lateral distance between the outermost edge of the metal portion and the outermost edge of the coil section is zero and the lateral distance between the outermost edge of the metal portion and the outermost edge of the coil section ranges from minus a lateral length of the coil section from zero to plus the lateral length of the coil section from zero.

18. An antenna device comprising:

a metal portion which has a surface and an outermost edge; and

an antenna which includes a core and a coil section wound around the core, provided above the surface of the metal portion, the coil section having an opening portion and having an outermost edge, when the outermost edge of the metal portion and the outermost edge of the coil section are aligned, a lateral distance between the outermost edge of the metal portion and the outmost edge of the coil section is zero and the core including a first edge and a second edge which is opposite to the first edge,

wherein a surface of the coil section in which the opening portion is formed is approximately perpendicular to the surface of the metal portion, and

wherein the antenna is disposed in the vicinity of an edge of the metal portion, the first edge of the core is disposed in the vicinity of a first edge of the metal portion and the second edge of the core faces a second edge of the metal portion, a first distance between the first edge of the core and the first edge of the metal portion is shorter than a second distance between the second edge of the core and the second edge of the metal portion, and the lateral distance between the outermost edge of the metal portion and the outmost edge of the coil section ranges from minus a lateral length of the coil section from zero to plus a lateral length of the coil section from zero and an axis of a magnetic field of the coil section is inclined, and

the antenna is spaced from the metal portion by a distance which is greater than the thickness of the core in a direction perpendicular to the surface of the metal portion.

19. An antenna device comprising:

a metal portion which has a surface; and

an antenna which includes a core and a coil section wound around the core and including one coil having one end connected to an input terminal and another end connected to an output terminal without another coil between the one coil and the input terminal and the one coil and the output terminal, the coil section provided above the surface of the metal portion and having an opening portion, the core including a first edge and a second edge which is opposite to the first edge,

wherein when an outermost edge of the metal portion and an outermost edge of the coil section are aligned a lateral distance between the outermost edge of the metal portion and the outermost edge of the coil section is zero and the lateral distance between the outermost edge of the metal portion and the outermost edge of the coil section ranges from minus a lateral length of the coil section from zero to plus the lateral length of the coil section from zero and an axis of a magnetic field of the coil section is inclined,

wherein a surface of the coil section in which the opening portion is formed is approximately perpendicular to the surface of the metal portion, and

wherein the antenna is disposed in the vicinity of an edge of the metal portion, the first edge of the core is disposed in the vicinity of a first edge of the metal portion and the second edge of the core faces a second edge of the metal portion, a first distance between the first edge of the core and the first edge of the metal portion is shorter than a second distance between the second edge of the core and the second edge of the metal portion, and

the antenna is separated from the metal portion by a distance which is longer than the thickness of the core in a direction perpendicular to the surface of the metal portion.