Electronic device

1. An electronic device, comprising:

a case that includes a conductor part;

an antenna that is provided on a case surface on an inner side of the conductor part and includes an antenna element that extends in a first direction parallel to the case surface, the antenna element is grounded to the case surface, wherein one end of the antenna element is a fixed end that is provided with a short pin, and another end of the antenna element is an open end; and

a slit that extends in the first direction is formed in an area of the case surface, the area is parallel to the antenna element, wherein the slit extends from the fixed end as a start point in a direction toward the open end,

wherein the antenna includes a first parasitic element disposed subsequent to the fixed end of the antenna element, and extends in a direction opposite to the first direction,

wherein the antenna includes a second parasitic element disposed between the antenna element and the case surface, and extends in the first direction, and

wherein an additional slit that extends in the first direction, from a fixed end of the second parasitic element, is formed in the area of the case surface.

2. The electronic device according to claim 1 ,

wherein the area of the case surface, in which the slit is formed, operates as a parasitic element of the antenna, and the parasitic element causes a first excitation.

3. The electronic device according to claim 2 ,

wherein the slit has a length equal to 4/9 to ½ of a wavelength that corresponds to a frequency of the first excitation.

4. The electronic device according to claim 1 , wherein

a grounding point at which the second parasitic element is grounded to the case surface is apart from an end point on a side of the fixed end of the slit by 1/12 of a length of the slit inwardly of the slit.

5. The electronic device according to claim 1 ,

wherein the area of the case surface is parallel to the antenna element.

6. The electronic device according to claim 5 ,

wherein the area of the case surface, in which the slit is formed, operates as a parasitic element of the antenna, and the parasitic element causes a first excitation, and

the area of the case surface, in which the additional slit is formed, operates as a parasitic element of the antenna, and the parasitic element causes a second excitation.

7. The electronic device according to claim 6 ,

wherein the second excitation is an excitation with a frequency of a second harmonic for a frequency of the first excitation.

8. The electronic device according to claim 1 ,

wherein the antenna is an inverted-F antenna.

9. The electronic device according to claim 1 ,

wherein the antenna operates in dual band wireless LAN and WiMAX.

10. The electronic device according to claim 1 ,

wherein a shape of the first parasitic element is an inverted-L shape.