Antenna device and electric equipment

1. An antenna device comprising:

a short circuit path, a first end of which is connected to a ground point that is located near a feed point;

a first open-ended element that has a second end being open, and extends from a second end of the short circuit path;

a feed side element that extends from near the feed point in a direction in which the first open-ended element extends to have an edge close to ground;

a second open-ended element that has a second end being open, and extends from a point connected to the feed side element in the direction in which the first open-ended element extends; and

a short circuit element that connects between a first end of the first open-ended element and either a point on an edge of the feed side element opposite the edge close to the ground or a point on the second open-ended element, wherein

a length, from the ground point to the second end of the first open-ended element through the short circuit path and the first open-ended element, is substantially a quarter of a wavelength of a first resonant frequency, and

a length, from the ground point to the second end of the second open-ended element through the short circuit path, the short circuit element, and the second open-ended element, is substantially a quarter of a wavelength of a second resonant frequency.

2. The antenna device of claim 1 , wherein the feed point is spaced apart from the ground point in the direction in which the first open-ended element extends by a distance equal to or less than substantially a twentieth of the wavelength of lower one of the first resonant frequency or the second resonant frequency.

3. The antenna device of claim 1 , wherein the feed side element has a length equal to or more than substantially a fiftieth of the wavelength of lower one of the first resonant frequency or the second resonant frequency in the direction in which the first open-ended element extends.

4. The antenna device of claim 1 , wherein the short circuit element connects between the first end of the first open-ended element and the point near the second end of the feed side element.

5. The antenna device of claim 1 , wherein

the feed side element is located between the first open-ended element and a ground conductor, and

the edge of the feed side element close to the ground is spaced apart from the ground conductor by a distance equal to or less than substantially a hundredth of the wavelength of lower one of the first resonant frequency or the second resonant frequency.

6. The antenna device of claim 1 , further comprising a parasitic element near the feed side element.

7. The antenna device of claim 1 , wherein the short circuit path bends at least three points to form a projection on apart of the short circuit path.

8. The antenna device of claim 1 being implemented within an electronic device.

9. The antenna device of claim 8 , wherein the feed point is spaced apart from the ground in the direction in which the first open-ended element extends by a distance equal to or less than substantially a twentieth of the wavelength of a lower one of the first resonant frequency or the second resonant frequency.

10. The antenna device of claim 8 , wherein the feed side element has a length equal to or more than substantially a fiftieth of the wavelength of a lower one of the first resonant frequency or the second resonant frequency in the direction in which the first open-ended element extends.

11. The antenna device of claim 8 , wherein the short circuit element connects between the first end of the first open-ended element and the point near the second end of the feed side element.

12. The antenna device of claim 8 , wherein

the feed side element is located between the first open-ended element and a ground conductor, and

the edge of the feed side element close to the ground is spaced apart from the ground conductor by a distance equal to or less than substantially a hundredth of the wavelength of a lower one of the first resonant frequency or the second resonant frequency.

13. The antenna device of claim 8 further comprising a parasitic element near the feed side element.

14. The antenna device of claim 8 , wherein the short circuit path bends at least three points to form a projection on apart of the short circuit path.

15. An antenna device comprising:

a short circuit path, a first end of which is connected to a ground conductor;

a first open-ended element that has a second end being opened, and extends from a second end of the short circuit path;

a feed side element provided between the first open-ended element and the ground conductor, and extending from a feed point in an extending direction of the first open-ended element;

a second open-ended element coupled to the feed side element and extending in the extending direction of the first open-ended element from a point coupled to the feed side element, the point being a second end of the feed side element, a second end of the second open-ended element being opened; and

a short circuit element that connects between a first end of the first open-ended element and either a point on a first edge of the feed side element opposite a second edge of the feed side element close to the ground conductor, wherein

a length, from the feed point to the second end of the first open-ended element through an outer edge of the feed side element comprising the first edge of the feed side element, the short circuit element, and the first open-ended element, is substantially a quarter of a wavelength of a first resonant frequency, and

a length, from the feed point to the second end of the second open-ended element through the outer edge of the feed side element and the second open-ended element, is substantially a quarter of a wavelength of a second resonant frequency.

16. The antenna device of claim 15 being implemented within an electronic device.