Antenna apparatus

Abstract

An antenna apparatus has a ground and an antenna element. The antenna element includes a feeding portion and two turnback potions. The two turnback portions are on different radial lines, which originate from the feeding point to depart from each other on a surface of the antenna element. The two turnback portions are individually coupled with the ground via connection portions to thereby form two loops starting from the feeding portion and returning to the ground. A high dielectric member is provided as having a predetermined thickness and a surface identical to the surface of the ground and opposing the ground face-to-face. Therefore, the high frequency electric current applied to the feeding portion turns back at the turnback portions to return to the ground via the connection portions while forming two current loops.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features, and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings:

FIG. 1 is an oblique front view of an antenna apparatus according to a first embodiment of the present invention;

FIG. 2 is an oblique rear view of the antenna apparatus in FIG. 1;

FIG. 3 is a view illustrating a feeding portion and grounding portion of the antenna apparatus in FIG. 1;

FIG. 4 is a diagram illustrating VSWR measurement results from the antenna apparatus in FIG. 1;

FIG. 5 is an oblique front view of an antenna apparatus according to a second embodiment of the present invention;

FIG. 6 is an oblique front view of an antenna apparatus according to a third embodiment of the present invention;

FIG. 7 is an oblique front view of an antenna apparatus according to a fourth embodiment of the present invention;

FIG. 8 is an oblique front view of an antenna apparatus according to a fifth embodiment of the present invention;

FIG. 9 is a diagram illustrating VSWR measurement results from the antenna apparatus in FIG. 8;

FIG. 10 is an oblique front view of an antenna apparatus according to a sixth embodiment of the present invention;

FIG. 11 is an oblique front view of an antenna apparatus according to a seventh embodiment of the present invention;

FIG. 12 is an oblique rear view of the antenna apparatus in FIG. 11;

FIG. 13 is an oblique front view of an antenna apparatus according to an eighth embodiment of the present invention;

FIG. 14 is an oblique front view of an antenna apparatus according to another embodiment of the present invention; and

FIG. 15 is an oblique front view of an antenna apparatus according to yet another embodiment of the present invention.

Claims

1. An antenna apparatus comprising: a ground shaped of a flat plate; andan antenna element shaped of a flat plate, wherein a surface of the ground and a surface of the antenna element are approximately on a plane, the antenna element including a feeding portion and at least two turnback portions, the at least two turnback portions which are on different radial lines, which originate from the feeding point to depart from each other on the surface of the antenna element,wherein the at least two turnback portions are individually coupled with the ground via connection portions to thereby form at least two loops, which individually link the feeding portion with the ground.

2. The antenna apparatus of claim 1, further comprising: a high dielectric member having a predetermined thickness and a surface, which is parallel with the plane and has a shape approximately identical to a shape of the surface of the ground, so that the high dielectric member is configured to oppose the ground face-to-face.

3. The antenna apparatus of claim 1, further comprising: a dielectric substrate, whereineach of the antenna element and the ground is made of a conductor pattern provided on the dielectric substrate.

4. The antenna apparatus of claim 1, wherein each of the antenna element and the ground is made of a conductive plate.

5. The antenna apparatus of claim 1, further comprising: a parasitic element adjacent to the antenna element.

6. The antenna apparatus of claim 1, further comprising: an additional antenna element shaped of a flat plate and having a surface, which is approximately on the plane and has a shape approximately identical to a shape of the surface of the antenna element, the additional antenna element including an additional feeding portion and at least two additional turnback portions, the at least two additional turnback portions which are on different radial lines, which originate from the additional feeding point to depart from each other on the surface of the additional antenna element,wherein the at least two additional turnback portions are individually coupled with the ground via additional connection portions to thereby form at least two additional loops, which individually link the additional feeding point with the ground, andwherein a first pair of the antenna element and the ground and a second pair of the additional antenna element and the ground are arranged to allow a diversity reception.

7. An antenna apparatus comprising: a ground shaped of a flat plate;an antenna element shaped of a flat plate, wherein a surface of the ground and a surface of the antenna element are approximately on a plane, the antenna element including a feeding portion and at least two turnback portions, the at least two turnback portions which are on different radial lines, which originate from the feeding point to depart from each other on the surface of the antenna element, wherein the at least two turnback portions are individually coupled with the ground via connection portions to thereby form at least two loops, which individually link the feeding portion with the ground; anda high dielectric member having a predetermined thickness and a surface, which is parallel with the plane and has a shape approximately identical to a shape of the surface of the ground, so that the high dielectric member is configured to oppose the ground face-to-face.

8. The antenna apparatus of claim 7, further comprising: a dielectric substrate, whereineach of the antenna element and the ground is made of a conductor pattern provided on the dielectric substrate.

9. The antenna apparatus of claim 7, wherein each of the antenna element and the ground is made of a conductive plate.

10. The antenna apparatus of claim 7, further comprising: a parasitic element adjacent to the antenna element.

11. The antenna apparatus of claim 7, further comprising: an additional antenna element shaped of a flat plate and having a surface, which is approximately on the plane and has a shape approximately identical to a shape of the surface of the antenna element, the additional antenna element including an additional feeding portion and at least two additional turnback portions, the at least two additional turnback portions which are on different radial lines, which originate from the additional feeding point to depart from each other on the surface of the additional antenna element,wherein the at least two additional turnback portions are individually coupled with the ground via additional connection portions to thereby form at least two additional loops, which individually link the additional feeding point with the ground, andwherein a first pair of the antenna element and the ground and a second pair of the additional antenna element and the ground are arranged to allow a diversity reception.