Broadband antenna unit comprising a ground plate having a lower portion where both side corner portions are deleted

Abstract

In a broadband antenna unit having a ground plate and an elliptically shaped radiation element disposed at an upper portion of the ground plate in a plane where the ground plate extends, the ground plate has a semi-elliptically shaped upper edge and a lower portion where both side corner portions are deleted with a central portion left. The ground plate and the radiation element are formed on a substrate.

Description

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a plan view showing a first conventional broadband antenna unit;

FIG. 2 is an enlarged plan view showing a radiation element for use in the broadband antenna unit illustrated in FIG. 1;

FIG. 3A is a plan view showing of a second conventional broadband antenna unit;

FIG. 3B is a side view showing the second conventional broadband antenna unit illustrated in FIG. 3A;

FIG. 4 is a view showing a frequency characteristic of VSWR of the broadband antenna unit illustrated in FIGS. 3A and 3B;

FIG. 5A is a view showing a radiation pattern of the second conventional broadband antenna unit illustrated in FIGS. 3A and 3B at a frequency f of 6 GHz;

FIG. 5B is a view showing a radiation pattern of the first conventional broadband antenna unit illustrated in FIG. 1 at a frequency f of 6 GHz;

FIG. 6 is a view showing frequency characteristics of gains in a +z direction of the first and the second conventional broadband antenna units illustrated in FIG. 1 and FIGS. 3A and 3B;

FIG. 7A is a plan view showing a broadband antenna unit according to an embodiment of this invention;

FIG. 7B is a side view showing the broadband antenna unit illustrated in FIG. 7A;

FIG. 8 is a view showing a frequency characteristic of VSWR of the broadband antenna unit illustrated in FIGS. 7A and 7B;

FIG. 9A is a view showing a radiation pattern of the broadband antenna unit illustrated in FIGS. 7A and 7B at a frequency f of 10 GHz;

FIG. 9B is a view showing a radiation pattern of the second conventional broadband antenna unit illustrated in FIGS. 3A and 3B at a frequency f of 10 GHz; and

FIG. 10 is a view showing frequency characteristics of gains in a +z direction of the broadband antenna units illustrated in FIGS. 7A and 7B and FIGS. 3A and 3B.

Claims

1. A broadband antenna unit comprising: a ground plate; andan elliptically shaped radiation element disposed at an upper portion of said ground plate in a plane where said ground plate extends,wherein said ground plate has a semi-elliptically shaped upper edge and a lower portion where both side corner portions are deleted with a central portion left.

2. The broadband antenna unit as claimed in claim 1, wherein further comprises a substrate on which said ground plate and said radiation element are formed.

3. The broadband antenna unit as claimed in claim 1, wherein said radiation element and said ground plate are apart from each other by a predetermined feeding distance.

4. The broadband antenna unit as claimed in claim 1, said elliptically shaped radiation element having a major outside diameter in an ellipse's major axis direction and a minor outside diameter in an ellipse's minor axis direction, wherein a ratio between the major outside diameter and the minor outside diameter is 8:5.

5. The broadband antenna unit as claimed in claim 1, wherein said elliptically shaped radiation element has an elliptically shaped opening which is concentric with said elliptically shaped radiation element.

6. The broadband antenna unit as claimed in claim 5, said elliptically shaped opening having a minor inside diameter in the ellipse's minor axis direction, wherein the minor inside diameter is half of the minor outside diameter.

7. The broadband antenna unit as claimed in claim 5, said elliptically shaped opening having a major inside diameter in the ellipse's major axis direction, wherein the major inside diameter is not more than half of the major outside diameter.