Antenna device
An antenna device includes: a patch antenna; and a ground portion at which the patch antenna is disposed, the ground portion having an external form obtained by forming a cutout portion in a rectangle, the cutout portion overlapping with at least a part of the patch antenna, in side view. Further, a first center of the patch antenna is shifted toward a long side of the rectangle having the cutout portion formed therein, relative to a second center of the rectangle.
1 . An antenna device comprising:
a patch antenna; and
a ground portion at which the patch antenna is disposed, the ground portion having an external form obtained by forming a cutout portion in a rectangle, the cutout portion overlapping with at least a part of the patch antenna, in side view, wherein
the patch antenna includes a first feeding portion and a second feeding portion, and
the cutout portion is formed such that a difference in reflection loss caused by a difference between a minimum value of a voltage standing wave ratio (VSWR) in the first feeding portion and a minimum value of a VSWR in the second feeding portion is 3 dB or less.
2 . The antenna device according to claim 1 , wherein a first center of the patch antenna is shifted toward a long side of the rectangle having the cutout portion formed therein, relative to a second center of the rectangle.
3 . The antenna device according to claim 2 , wherein the external form of the ground portion is line-symmetrical with respect to an axis passing through the second center of the rectangle, the axis being parallel to a short side of the rectangle.
4 . The antenna device according to claim 1 , wherein the cutout portion includes a first cutout portion positioned at a first corner of the rectangle.
5 . The antenna device according to claim 4 , wherein
the rectangle includes a second corner located so as to sandwich the patch antenna between the first corner and the second corner, and
the cutout portion further includes a second cutout portion positioned at the second corner.
6 . The antenna device according to claim 5 , wherein the first cutout portion and the second cutout portion are positioned so as to be line-symmetrical with respect to an axis passing through the second center of the rectangle, the axis being parallel to a short side of the rectangle.
7 . The antenna device according to claim 1 , wherein the area of the cutout portion is ab-a 2 or less, where a is a length of a short side and b is a length of the long side, in the rectangle.
8 . The antenna device according to claim 7 , wherein the area of the cutout portion is (ab-a 2 )/2 or more.
9 . An antenna device comprising:
a patch antenna; and
a ground portion at which the patch antenna is disposed, the ground portion having an external form obtained by forming a cutout portion in a rectangle, the cutout portion overlapping with at least a part of the patch antenna, in side view, wherein
the area of the cutout portion is (ab-a 2 ) or less,
where a is a length of a short side and b is a length of the long side, in the rectangle.
10 . The antenna device according to claim 9 , wherein a first center of the patch antenna is shifted toward a long side of the rectangle having the cutout portion formed therein, relative to a second center of the rectangle.
11 . The antenna device according to claim 10 , wherein the external form of the ground portion is line-symmetrical with respect to an axis passing through the second center of the rectangle, the axis being parallel to a short side of the rectangle.
12 . The antenna device according to claim 9 , wherein the cutout portion includes a first cutout portion positioned at a first corner of the rectangle.
13 . The antenna device according to claim 12 , wherein
the rectangle includes a second corner located so as to sandwich the patch antenna between the first corner and the second corner, and
the cutout portion further includes a second cutout portion positioned at the second corner.
14 . The antenna device according to claim 13 , wherein the first cutout portion and the second cutout portion are positioned so as to be line-symmetrical with respect to an axis passing through the second center of the rectangle, the axis being parallel to a short side of the rectangle.
15 . The antenna device according to claim 9 , wherein the area of the cutout portion is (ab-a 2 )/2 or more.