US-12627058-B2 - Antenna and antenna apparatus for vehicle

US12627058B2US 12627058 B2US12627058 B2US 12627058B2US-12627058-B2

Abstract

An antenna and an antenna apparatus for vehicle that can achieve reduction in size are provided. The antenna includes a dielectric body, a radiation conductor disposed on a first principal surface side of the dielectric body, and a ground conductor disposed on a second principal surface side of the dielectric body. The ground conductor is a planar conductor disposed within a rectangular region having a length L G1 in a first direction and a length L G2 in a second direction. When the ground conductor is divided into a first region and a second region, the ground conductor includes a slit that starts extending toward the inside of the ground conductor starting from an outer edge of the ground conductor in the first region.

Inventors

Yusuke Kato
Shoichi Takeuchi
Hideaki Shoji
Toshiki SAYAMA

Assignees

AGC Inc.

Dates

Publication Date: 20260512
Application Date: 20240110
Priority Date: 20210716

Claims (20)

1 . An antenna comprising: a dielectric body; a radiation conductor disposed on a first principal surface side of the dielectric body; and a ground conductor disposed on a second principal surface side of the dielectric body, wherein the ground conductor is disposed within a rectangular region having a length L G1 in a first direction and a length L G2 in a second direction orthogonal to the first direction in a plan view of the dielectric body, when a wavelength of radio waves, in the air, to be transmitted/received by the radiation conductor is set as λ, L G1 satisfies 0.7×(λ/2)≤L G1 ≤1.4×(λ/2), and L G2 satisfies 0.7×(λ/2)≤L G2 ≤1.4×(λ/2), when the ground conductor is divided into a first region and a second region by a virtual line connecting a virtual feeding point obtained by projecting a feeding point at which power is fed to the radiation conductor in a thickness direction of the dielectric body, and a center of gravity in a plan view of the ground conductor, the ground conductor includes a first slit extending toward the inside of the ground conductor starting from an outer edge of the ground conductor in the first region, and an end portion of the first slit is located inside of the outer edge of the ground conductor, wherein when in a plan view of the ground conductor, a perimeter of the first slit is set as D S1 , and a wavelength of radio waves, in the air, to be transmitted/received by the radiation conductor is set as λ, 0.13×λ≤D S1 ≤0.45×λ is satisfied.
2 . The antenna according to claim 1 , wherein the radiation conductor is disposed within a rectangular region having a length L R1 in the first direction and a length L R2 in the second direction, and the length L R1 and the length L R2 satisfy L R1 =L R2 .
3 . The antenna according to claim 1 , wherein the ground conductor has a quadrangular shape in a plan view of the dielectric body.
4 . The antenna according to claim 3 , wherein when among four sides constituting the ground conductor, a side closest to the virtual feeding point is set as a closest side, a side adjacent to the closest side and including an outer edge of the first region is set as a first side, and a length of the first side is set as L G11 in a plan view of the dielectric body, the first slit starts from a position within a range of a midpoint of the first side±0.4×L G11 .
5 . The antenna according to claim 1 , wherein the ground conductor has a second slit extending toward the inside of the ground conductor starting from an outer edge of the ground conductor in the second region.
6 . The antenna according to claim 5 , wherein the ground conductor has a quadrangular shape in a plan view of the dielectric body, and when among four sides constituting the ground conductor, a side closest to the virtual feeding point is set as a closest side, a side adjacent to the closest side and including an outer edge of the second region is set as a second side, and a length of the second side is set as L G12 in a plan view of the dielectric body, the second slit starts from a position within a range of a midpoint of the second side±0.4×L G12 .
7 . The antenna according to claim 5 , wherein when in a plan view of the ground conductor, a perimeter of the second slit is set as D S2 , and a wavelength of radio waves, in the air, to be transmitted/received by the radiation conductor is set as λ, 0.13×λ≤D S2 ≤0.45×λ is satisfied.
8 . The antenna according to claim 7 , wherein the perimeter D S2 of the second slit is substantially equal to the perimeter D S1 of the first slit.
9 . The antenna according to claim 5 , wherein the ground conductor has a third slit extending toward the inside of the ground conductor in a plan view of the ground conductor starting from a position between the starting point of the first slit and the starting point of the second slit.
10 . The antenna according to claim 9 , wherein the ground conductor has a quadrangular shape in a plan view of the dielectric body, and when among four sides constituting the ground conductor, a side closest to the virtual feeding point is set as a closest side, a side facing the closest side is set as a third side, and a length of the third side is set as L G13 in a plan view of the dielectric body, the third slit starts from a position within a range of a midpoint of the third side±0.4×L G13 .
11 . The antenna according to claim 9 , wherein when in a plan view of the ground conductor, a perimeter of the third slit is set as D S3 and a wavelength, in the air, of radio waves to be transmitted/received by the radiation conductor is set as λ, 0.13×λ≤D S3 ≤0.45×λ is satisfied.
12 . The antenna according to claim 11 , wherein the perimeter D S3 of the third slit is substantially equal to the perimeter D S1 of the first slit and the perimeter D S2 of the second slit.
13 . The antenna according to claim 1 , wherein the radiation conductor has a quadrangular shape in a plan view of the dielectric body and includes a first notch and a second notch at two corners that are opposing corners among four corners.
14 . The antenna according to claim 13 , wherein the radiation conductor is capable of transmitting/receiving circularly polarized waves.
15 . An antenna apparatus for vehicle comprising: the antenna according to claim 14 , wherein the antenna is attached to a vehicle, and the radiation conductor is installed so that a normal direction is at an angle within 30° with respect to a vertical direction.
16 . The antenna apparatus for vehicle according to claim 15 , wherein the antenna is installed inside a vehicle so as to face a roof glass.
17 . The antenna according to claim 1 , wherein the radiation conductor is capable of transmitting/receiving linearly polarized waves.
18 . An antenna apparatus for vehicle comprising: the antenna according to claim 17 , wherein the antenna is attached to a vehicle, and the radiation conductor is installed so that a normal direction is at an angle within 30° with respect to a traveling direction of the vehicle.
19 . The antenna apparatus for vehicle according to claim 18 , wherein the antenna is installed inside a vehicle so as to face a windshield.
20 . An antenna comprising: a dielectric body; a radiation conductor disposed on a first principal surface side of the dielectric body; and a ground conductor disposed on a second principal surface side of the dielectric body, wherein the ground conductor is disposed within a rectangular region having a length L G1 in a first direction and a length L G2 in a second direction orthogonal to the first direction in a plan view of the dielectric body, when a wavelength of radio waves, in the air, to be transmitted/received by the radiation conductor is set as λ, L G1 satisfies 0.7×(λ/2)≤L G1 ≤1.4×(λ/2), and L G2 satisfies 0.7×(λ/2)≤L G2 ≤1.4×(λ/2), when the ground conductor is divided into a first region and a second region by a virtual line connecting a virtual feeding point obtained by projecting a feeding point at which power is fed to the radiation conductor in a thickness direction of the dielectric body, and a center of gravity in a plan view of the ground conductor, the ground conductor includes a first slit extending toward the inside of the ground conductor starting from an outer edge of the ground conductor in the first region, and an end portion of the first slit is located inside of the outer edge of the ground conductor, wherein the ground conductor has a second slit extending toward the inside of the ground conductor starting from an outer edge of the ground conductor in the second region, and when in a plan view of the ground conductor, a perimeter of the second slit is set as D S2 , and a wavelength of radio waves, in the air, to be transmitted/received by the radiation conductor is set as λ, 0.13×λ≤D S2 ≤0.45×λ is satisfied.

Description

INCORPORATION BY REFERENCE This application is based upon and claims the benefit of priority from Japanese patent application No. 2021-117657, filed on Jul. 16, 2021, and PCT application No. PCT/JP2022/027336 filed on Jul. 12, 2022, the disclosure of which is incorporated herein in its entirety by reference. BACKGROUND The present invention relates to an antenna and an antenna apparatus for vehicle. In recent years, antenna apparatuses for vehicle such as flat-type patch antennas that transmit/receive radio waves in a frequency of a GHz band have been introduced into vehicles such as automobiles. Examples of the patch antennas described above can include a patch antenna that receives signals transmitted from satellites. For example, Japanese Unexamined Patent Application Publication No. 2004-048145 and Japanese Unexamined Patent Application Publication No. 2019-193167 disclose patch antennas capable of receiving global navigation satellite system (GNSS) signals including global positioning system (GPS) signals in a predetermined frequency band. Japanese Unexamined Patent Application Publication No. 2019-193167 discloses such a patch antenna that is mounted on the roof of a vehicle, and covered by an antenna case, as an example. SUMMARY Here, in the patch antennas disclosed in Japanese Unexamined Patent Application Publication No. 2004-048145 and Japanese Unexamined Patent Application Publication No. 2019-193167, an area of a ground conductor that faces a radiation conductor via a dielectric substrate, is required to be larger than an area of the radiation conductor that transmits/receives radio waves of a predetermined frequency. Thus, in a case where the patch antenna is installed in a vehicle, the patch antenna should be installed in consideration of the area of the ground conductor, and it is necessary to secure a certain installation space. It is therefore desired to implement an antenna including a patch antenna that can be disposed in a vehicle without considering an area of a ground conductor of the patch antenna. The present invention is directed to providing an antenna and an antenna apparatus for vehicle that can achieve reduction in size. An antenna according to one aspect of the present invention includes a dielectric body, a radiation conductor disposed on a first principal surface side of the dielectric body, and a ground conductor disposed on a second principal surface side of the dielectric body, in which the ground conductor is disposed within a rectangular region having a length LG1 in a first direction and a length LG2 in a second direction, and when a wavelength of radio waves, in the air, to be transmitted/received by the radiation conductor is set as λ, LG1 satisfies 0.7×(λ/2)≤LG1≤1.4×(λ/2), and LG2 satisfies 0.7×(λ/2)≤LG2≤1.4×(λ/2), and when the ground conductor is divided into a first region and a second region by a virtual line connecting a virtual feeding point obtained by projecting a feeding point at which power is fed to the radiation conductor in a thickness direction of the dielectric body, and a center of gravity in a plan view of the ground conductor, the ground conductor includes a first slit that extending toward the inside of the ground conductor starting from an outer edge of the ground conductor in the first region, and an end portion of the first slit is located inside of the outer edge of the ground conductor. In the above-described antenna, the radiation conductor may be disposed within a rectangular region having a length LR1 in the first direction and a length LR2 in the second direction, and the length LR1 and the length LR2 may satisfy LR1=LR2. In the above-described antenna, the ground conductor may have a quadrangular shape in a plan view of the dielectric body. In the above-described antenna, when in a plan view of the dielectric body, among four sides constituting the ground conductor, a side closest to the virtual feeding point is set as a closest side, a side adjacent to the closest side and including an outer edge of the first region is set as a first side, and a length of the first side is set as LG11, the first slit may start from a position within a range of a midpoint of the first side±0.4×LG11. In the above-described antenna, when in a plan view of the ground conductor, a perimeter of the first slit is set as DS1, and a wavelength of radio waves, in the air, to be transmitted/received by the radiation conductor is set as 0.13×λ≤DS1≤0.45×λ may be satisfied. In the above-described antenna, the ground conductor may have a second slit extending toward the inside of the ground conductor starting from an outer edge of the ground conductor in the second region. In the above-described antenna, the ground conductor may have a quadrangular shape in a plan view of the dielectric body, and when in a plan view of the dielectric body, among four sides constituting the ground conductor, a side closest to the virtual feeding point is set as a closest side, a side adj