JP2023079846A - antenna device - Google Patents

Abstract

To provide an antenna device capable of suitably performing broadband communication in a sub-6 GHz band in a fifth generation mobile communication system.SOLUTION: An antenna device includes a substrate 1 and an antenna element 2 formed on the substrate 1. The antenna element 2 includes an electrode section 21, a dipole section 22, and a transmission path section 23 connecting the electrode section 21 and the dipole section 22.SELECTED DRAWING: Figure 3

Description

The present invention relates to an antenna device.

Conventionally, glass antennas for vehicles are known (see, for example, Patent Document 1).

The glass antenna of Patent Document 1 is configured to be suitable for transmitting and receiving radio waves in the VHF band (30 MHz to 300 MHz) and UHF band (300 MHz to 3 GHz).

JP 2020-123922 A

Here, since the 5th generation mobile communication system uses the sub-6 GHz band of 3.1 GHz to 4.99 GHz, there is a demand for an antenna device suitable for the sub-6 GHz band.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an antenna device capable of suitably performing wideband communication in the sub-6 GHz band in the 5th generation mobile communication system. It is to be. This antenna device is suitable for a glass antenna.

An antenna device according to the present invention comprises a substrate and an antenna element formed on the substrate. The antenna element includes an electrode section, a dipole section, and a transmission line section connecting the electrode section and the dipole section.

With this configuration, the dipole section functions as a main radiation element, and the transmission line section functions as an additional radiation element, making it suitable for broadband communication in the sub-6 GHz band in the 5th generation mobile communication system. can be done.

According to the antenna device of the present invention, broadband communication in the sub-6 GHz band in the fifth generation mobile communication system can be preferably performed.

1 is a perspective view showing an antenna device according to this embodiment; FIG. FIG. 2 is an exploded perspective view for explaining the antenna device of FIG. 1; 3 is a diagram for explaining an antenna element of the antenna device of FIG. 2; FIG. FIG. 3 is an exploded perspective view for explaining an adapter of the antenna device of FIG. 2; It is the graph which showed S11 of S parameter in the antenna device of this embodiment. It is the graph which showed VSWR in the antenna device of this embodiment. It is a figure for demonstrating the antenna element by the 1st modification of this embodiment. It is a figure for demonstrating the antenna element by the 2nd modification of this embodiment.

An embodiment of the present invention will be described below.

First, the configuration of an antenna device 100 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG.

The antenna device 100 is a glass antenna used in vehicles, buildings, and the like. For example, the antenna device 100 can be applied to a vehicle windshield, a vehicle glass roof, a vehicle rear glass, a vehicle side window glass, a building window glass, and the like. This antenna device 100 is small and does not block the view easily.

Also, the antenna device 100 is for the fifth generation mobile communication system and is configured to be suitable for communication in the sub-6 GHz band of 3.1 GHz to 4.99 GHz. The antenna device 100 includes a substrate 1, an antenna element 2, an adapter 3, and a connector 4, as shown in FIGS.

The substrate 1 is made of glass such as borosilicate glass and is transparent. Substrate 1 is formed, for example, in a rectangular plate shape and has a thickness of 1 mm. An antenna element 2, an adapter 3, and a connector 4 are provided on one surface of the substrate 1 (the surface on the Z1 direction side).

The antenna element 2 is composed of a conductive sheet (thin film). The antenna element 2 may be made of a transparent material or an opaque material such as copper. The antenna element 2 includes an electrode portion 21, a dipole portion 22, a transmission line portion 23, and an extension line 24, as shown in FIG.

A connector 4 is provided on the upper side of the electrode portion 21 via an adapter 3 . The electrode section 21 is of a coplanar type and has a first electrode (feeding electrode) 211 and a second electrode (earth electrode) 212 . The first electrode 211 is formed in an L shape in a plan view and has linear portions 211a and 211b. The linear portion 211a is formed to extend linearly in the lateral direction of the substrate 1 (Y1 and Y2 directions). The linear portion 211b is formed to extend linearly in the longitudinal direction of the substrate 1 (X1 and X2 directions). One end of the linear portion 211a (the end in the Y1 direction) is connected to one end of the linear portion 211b (the end in the X1 direction). The second electrode 212 is formed in a U shape (concave shape) when viewed in a plan view, and is arranged so that the open end faces the Y1 direction. A straight portion 211 a is arranged between the U-shaped second electrodes 212 , and a straight portion 211 b is arranged on the Y1 direction side of the second electrode 212 .

Dipole section 22 is configured to function as the primary radiating element. The dipole portion 22 is arranged on the other side (the X2 direction side) of the substrate 1 in the longitudinal direction with respect to the electrode portion 21 . The dipole section 22 has a first arm 221 and a second arm 222 . The first arm 221 and the second arm 222 are arranged on the same straight line and formed to extend linearly in the longitudinal direction of the substrate 1 . For example, the first arm 221 has a length Ld1 of 13.5 mm and a width Wd1 of 2 mm. The second arm 222 has a length Ld2 of 13.5 mm and a width Wd2 of 2 mm. A gap Gd between the first arm 221 and the second arm 222 is 0.25 mm.

The transmission line portion 23 is configured to connect the electrode portion 21 and the dipole portion 22 and to function as an additional radiation element. The transmission line section 23 is formed asymmetrically and serves as an unbalanced transmission line. The transmission line section 23 has a first line 231 and a second line 232 extending side by side. The first line 231 and the second line 232 are L-shaped in plan view and connect the electrode portion 21 and the base end portion of the dipole portion 22 .

The first line 231 has straight portions 231 a and 231 b and is configured to connect the first electrode 211 and the first arm 221 . The linear portion 231a is formed to extend linearly in the longitudinal direction of the substrate 1. As shown in FIG. The linear portion 231b is formed to extend linearly in the lateral direction of the substrate 1. As shown in FIG. One end (the end in the X1 direction) of the straight portion 231a is connected to the other end (the end in the X2 direction) of the straight portion 211b. One end of the linear portion 231b (the end in the Y1 direction) is connected to the other end of the linear portion 231a (the end in the X2 direction). The other end of the linear portion 231b (the end in the Y2 direction) is connected to the base end of the first arm 221 (the end in the X1 direction). That is, the linear portion 231 a is arranged parallel to the dipole portion 22 , and the linear portion 231 b is arranged so as to be perpendicular to the dipole portion 22 .

The second line 232 has straight portions 232 a and 232 b and is configured to connect the second electrode 212 and the second arm 222 . The linear portion 232 a is formed to extend linearly in the longitudinal direction of the substrate 1 . The linear portion 232b is formed to extend linearly in the lateral direction of the substrate 1. As shown in FIG. One end of the linear portion 232a (the end in the X1 direction) is connected to the end of the second electrode 212 in the Y1 direction. One end of the linear portion 232b (the end in the Y1 direction) is connected to the other end of the linear portion 232a (the end in the X2 direction). The other end of the linear portion 232b (the end in the Y2 direction) is connected to the base end of the second arm 222 (the end in the X2 direction). That is, the linear portion 232 a is arranged parallel to the dipole portion 22 , and the linear portion 232 b is arranged so as to be perpendicular to the dipole portion 22 .

For example, the first line 231 has a linear portion 231a with a length Lta1 of 24.625 mm, a linear portion 231b with a length Ltb1 of 5.2 mm, and a width Wt1 of 1 mm. The second line 232 has a linear portion 232a with a length Lta2 of 23.375 mm, a linear portion 232b with a length Ltb2 of 3.95 mm, and a width Wt2 of 1 mm. A gap Gt between the first line 231 and the second line 232 is 0.25 mm.

The extension line 24 is provided to enhance the mutual coupling between the dipole section 22 and the unbalanced transmission line section 23 . Extension line 24 is intended to act as an additional radiating element to make transmission line section 23 more unbalanced and broaden the bandwidth. The extension line 24 is formed to extend from the end of the second electrode 212 on the Y2 direction side toward the dipole portion 22 . The extension line 24 is formed to extend linearly in the longitudinal direction of the substrate 1 and arranged on the same straight line as the dipole portion 22 . For example, the extension line 24 has a length Le of 9 mm and a width We of 2 mm. A distance D between the extension line 24 and the dipole portion 22 is 0.875 mm.

As shown in FIG. 1, the connector 4 is of the SMA type and is configured to allow attachment of a 50Ω coaxial cable (not shown). A coaxial cable has an inner conductor, an insulator surrounding the inner conductor, an outer conductor surrounding the insulator, and a sheath surrounding the outer conductor. This coaxial cable has one end connected to a high frequency power supply and the other end provided with a plug. A plug of the coaxial cable is configured to be attachable to the connector 4 . For example, a coaxial cable plug includes an internal thread, a connecting pin provided inside (center) of the internal thread, and an insulator that insulates the internal thread and the connecting pin. A connecting pin is connected with the inner conductor and an internal thread is connected with the outer conductor.

The connector 4 also includes a male threaded portion, a connection terminal provided inside (at the center) of the male threaded portion, and an insulator that insulates the male threaded portion and the connection terminal. The plug is attached to the connector 4 by screwing the female threaded portion of the plug into the male threaded portion of the connector 4 . At this time, the connection pins and the connection terminals are electrically connected by inserting the connection pins of the plug into the connection terminals of the connector 4 . The female threaded portion and the male threaded portion are also electrically connected.

The adapter 3 is interposed between the electrode portion 21 of the antenna element 2 and the connector 4 . The adapter 3 is provided to electrically connect the connection terminal of the connector 4 and the first electrode 211 of the electrode portion 21 and to electrically connect the male screw portion of the connector 4 and the second electrode 212 of the electrode portion 21 .

Specifically, as shown in FIG. 4, the adapter 3 includes a substrate 31 made of an insulator, a conductive layer 32 formed on one surface of the substrate 31 (the surface on the Z1 direction side), and the other surface of the substrate 31 (the Z1 direction surface). A conductive layer 33 formed on the Z2 direction side) and a plurality of pins 34 connecting the conductive layers 32 and 33 are included.

A through hole 311 and a plurality of via holes 312 are formed in the substrate 31 . The insertion hole 311 is arranged at a position corresponding to the straight portion 211a (see FIG. 3) of the first electrode 211, and is configured so that the connection terminal of the connector 4 is inserted therethrough. A connection terminal of the connector 4 is inserted through the insertion hole 311 and connected to the first electrode 211 . The via hole 312 is arranged around the insertion hole 311 and configured to receive the pin 34 .

The conductive layer 32 has a circular hole 321 and the insertion hole 311 is arranged inside the circular hole 321 . The conductive layer 32 is provided for electrically connecting the male screw portion of the connector 4 and the pin 34 . The conductive layer 33 is formed in a U shape so as to correspond to the second electrode 212 (see FIG. 3). An insertion hole 311 is arranged inside the U-shaped conductive layer 33 . The conductive layer 33 is provided to electrically connect the pin 34 and the second electrode 212 .

Therefore, when the coaxial cable is attached to the connector 4, the inner conductor of the coaxial cable is connected to the first electrode 211 of the electrode section 21 and the outer conductor of the coaxial cable is connected to the second electrode 212 of the electrode section 21. It is supposed to be connected.

-effect-
In this embodiment, as described above, the dipole portion 22 and the unbalanced transmission line portion 23 are provided in the glass antenna, so that the dipole portion 22 functions as a main radiation element and the transmission line portion 23 as an additional radiating element, broadband communication in the sub-6 GHz band in the 5th generation mobile communication system can be performed favorably.

FIG. 5 shows the result of analyzing S11 (input reflection coefficient) of the S parameter of the antenna device 100 according to this embodiment. In the graph of FIG. 5, the horizontal axis is the frequency, the vertical axis is the S parameter S11 value, and the sub-6 GHz band from 3.1 GHz to 4.99 GHz is indicated by an arrow. As shown in FIG. 5, in the antenna device 100, S11 was less than -10 dB in most of the sub-6 GHz band.

FIG. 6 shows the result of analyzing the VSWR (voltage standing wave ratio) of the antenna device 100 according to this embodiment. VSWR is the ratio of the maximum amplitude to the minimum amplitude of the voltage standing wave. In the graph of FIG. 6, the horizontal axis is frequency, the vertical axis is VSWR value, and the sub-6 GHz band from 3.1 GHz to 4.99 GHz is indicated by an arrow. As shown in FIG. 6, in the antenna device 100, the VSWR was less than 2 in most of the sub-6 GHz band.

In addition, in the present embodiment, the connector 4 is provided on the substrate 1 through the adapter 3, and the coaxial cable is attached to the connector 4, whereby the electrode section 21 and the coaxial cable can be electrically connected. . That is, there is no need to solder the coaxial cable to the electrode portion 21 .

-Other embodiments-
In addition, the embodiment disclosed this time is an example in all respects, and does not serve as a basis for a restrictive interpretation. Therefore, the technical scope of the present invention is not to be interpreted only by the above-described embodiments, but is defined based on the claims. In addition, the technical scope of the present invention includes all modifications within the meaning and range of equivalence to the claims.

For example, in the above embodiment, the example in which the substrate 1 is made of glass was shown, but the substrate is not limited to this, and may be made of resin such as PTFE (polytetrafluoroethylene).

Moreover, in the above-described embodiment, an example in which the substrate 1 is transparent was shown, but the substrate is not limited to this, and may be opaque.

Further, in the above-described embodiment, an example in which the extension line 24 is provided has been shown, but the present invention is not limited to this, and the extension line may not be provided like the antenna element 2a according to the first modified example shown in FIG. .

Further, in the above embodiment, the L-shaped first electrode 211 is connected to the first arm 221 on the far side from the electrodes, and the U-shaped second electrode 212 is connected to the side close to the electrodes. Although an example in which the antenna element is connected to the second arm 222 of is shown, it is not limited to this, and may be formed like the antenna element 2b according to the second modification shown in FIG. The antenna element 2b includes an electrode portion 21b, a dipole portion 22b, a transmission line portion 23b, and an extension line 24. The electrode portion 21b has an L-shaped electrode and a U-shaped electrode. The dipole portion 22b has an arm closer to the electrode and an arm farther from the electrode. The transmission line portion 23b is configured to connect the L-shaped electrode and the arm closer to the electrode, and to connect the U-shaped electrode and the arm farther from the electrode. ing.

In the above embodiment, the adapter 3 and the connector 4 may be provided on the substrate 1 without using solder or adhesive, or may be provided on the substrate 1 using solder or adhesive.

INDUSTRIAL APPLICABILITY The present invention is applicable to antenna devices.

1 substrate 2, 2a, 2b antenna element 21, 21b electrode section 22, 22b dipole section 23, 23b transmission line section 100 antenna device

Claims (1)

a substrate;
An antenna device comprising an antenna element formed on the substrate,
The antenna device, wherein the antenna element includes an electrode section, a dipole section, and a transmission line section connecting the electrode section and the dipole section.

Images