JP2019121808A - Antenna and window glass - Google Patents

Abstract

An object of the present invention is to provide a glass antenna which can obtain high sensitivity in the entire region of the UHF band.
The antenna is provided on a window glass of a vehicle, and extends substantially horizontally from a core-side feed portion, a ground-side feed portion disposed adjacent to the core-side feed portion, and the core-side feed portion. A core wire side element including at least one wire, and a ground side element including at least two wires extending substantially horizontally in parallel to each other from the ground side feeding portion.
[Selected figure] Figure 1

Description

  The present invention relates to a glass antenna disposed on the surface of a glass plate, and more particularly to an antenna for receiving broadcast waves in the UHF band.

  In the UHF band, broadcasting is performed in a wide band, and for example, radio waves in the band of 300 MHz of 470 to 770 MHz are used in terrestrial digital TV broadcasting, telecommunications, mobile / broadcasting, and the like. This requires a band of about ± 25% (150 MHz) of the center frequency (620 MHz).

  On the other hand, it is difficult to design a glass antenna that achieves high sensitivity over the wide band of the UHF band.

  As an antenna that solves this problem, Patent Document 1 discloses a UHF band receiving antenna with improved receiving gain and directivity. The antenna disclosed in Patent Document 1 is an antenna in which horizontal and vertical lines each having a length matched to a desired frequency band are respectively extended from a common feeding point, and both horizontal polarization and vertical polarization are obtained. Can be received to improve the directivity characteristics. Furthermore, by providing a plurality of horizontal streaks and vertical streaks, the resonance frequency can be broadened, and the reception sensitivity can be enhanced over a wide band.

  Further, Patent Document 2 discloses a glass antenna which can reduce the electrical influence from the body flange and can favorably obtain the reception sensitivity of the terrestrial digital TV broadcast wave. The antenna disclosed in Patent Document 2 includes a core-side feed point, a core-side element connected to the core-side feed point, a ground-side feed point, and a ground-side element connected to the ground-side feed point. The core side element extends in the horizontal direction from the core side feed point, and the linear first element including a linear or L-shaped portion, the first element, the body flange, and the like. And a second element including a filar extending parallel to or substantially parallel to a horizontally extending portion of the first element.

JP-A-7-212119 JP, 2017-60069, A

  However, in the antenna described in Patent Document 1, when connecting a plurality of horizontal streaks and vertical streaks, when adjacent horizontal streaks or adjacent vertical streaks are adjacent to each other, the streaks become as thick as they become thick. Only the effect of broadening the reception band was obtained.

  An object of the present invention is to provide a glass antenna which can obtain high sensitivity over the wide range of the UHF band.

  That is, the present invention is an antenna provided on a window glass of a vehicle, wherein the core side feed portion, the ground side feed portion disposed adjacent to the core side feed portion, and the core side feed portion are substantially horizontal. It is an antenna characterized by comprising: a core wire side element including at least one extending line; and a ground side element including at least two lines extending parallel to each other and substantially horizontally from the ground side feeding portion.

  Further, according to the present invention, there is provided a first passive element which is disposed between the core wire side feed portion and the upper side of the body flange above the core wire side feed portion and extends substantially horizontally, and a lower portion of the core wire side feed portion. And a second parasitic element extending substantially horizontally.

  Further, in the present invention, the core side element is constituted by a core side first element and a core side second element extending in parallel below the core side first element, and the earth side element is on the ground side The first element and a ground-side second element extending in parallel below the ground-side first element are provided, and the core-side second element and the ground-side first element are disposed on a substantially straight line The antenna according to the present invention is characterized in that the ground side second element and the second parasitic element are disposed on a substantially straight line.

  Further, according to the present invention, in the second parasitic element, the end on the body flange side is bent downward to form a vertical portion, and the vertical portion is disposed along the side of the body flange. Is an antenna characterized by

  Further, the present invention is a window glass provided with any one of the above-mentioned antennas.

  According to an exemplary embodiment of the present invention, a wide band flat gain characteristic of 300 to 300 MHz wide from 470 to 770 MHz can be obtained.

It is the top view which looked at the glass antenna of Embodiment 1 of this invention from the vehicle inner side. It is a figure explaining the function of the glass antenna of Embodiment 1 of this invention. It is a figure explaining the function of the glass antenna of Embodiment 1 of this invention. It is a figure explaining the function of the glass antenna of Embodiment 1 of this invention. It is the top view which looked at the glass antenna of Embodiment 2 of this invention from the vehicle inner side. It is the top view which looked at the glass antenna of the reference example from the vehicle inner side. It is a figure which shows the characteristic of the glass antenna of embodiment of this invention. It is a figure which shows the characteristic of the glass antenna of embodiment of this invention. It is a figure which shows the characteristic of the glass antenna of embodiment of this invention. It is a figure which shows the characteristic of the glass antenna of embodiment of this invention.

  FIG. 1 is a plan view of a glass antenna according to a first embodiment of the present invention as viewed from the inside of a vehicle.

  The glass antenna of Embodiment 1 is provided at the upper left corner as viewed from the inside of the front window glass of a car. That is, in the figure, the left is the A-pillar side, and the right is the glass center (room mirror) side.

  The glass antenna according to the first embodiment includes a core side element 3 extending from the core side feed portion 1, a ground side element 4 extending from the ground side feed portion 2, and a first non-feed provided on the core wire side feed portion 1. It has an element 5 and a second parasitic element 6 provided at the lower part of the core-side feed portion 1.

  The core side element 3 is composed of a core side first element 31 and a core side second element 32 extending parallel and substantially horizontally from the core side feed portion 1 to the left. In addition, the core line side element 3 may be comprised by one element, and may be comprised by three or more elements.

  The ground-side element 4 is constituted of a ground-side first element 41 and a ground-side second element 42 which extend substantially horizontally rightward in parallel from the ground-side power feeding unit 2. The ground-side element 4 may be composed of three or more elements.

  The first parasitic element 5 is provided between the core wire-side power supply unit 1 and the body flange 7 and extends substantially horizontally. The first parasitic element 5 and the core-side first element 31 are disposed at positions close to capacitive coupling with each other, and function as one element in a high frequency range as described later. The first parasitic element 5 absorbs the electric field radiated from the core side feed portion 1 and the core side element 3 to reduce the high frequency current flowing to the vehicle body, and the influence of the vehicle body (body flange 7) on the antenna characteristics is It is relaxing.

  The second parasitic element 6 is provided at a lower portion of the core-side power feeding unit 1 and in proximity to a position on a substantially straight line with the ground-side second element 42. For this reason, the second parasitic element 6 and the ground-side second element 42 are capacitively coupled and function as one element in a high frequency region as described later.

  The left side of the second parasitic element 6 may extend substantially horizontally to the left end, but as shown in FIG. 1, along the body flange 7 of the left side (passenger side A pillar of the right-hand drive vehicle) It may be bent. When the left side of the second parasitic element 6 is bent downward, the vertical portion of the second parasitic element 6 disposed along the body flange 7 can be concealed in the interior to improve the appearance of the interior of the vehicle. In addition, the vertical portion of the second parasitic element 6 can improve the sensitivity to radio waves coming from the lateral direction, and can improve the directivity in the lateral direction.

  The glass antenna according to the present embodiment may be provided in the upper right corner of the front window glass of an automobile as viewed from the inner side of the front window glass, and the antenna provided in the upper right corner of the front window glass is the antenna shown in FIG. The configuration is line-symmetrical in the left-right direction. The two antennas provided at the upper left corner and the upper right corner of the front window glass may constitute diversity.

  Next, the function of each element of the antenna of this embodiment will be described.

  2 to 4 are diagrams showing the operation of the glass antenna according to the first embodiment of the present invention. In each of the figures, elements functioning mainly in each frequency range are indicated by solid lines, and elements not functioning substantially are indicated by double broken lines.

  In a high frequency region, for example, 700 to 770 MHz, as shown in FIG. 2, the first non-feeding element 5 and the core-side feed portion 1 are disposed at a position close to the degree of capacitive coupling. In the element 5, the left side portion of the core side feed portion 1 and the core side first element 31 have a U-shaped reverse V-shaped dipole antenna whose left side is open with a length of about λ / 2 of the central wavelength of the band. Act as. In addition, the right side portion of the first parasitic element 5 and the ground-side power feeding unit 2 are capacitively coupled. In addition, the right side portion of the first parasitic element 5 from the core-side feed portion 1 contributes to impedance adjustment in a high frequency range.

  In the middle frequency range, for example, 600 to 700 MHz, as shown in FIG. 3, the core side second element 32 and the ground side first element 41 form a dipole antenna of about λ / 2 at the center wavelength of the band. Ru. The length of the core-line-side second element 32 and the length of the ground-side first element 41 are not necessarily equal due to the influence of the vehicle body (particularly the side body flange 7).

  In the low frequency region, for example, 470 to 600 MHz, as shown in FIG. 4, the second parasitic element 6 and the core-side feed portion 1 are disposed at a position close to the degree of capacitive coupling. The feed element 6 and the ground side second element 42 function as a dipole antenna of approximately λ / 2 at the center wavelength of the band. The length of the second parasitic element 6 and the length of the ground-side second element 42 are not necessarily equal due to the influence of the vehicle body (in particular, the side body flange 7).

  The above-mentioned illustration of the high frequency range, the medium frequency range, and the low frequency range is an example in the case of receiving the frequency of the 470 to 770 MHz band by the glass antenna. In the case of receiving a band of 470 to 710 MHz, which is a band of terrestrial digital TV broadcasting in Japan, with the glass antenna, the high frequency band is, for example, 650 to 710 MHz, and the middle frequency band is, for example, 570 to You may set 650 MHz and the said low frequency region to 470-570 MHz, for example.

In a typical example of the antenna of Embodiment 1, the length of each element is as follows.
Core side first element 31: 65 mm
Core side second element 32: 65 mm
Ground side first element 41: 105 mm
Ground side second element 42: 105 mm
First parasitic element 5: 105 to 130 mm
Second parasitic element 6: 110 to 130 mm
Distance between core line first element 31 and first parasitic element 5: 14 mm
Distance between core wire side second element 32 and second parasitic element 6: 12 mm
Distance between ground-side first element 41 and ground-side second element 42: 12 mm

  Next, a second embodiment of the present invention will be described. The second embodiment is an antenna in which the configuration of the glass antenna of the first embodiment is simplified. In the second embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and detailed description will be omitted.

  FIG. 5 is a plan view of a glass antenna according to a second embodiment of the present invention as viewed from the inside of a vehicle.

  The glass antenna of Embodiment 2 is provided at the upper left corner as viewed from the inside of the front window glass of a car. That is, in the figure, the left is the A-pillar side, and the right is the glass center side.

  The glass antenna according to the first embodiment includes a core side element 3 extending from the core side feed portion 1 and a ground side element 4 extending from the ground side feed portion 2.

  The core side element 3 is composed of a core side first element 31 and a core side second element 32 extending parallel and substantially horizontally from the core side feed portion 1 to the left. In addition, the core line side element 3 may be comprised by one element, and may be comprised by three or more elements.

  The ground-side element 4 is constituted of a ground-side first element 41 and a ground-side second element 42 which extend substantially horizontally rightward in parallel from the ground-side power feeding unit 2. The ground-side element 4 may be composed of three or more elements.

  In the antenna of the second embodiment, as shown in FIG. 3, a core antenna side second element 32 and a ground side first element 41 form a dipole antenna of about λ / 2. The length of the core-line-side second element 32 and the length of the ground-side first element 41 are not necessarily equal due to the influence of the vehicle body (particularly the side body flange 7).

  The glass antenna of the present embodiment may be provided at the upper right corner of the front window glass of an automobile as viewed from the inside of the front window glass, and the antenna provided at the upper right corner of the front window glass is the antenna shown in FIG. The configuration is line-symmetrical in the left-right direction. The two antennas provided at the upper left corner and the upper right corner of the front window glass may constitute diversity.

  In a typical example of the antenna of the second embodiment, the length of each element may be the same as the antenna of the first embodiment.

  The conductors (filaments, feeding parts) constituting the antenna of the first and second embodiments are printed on the glass surface with a conductive ceramic paste with a width of about 0.7 mm of each filament, dried and then baked by a heating furnace It is formed. The antenna conductor may be formed of a conductive pattern formed on the light transmitting resin film, and the resin film may be attached to the glass plate.

  Next, the characteristics of the antenna according to the embodiment of the present invention will be described.

  FIG. 7 is a graph showing the characteristics of the glass antenna of Embodiment 1, and shows the frequency characteristics of the sensitivity of the antenna of Embodiment 1 and the antenna of the reference example shown in FIG. According to the measurement results, it can be seen that the antenna of Embodiment 1 has better sensitivity than the antenna of the reference example in the low frequency band (470 to 600 MHz).

  8 to 10 are diagrams showing the directivity of the glass antenna according to Embodiment 1. FIG. 8 shows a low frequency band (470 MHz), FIG. 9 shows an intermediate frequency band (590 MHz), and FIG. 10 shows a high frequency band (710 MHz). Show the directional characteristics of

  In the low frequency band shown in FIG. 8, it can be seen that the antenna of Embodiment 1 has good sensitivity in all directions as compared with the antenna of the reference example (FIG. 6). In addition, in the middle frequency range shown in FIG. 9, it can be seen that the antenna of the embodiment 1 has a better sensitivity on the pillar side than the antenna of the reference example. In addition, it can be seen that in the high frequency range shown in FIG. 10, the antenna of Embodiment 1 has obtained the same sensitivity as the antenna of the reference example.

  As described above, in the glass antenna according to the embodiment of the present invention, high sensitivity can be obtained in the entire region of the UHF band. In particular, good sensitivity can be obtained with a low frequency channel to which many broadcasts are assigned in digital television broadcasting in Japan, and digital television can be viewed with a high quality image with less block noise.

  Further, since the antenna is constituted by the element extending substantially in the horizontal direction and the element disposed along the side body flange 7, the dimension in the vertical direction is small and there is no element extending in the central direction of the glass. The antenna can be configured to have little influence on the forward view.

  Although the present invention has been described in detail with reference to the accompanying drawings, the present invention is not limited to such a specific configuration, and various modifications and equivalents may be made within the scope of the appended claims. It includes the configuration.

1 core side feed portion 2 ground side feed portion 3 core side element 31 core side first element 32 core side second element 4 ground side element 41 ground side first element 42 ground side second element 5 first parasitic element 6 first 2 parasitic element

Claims (5)

An antenna provided on a window glass of a vehicle,
Core wire side feeding part,
A ground side feeding portion disposed adjacent to the core wire side feeding portion;
A core side element including at least one filament extending substantially horizontally from the core side feed portion;
An antenna, comprising: an earth side element including at least two filaments extending parallel to each other and substantially horizontally from the earth side feeding portion. A first non-feed element disposed between the core wire side feed portion and the upper side of the body flange above the core wire side feed portion and extending substantially horizontally;
The antenna according to claim 1, further comprising: a second parasitic element disposed below the core-side feed portion and extending substantially horizontally. The core side element is composed of a core side first element and a core side second element extending in parallel below the core side first element,
The ground side element is constituted of a ground side first element and a ground side second element extending in parallel below the ground side first element,
The core side second element and the ground side first element are disposed on a substantially straight line,
The antenna according to claim 2, wherein the ground-side second element and the second parasitic element are disposed on a substantially straight line. In the second parasitic element, the end on the body flange side is bent downward to form a vertical portion,
The antenna according to claim 2 or 3, wherein the vertical portion is disposed along a side of the body flange.   A window glass provided with the antenna according to any one of claims 1 to 4.

Images