WO2012049918A1

WO2012049918A1 - Antenna

Info

Publication number: WO2012049918A1
Application number: PCT/JP2011/070166
Authority: WO
Inventors: 正典貝發; 友嗣片田; 山本　政博
Original assignee: セントラル硝子株式会社
Priority date: 2010-10-13
Filing date: 2011-09-05
Publication date: 2012-04-19
Also published as: JP5633295B2; JP2012085153A

Abstract

An antenna is provided with a core side element including a core side feeding point and a ground side element including a ground side feeding point, and is characterized in that the ground side element is arranged to have capacitive coupling with a grounded metal flange, the core side element comprises a first perpendicular wire extending from the core side feeding point in the perpendicular direction departing from the metal flange, and a U-shaped wire connected to an tip end of the first perpendicular wire and having an opening on the side, the total length of the wire from the core side feeding point to one end of the opening of the U-shaped wire is adjusted to be approximately αλ/4 and approximately (2n+1)αλ'/4 (n is an integer of 0 or more), and the total length of the wire from the core side feeding point to the other end of the opening of the U-shaped wire is approximately αλ/6.

Description

antenna

The present invention relates to an antenna, and more particularly to an antenna suitable for receiving terrestrial digital radio broadcast waves (DAB: Digital Audio Broadcasting) provided on a window glass of a vehicle.

In recent years, various radio modulation digital radios with low noise and high quality have been developed in radio broadcasting compared to conventional analog and AM radio broadcasting, and DAB (Digital Audio Broadcasting) has been developed around the world. Digital radio broadcasting of various broadcasting standards such as DRM (Digital Radio Mondiale), DMB (Digital Multimedia Broadcasting), ISDB (Integrated Services Digital Broadcasting, integrated digital broadcasting service) has been put into practical use.

Of these various digital radio broadcasting standards, the DAB standard is used in almost all countries of the world except Japan and the United States, and is a standard. In the DAB standard, two separate frequency bands, band 3 of 174 to 240 MHz and L band of 1452 to 1492 MHz, are used, and any one band is adopted for each country.

If the antenna is adjusted to resonate at a frequency within a high frequency band such as the L band of the DAB standard, high reception sensitivity can be obtained in a wide band before and after the band centered on the resonance frequency.

On the other hand, when the antenna is adjusted so as to resonate at a frequency in a slightly lower frequency band as in band 3, the bandwidth for obtaining high reception sensitivity including the band centered on the resonance frequency may be narrowed. It was.

Thus, band 3 having a frequency band of 174 to 240 MHz has a wide bandwidth of 66 MHz. For this reason, when the antenna has only one resonance frequency within this band, since the width of the practical resonance frequency band is narrow, it is not possible to obtain good reception sensitivity at all frequencies within the band. was there. For this reason, antennas that have been devised in various ways to improve them have been developed.

For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2000-295023) discloses a composite antenna element composed of a resin film, a strip-shaped thin film conductor formed on the surface of the resin film, and the composite antenna element. A power supply cable connected to a power supply unit, and the composite antenna element is provided alongside the first antenna element and the first antenna element provided so as to conform to the first frequency band, A second antenna element provided so as to be adapted to a second frequency band having a frequency level lower than that of the first frequency band, wherein the second antenna element is the first frequency generated on the element. A DAB film antenna characterized by being bent at the zero level point portion of the current distribution based on the electromagnetic wave in the band is described.

Patent Document 2 (Japanese Patent Laid-Open No. 10-327090) discloses a plurality of bands for receiving broadcast signals of a first frequency band from about 174 to about 240 MHz and a second frequency band from about 1452 to about 1492 MHz. A compatible antenna, a support surface, first and second antenna feed points provided on the support surface, and a first dipole conductor provided directly on the support surface and connected to the first feed point A second dipole conductor directly connected to the second feeding point and provided on the support surface; and a conductive material provided on the support surface that is substantially rectangular in which the horizontal side is longer than the vertical side. A loop, a first impedance circuit that connects the conductive loop to the first feeding point, and a second impedance circuit that connects the conductive loop to the second feeding point. The sum of the lengths of the first and second dipole conductors is substantially equal to half of the electric wavelength in several bands, and the first and second impedance circuits are more in the first frequency band than in the first frequency band. A multi-band adaptive antenna characterized in that a large impedance is generated in two frequency bands, and the entire antenna is equivalent to a loop antenna in the first frequency band and a half-wave dipole antenna in the second frequency band. Is described.

The antenna described in Patent Document 1 is a single antenna that receives radio waves in both the band 3 and the L band of the DAB standard. However, since no ground side element is provided, the defogger or There was a problem of being easily affected by noise from the metal body.

The antenna described in Patent Document 2 also receives radio waves in both bands 3 and L of the DAB standard with only one antenna. However, in band 3 (first frequency band), the antenna is a loop antenna. The L band (second frequency band) is equivalent to a half-wave dipole antenna, and since the two feeding points 17 and 18 are connected by a closed loop antenna, the resonance frequency band becomes narrower, and band 3 There was a problem that good sensitivity could not be obtained in the entire area.

The present invention, when receiving a DAB digital radio broadcast, has two separate frequency bands, band 3 having a frequency band of 174 to 240 MHz and L band having a frequency band of 1452 to 1492 MHz. An object of the present invention is to obtain a good reception gain in both bands, and to obtain a satisfactory reception sensitivity that can be satisfied over the entire band 3 which is a wider band.

That is, according to the representative embodiment of the present invention, the core wire side element including the core wire side feed point and the ground side element including the ground side feed point are disposed on the glass plate provided in the opening of the metal flange. In the non-grounded antenna, the ground side feed point and the core wire side feed point are provided at positions close to each other, and the ground side element is capacitively coupled to the grounded metal flange. The core-side element is disposed close to the upper side or the lower side of the opening of the metal flange, and the core-wire-side element extends in a vertical direction away from the metal flange from the core-wire-side feeding point, and A U-shaped line connected to the tip of one vertical line and having an open side, the U-shaped line extending in a horizontal direction, and a first horizontal line extending in the horizontal direction Arranged in parallel And the second vertical wire connecting between the horizontal wire and the end portion on the same side of the folded wire, the first horizontal wire at the substantially middle point, Is connected to one vertical line, λ is the wavelength of the approximate center frequency of the first frequency band, λ ′ is the wavelength of the approximate center frequency of the second frequency band, and α is the wavelength shortening rate of the glass plate In this case, the total length of the filaments from the core wire-side feeding point to one end of the opening of the U-shaped filament is approximately αλ / 4, and approximately (2n + 1) αλ ′ / 4 (n is The total length of the filaments from the core wire side feeding point to the other end of the opening of the U-shaped filament is approximately αλ / 6. Features.

In the antenna according to the present invention, the length from the core wire side feeding point to the two ends of the extending wire is approximately αλ / 4 (λ: wavelength of the intermediate frequency of band 3), and the wire having approximately αλ / 6. By providing two lines, good reception characteristics can be obtained over the entire band 3 of the DAB standard for digital radio broadcasting.

The front enlarged view of the antenna pattern of Example 1 of this invention. The front enlarged view of the antenna pattern of Example 2 of this invention. The front enlarged view of the antenna pattern of Example 3 of this invention. The front enlarged view of the antenna pattern of Example 4 of this invention. The front enlarged view of the antenna pattern of Example 5 of this invention. The front enlarged view of the antenna pattern of Example 6 of this invention. The front enlarged view of the antenna pattern of Example 7 of this invention. The front enlarged view of the antenna pattern of the comparative example 1. FIG. The figure which compares the frequency characteristic in the DAB specification band 3 of Example 1 of this invention, and the comparative example 1. FIG. The figure which compares the frequency characteristic in the DAB specification L band of Example 1 of this invention and Comparative Example 1. FIG. The figure which compares the directional characteristics in the DAB specification band 3 of Example 1 and Example 6 of this invention. The figure which compares the directional characteristics in the DAB specification band 3 of Example 1 and Example 6 of this invention.

The antenna of the embodiment of the present invention is an antenna that can receive with high sensitivity to any radio wave in two separate frequency bands, and further has a wide bandwidth in each band, It is a non-grounded antenna provided on a front window glass, a rear window glass, and a side fixed and fixed window for an automobile. That is, the antenna according to the embodiment of the present invention is an antenna used for both the DAB standard band 3 having a frequency of 174 to 240 MHz and the L band having a frequency of 1452 to 1492 MHz. This is a non-grounded vehicle antenna including a core wire side element 10 that extends and a ground side element 20 that extends from the ground side feeding point 7.

The ground side element 20 includes the ground side feeding point 7 and is capacitively coupled close to the upper side of the opening of the grounded metal flange 3 as shown in FIGS. In the illustrated antenna, the ground-side feeding point 7 is disposed at a position close to the upper side of the opening of the metal flange 3, but may be disposed at a position close to the lower side of the opening of the metal flange 3. Good.

That is, the grounding side element 20 is preferably provided with a horizontal line 21 extending from the grounding side feeding point 7 in the horizontal direction away from the core side feeding point 6 as shown in FIGS. In this case, the distance between the ground side feeding point 7 and the metal flange 3 is preferably 5 to 20 mm.

Further, as shown in FIG. 7, the horizontal filament 21 is not necessarily provided, and the length of the horizontal filament 21 can be set to 0 to 100 mm. For this reason, when the length of the horizontal line 21 is long, it is necessary between the ground side feed point 7 and the metal flange 3 even if the distance between the ground side feed point 7 and the metal flange 3 is wide within the above range. Capacitive coupling can be ensured, and when the length of the horizontal wire 21 is short or not provided, the distance between the ground-side feeding point 7 and the metal flange 3 is narrowed to reduce the ground-side feeding point 7 and the metal flange. The degree of capacitive coupling with 3 should be increased.

In addition, as shown in FIG. 2, the ground-side feed point 7 and the core-wire-side feed point 6 are both provided at the same distance from the metal flange 3, and the ground-side feed point 7 faces the metal flange 3. The grounding side element 20 may be configured by extending the vertical line 22 and providing the horizontal line 21 in the horizontal direction away from the core line side feeding point 6 from the tip of the vertical line 22.

In this case, the grounding side feeding point 7 can be provided closer to the metal flange 3 as compared with the case where the horizontal wire 21 is directly extended horizontally from the grounding side feeding point 7. For this reason, the ground-side element 20 is disposed close to the metal flange 3, and it is convenient to increase the capacitive coupling with the metal flange 3, and the ground-side feed point 7 is disposed away from the metal flange 3. Since both the core wire side feeding point 6 which is convenient to be away from the influence of the flange 3) are provided at the same distance from the metal flange 3, it is preferable in terms of the appearance of the antenna.

Furthermore, as shown in FIG. 5, a horizontal line 21 extending from the ground-side feeding point 7 is provided in the horizontal direction away from the core-side feeding point 6, and in the vertical direction away from the body flange 3 from the tip of the horizontal line 21. The grounding side element 20 may be configured by providing the auxiliary vertical line 23 that extends.

The core wire side element 10 includes a core wire side feed point 6, is connected to the core wire side feed point 6 provided close to the ground side feed point 7, and extends vertically in a direction away from the metal flange 3. A horizontal filament 12 extending in the horizontal direction from the tip of the vertical filament 11 and a folded filament 14 arranged in parallel to the horizontal filament 12 are provided. The front end of the vertical filament 11 is connected to the substantially middle point 15 of the horizontal filament 12. The horizontal line 11 and the folded line 14 are formed by connecting the end portions on the same side of both lines with the vertical line 13 to form a square U-shaped (U-shaped) line facing sideways. Constitute. When the wavelength of the substantially intermediate frequency of the band 3 is λ, the wavelength shortening rate of the glass is α, and the wavelength of the substantially intermediate frequency of the L band is λ ′, the opening of the U-shaped filament from the core wire side feeding point 6 The line length to one end of the wire is adjusted to be an odd multiple of αλ ′ / 4 together with substantially αλ / 4, and from the core wire side feeding point 6 to the other end of the opening. The total length of the filaments was adjusted to approximately αλ / 6, and impedance matching was obtained even in the L band (second frequency band).

That is, the sum of the length of the vertical line 11 extending from the core wire side feeding point 6 and the length of the line 12b from the connection point 15 between the horizontal line 12 and the vertical line 11 to the open end is approximately αλ / It was set to 6.

The length of each filament of the core wire side element is 50 to 100 mm in the length of the vertical filament 11, and the line from the connection point 15 of the horizontal filament 12 to the vertical filament 11 to the connection point of the vertical filament 13. The length of the strip 12a is 40 to 100 mm, the length of the strip 12b from the connection point 15 between the horizontal strip 12 and the vertical strip 11 to the open end is 40 to 100 mm, and the length of the vertical strip 13 is 5 to It is desirable that the length of the folded line 14 is 20 mm and 50 to 150 mm.

Further, as shown in FIGS. 1 to 5 and 7, the auxiliary horizontal line that branches off from the vicinity of the connection point 15 of the vertical line 11 and the U-shaped line of the core wire side element 10 and extends in the horizontal direction. Article 17 may be provided. The length of the auxiliary horizontal line 17 is preferably 20 to 100 mm, and the distance between the auxiliary horizontal line 17 and the horizontal line 12 is preferably 5 to 20 mm. By providing this auxiliary horizontal filament 17, the directivity can be improved as shown by the solid line in FIG. In addition, you may arrange | position the auxiliary | assistant horizontal filament 17 in any horizontal direction on either side.

The U-shaped line connected to the tip 15 of the vertical line is an angular U-shaped (reverse U-shaped) line that opens on the right side (see FIGS. 1, 2, and 4 to 7). Alternatively, it may be an angular U-shaped (U-shaped) filament (see FIG. 3) with an opening on the left side.

The filament width of the core wire side element 10 is about 0.3 to 0.8 mm.

The two separate frequency bands are specifically two frequencies: a band 3 whose frequency band of the terrestrial digital radio broadcast wave is 174 to 240 MHz and an L band whose frequency band is 1452 to 1492 MHz. It is a band.

The antenna according to the present embodiment for receiving the terrestrial digital radio broadcast wave is a fixed window glass for vehicles, that is, an upper side or a lower side of a metal flange of a front window glass, a rear window glass, or a side fixed window glass. It is provided in the vicinity of either.

Even if it is provided alone on the core wire side feed point 6 of the antenna for receiving terrestrial digital radio broadcast waves on the rear window glass, or on the upper side or the lower side of the metal flange of the side fitting and fixing window, satisfactory reception is possible. Although gain can be obtained, if a diversity antenna is constructed by providing a plurality of locations on one of the window glasses or combining with other terrestrial digital radio broadcast wave receiving antennas, radio waves coming from the side of the vehicle Even so, the reception gain can be improved and the directivity can be improved.

For example, when a glass plate printed on the periphery with an insulating ceramic paste layer (not shown) colored black or the like is used as a window glass for an automobile, the ceramic paste layer is dried and then terrestrial digital radio is used. By disposing the core-side feeding point 6 and the ground-side feeding point 7 of the antenna for use on the ceramic paste layer, the feeding points 6 and 7 of the antenna become invisible from the outside of the vehicle, so that the appearance can be improved. .

The antenna of this embodiment is formed by baking a conductive ceramic paste screen-printed on a glass plate surface of a vehicle, but an antenna pattern may be provided on the surface of another insulator. For example, an antenna attached to a window glass, a wall surface, or a roof of a building may be used. Moreover, the antenna which formed the antenna pattern in the sheet | seat made from a synthetic resin for affixing on the desired position of a window glass may be sufficient.

Hereinafter, the operation of the invention of the antenna of the present embodiment will be described.

In the antenna according to the present embodiment, the core wire side element 10 is provided with an angular U-shape with an opening on the left side or an angular U-shape with an opening on the right side. Then, when the wavelength of the substantially intermediate frequency of the band 3 is λ, the wavelength shortening rate of the glass is α, and the wavelength of the substantially intermediate frequency of the L band is λ ′, The reason why the longer one of the total lengths of the wires to the ends of the two

wires

12, 14 is approximately αλ / 4 is to resonate most in the band 3, and the shorter one is approximately αλ / The reason for setting it to 6 is to obtain a preferable reception gain over a wide band 3 by resonating at a frequency shifted from the center frequency. Further, the length of the filament from the core wire side feed point 6 to the end of the U-shaped wire 14 is adjusted to be an odd multiple of αλ ′ / 4. Since the length of the line to the end of the line 12 is adjusted so as to be impedance-matched in the L band, a desired reception gain can be obtained even in the L band. For this reason, the antenna pattern can be made common throughout the world.

Furthermore, the directivity can be improved by providing the auxiliary horizontal filament 17 on the core wire side element.

In addition, the ground side element 20 is capacitively coupled close to the metal flange, and the core side element is extended in the vertical direction away from the metal flange, that is, the core side element 10 simulating a dipole antenna is separated from the ground side element 20. A higher receiving gain can be obtained.

Further, the ground-side feeding point 7 or a horizontal line 21 extending in the horizontal direction from the ground-side feeding point 7 is brought close to the metal flange 3, and the ground-side feeding point 7 or the horizontal line 21 and the metal flange 3 are capacitively coupled. Therefore, it is possible to reduce the fluctuation of the reception gain and obtain a stable gain. Further, by increasing the capacitive coupling between the ground side element 20 and the metal flange 3, noise from the body can be blocked.

Hereinafter, each example of the present invention will be described.

[Example 1]
In Example 1, the antenna shown in FIG. 1 was disposed on the glass surface adjacent to the upper side of the opening of the metal flange 3 in the upper margin of the defogger of the rear window glass 1 of the automobile. The antenna according to the first embodiment is a non-grounded terrestrial digital radio antenna including two elements, a core wire side element 10 and a ground side element 20.

The grounding side element 20 has a horizontal line 21 that is close to the upper side of the opening of the metal flange 3 from the upper side of the square grounding side feeding point 7 having a side of 12 mm. The horizontal filaments 21 are disposed substantially parallel to the metal flange 3 at intervals of 10 mm so as to be capacitively coupled to the metal flange 3.

Also, the core wire side element 10 extends in a horizontal left direction from a square wire 11 having a side of 12 mm, a vertical wire 11 having a length of 60 mm extending in the vertical direction, and a lower end of the vertical wire 11. A horizontal line 12a having a length of 55 mm, a horizontal line 12b having a length of 80 mm extending in the horizontal right direction from the lower end of the vertical line 11, and a vertical line 13 having a length of 5 mm extending downward from the left end of the horizontal line 12a; In addition, a folded line 14 having a length of 130 mm extending in the horizontal right direction from the lower end of the vertical line 13 and an auxiliary horizontal line 17 extending in the horizontal direction from the vertical line 11 are included. The horizontal line 12, the vertical line 13, and the folded line 14 form an angular U-shaped line having an opening on the right side.

That is, the total length (longer one) from the core wire-side feeding point 6 to one end of the U-shaped line opening is 60 mm for the vertical line 11 and 55 mm for the horizontal line 12a. When the wavelength shortening rate of the glass plate is α (approximately 0.6), the frequency in the band 3 is 180 MHz. The vertical strip 13 has a length of 5 mm and the folded strip 14 has a length of 130 mm. The length at which strong resonance is obtained at (wavelength = λ) is approximately αλ / 4.

Further, the total of the lengths (shorter) from the core wire side feeding point 6 to the other end of the opening of the U-shaped line is 60 mm for the vertical line 11 and 80 mm for the horizontal line 12b. The total length is 140 mm, and the most resonating length at the frequency 215 MHz (wavelength = λ) in the band 3 is approximately αλ / 6.

Further, as described above, of the length from the core wire side feeding point 6 to the end of the opening of the U-shaped line, the length of the longer line is the L band frequency 1450 MHz (wavelength = Λ ′), which is an odd multiple of the length αλ ′ / 4 at which strong resonance is obtained, and the length of the shorter filament is adjusted so that impedance matching is obtained in the vicinity of the L-band frequency of 1450 MHz. .

The distance between the core wire side feeding point 6 and the ground side feeding point 7 is 15 mm, and the distance between each feeding point and the metal flange 3 is 10 mm.

The vehicle antenna pattern is printed at a predetermined position on the indoor surface side of the window glass plate with a conductive ceramic paste at a width of about 0.7 mm, dried, baked in a heating furnace, and further illustrated. The central conductor of the coaxial cable connected to the tuner that is not connected was connected to the core-side feeding point 6, and the outer conductor was connected to the ground-side feeding point 7.

The terrestrial digital radio broadcast wave receiving antenna of Example 1 created in this way is arranged on the rear window glass of the automobile, and the terrestrial digital radio broadcast wave of the band 3 of 174 to 240 MHz and the L band of 1452 to 1492 MHz is transmitted. Recieved.

FIG. 9 shows frequency characteristics in the band 3 of each antenna of the antenna of the first embodiment (FIG. 1) and the antenna of the first comparative example (FIG. 8), and FIG. 10 shows the frequency characteristics in the L band.

As shown in FIG. 9, for band 3, the average reception sensitivity of the antenna of Example 1 indicated by a solid line is +2.2 dB, the minimum reception sensitivity is −1 dB, and the average reception sensitivity of the antenna of Comparative Example 1 indicated by a broken line Was -2.3 dB, and the minimum reception sensitivity was -7 dB. It was found that the reception performance of the antenna of Example 1 was superior to the reception characteristics of the antenna of Comparative Example 1.

Also, as shown in FIG. 10, for the L band, the average reception sensitivity of the antenna of Example 1 indicated by a solid line is -1 dB, the minimum reception sensitivity is -4 dB, and the average reception of the antenna of Comparative Example 1 indicated by a dotted line is shown. The sensitivity was −7 dB and the minimum reception sensitivity was −9 dB, and it was found that the reception performance of the antenna of Example 1 was superior to the reception characteristics of the antenna of Comparative Example 1.

[Example 2]
The antenna of the second embodiment shown in FIG. 2 has a vertical line 22 in which the ground-side element 20 extends from the ground-side feeding point 7 in the direction of the metal flange 3, compared to the antenna of the first embodiment shown in FIG. Other points are the same as those of the first embodiment except that a horizontal line 23 extending in the direction away from the core-side feeding point 6 along the metal flange 3 from the tip of the vertical line 22 is included. . For this reason, the same code | symbol is attached | subjected to the same structure as Example 1, and those description is abbreviate | omitted.

The length of the vertical line 22 of the ground side element 20 is 5 mm, and the distance between the horizontal line 21 and the metal flange 3 is 5 mm, which is narrower than the distance between the horizontal line 21 and the metal flange 3 of Example 1. As a result, the ground-side feeding point 7 is separated from the metal flange 3 at the same interval as the core-side feeding point 6, but the ground-side element 20 is close to the metal flange 3, so that the ground-side element 20 of the first embodiment is used. As compared with the above, the ground side element 20 of the second embodiment is more strongly capacitively coupled to the metal flange 3.

As in Example 1, the antenna pattern of Example 2 was printed with a conductive ceramic paste at a predetermined position on the indoor surface side of the window glass plate, dried, baked in a heating furnace, and further applied to a tuner (not shown). The central conductor of the coaxial cable to be connected was connected to the core wire side feed point 6, and the outer conductor was connected to the ground side feed point 7.

The terrestrial digital radio broadcast wave receiving antenna according to the second embodiment created in this way is arranged on the rear window glass of the automobile, and the terrestrial digital radio broadcast wave of the band 3 having a frequency of 174 to 240 MHz and the L band of 1452 to 1492 MHz. As a result, a sufficient reception sensitivity was obtained as in the first embodiment.

[Example 3]
The antenna of the third embodiment shown in FIG. 3 is different from the antenna of the first embodiment shown in FIG. 1 in the direction of the opening of the U-shaped filament of the core wire side element 10, and other configurations are the same as those of the first embodiment. Are the same. For this reason, the same code | symbol is attached | subjected to the same structure as Example 1, and those description is abbreviate | omitted.

That is, the vertical wire 13 connecting the horizontal wire 12 and the folded wire 14 of the core wire side element 10 is arranged on the right side, and the opening of the U-shaped wire is provided on the left side.

As in Example 1, the antenna pattern of Example 3 was printed with a conductive ceramic paste at a predetermined position on the indoor surface side of the window glass plate, dried, baked in a heating furnace, and further applied to a tuner (not shown). The central conductor of the coaxial cable to be connected was connected to the core wire side feed point 6, and the outer conductor was connected to the ground side feed point 7.

The terrestrial digital radio broadcast wave receiving antenna of the third embodiment created in this way is provided on the rear window glass of the automobile, and the terrestrial digital radio broadcast wave of the band 3 of frequency 174 to 240 MHz and the L band of 1452 to 1492 MHz is transmitted. As a result of reception, sufficient reception sensitivity was obtained as in the first embodiment.

[Example 4]
The antenna of the fourth embodiment shown in FIG. 4 differs from the antenna of the first embodiment shown in FIG. 1 in that the auxiliary horizontal filament 17 of the core wire side element 10 extends rightward from the vertical filament 11, and the other The configuration is the same as in the first embodiment. For this reason, the same code | symbol is attached | subjected to the same structure as Example 1, and those description is abbreviate | omitted.

The antenna pattern of Example 4 is printed with a conductive ceramic paste at a predetermined position on the indoor side of the window glass plate in the same manner as in Example 1, dried, baked in a heating furnace, and connected to a tuner (not shown). The center conductor of the coaxial cable to be connected was connected to the core wire side feed point 6, and the outer conductor was connected to the ground side feed point 7.

The terrestrial digital radio broadcast wave receiving antenna of Example 4 created in this way is provided on the rear window glass of the automobile, and the terrestrial digital radio broadcast wave of the band 3 of frequency 174 to 240 MHz and the L band of 1452 to 1492 MHz is transmitted. As a result of reception, sufficient reception sensitivity was obtained as in the first embodiment.

[Example 5]
The antenna of the fifth embodiment shown in FIG. 5 is different from the antenna of the first embodiment shown in FIG. 1 in that an auxiliary vertical wire 23 is extended below the tip of the horizontal wire 21 of the ground side element 20. The configuration is the same as that of the first embodiment. For this reason, the same code | symbol is attached | subjected to the same structure as Example 1, and those description is abbreviate | omitted.

In the antenna of the fifth embodiment, the antenna impedance can be adjusted while minimizing the influence on the antenna characteristics by the auxiliary vertical wire 23 extending to the tip of the horizontal wire of the ground side element 20. For this reason, the sensitivity can be further improved.

The antenna pattern of Example 5 was printed with a conductive ceramic paste at a predetermined position on the indoor surface side of the window glass plate in the same manner as in Example 1, dried, baked in a heating furnace, and further connected to a tuner (not shown). The center conductor of the coaxial cable to be connected was connected to the core wire side feed point 6, and the outer conductor was connected to the ground side feed point 7.

The terrestrial digital radio broadcast wave receiving antenna of Example 5 created in this way is provided on the rear window glass of the automobile, and the terrestrial digital radio broadcast wave of the band 3 of 174 to 240 MHz and the L band of 1452 to 1492 MHz is transmitted. As a result of reception, sufficient reception sensitivity was obtained as in the first embodiment.

[Example 6]
The antenna of Example 6 shown in FIG. 6 is an antenna from which the auxiliary horizontal filament 17 of the core wire side element 10 of Example 1 shown in FIG. 1 is removed, and the other configuration is the same as that of Example 1. For this reason, the same code | symbol is attached | subjected to the same structure as Example 1, and those description is abbreviate | omitted.

The antenna pattern of Example 6 was printed with a conductive ceramic paste at a predetermined position on the indoor surface side of the window glass plate in the same manner as in Example 1, dried, baked in a heating furnace, and further connected to a tuner (not shown). The center conductor of the coaxial cable to be connected was connected to the core wire side feed point 6, and the outer conductor was connected to the ground side feed point 7.

The terrestrial digital radio broadcast wave receiving antenna of Example 6 created in this way is provided on the rear window glass of the automobile, and the terrestrial digital radio broadcast wave of the band 3 of 174 to 240 MHz and the L band of 1452 to 1492 MHz is transmitted. As a result of reception, sufficient reception sensitivity was obtained as in the first embodiment.

However, while the antenna of Example 1 having the auxiliary horizontal line 17 has a flat directivity as shown by the solid line in FIGS. 11A and 11B, the antenna of Example 6 having no auxiliary horizontal line 17 is As shown by a dotted line in FIG. 11, a slight dip is seen in the directivity characteristics at some angles on the left front side of the automobile. Thus, it can be seen that the auxiliary horizontal filament 17 of Example 1 is provided in order to improve the directivity in the band 3.

[Example 7]
The antenna of the seventh embodiment shown in FIG. 7 has a line extending from the ground-side feeding point 7 only in the ground-side feeding point 7 constituting the ground-side element 20 as compared with the first embodiment shown in FIG. The pattern and the line length of the other core wire side elements 10 are the same as those of the first embodiment.

The ground-side feeding point 7 is a square with a side of 12 mm, and is arranged at a position 5 mm away from the metal flange 3. Since the ground-side feeding point 7 is arranged close to the metal flange 3, it does not have a linear element, but is capacitively coupled to the metal flange 3.

The antenna pattern of Example 7 is printed with a conductive ceramic paste at a predetermined position on the indoor surface side of the window glass plate in the same manner as in Example 1, dried, baked in a heating furnace, and connected to a tuner (not shown). The center conductor of the coaxial cable to be connected was connected to the core wire side feed point 6, and the outer conductor was connected to the ground side feed point 7.

The terrestrial digital radio broadcast wave receiving antenna of Example 7 created in this way is provided on the rear window glass of the automobile, and the terrestrial digital radio broadcast wave of the band 3 of 174 to 240 MHz and the L band of 1452 to 1492 MHz is transmitted. As a result of reception, sufficient reception sensitivity was obtained as in the first embodiment.

Although the preferred embodiments have been described above, the present invention is not limited to these, and various applications are possible.

[Comparative Example 1]
The comparative example 1 shown in FIG. 8 includes a core wire side element 10 ′ extending from the core wire side feeding point 6 ′ and a ground side element 20 ′ extending from the ground side feeding point 7 ′. The core wire side element 10 ′ extends vertically from the core wire side feeding point 6 ′ to the vertical line 11 ′ extending away from the metal flange 3 and horizontally from the tip of the vertical wire 11 ′ to the ground side feeding point 7 ′. Horizontal line 12 to be included. The ground side element 20 ′ includes a horizontal line 21 ′ extending in the horizontal direction away from the core wire side feeding point 6.

The antenna pattern of Comparative Example 1 was printed with a conductive ceramic paste at a predetermined position on the indoor side of the window glass plate in the same manner as in Example 1, dried, baked in a heating furnace, and connected to a tuner (not shown). The center conductor of the coaxial cable to be connected was connected to the core-side feeding point 6 ′, and the outer conductor was connected to the ground-side feeding point 7 ′.

The terrestrial digital radio broadcast wave receiving antenna of Comparative Example 1 created in this way is provided on the rear window glass of the automobile, and band 3 of frequency 174 to 240 MHz and L band of terrestrial digital radio broadcast wave band of 1452 to 1492 MHz are provided. As a result, the frequency characteristic indicated by the dotted line in FIG. 9 was shown in the band 3 and the frequency characteristic indicated by the dotted line in FIG. 10 was shown in the L band.

Although the present invention has been described in detail with reference to the accompanying drawings, the present invention is not limited to such specific configurations, and various modifications and equivalents within the spirit of the appended claims Includes configuration.

This application claims priority based on Japanese Patent Application No. 2010-230524 filed with the Japan Patent Office on October 13, 2010, the entire contents of which are incorporated herein by reference.

Claims

In a non-grounded antenna provided on a glass plate provided at an opening of a metal flange, comprising a core wire side element including a core wire side feed point and a ground side element including a ground side feed point.
The grounding side feeding point and the core wire side feeding point are provided at positions close to each other,
The ground side element is disposed close to the upper side or the lower side of the opening of the metal flange so as to be capacitively coupled to the grounded metal flange.
The core-wire-side element is connected to a first vertical wire extending in a vertical direction away from the metal flange from the core-wire-side feeding point, and a U-shape having a side opening connected to a tip portion of the first vertical wire Including the filaments,
The U-shaped line includes: a first horizontal line extending in a horizontal direction; a folded line disposed in parallel to the first horizontal line; and an end on the same side of the horizontal line and the folded line A second vertical wire connecting between the two,
The first horizontal filament is connected to the first vertical filament at a substantially midpoint thereof,
When the wavelength of the substantially center frequency of the first frequency band is λ, the wavelength of the substantially center frequency of the second frequency band is λ ′, and the wavelength reduction rate of the glass plate is α, The total length of the line to the one end of the opening of the U-shaped line is approximately αλ / 4, and is approximately (2n + 1) αλ ′ / 4 (n is an integer of 0 or more). The antenna is characterized in that the total length of the line from the core-side feeding point to the other end of the opening of the U-shaped line is approximately αλ / 6.
The antenna according to claim 1,
Adjusting the length from the end of the opening closest to the connection point of the U-shaped line to the first vertical line to the connection point, and impedance matching in the second frequency band, Antenna.
The antenna according to claim 1,
The antenna according to claim 1, wherein the core side element includes an auxiliary horizontal line having a length of 20 to 100 mm extending in parallel with the first horizontal line from the first vertical line.
The antenna according to claim 1,
The ground side element includes a second horizontal line extending in a horizontal direction from the ground side feeding point,
The antenna according to claim 1, wherein the grounding side element and the metal flange are capacitively coupled by arranging the second horizontal filament close to the metal flange.
The antenna according to claim 4, wherein
An antenna comprising an auxiliary vertical line extending in a vertical direction from a tip of the second horizontal line.
The antenna according to claim 1,
The antenna according to claim 1, wherein the first frequency band is a DAB standard band 3 of 174 to 240 MHz, and the second frequency band is a DAB standard L band of 1452 to 1492 MHz.