JP6481377B2 - Glass antenna and window glass - Google Patents

Description

  The present invention relates to a glass antenna disposed on the surface of a glass plate, and more particularly to a broadband and high sensitivity antenna.

  Broadcasting is carried out in a wide band in the VHF band. For example, a foreign FM radio broadcast uses a 20 MHz band of 88 to 108 MHz (76 to 90 MHz in Japan). This is a band of about ± 10% of the center frequency (98 MHz). Further, a defogger heating wire for anti-fogging is arranged at the center of the rear glass of the automobile, and the antenna can be arranged only in the margin of the defogger. Furthermore, the VHF band has a long wavelength, and it is difficult to design a small antenna.

  As an antenna for solving this problem, Patent Document 1 includes two antennas for FM broadcast waves arranged in a defogger upper margin of a rear glass for an automobile, and each antenna is heated at the top of the defogger. An antenna is described having horizontal filaments that are arranged close to the horizontal filaments and have different lengths.

  Patent Document 2 describes an antenna that efficiently couples a reception voltage of a radio wave induced in a defogger to the antenna conductor by capacitively coupling an antenna conductor having a loop portion close to the defogger.

JP 2012-248981 A JP-A-8-321711

  However, in the antenna described in Patent Document 1, diversity is configured with two antennas, and high sensitivity is not obtained with one antenna. The antenna described in Patent Document 2 is a system in which a defogger is electrically floated from the ground. With this system, radio waves induced by heat rays can be efficiently picked up. It is not a high sensitivity.

  An object of the present invention is to provide a glass antenna capable of obtaining high sensitivity in a wide band in the VHF band.

  That is, the present invention is a glass antenna provided on a rear window glass of a vehicle, and includes a first antenna that receives broadcast waves, and the window glass includes a heating wire extending substantially horizontally and the heating wire. An electric heating type defogger having a vertical line provided on the vertical center line of the window glass and a pair of bus bars for supplying power to the end of the heating line is provided. The first antenna includes a rectangular loop portion disposed near one side of the window glass, a first horizontal line extending laterally from the loop portion, along a bottom side of the loop portion, and And a second horizontal filament arranged along the heating filament on the uppermost side of the defogger, wherein the second horizontal filament is shorter than the bottom of the loop portion, and the wavelength reduction rate of the window glass is α As the wave of the center frequency of the reception frequency band Is a length of the first horizontal filament is approximately αλ / 4, and both sides of the loop portion are arranged at positions different from the extension of the vertical filament. It is.

  Further, the present invention is the glass antenna, wherein the loop portion intersects with a vertical center line of the window glass, and the second horizontal filament is connected to the loop portion.

  Further, according to the present invention, when the loop portion is divided by the vertical center line, an area ratio between a portion where the area of the loop portion is large and a portion where the area is small is between 6: 1 and 4: 1. This is a glass antenna.

  Further, the present invention is characterized in that at least a most part of the loop part and at least a most part of the second horizontal filament are arranged on the same side divided by a vertical center line. It is a glass antenna.

  In the present invention, the first antenna further includes a third horizontal line connected to the loop portion, disposed along the heating line on the uppermost side of the defogger, and shorter than the second horizontal line. This is a glass antenna.

  Moreover, the present invention is the glass antenna according to the present invention, wherein the loop portion intersects with the extension line of the vertical line and is larger than half of the left and right width of the window glass.

  Moreover, the present invention is the glass antenna, wherein the first horizontal filament is adjusted so as to be suitable for reception of FM radio broadcast waves or AM radio broadcast waves.

  Moreover, this invention is provided with the 2nd antenna connected to a 2nd electric power feeding part in the margin part of the said defogger, It is a glass antenna characterized by the above-mentioned.

  The present invention is the glass antenna, wherein the first antenna and the second antenna constitute a diversity antenna.

  Moreover, this invention is a window glass provided with one of the said glass antennas.

  According to the representative embodiment of the present invention, high sensitivity can be obtained in a wide band.

It is a figure which shows the antenna pattern of 1st Example of this invention. It is a figure which shows the antenna pattern of 2nd Example of this invention. It is a figure which shows the antenna pattern of 3rd Example of this invention. It is a figure which shows the antenna pattern of 4th Example of this invention. It is a figure which shows the antenna pattern of 5th Example of this invention. It is a figure which shows the antenna pattern of 6th Example of this invention. It is a figure which shows the antenna pattern of 7th Example of this invention. It is a figure which shows the antenna pattern of 8th Example of this invention. It is a figure which shows the antenna pattern of 9th Example of this invention. It is a figure which shows the antenna pattern of 10th Example of this invention. It is a figure which shows the modification of the antenna pattern of 1st Example of this invention. It is a figure which shows the antenna pattern of the comparative example 1. It is a figure which shows the antenna pattern of the comparative example 2. It is a frequency characteristic figure of the antenna of 1st Example.

  1 to 10 are views of a glass antenna according to an embodiment of the present invention as viewed from the inside of a vehicle.

  As shown in FIG. 1, the glass antenna of the embodiment of the present invention is configured by a first antenna 2. The first antenna 2 is provided on the rear glass 5 of the automobile, and includes a power feeding unit 20, a first horizontal line 22 that is connected to the power feeding unit 20 and extends horizontally, and a loop unit 23 that is connected to the left side of the first horizontal line 22. And have. Below the first horizontal line 22 and the loop portion 23, a second horizontal line 211 and a third horizontal line 212 are provided adjacent to the heating line 311 on the uppermost side of the defogger 3. The second horizontal line 211 and the third horizontal line 212 maintain a distance of 20 mm to 40 mm from the heating line 311 on the uppermost side of the defogger 3, but if this distance is narrow, the effective capacity of the antenna itself increases, but the heat ray However, if the interval is wide, the reactive capacity with the heat ray is reduced, but the effective capacity of the antenna itself is also reduced and the sensitivity is lowered. In consideration of this, the interval is kept balanced so that the sensitivity of the antenna itself is easily improved.

  The left end of the second horizontal line 211 is connected to the loop part 23 by a connecting line 241 extending downward from the loop part 23. The right end of the third horizontal line 212 is connected to the loop part 23 by a connecting line 242 extending horizontally from the loop part 23 in the right direction.

  The second horizontal filament 211 is adjusted to a length that resonates with the reception frequency, and is shorter than the lower side of the loop portion 23 and longer than the third horizontal filament 212. The second horizontal filament 211 is provided on the left side of the longitudinal center line of the rear glass 5. In addition, you may extend | stretch the front-end | tip part of the 2nd horizontal filament 211 slightly to the right side from the vertical center line.

  The left side of the loop part 23 is provided on the left side of the rear glass 5, and the right side of the loop part 23 is provided on the right side of the vertical center line of the rear glass 5. In addition, the vertical filament 34 which connects the heating filament 31 of the defogger 3 is provided on a vertical center line. For this reason, most of the loop portion is arranged on the left side of the rear glass 5. Inside the loop portion 23, a linear strip 231 extending left and right is provided.

  For this reason, both the most part of the loop part 23 and the most part of the 2nd horizontal filament 211 are provided in the left side rather than the vertical centerline of the rear glass 5. FIG.

  Further, the first antenna 2 includes an auxiliary wire 25 extending to the right side of the loop portion 23 and an auxiliary wire 26 extending horizontally below the first horizontal wire 22.

  A defogger 3 is provided at the center of the rear glass 5. The defogger 3 connects a pair of bus bars 32 provided on the left and right sides of the rear glass 5, a plurality of heating wires 31 that connect the two bus bars 32, and a plurality of heating wires 31, on the longitudinal center line of the rear glass 5. And a vertical line 34 located at the bottom. By providing the vertical line 34, it is possible to improve the reception sensitivity for vertically polarized waves and obliquely polarized radio waves.

  The loop portion 23 may include a line 231 as illustrated in FIG. 1, and may not include a line inside as illustrated in FIG. 2.

  Moreover, the 2nd horizontal filament 211 may be connected with the loop part 23 in the left end, as shown in FIG. 1, and may be connected with the loop part 23 in the right end, as shown in FIG. 3, FIG.

  In addition, as shown in FIG. 4, an inverted T-shaped auxiliary filament 27 extending downward from the loop portion 23 may be provided.

  Further, as shown in FIG. 5, two third horizontal filaments 212 may be provided.

  Moreover, as shown in FIG. 6, you may fold the front-end | tip of the auxiliary filament 26. FIG.

  In addition, as shown in FIG. 7, the power feeding unit 20 may be provided on the upper side of the loop unit 23.

  Further, as shown in FIGS. 8, 9, and 10, a second antenna 6 may be provided, and the first antenna 2 and the second antenna 6 may constitute a diversity antenna.

  In the glass antenna according to the embodiment of the present invention, the pattern is printed at a predetermined position on the indoor surface side of the glass plate with a conductive ceramic paste at a width of about 0.7 mm, dried, and then baked in a heating furnace. Formed. Further, an antenna may be formed by a conductive pattern formed on a light-transmitting resin film and attached to a glass plate.

  In addition, although the element of the antenna of this embodiment is adjusted so that it may suit FM radio broadcast band, it can also receive AM radio broadcast.

  Next, the effect | action of the glass antenna of embodiment of this invention is demonstrated.

  The first antenna 2 that receives broadcast waves extends in a rectangular loop portion 23 that is disposed near one side (for example, the left side) of the rear glass 5 and from the loop portion 23 to the side (for example, the right direction). It has the 1st horizontal filament 22 and the 2nd horizontal filament 211 arrange | positioned along the bottom line of the loop part 23, and along the heating filament of the uppermost side of a defogger. The second horizontal filament 211 is shorter than the bottom of the loop portion 23 and is adjusted to a length suitable for the wavelength of the reception frequency. Moreover, since the both sides of the loop part 23 are arrange | positioned in the position different from the extension line | wire of the vertical filament 34, a sensitivity can be improved in a wide band.

  Further, since at least the most part of the loop part 23 and at least the most part of the second horizontal filament 211 are arranged on the same side of the window glass 5 divided by the vertical center line, the area of the loop part 23 is increased. The sensitivity can be improved over a wide band.

  Moreover, since the loop part 23 cross | intersects the vertical center line of the window glass 5, and the 2nd horizontal wire 211 is connected to the lower side of the loop part 23, adjustment of an impedance can be made easy.

  Moreover, when the loop part 23 is divided by the vertical center line of the window glass 5, the area ratio of the part where the area of the loop part 23 is large and the part where the area is small is between 6: 1 and 4: 1. Therefore, the impedance can be easily adjusted within the range.

  In addition, the first antenna 2 is connected to the loop portion 23, is disposed along the heating line 311 on the uppermost side of the defogger 3, and further includes a third horizontal line 212 shorter than the second horizontal line 211, The impedance of the antenna can be easily adjusted.

  Moreover, since the loop part 23 crosses the extension line | wire of the vertical filament 34 and is larger than the half of the left-right width of the rear glass 5, it can improve a sensitivity in a wide band.

  In addition, since the second antenna 6 connected to the second power feeding unit 60 is provided in the upper or lower margin of the defogger 3 on the rear glass 5, and the first antenna 2 and the second antenna 6 constitute a diversity antenna. When a receiving antenna is selected with a radio tuner, an antenna with high receiving sensitivity can always be selected, and a stable receiving state can be maintained.

  Hereinafter, various embodiments of the present invention will be described.

<Example 1>
FIG. 1 is a front view of a glass antenna (in-vehicle view) provided on a rear glass 5 of an automobile, showing an antenna pattern of a first embodiment of the present invention.

  The glass antenna of the first embodiment includes a first antenna 2, and the first antenna 2 includes a power feeding unit 20, a first horizontal line 22, a loop part 23, a second horizontal line 211, and a third horizontal line. It has the line 212, the auxiliary line 25, and the auxiliary line 26.

  A defogger 3 is provided at the center of the rear glass 5. The defogger 3 has a pair of bus bars 32 provided on the left and right sides of the rear glass 5, a plurality of heating wires 31 connecting the two bus bars 32, and a vertical wire 34 connecting the plurality of heating wires 31. . The vertical filament 34 is provided on the longitudinal center line of the rear glass 5.

  The first horizontal filament 22 is connected to the power feeding unit 20 and extends substantially horizontally in the left direction.

  The loop portion 23 is connected to the left side of the first horizontal filament 22 and includes a filament 231 that connects the left side and the right side and extends substantially horizontally. The left side of the loop part 23 is provided at a position close to the left side of the rear glass 5, and the right side of the loop part 23 is provided on the right side of the vertical center line of the rear glass 5. That is, the loop portion 23 straddles the vertical center line, and most of the loop portion 23 is disposed on the left side of the rear glass 5.

  The second horizontal line 211 is provided on the lower side of the loop part 23 so as to be adjacent to the heating line 311 on the uppermost side of the defogger 3 and is looped by the connecting line 241 extending downward from the lower left corner of the loop part 23. Connected to the unit 23. That is, the second horizontal filament 211 is provided on the left side of the longitudinal center line of the rear glass 5. In addition, you may extend | stretch the front-end | tip part of the 2nd horizontal filament 211 slightly to the right side from the vertical center line.

  The second horizontal line 211 is adjusted to a length that resonates with the reception frequency, and is shorter than the lower side of the loop portion 23 and longer than the third horizontal line 212.

  The third horizontal line 212 is provided on the lower side of the first horizontal line 22 so as to be adjacent to the heating line 311 on the uppermost side of the defogger 3, and is a connecting line extending horizontally from the lower right corner of the loop portion 23 to the right. It is connected to the loop portion 23 by the strip 242. The connecting wire 242 and the third horizontal wire 212 function as a radiating element.

  The auxiliary filament 25 is disposed so as to extend the uppermost side of the loop portion 23 to the right side. The auxiliary filament 26 is disposed below the first horizontal filament 22 so as to extend substantially parallel to the first horizontal filament 22. The impedance of the antenna can be adjusted in a wide range by the auxiliary wire 25 and the auxiliary wire 26. Specifically, the auxiliary filament 25 is an element that contributes to the improvement of the sensitivity of the AM radio broadcast band and functions for adjusting the impedance of the FM radio broadcast band. That is, by increasing the length of the auxiliary wire 25 provided at the top, the sensitivity of the AM radio broadcast band is improved, and the impedance in the FM radio broadcast band is adjusted. For this reason, the length of the auxiliary filament 25 is adjusted to an optimum length so that the sensitivity of both the AM radio broadcast band and the FM radio broadcast band is improved. The auxiliary filament 26 functions as an impedance adjusting element. By arranging the auxiliary wire 26 close to the connection wire 242, and capacitively coupling the auxiliary wire 26 and the connection wire 242, the radiation efficiency of the connection wire 242 which is a radiating element can be improved. .

  FIG. 1 also shows an example of the length of each filament of the glass antenna of the first embodiment.

  The upper side of the loop part 23 is 610 mm, and the right side of the loop part 23 is located 100 mm to the right of the center line of the rear glass 5. The auxiliary filament 25 has a length of 400 mm and extends substantially horizontally from the upper right corner of the loop portion 23 to the right. The second horizontal filament 211 has a length of 520 mm and extends substantially horizontally at a distance of 40 mm from the lower side of the loop portion 23. Moreover, the 3rd horizontal filament 212 is extended | stretched by the length of 230 mm in parallel with the space | interval of 40 mm below the connecting filament 242. FIG. The auxiliary wire 26 extends parallel to the upper side of the connecting wire 242 at an interval of 10 mm.

  Further, in the first embodiment, the length of the first horizontal filament 22 may be αλ / 4 (the wavelength shortening rate α of the rear glass 5 is 0.6, and the wavelength λ of the center frequency of the FM radio broadcast band is 98 MHz). .

  Furthermore, as in the modification shown in FIG. 11, the length of the second horizontal filament 211 may be αλ / 4 (the wavelength shortening rate α = 0.6 of the rear glass 5 and the wavelength λ of the center frequency of the FM radio broadcasting band). = 98 MHz). In this case, as shown in FIG. 11, the left side of the loop portion 23 is moved inward to reduce the horizontal size of the loop portion 23 and shorten the right horizontal position of the second horizontal filament 211 without changing it. Also good. Further, the size of the loop portion 23 may be the same, and may be shortened without changing the right end position of the second horizontal line 211, and further, may be shortened without changing the left end position of the second horizontal line 211. Good.

  In the glass antenna of the first embodiment, by providing the loop portion 23 from the left side of the rear glass 5 to the region exceeding the longitudinal center line of the rear glass 5, the area of the loop portion 23 can be increased, and a wide band (for example, 88 to The sensitivity of the 108 MHz FM radio broadcast band can be improved.

  In addition, two horizontal filaments (second horizontal filament 211, third horizontal filament 212) are provided at positions adjacent to the defogger 3, and the second horizontal filament 211 is adjusted to a length that resonates with the reception frequency. Good sensitivity can be obtained in the reception frequency band. In addition, the impedance of the antenna can be easily adjusted by making the third horizontal line 212 shorter than the second horizontal line 211 and using it for impedance adjustment.

<Example 2>
FIG. 2 is a front view of a glass antenna (in-vehicle view) provided on a rear glass 5 of an automobile, showing an antenna pattern according to a second embodiment of the present invention.

  The glass antenna of the second embodiment is different from the first embodiment in that the filament 231 is not provided inside the loop portion 23.

  The glass antenna of the second embodiment has a first antenna 2, and the first antenna 2 includes a power feeding unit 20, a first horizontal line 22, a loop part 23, a second horizontal line 211, and a third horizontal line. It has the line 212, the auxiliary line 25, and the auxiliary line 26.

  In the second embodiment, the line 231 is not provided inside the loop portion 23. Since the configurations of the second embodiment other than those described above are the same as those of the first embodiment, the same reference numerals are given and description thereof is omitted.

  In the second embodiment, the antenna sensitivity can be improved over a wide band as in the effects of the other embodiments described above. Further, the impedance of the antenna can be easily adjusted.

<Example 3>
FIG. 3 is a front view of a glass antenna (in-vehicle view) provided on a rear glass 5 of an automobile, showing an antenna pattern according to a third embodiment of the present invention.

  The glass antenna of the third embodiment is different from the first embodiment in that the second horizontal filament 211 is connected to the loop portion 23 at the right end.

  The glass antenna of the third embodiment has a first antenna 2, and the first antenna 2 includes a power feeding unit 20, a first horizontal line 22, a loop part 23, a second horizontal line 211, and a third horizontal line. It has the line 212, the auxiliary line 25, and the auxiliary line 26.

  In 3rd Example, the 2nd horizontal filament 211 is provided in the lower part of the loop part 23 so that it may adjoin with the heating filament 311 of the uppermost side of the defogger 3, and the right end (for example, position near vertical centerline). In FIG. 5, the connecting wire 241 is connected to the lower side of the loop portion 23. That is, most of the second horizontal filament 211 is provided on the left side of the longitudinal center line of the rear glass 5.

  Since the configuration of the third embodiment other than that described above is the same as that of the first embodiment, the same reference numerals are given and description thereof is omitted.

  In the third embodiment, the antenna sensitivity can be improved over a wide band as in the effects of the other embodiments described above. Further, the impedance of the antenna can be easily adjusted.

<Example 4>
FIG. 4 is a front view of a glass antenna (in-vehicle view) provided on a rear glass 5 of an automobile, showing an antenna pattern according to a fourth embodiment of the present invention.

  The glass antenna of the fourth embodiment is different from the first embodiment in that an inverted T-shaped auxiliary filament 27 extending downward from the loop portion 23 is provided.

  The glass antenna of the fourth embodiment includes a first antenna 2, and the first antenna 2 includes a power feeding unit 20, a first horizontal line 22, a loop part 23, a second horizontal line 211, and a third horizontal line. It has the strip 212, the auxiliary filament 25, the auxiliary filament 26, and the auxiliary filament 27.

  In the fourth embodiment, an inverted T-shaped auxiliary filament 27 having a connecting portion extending below the loop portion 23 and a horizontal portion extending horizontally from the lower end of the connecting portion is provided. That is, the auxiliary line 27 extends between the lower side of the loop portion 23 and the second horizontal line 211 and between the connection line 242 and the third horizontal line 212 and is close to the upper and lower lines. For this reason (in the figure, it is 20 mm, but it may be about 10 mm), it is capacitively coupled to the upper and lower filaments. The length of the auxiliary filament 27 is 100 mm to 150 mm on each of the left and right sides from the center, and the total length is 200 mm to 300 mm. This length resonates at about 3λ / 4 at the center frequency of the FM radio broadcast band, and the auxiliary filament 27 functions as a radiating element.

  Since the configuration of the fourth embodiment other than that described above is the same as that of the first embodiment, the same reference numerals are given and description thereof is omitted.

  In the fourth embodiment, in addition to the effects of the other embodiments described above, the horizontal portion of the auxiliary filament 27 is adjusted to a length that resonates with the reception frequency. it can.

<Example 5>
FIG. 5 is a front view of a glass antenna (in-vehicle view) provided on a rear glass 5 of an automobile, showing an antenna pattern of a fifth embodiment of the present invention.

  The glass antenna of the fifth embodiment differs from the first embodiment in that two third horizontal filaments 212 are provided.

  The glass antenna of the fifth embodiment has a first antenna 2, and the first antenna 2 includes a power feeding unit 20, a first horizontal line 22, a loop part 23, a second horizontal line 211, and a third horizontal line. It has the line 212, the auxiliary line 25, and the auxiliary line 26.

  In the fifth embodiment, two third horizontal filaments 212 are provided below the first horizontal filament 22 along the heating filament 311 on the uppermost side of the defogger 3, and from the lower right corner of the loop portion 23 to the right. It is connected to the loop part 23 by a connecting wire 242 extending horizontally. Note that the lengths of the two third horizontal filaments 212 may be the same or different.

  Since the configuration of the fifth embodiment other than that described above is the same as that of the first embodiment, the same reference numerals are given and description thereof is omitted.

  In the fifth embodiment, since two third horizontal wires 212 for impedance adjustment are provided, even in a vehicle in which the effect was not obtained in one state, the impedance of the antenna can be adjusted by using two. Can do. In addition, since two third horizontal filaments 212 are provided, it is possible to improve the sensitivity on the low frequency side of the reception band (near 88 MHz to 90 MHz).

<Example 6>
FIG. 6 is a front view of a glass antenna (in-vehicle view) provided on a rear glass 5 of an automobile, showing an antenna pattern according to a sixth embodiment of the present invention.

  The glass antenna of the sixth embodiment differs from that of the first embodiment in that a folded portion is provided at the tip of the auxiliary filament 26.

  The glass antenna of the sixth embodiment includes a first antenna 2, and the first antenna 2 includes a power feeding unit 20, a first horizontal line 22, a loop part 23, a second horizontal line 211, and a third horizontal line. It has the line 212, the auxiliary line 25, and the auxiliary line 26.

  The auxiliary filament 26 is disposed below the first horizontal filament 22 so as to extend substantially parallel to the first horizontal filament 22. In the sixth embodiment, the tip of the auxiliary filament 26 is folded, and the folded portion is arranged in parallel with the auxiliary filament 26 to form a folded portion. For this reason, even when the area where the antenna can be arranged is small (for example, when the rear glass is small, or when the line forming the right side of the loop portion 23 is largely shifted to the right side from the glass center line) An auxiliary filament 26 can be arranged.

  Since the configuration of the sixth embodiment other than that described above is the same as that of the first embodiment, the same reference numerals are given and description thereof is omitted.

  In the sixth embodiment, since the folded portion is provided at the tip of the auxiliary wire 26, the impedance of the antenna can be adjusted in a wide range even when the glass is small such as a small car and the necessary antenna length cannot be secured.

<Example 7>
FIG. 7 is a front view of a glass antenna (in-vehicle view) provided on a rear glass 5 of an automobile, showing an antenna pattern according to a seventh embodiment of the present invention.

  The glass antenna of the seventh embodiment is different from that of the first embodiment in that the feeding portion 20 is provided on the upper side of the loop portion 23.

  The glass antenna of the seventh embodiment includes a first antenna 2, and the first antenna 2 includes a power feeding unit 20, a first horizontal line 22, a loop part 23, a second horizontal line 211, and a third horizontal line. It has the line 212, the auxiliary line 25, and the auxiliary line 26.

  The loop portion 23 is disposed at the upper left portion of the rear glass 5. A power feeding unit 20 is provided on the upper side of the loop unit 23. The loop portion 23 includes therein a line 231 that connects the left side and the right side and extends substantially horizontally. The left side of the loop part 23 is provided at a position close to the left side of the rear glass 5, and the right side of the loop part 23 is provided on the right side of the vertical center line of the rear glass 5. That is, the loop portion 23 straddles the vertical center line, and most of the loop portion 23 is disposed on the left side of the rear glass 5.

  The 1st horizontal filament 22 is arrange | positioned so that the upper side of the loop part 23 may be extended substantially horizontally to the right side.

  The auxiliary filament 26 extends downward from the right end of the first horizontal filament 22 and is disposed below the first horizontal filament 22 so as to extend substantially parallel to the first horizontal filament 22.

  Since the configurations of the seventh embodiment other than those described above are the same as those of the first embodiment, the same reference numerals are given and descriptions thereof are omitted.

  In the seventh embodiment, since the power feeding unit 20 is provided on the upper side of the loop unit 23, the sensitivity can be improved. Further, the present invention can be applied even when the antenna wire cannot be drawn to the left and right of the rear glass 5.

<Example 8>
FIG. 8 is a front view of a glass antenna (in-vehicle view) provided on a rear glass 5 of an automobile, showing an antenna pattern according to an eighth embodiment of the present invention.

  The glass antenna of the eighth embodiment is different from the first embodiment in that it has a first antenna 2 and a second antenna 6 and the first antenna 2 and the second antenna 6 constitute a diversity antenna.

  The first antenna 2 of the eighth embodiment includes a power feeding part 20, a first horizontal line 22, a loop part 23, a second horizontal line 211, a third horizontal line 212, an auxiliary line 25, and an auxiliary line. Article 26. Since the configuration of the first antenna 2 of the eighth embodiment is the same as that of the first embodiment, the same reference numerals are given and description thereof is omitted.

  The second antenna 6 shown in FIG. 8 is provided in a blank portion between the first antenna 2 and the defogger 3 and includes a power feeding unit 60 and a horizontal line 61 extending horizontally in the right direction. The horizontal filament 61 is adjusted to a length that resonates with the reception frequency.

  FIG. 9 shows another antenna pattern of the eighth embodiment of the present invention, and is a front view of a glass antenna (in-vehicle view) provided on the rear glass 5 of the automobile. The second antenna 6 shown in FIG. 9 is provided in a blank portion at the lower right side of the defogger 3 and includes a power feeding unit 60 and a horizontal line 61 extending substantially horizontally from the power feeding unit 60 in the left direction. The horizontal filament 61 is adjusted to a length that resonates with the reception frequency.

  FIG. 10 shows another antenna pattern of the eighth embodiment of the present invention, and is a front view of a glass antenna (in-vehicle view) provided on the rear glass 5 of the automobile. The second antenna 6 shown in FIG. 10 is provided in a left-side lower margin of the defogger 3 and includes a power feeding unit 60 and a horizontal line 61 extending substantially horizontally from the power feeding unit 60 in the right direction. The horizontal filament 61 is adjusted to a length that resonates with the reception frequency.

  In the eighth embodiment, the first antenna 2 and the second antenna 6 are provided, and the first antenna 2 and the second antenna 6 constitute a diversity antenna. Therefore, when the reception antenna is selected by the radio tuner, the reception sensitivity is always set. A high antenna can be selected, and a stable reception state can be maintained.

  FIG. 12 shows the antenna pattern of Comparative Example 1, and is a front view of a glass antenna (in-vehicle view) provided on the rear glass 5 of the automobile. In the antenna shown in FIG. 12, the second horizontal filament 211 is not provided. For this reason, the lower side of the loop portion 23 and the uppermost side of the defogger 3 are arranged at an interval of 20 to 40 mm so as to be capable of capacitive coupling.

  FIG. 13 is a front view of a glass antenna (in-vehicle view) provided on the rear glass 5 of the automobile, showing the antenna pattern of Comparative Example 2. In the antenna shown in FIG. 13, the second horizontal filament 211 is longer than the horizontal size of the loop portion 23 and extends to the right from the vertical center line. The length of the second horizontal filament 211 is approximately αλ / 4 (the wavelength shortening rate α of the rear glass 5 is 0.6 and the wavelength λ of the center frequency of the FM radio broadcast band is 98 MHz).

FIG. 14 shows the sensitivity characteristics of the antenna of the first embodiment, the antenna of the comparative example, and the antenna of the modified example of the first embodiment (FIG. 11). Note that the antennas of Comparative Examples 1 and 2 exhibit substantially the same characteristics. According to this measurement result, the following can be understood.
-The antenna of Example 1 has a flat sensitivity in the whole reception frequency band (88-108 MHz), and a higher sensitivity than the antenna of a comparative example is acquired.
-The antenna of the modification of Example 1 has higher sensitivity than the antenna of the comparative example in the entire reception frequency band (88 to 108 MHz).
-The antenna of Example 1 has a higher sensitivity than the antenna of the modification of Example 1 on the low frequency side (88 to 96 MHz) of the reception frequency 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.

2 1st antenna 20 Feed part 22 1st horizontal line 23 Loop part 25, 26, 27 Auxiliary line 211 2nd horizontal line 212 3rd horizontal line 231 Internal line 241, 242 Connection line 3 Defogger 31, 311 Heating line Article 32 Bus bar 33 FM coil 34 Vertical line 5 Rear glass 6 Second antenna 60 Feeding part 61 Horizontal line

Claims (8)

A glass antenna provided on a rear window glass of a vehicle,
A first antenna for receiving broadcast waves;
In the window glass, a heating wire extending substantially horizontally, a vertical wire provided on a longitudinal center line of the window glass intersecting the heating wire, and a power source at an end of the heating wire An electrically heated defogger having a pair of bus bars to be supplied is provided,
The first antenna is
A rectangular loop portion disposed near one side of the window glass;
A first horizontal filament extending laterally from the loop portion;
A second horizontal filament disposed along the bottom of the loop portion and along the heating filament on the uppermost side of the defogger;
The second horizontal filament is shorter than the bottom of the loop portion, the wavelength reduction rate of the window glass is α, the wavelength of the center frequency of the reception frequency band is λ, and the length of the second horizontal filament is approximately αλ / 4,
Both sides of the loop portion are arranged at different positions from the extension line of the vertical line so that the loop part intersects the extension line of the vertical line,
The said loop part is larger than the half of the left-right width of the said window glass, and does not contain a filament inside, The glass antenna characterized by the above-mentioned. The loop portion intersects the vertical center line of the window glass,
The glass antenna according to claim 1, wherein the second horizontal line is connected to a lower side of the loop portion.   When the loop portion is divided by the vertical center line, an area ratio between a portion where the area of the loop portion is large and a portion where the area is small is between 6: 1 and 4: 1. The glass antenna according to claim 2.   The first antenna may further include a third horizontal line connected to the loop portion, arranged along the heating line on the uppermost side of the defogger, and shorter than the second horizontal line. Item 4. The glass antenna according to any one of Items 1 to 3.   5. The glass antenna according to claim 1, wherein a length of the first horizontal filament is approximately αλ / 4.   The glass antenna according to any one of claims 1 to 5, further comprising a second antenna connected to a second power feeding unit in a blank portion of the defogger.   The glass antenna according to claim 6, wherein the first antenna and the second antenna constitute a diversity antenna.   A window glass provided with the glass antenna according to claim 1.

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