JP5141500B2 - Glass antenna for vehicle and window glass for vehicle - Google Patents

Description

  The present invention relates to a glass antenna for a vehicle in which an antenna conductor and a power feeding portion are provided on a vehicle window glass. Moreover, it is related with the window glass for vehicles provided with the glass antenna for vehicles.

As a conventional technique, a glass antenna for a vehicle that can receive digital audio broadcasting (DAB) is known (see, for example, Patent Documents 1 and 2). DAB is composed of two different frequency bands, band III (band 3) of 174 to 240 MHz and L band (L band) of 1452 to 1492 MHz.
Japanese Patent Laid-Open No. 10-327090 JP 2000-307321 A

  However, when the frequency band is a dual band like the above-described DAB, the band is separated, so it is difficult to design and manufacture a glass antenna for a vehicle having sufficient reception performance that can handle both bands.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle glass antenna having a reception characteristic compatible with a dual band such as DAB and a vehicle window glass including the vehicle glass antenna.

In order to achieve the above object, a glass antenna for a vehicle according to the present invention comprises:
A glass antenna for a vehicle in which an antenna conductor and a power feeding portion are provided on a vehicle window glass,
The antenna conductor is
A loop element formed in a loop shape;
A first antenna element extending in a first direction starting from a first point on the loop element, and a substantially right angle to the first direction starting from a terminal end of the extension of the first antenna element An L-shaped element configured in an L-shape from a second antenna element extending in a second direction, which is a different direction;
A connection element that connects the power supply unit and a second point on the loop element;
Equipped with a,
There is a desired first broadcast frequency band and a desired second broadcast frequency band having a higher band than the first broadcast frequency band. A wavelength in the air at the center frequency of the first broadcast frequency band is λ _01. The wavelength in the air at the center frequency of the second broadcast frequency band is referred to as λ ₀₂ , the glass wavelength shortening rate is referred to as k (where k = 0.64), λ _g1 = λ ₀₁ · k, When λ _g2 = λ ₀₂ · k,
The loop element has a loop circumference of 0.92 · λ _{g2 to} 1.23 · λ _g2 ,
An imaginary line segment having both ends of the conductor length of the first antenna element, the conductor length of the second antenna element, the conductor length of the connection element, and the first point and the second point. the length of the first direction component, the total length was total and the length of the second direction component of the virtual line segment is a _{0.25 · λ g1 ~0.41 · λ g1} , and characterized in that To do.
In addition, the glass antenna for a vehicle according to the present invention is
A glass antenna for a vehicle in which an antenna conductor and a power feeding portion are provided on a vehicle window glass,
The antenna conductor is
A loop element formed in a loop shape;
A first antenna element extending in a first direction starting from a first point on the loop element, and a substantially right angle to the first direction starting from a terminal end of the extension of the first antenna element An L-shaped element configured in an L-shape from a second antenna element extending in a second direction, which is a different direction;
A connection element that connects the power supply unit and a second point on the loop element;
With
The loop element has a loop circumference of 120 to 160 mm,
An imaginary line segment having both ends of the conductor length of the first antenna element, the conductor length of the second antenna element, the conductor length of the connection element, and the first point and the second point. The total length of the length of the first direction component and the length of the second direction component of the imaginary line segment is 230 to 380 mm.

Here, the conductor length of the second antenna element is
An imaginary line segment having both ends of the conductor length of the first antenna element, the conductor length of the second antenna element, the conductor length of the connection element, and the first point and the second point. The total length of the first direction component and the length of the second direction component of the imaginary line segment is preferably 75% or less with respect to the total length.

  In addition, the vehicle window glass includes a second antenna conductor different from the antenna conductor including the loop element, the L-shaped element, and the connection element, a plurality of heater wires, and a bus bar that supplies power to the heater wires. It is preferable that a current-fed defogger having the above-mentioned is provided, and the second antenna element extends to a blank area between the second antenna conductor and the defogger.

  Further, it is preferable that the second direction is a horizontal or substantially horizontal direction in a state where the vehicle window glass is attached to a vehicle, and the connection element is in a direction opposite to the first direction. It is more preferable that the film is stretched starting from the second point.

  Furthermore, this invention provides the window glass for vehicles provided with the glass antenna for vehicles which concerns on this invention.

  According to the present invention, it is possible to obtain reception characteristics that are compatible with dual bands such as DAB.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Note that in the drawings for describing the embodiments, the directions on the drawings are used unless otherwise specified. In addition, these drawings are views of the interior of the vehicle (or the exterior of the vehicle) with the window glass attached to the vehicle, and the left-right direction on the drawing corresponds to the horizontal direction. For example, when the window glass is a rear glass attached to the rear part of the vehicle, the left-right direction on the drawing corresponds to the vehicle width direction. In addition, this invention is not limited to a rear glass, The windshield attached to the front part of a vehicle and the side glass attached to the side part of a vehicle may be sufficient.

  FIG. 1 is a plan view of a glass antenna 100 for a vehicle that is an embodiment of the present invention. The glass antenna 100 for vehicles is a glass antenna for vehicles which provided the antenna conductor and the electric power feeding part in the window glass 12 for vehicles. The glass antenna 100 for a vehicle has a loop element 5 formed in a loop shape, and a first point extending in a first direction substantially perpendicular to the horizontal direction starting from a first point 5a which is a point on the loop element 5. The antenna element 1 is the second antenna element 1 and the second end direction is substantially perpendicular to the first direction starting from the first terminal end 1g that is the end point of the extension of the antenna element 1 in the first direction. Starting from an L-shaped element configured in an L-shape from the antenna element 2 which is a second antenna element extending in the direction, and a second point 5b which is a point on the loop element 5, the L-shaped element The connection element 6 that extends in the third direction (in FIG. 1, 180 ° opposite to the first direction) and is connected to the feeder 18 at the connection point 6a is used as an antenna conductor. Is an example was structure. Note that the L-shape includes a L-symmetric shape, and the corner may be bent with a curvature. Moreover, the termination | terminus part may be the termination | terminus which the antenna element extends | stretches, and may be the termination | terminus vicinity which is a conductor part before the termination | terminus.

  The glass antenna 100 for a vehicle is a monopole antenna, and a reception signal obtained by the antenna conductor can be taken out from the power supply unit 18 on the positive electrode side (hot side), and the reception signal is received by the receiver. (Not shown). In the case of a monopole antenna, the vehicle body opening to which the window glass 12 is attached and the vicinity thereof may be a part that can be used as a ground (so-called body grounding can be taken). The glass antenna 400 for vehicles is a suitable form when the electric power feeding part 18 is arrange | positioned in the vicinity of the upper edge part or lower edge part of a vehicle body opening part. In the case of FIG. 1, it arrange | positions in the vicinity of the upper edge part 15a of a vehicle body opening part.

  The power supply unit 18 is a power supply point to which a power supply line connected to the receiver is electrically connected. When an AV line is used as a power supply line, the power supply unit 18 and an amplifier installed on the vehicle side are connected, and a body ground is established on the ground of the amplifier. At this time, it becomes easy to attach the AV line to the power supply unit 18 by configuring the connector for electrically connecting the AV line and the power supply unit 18 to the power supply unit 18.

  When a coaxial cable is used, the inner conductor of the coaxial cable is electrically connected to the power feeding portion 18, and the outer conductor of the coaxial cable is electrically connected to the ground portion provided on the vehicle body or the window glass 12. . By configuring the connector for electrically connecting the coaxial cable and the power supply unit 18 to the power supply unit 18, the coaxial cable can be easily attached to the power supply unit 18.

  When an amplifier circuit for amplifying a received signal that can be extracted from the power supply unit 18 is built in the connector mounted on the power supply unit 18, the ground of the amplifier circuit is electrically connected to a ground part such as an outer conductor of the coaxial cable. It is preferable that the power feeding unit 18 is electrically connected to the input side of the amplifier circuit, and the inner conductor of the coaxial cable is connected to the output side of the amplifier circuit.

  The shape of the power supply unit 18 is the shape of the tip of a power supply line directly attached to the power supply unit 18 or the shape of a connection member for connecting the power supply unit 18 and the power supply line (for example, the shape of a connector mounting surface or a contact terminal). It is good to decide accordingly. For example, a square shape or a polygonal shape such as a square, a substantially square, a rectangle, or a substantially rectangle is preferable for mounting. It may be a circle such as a circle, a substantially circle, an ellipse, or a substantially ellipse.

  FIG. 1 shows a rectangular power supply unit 18. A connection point 6 a with the connection element 6 is located on the lower side of the power feeding unit 18. The connection point 6a in FIG. 1 is the center point of the lower side of the power feeding unit 18, but may be an arbitrary position on the lower side, or may be the intersection of the right side or the left side and the lower side of the power feeding unit 18. The connection element 6 extends in a direction in which the power feeding unit 18 and the loop element 5 are separated from each other, and connects the power feeding unit 18 and the loop element 5.

  The loop element 5 is an antenna conductor formed in a loop shape. The loop shape is not limited to a loop shape formed with the same line width, but may have a partly increased line width, and may be formed in a loop shape. The shape of the loop element may be a circle such as a circle, a substantially circle, an ellipse, or a substantially ellipse, or a square such as a square, a substantially square, a rectangle, a substantially rectangular, a parallelogram, a substantially parallelogram, a rhombus, or a roughly rhombus. Or polygonal shape. The shape of the loop element 5 in FIG. 1 is a square. On the conductor portion of the loop element 5, a connection point 5 a with the antenna element 1 and a connection point 5 b with the connection element 6 are located. The connection point 5a is located on one side (lower side) and the connection point 5b is located on the other side (upper side) with respect to the horizontal virtual straight line passing through the center of gravity of the loop element 5. The connection points 5a and 5b in FIG. 1 are located on a straight line parallel to the first direction. 1 is the center point of the upper side of the loop element 5, but may be an arbitrary position on the upper side, and may be an intersection of the left side or the right side of the loop element 5 and the upper side (in the present invention). (Refer FIG.2, 3 which is a top view of the glass antenna 200 for vehicles which is embodiment.).

  Further, the connection point 5 b with the connection element 6 may be an arbitrary position on the right side or the left side of the loop element 5. FIG. 11 is a plan view of a glass antenna 400 for a vehicle that is an embodiment of the present invention. The glass antenna 400 for vehicles is a suitable form when the electric power feeding part 18 is arrange | positioned in the vicinity of the left edge part or right edge part of a vehicle body opening part. In the case of FIG. 11, it is disposed in the vicinity of the right edge 15b of the vehicle body opening.

  The antenna element 1 may be extended downward from the connection point 5a (first direction) starting from the terminal end 1g. The connection point 5a in FIG. 1 is the center point of the lower side of the loop element 5, but may be an arbitrary position on the lower side and may be an intersection of the left side or the right side and the lower side of the loop element 5 (see FIGS. 2 and 3). ).

  The antenna element 2 may be extended in the left direction (second direction) starting from the terminal end 1g and starting from the terminal end 2g. The film may be stretched in the right direction (that is, 180 ° opposite to the second direction). When the window glass 12 is attached to the vehicle body opening, the extending direction (second direction) of the antenna element 2 is parallel or substantially parallel to the horizontal direction. This is preferable in terms of points.

  The conductor length x2 of the antenna element 2 is a virtual length having the conductor length x1 of the antenna element 1, the conductor length x2 of the antenna element 2, the conductor length x6 of the connection element 6, and the connection point 5a and the connection point 5b. The total length of the length of the first direction component of the straight line segment (Ly in the case of FIG. 1) and the length of the second direction component of the virtual line segment (zero in the case of FIG. 1) Thus, it is preferably 75% or less (particularly 50% or less) from the viewpoint of improving the antenna gain.

In the present invention, the air in the desired first wavelength in the air at the center frequency of the broadcasting frequency band and lambda _01, the first center frequency of a desired second broadcasting frequency band higher than the broadcasting frequency band The inner wavelength is called λ ₀₂ , the glass wavelength shortening rate is called k (where k = 0.64), λ _g1 = λ ₀₁ · k, and λ _g2 = λ ₀₂ · k, the total length (x1 + x2 + x6 + Ly) Is preferably 0.25 · λ _{g1 to} 0.41 · λ _g1 , particularly 0.27 · λ _{g1 to} 0.39 · λ _g1 in terms of improvement in antenna gain. Of the antenna (Lx × 2 + Ly × 2) is 0.92 · λ _{g2 to} 1.23 · λ _g2 , particularly 0.98 · λ _{g2 to} 1.17 · λ _g2 , thereby improving the antenna gain. This is preferable.

  That is, the total length (x1 + x2 + x6 + Ly) is set based on the length that resonates in the band 3, and the circumference of the loop (Lx × 2 + Ly × 2) is set based on the length that resonates in the L band.

For example, when band 3 (174 to 240 MHz) is set as the first broadcast frequency band, the center frequency is 207 MHz, λ _g1 at 207 MHz is 927.5 mm, and L is set as the second broadcast frequency band. When a band (1452-1492 MHz) is set, the center frequency is 1472 MHz, and λ _g2 at 1472 MHz is 130.4 mm.

  Therefore, specifically, the total length (x1 + x2 + x6 + Ly) is preferably 230 to 380 mm (especially 250 to 360 mm) from the viewpoint of improving the antenna gain in the band 3, and the circumference of the loop of the loop element 5 (Lx (X2 + Lyx2) is preferably 120 to 160 mm (particularly 128 to 152 mm) from the viewpoint of improving the antenna gain in the L band. When the shape of the loop element 5 is a square, one side corresponds to 30 to 40 mm (particularly, 32 to 38 mm).

  The relationship between the maximum horizontal width Lx in the horizontal direction of the loop shape of the loop element 5 and the maximum vertical width Ly in the vertical direction orthogonal to the horizontal direction is Lx / Ly = 0.17 to 6.00 (particularly 0.27). ˜3.67) is preferable from the viewpoint of improving the antenna gain in the L band. Specifically, Lx: 10 mm / Ly: 60 mm to Lx: 60 mm / Ly: 10 mm (particularly Lx: 15 mm / Ly: 55 mm to Lx: 55 mm / Ly: 15 mm) This is preferable in terms of gain improvement.

  For example, when the shape of the loop element 5 is a rectangle, the maximum vertical width Ly and the maximum horizontal width Lx correspond to the lengths of the short side and the long side of the rectangle. In the case of FIG. 1, since the shape of the loop element 5 is a square, Lx / Ly = 1.

Further, in the present invention, there is a desired first broadcast frequency band and a desired second broadcast frequency band having a higher band than the first broadcast frequency band, and in the air at the center frequency of the first broadcast frequency band. Λ ₀₁ , glass wavelength shortening rate k (where k = 0.64), and λ _g1 = λ ₀₁ · k, the conductor length x6 of the connecting element 6 is 0.16 · λ _G1 or less, particularly 0.083 · _λg1 or less is preferable from the viewpoint of improving the antenna gain of band 3. Specifically, the conductor length x6 is preferably 141 mm or less, particularly 77 mm or less, from the viewpoint of improving the antenna gain of the band 3.

Further, it is preferable that the conductor length x6 of the connection element 6 is 0.011 · λ _g1 or less, particularly 0.005 · λ _g1 or less from the viewpoint of improving the antenna gain of the band 3 near 200 MHz. Specifically, the conductor length x6 is preferably 10 mm or less, particularly 5 mm or less from the viewpoint of improving the antenna gain.

  FIG. 4 shows an example in which the glass antenna according to the present invention is arranged on the window glass 12. Four glass antennas are disposed in the upper left region, upper right region, lower left region, and lower right region of the window glass 12, respectively. 15a is a vehicle body opening edge on the vehicle body upper side, 15b is a vehicle body opening edge on the vehicle body right side, 15c is a vehicle body opening edge on the vehicle body lower side, and 15d is a vehicle body opening edge on the vehicle body left side. In FIG. 4, when the window glass 12 is a rear glass, a defogger (not shown) is formed in the central region. However, the present invention is not limited to this, and may be provided in at least one of the four regions. Moreover, you may provide in the center upper area | region, the center lower area | region, the center left area | region, and the center right area | region instead of the left side and the right side.

  Further, in the present invention, when the glass antenna in the upper right region is disposed in a state as shown in FIG. 4, the shape of the glass antenna in the upper right region is symmetrical with the shape of the glass antenna in the upper left region in FIG. 4. A glass antenna may be provided in the state illustrated. The same applies to the lower region.

  When a plurality of glass antennas are installed as described above, diversity reception is achieved and reception characteristics are improved, which is preferable.

  The glass antenna described above is not provided with an auxiliary antenna conductor. However, the present invention is not limited to this, and for impedance matching, phase adjustment, directivity adjustment, etc., an auxiliary element such as a substantially T-shape, a substantially L-shape, a loop shape, etc. with or without a connecting conductor on the antenna element. An antenna element may be attached.

  Further, a conductor layer made of an antenna conductor may be provided inside or on the surface of the synthetic resin film, and the synthetic resin film with a conductor layer may be formed on the vehicle inner surface or vehicle outer surface of the window glass plate to form a glass antenna. Furthermore, it is good also as a glass antenna by forming the flexible circuit board in which the antenna conductor was formed in the vehicle inner surface or vehicle outer surface of a window glass board.

  The attachment angle of the window glass plate to the vehicle is preferably 15 to 90 °, particularly 30 to 90 ° with respect to the horizontal direction.

  The antenna conductor is formed by printing and baking a paste containing a conductive metal such as a silver paste on the inner surface of the window glass plate. However, the present invention is not limited to this method, and a linear body or a foil-like body made of a conductive material such as copper may be formed on the vehicle side surface or the vehicle outer surface of the window glass plate and adhered to the window glass. You may form with an agent etc. and may provide in the inside of window glass itself. The same applies to the power feeding unit 18.

  Further, a concealing film may be formed on the surface of the window glass, and a part or the whole of the antenna conductor may be provided on the concealing film. The concealing film may be a ceramic such as a black ceramic film. In this case, when viewed from the outside of the window glass, the portion of the antenna conductor provided on the masking film by the masking film becomes invisible from the outside of the vehicle, and the window glass has an excellent design. In the configuration shown in the drawing, at least a part of the feeding portion and the antenna conductor is formed on the concealing film, so that only a thin straight portion of the conductor is seen in the vehicle exterior view, which is preferable in terms of design.

  FIG. 5 (inside view or outside view) is an embodiment in which the glass antenna according to the present invention is provided on the rear glass 12, and shows an upper right side region of the rear glass 12. The rear glass 12 is provided with a plurality of heater wires and a plurality of bus bars (only one is shown in FIG. 5) for supplying power to the plurality of heater wires, and the plurality of heater wires and the plurality of bus bars are provided. The defogger 30 is configured as described above. In FIG. 5, 30a is the highest heater wire, and 30b is a bus bar. Reference numeral 40 denotes an example of a glass antenna for receiving digital television broadcasts arranged in the upper margin area of the defogger 30. Reference numeral 20 denotes an example of an AM broadcast receiving glass antenna disposed in the upper margin area of the defogger 30. Reference numeral 20 a denotes the lowest antenna element of the AM glass antenna 20. When the glass antenna according to the present invention is arranged so that the antenna element 2 extends in a blank area between the antenna element 20a and the heater wire 30a, it is preferable in terms of improving the antenna gain.

  That is, in the present invention, the vehicle window glass 12 has an independent conductor (in the case of FIG. 5, AM glass) that is not DC-connected to the antenna conductor including the loop element 5, the antenna elements 1 and 2, and the connection element 6. It is preferable that the antenna 20) is provided in the blank area on the peripheral side of the vehicle window glass from the antenna element 2 in terms of improving the L band antenna gain. Further, an energization heating type defogger (in the case of FIG. 5, defogger 30) having a plurality of heater wires and a bus bar for supplying power to the heater wires is provided, and the antenna element 2 is disposed in a blank area between the independent conductor and the defogger. It is more preferable that it is stretched.

In this case, there are a desired first broadcast frequency band and a desired second broadcast frequency band having a higher band than the first broadcast frequency band, and the wavelength in the air at the center frequency of the second broadcast frequency band is λ. ₀₂ , the glass wavelength shortening rate is k (where k = 0.64), and when λ _g2 = λ ₀₂ · k, the second directional component in the same horizontal plane between the antenna conductor and the independent conductor Is preferably 0.008 · λ _{g2 to} 0.39 · λ _g2 , particularly 0.008 · λ _{g2 to} 0.23 · λ _{g2 from} the viewpoint of improving the antenna gain. Specifically, the minimum value of the second direction component in the distance between the antenna conductor and the independent conductor on the same horizontal plane is preferably 1 mm to 50 mm, particularly 1 mm to 30 mm from the viewpoint of improving the antenna gain.

  The independent conductors run in parallel in the second direction and are electrically connected to a second power feeding unit (not shown in FIG. 5, for example, the power feeding unit provided at the left end of the AM glass antenna 20) different from the power feeding unit 18. When a plurality of linear conductors connected to each other are provided, it is preferable in that it can be used for reception of a frequency band of AM broadcasting. Further, the adjacent line conductors of the plurality of line conductors may have at least one short-circuit portion connected by a short-circuit line starting from the tip of at least one antenna conductor side of the adjacent line conductors. Good.

In that case, there are a desired first broadcast frequency band and a desired second broadcast frequency band having a higher band than the first broadcast frequency band, and the wavelength in the air at the center frequency of the second broadcast frequency band is λ. ₀₂ , the glass wavelength shortening rate is k (where k = 0.64), and when λ _g2 = λ ₀₂ · k, the independent conductor is the tip of the plurality of filament conductors on the antenna conductor side. The length of the first directional component of the short-circuit wire connected to the peripheral edge of the window glass for the vehicle is 0 to 0.19 · λ _g2 to improve the antenna gain of band III Is preferable. In particular, it is preferable that the 0~0.15 · λ _g2. Specifically, the independent conductor is the length of the first directional component of the short-circuit line connected to the peripheral edge of the vehicle window glass, of the plurality of linear conductors on the antenna conductor side. Is preferably 0 to 25 mm, and particularly preferably 0 to 20 mm, in terms of improving the band III antenna gain.

  Furthermore, in the present invention, there is at least one open end that is not connected by a short-circuit wire between at least one tip portion on the antenna conductor side of adjacent line conductors of the plurality of line conductors and a pair of line conductors. The total sum of the distances of the first direction component at the open end is 30 with respect to the distance of the first direction component between the highest level and the lowest level among the tip portions on the antenna conductor side of the plurality of line conductors. % Or more is preferable from the viewpoint of improving the antenna gain of band III. In particular, 60% or more is preferable.

  In the present invention, the independent conductor includes a plurality of linear conductors that run in parallel in the second direction, and the tip ends of the adjacent linear conductors of the plurality of linear conductors are connected in a direct current manner. It is preferable from the viewpoint of improving the antenna gain that it is not performed, that is, all are open (open end).

[Example 1]
With respect to the high-frequency glass antenna for an automobile manufactured by attaching the form of the glass antenna 100 shown in FIG. 1 to the upper right side of the rear glass of the actual vehicle, the glass antenna 100 is obtained by changing the circumference of the loop of the loop element 5. The antenna gain of the entire vehicle circumference was measured, and the average antenna gain was calculated.

The dimensions of each part of the glass antenna 100 shown in FIG.
x1: 78 mm
x2: 164mm
x6: 2 mm
And The conductor width of each antenna element of the glass antenna 100 is 0.8 mm.

  The antenna gain was measured by radiating radio waves to a vehicle mounted with the window glass inclined 15 ° with respect to the horizontal direction, and rotating the vehicle 360 ° every angle of 2 °. The radio wave was vertically polarized, and the frequency was changed every 10 MHz in the respective ranges of the band 3 and the L band. The elevation angle between the radio wave transmission position and the antenna conductor was measured in the horizontal direction (when the plane parallel to the ground is elevation angle = 0 ° and the zenith direction is elevation angle = 90 °, the elevation angle = 0 °). The antenna gain was standardized so that the half-wave dipole antenna was 0 dB with reference to the half-wave dipole antenna (both band III and L band).

  FIG. 6 is actual measurement data indicating the average value of the antenna gain acquired in the above-mentioned direction when the loop length of the loop element 5 is changed. In FIG. 6, the antenna gain on the vertical axis indicates the average value of the antenna gain for every 10 MHz at 170 to 240 MHz as the frequency corresponding to the band 3, and the antenna gain for every 10 MHz at 1450 to 1490 MHz as the frequency corresponding to the L band. The average value is shown.

As shown in FIG. 6, the antenna gain increases as the circumference of the loop is increased, and becomes maximum when the circumference of the loop is 140 mm. Therefore, it can be seen that an excellent antenna gain can be obtained by setting the circumference of the loop to 120 mm to 160 mm (particularly, 128 to 152 mm).
[Example 2]
Subsequently, with respect to the high-frequency glass antenna for an automobile manufactured by attaching the form of the glass antenna 100 shown in FIG. The antenna gain of the entire circumference of the glass antenna 100 was measured by changing the position of the direction, and the average antenna gain was calculated.

The dimensions of each part of the glass antenna 100 shown in FIG.
Full length (x1 + x2 + x6 + Ly): 279mm
x2: 164mm
Lx: 35 mm
Ly: 35 mm
And The conductor width of each antenna element of the glass antenna 100 is 0.8 mm. The antenna gain is measured in the same manner as in Example 1.

  FIG. 7 is actual measurement data indicating the average value of the antenna gain acquired in the above-described direction when x6 is changed. In FIG. 7, the antenna gain on the vertical axis indicates the average value of the antenna gain for every 10 MHz at 170 to 240 MHz as the frequency corresponding to the band 3, and the antenna gain for every 10 MHz at 1450 to 1490 MHz as the frequency corresponding to the L band. The average value is shown.

  As shown in FIG. 7, it can be seen that the antenna gain increases as x6 is decreased, and the antenna gain increases as x6 becomes smaller than around 140 mm. That is, it can be seen that an excellent antenna gain can be obtained particularly in the band 3 by shortening the connection element 6 (by bringing the loop element 5 closer to the power feeding unit 18).

  FIG. 8 shows the frequency characteristics of the antenna gain of the glass antenna 100 when x6 is 2.0 mm and 10.8 mm. In FIG. 8, the antenna gain on the vertical axis indicates the average value of the antenna gain for every 10 MHz at 170 to 240 MHz as the frequency corresponding to the band 3, and the antenna gain for every 10 MHz at 1450 to 1490 MHz as the frequency corresponding to the L band. The average value is shown.

In the result of FIG. 7, 2.0 mm and 10.8 mm showed a high antenna gain as an average value. However, as shown in FIG. 8, the antenna gain when x6 is 2.0 mm is 10.8 mm. Compared to the antenna gain, the antenna gain is improved at a specific frequency (around 200 MHz). Therefore, it can be seen that by setting the connection element 6 to 10 mm or less, an excellent antenna gain can be obtained over the entire frequency band of the band 3. Since the antenna characteristics in the L band were not substantially changed, the graph is omitted.
[Example 3]
Subsequently, the high frequency for an automobile produced by attaching the forms of the glass antennas 100, 200, and 300 shown in FIGS. For the glass antenna, the antenna gain of the entire circumference of each vehicle was measured, and the average antenna gain was calculated.

The dimensions of each part of the glass antenna 100, 200, 300 at this time are as follows:
x1: 78 mm
x2: 164mm
x6: 2 mm
Lx: 35 mm
Ly: 35 mm
And The conductor width of each antenna element of the glass antenna 100 is 0.8 mm. The antenna gain is measured in the same manner as in Example 1.

FIG. 10 shows the frequency characteristics (band 3) of the antenna gain when the arrangement of the loop elements 5 is changed, and FIG. 11 shows the frequency characteristics of the antenna gain when the arrangement of the loop elements 5 is changed (band 3). L band). As shown in FIGS. 10 and 11, even if the arrangement direction of the loop element 5 is changed, equivalent antenna characteristics can be obtained.
[Example 4]
Then, the high frequency glass antenna for motor vehicles was produced by attaching to the actual rear glass the pattern which the antenna element 2 extended | stretched in the blank area | region between AM glass antennas and a defogger.

FIG. 12 is a pattern diagram when the AM glass antenna 20A, which is the basic shape of the AM glass antenna, is arranged. The basic dimensions of each part of the AM glass antenna 20A are as follows:
w1: 375 mm
w2: 335mm
w3-w7: 20mm
w8: 40 mm
w9: 20 mm
w10: 10 mm
w11: 1070 mm
w12: 150mm
And w1 is an intermediate short-circuit wire 28 that short-circuits the plurality of line conductors 21 to 26 near the center of each line conductor and a plurality of line conductors 21 to 26 on the left ends of the respective line conductors (on the opposite side to the glass antenna 100) Is the distance in the vehicle width direction with the left short-circuit line 27 that short-circuits the front end portions of each other. w2 is a distance in the vehicle width direction between the intermediate short-circuit line 28 and the right short-circuit line 29 that short-circuits the right end portions of each of the line conductors 21 to 26. w3 to w7 are distances between the respective line conductors. w8 is the distance between the lowest line conductor 26 of the AM glass antenna 20A and the highest heater line 30a among the heater wires between the bus bars 30b and 30c of the defogger 30. w9 is the distance between the line conductor 26 and the antenna element 2. w10 is the shortest distance in the vehicle width direction between the glass antenna 100 and the AM glass antenna 20A (in the case of FIG. 12, the distance between the right short-circuit line 29 and the left side portion 5e of the loop element 5). w11 is the length of the heater wire 30a. w12 is the distance between the upper edge 15a of the vehicle body opening and the heater wire 30a. Note that the conductor width of each antenna element and the short-circuit wire of the AM glass antenna 20A is 0.8 mm.

  Further, as other shapes of the AM glass antenna, a high frequency glass antenna for automobile in the case of the AM glass antenna 20B shown in FIG. 13 and a high frequency glass antenna for automobile in the case of the AM glass antenna 20C shown in FIG. .

  The AM glass antenna 20B is not connected to the right end portions of the line conductors 21 to 26 (that is, by deleting the right short-circuit line 29 in FIG. 12), so that the vehicle width relative to the glass antenna 100 is reduced. Open ends 41 to 45 that are open in the direction are formed. In the pattern of FIG. 13, the dimensions and the left half form are omitted, but are the same as the pattern of FIG.

  The AM glass antenna 20 </ b> C is formed with two open ends 42 and 44 that open to the glass antenna 100 in the vehicle width direction. That is, the short-circuited portion 29b for short-circuiting the line conductors 22 and 23 and the short-circuited portion 29d for short-circuiting the line conductors 24 and 25 were slid from the right end to the center side in the vehicle width direction of the AM glass antenna 20C. By arranging them at positions, a meander shape is formed at the right end of the AM glass antenna 20C. In the pattern of FIG. 14, the dimensions and the left half form are omitted, but are the same as the pattern of FIG. In the case of the pattern of FIG. 14, the sum of the vertical lengths of the right short-circuited wires 29 a, 29 c, 29 e connecting the right end portions is the right end portion of the highest line conductor 21 and the lowest line conductor. This corresponds to 60% (= (3/5) × 100 [%]) with respect to the distance in the vertical direction between the right end portion of 26 (in other words, the total length of the right short-circuit line 29 in FIG. 12). In the case of the pattern of FIG. 13, this corresponds to 0%. In this case, the total length of the open ends corresponds to 40% with respect to the distance in the vertical direction between the right end of the highest line conductor 21 and the right end of the lowest line conductor 26. To do.

  Next, with respect to the high frequency glass antenna for an automobile manufactured by attaching the patterns of FIGS. 12, 13 and 14 having different forms of the AM glass antenna to the actual rear glass, the antenna gain of the entire circumference of each vehicle is measured and averaged. Antenna gain was calculated. The antenna gain is measured in the same manner as in Example 1.

FIG. 15 is actual measurement data showing the average value of the antenna gain of the glass antenna 100 according to the form of the AM glass antenna. “Open” is the pattern shown in FIG. 13, “Short” is the pattern shown in FIG. 12, “Meander” is the pattern shown in FIG. 14, and “Without-AM” is the case where the AM glass antenna itself is not provided. Indicates. As shown in FIG. 15, when an AM glass antenna corresponding to a parasitic conductor with respect to the glass antenna 100 is provided on the upper side of the antenna element 2 and on the left side of the antenna element 1, the antenna gain in the band 3 is kept high. The antenna gain in the L band is improved. Among these patterns, in order to improve the antenna gain of the glass antenna 100, a pattern in which at least a part of the right short-circuit line at the right end of the AM glass antenna is an open end (open) is preferable (pattern of FIG. 14). In particular, it is preferable that the right end portion is all open (pattern in FIG. 13).
[Example 5]
Subsequently, the antenna gain of the entire circumference of the glass antenna 100 is measured by changing the shortest distance w2 between the AM glass antenna and the glass antenna 100 for the patterns of FIGS. The average antenna gain was calculated. At this time, when the AM glass antenna itself was not provided, the antenna gain of “Without-AM” was calculated to be 0 dB with reference to the antenna gain of “Without-AM”.

  FIG. 16 is actual measurement data showing an average value of the antenna gain of the glass antenna 100 having the pattern of FIG. 13 when the shortest distance w10 is changed. FIG. 17 is actual measurement data showing the average value of the antenna gain of the glass antenna 100 having the pattern shown in FIG. 14 when the shortest distance w10 is changed. 16 and 17, the vertical axis antenna gain is the average value of the antenna gain for every 10 MHz at 170 to 240 MHz as the frequency corresponding to the band 3, and the frequency for the 10 MHz at 1450 to 1490 MHz as the frequency corresponding to the L band. The average value of the antenna gain is shown.

As shown in FIGS. 16 and 17, the antenna gain increases as the shortest distance w10 increases in both the pattern of FIG. 13 and the pattern of FIG. In particular, as shown in FIG. 17, in the case of the pattern of FIG. 14, the antenna gain in the L band increases significantly as the shortest distance w10 is increased. Therefore, when the AM glass antenna is provided, an excellent antenna gain can be obtained by setting the shortest distance in the vehicle width direction between the AM glass antenna and the glass antenna 100 to 10 mm or more (particularly, 20 mm or more).
[Example 6]
Subsequently, the length Hb of the right short-circuit line 29 of the AM glass antenna 20A in FIG. 12 was changed, and the antenna gain of the entire circumference of the vehicle of the glass antenna 100 was measured, and the average antenna gain was calculated in the same manner as in Example 5. In this case, without changing the position or length of the line conductors 21 to 26, the opening of the opening provided in the right end of the AM glass antenna 20A is gradually widened from the upper side (right-side short circuit). The length Hb of the right short-circuit line 29 is changed by gradually cutting away the line 29 from above.

  FIG. 18 is actual measurement data showing an average value of the antenna gain of the glass antenna 100 when the length Hb of the right short-circuit wire 29 is changed. In FIG. 18, the antenna gain on the vertical axis represents the average value of the antenna gain for every 10 MHz at 170 to 240 MHz as the frequency corresponding to the band 3, and the antenna gain for every 10 MHz at 1450 to 1490 MHz as the frequency corresponding to the L band. The average value is shown. Further, when the length Hb is 100 mm, the shape of the pattern of the AM glass antenna 20A in FIG. 12 is shown, and when the length Hb is 0 mm, the shape of the pattern of the AM glass antenna 20B in FIG. 13 is shown.

  As shown in FIG. 18, as the right short circuit line 29 is gradually cut from the upper side and the length Hb is shortened, the antenna gain in the band 3 is increased while the antenna gain in the L band is kept high. It has improved. Therefore, when the AM glass antenna is provided, the total length Hb of the lengths of the first direction components of the short-circuit wires connecting the tip portions of the line conductors 21 to 26 is the right side of the highest level line conductor 21. An excellent antenna gain can be obtained by setting it to 70% or less with respect to the length H of the vertical component between the tip and the right tip of the lowest line conductor 26. In other words, the front edge of the opening end provided at the right end of the AM glass antenna 20A has a vertical component between the right end of the highest line conductor 21 and the right end of the lowest line conductor 26. By setting the length H to 30% or more (particularly, 60% or more), an excellent antenna gain can be obtained.

  FIG. 19 is actual measurement data showing the average value of the antenna gain of the entire circumference of the glass antenna 100 according to the difference in the length Hb of the right short-circuit wire 29 and the arrangement location thereof. The calculation of the antenna gain is the same method as in Example 5. “Short circuit 20 mm from upper end” connects only the line conductor 21 and the line conductor 22 close to the upper edge 15a of the vehicle body opening with the right short line 29, and the line conductors 22 to 26 are open ends. This is the case. “Opening 20 mm from upper end” opens only the line conductor 21 and the line conductor 22 close to the upper edge 15 a of the vehicle body opening, and the line conductors 22 to 26 are connected to each other by the right short-circuit line 29. This is the case.

  As shown in FIG. 19, when the line conductor 21 close to the upper edge 15 a of the vehicle body opening is connected to the right short-circuit line 29, the band 3 even if the line conductors 22 to 26 are open ends. It turns out that gets worse. On the other hand, even if the line conductors 22 to 26 are connected to the right short-circuit line 29 by the line conductor 21 and the line conductor 22 being open ends, the band 3 is improved. That is, when the wire conductor 21 close to the upper edge 15a of the vehicle body opening is connected to the right short-circuit wire 29, it is preferable to shorten the length of the right short-circuit wire 29.

Therefore, there is a desired first broadcast frequency band and a desired second broadcast frequency band having a higher band than the first broadcast frequency band, and the wavelength in the air at the center frequency of the second broadcast frequency band is λ _02. When the glass wavelength shortening rate is k (where k = 0.64) and λ _g2 = λ ₀₂ · k, it is connected to the line conductor 21 close to the upper edge 15a of the vehicle body opening. the length of the first direction component of the short-circuit line which is, on the basis of FIG. 19, 0~0.19 · λ _g2, it particularly is 0 to 0.15 · lambda _g2, in terms of improved antenna gain preferable. Specifically, the length of the short-circuit line is preferably 0 mm to 25 mm, particularly 0 mm to 20 mm, from the viewpoint of improving the antenna gain.

It is a top view of the glass antenna 100 for vehicles which is one Embodiment of this invention. It is a top view of the glass antenna 200 for vehicles which is one Embodiment of this invention. It is a top view of the glass antenna 300 for vehicles which is one Embodiment of this invention. It is the 1st example of arrangement to the window glass of the glass antenna for vehicles. It is a 2nd example of arrangement | positioning to the window glass of the glass antenna for vehicles. It is actual measurement data which shows the average value of an antenna gain when changing the circumference of the loop of the loop element 5. It is actual measurement data which shows the average value of an antenna gain when x6 is changed. It is a frequency characteristic of the antenna gain of the glass antenna 100 when x6 is 2.0 mm and 10.8 mm. It is a frequency characteristic (band 3) of the antenna gain when the arrangement of the loop elements 5 is changed. It is a frequency characteristic (L band) of the antenna gain when the arrangement of the loop elements 5 is changed. It is a top view of the glass antenna 400 for vehicles which is one Embodiment of this invention. It is a pattern figure at the time of arrange | positioning AM glass antenna 20A which is the basic shape of AM glass antenna. It is a pattern figure at the time of arrange | positioning AM glass antenna 20B. It is a pattern figure at the time of arrange | positioning AM glass antenna 20C. It is actual measurement data which shows the average value of the antenna gain of the glass antenna 100 according to the form of AM glass antenna. It is actual measurement data which shows the average value of the antenna gain of the glass antenna 100 of the pattern of FIG. 13 when changing the shortest distance w10. 15 is actual measurement data showing an average value of antenna gains of the glass antenna 100 having the pattern of FIG. 14 when the shortest distance w10 is changed. It is actual measurement data which shows the average value of the antenna gain of the glass antenna 100 when changing the length Hb of the right side short circuit wire 29. FIG. It is actual measurement data which shows the average value of the antenna gain of the glass antenna 100 by the difference in the length Hb of the right side short circuit wire 29, and its arrangement location.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Antenna element 5 Loop element 5e Left side part 6 Connection element 12 Window glass board 15 Car body opening edge of window 18 Feeding part 20, 20A, 20B, 20C AM antenna 21-26 Wire conductor (AM antenna element)
27 Short-circuited left side 28 Intermediate short-circuited line 29 Short-circuited right side 30 Defogger 40 Antenna for digital television broadcasting 41 to 45 Opening 100, 200, 300 Glass antenna

Claims (19)

A glass antenna for a vehicle in which an antenna conductor and a power feeding portion are provided on a vehicle window glass,
The antenna conductor is
A loop element formed in a loop shape;
A first antenna element extending in a first direction starting from a first point on the loop element, and a substantially right angle to the first direction starting from a terminal end of the extension of the first antenna element An L-shaped element configured in an L-shape from a second antenna element extending in a second direction, which is a different direction;
A connection element that connects the power supply unit and a second point on the loop element;
Equipped with a,
There is a desired first broadcast frequency band and a desired second broadcast frequency band having a higher band than the first broadcast frequency band. A wavelength in the air at the center frequency of the first broadcast frequency band is λ _01. The wavelength in the air at the center frequency of the second broadcast frequency band is referred to as λ ₀₂ , the glass wavelength shortening rate is referred to as k (where k = 0.64), λ _g1 = λ ₀₁ · k, When λ _g2 = λ ₀₂ · k,
The loop element has a loop circumference of 0.92 · λ _{g2 to} 1.23 · λ _g2 ,
An imaginary line segment having both ends of the conductor length of the first antenna element, the conductor length of the second antenna element, the conductor length of the connection element, and the first point and the second point. the length of the first direction component, the total length was total and the length of the second direction component of the virtual line segment is a _{0.25 · λ g1 ~0.41 · λ g1} , and characterized in that A glass antenna for a vehicle. A glass antenna for a vehicle in which an antenna conductor and a power feeding portion are provided on a vehicle window glass,
The antenna conductor is
A loop element formed in a loop shape;
A first antenna element extending in a first direction starting from a first point on the loop element, and a substantially right angle to the first direction starting from a terminal end of the extension of the first antenna element An L-shaped element configured in an L-shape from a second antenna element extending in a second direction, which is a different direction;
A connection element that connects the power supply unit and a second point on the loop element;
Equipped with a,
The loop element has a loop circumference of 120 to 160 mm,
An imaginary line segment having both ends of the conductor length of the first antenna element, the conductor length of the second antenna element, the conductor length of the connection element, and the first point and the second point. The glass antenna for vehicles , wherein the total length of the length of the first direction component and the length of the second direction component of the imaginary line segment is 230 to 380 mm . The glass antenna for a vehicle according to claim 1 , wherein the loop element has a loop circumference of 120 to 160 mm. An imaginary line segment having both ends of the conductor length of the first antenna element, the conductor length of the second antenna element, the conductor length of the connection element, and the first point and the second point. wherein a length of the first direction component, the total length was total and the length of the second direction component of the virtual line segment is a 230～380Mm, glass antenna according to claim 1. There is a desired first broadcast frequency band and a desired second broadcast frequency band having a higher band than the first broadcast frequency band. A wavelength in the air at the center frequency of the first broadcast frequency band is λ _01. When the glass wavelength shortening rate is k (where k = 0.64) and λ _g1 = λ ₀₁ · k,
The glass antenna for vehicles according to any one of claims 1 to 4 whose conductor length of said connection element is 0.16 * lambda _g1 or less. The glass antenna for vehicles according to any one of claims 1 to 5 whose conductor length of said connecting element is 141 mm or less. The conductor length of the second antenna element is
An imaginary line segment having both ends of the conductor length of the first antenna element, the conductor length of the second antenna element, the conductor length of the connection element, and the first point and the second point. the length of the first direction component, the relative overall length of the sum and the length of the second direction component of the virtual line segment is 75% or less, according to any one of claims 1 to 6 Vehicle glass antenna. The glass antenna for a vehicle according to any one of claims 1 to 7 , wherein the loop element has a quadrilateral loop shape and each side is 30 to 40 mm. 2. The vehicle window glass is provided with an independent conductor that is not DC-connected to the antenna conductor in a blank area on a peripheral edge side of the vehicle window glass from the second antenna element. The glass antenna for vehicles as described in any one of Claims 8 . There is a desired first broadcast frequency band and a desired second broadcast frequency band having a higher band than the first broadcast frequency band. A wavelength in the air at the center frequency of the second broadcast frequency band is λ _02. When the glass wavelength shortening rate is k (where k = 0.64) and λ _g2 = λ ₀₂ · k,
10. The vehicle according to claim 9 , wherein a minimum value of the second direction component in a distance between the antenna conductor and the independent conductor on the same horizontal plane is 0.008 · λ _{g2 to} 0.39 · λ _g2 . Glass antenna. The glass antenna for vehicles according to claim 9 or 10 whose minimum value of said 2nd direction ingredient in the interval in the same level surface of said antenna conductor and said independent conductor is 1 mm-50 mm. The independent conductor includes a plurality of linear conductors running in parallel in the second direction,
The adjacent linear conductors of the plurality of linear conductors have at least one short-circuit portion connected by a short-circuit line starting from at least one end of the adjacent linear conductor on the antenna conductor side. The glass antenna for vehicles as described in any one of 9 to 11 . There is a desired first broadcast frequency band and a desired second broadcast frequency band having a higher band than the first broadcast frequency band. A wavelength in the air at the center frequency of the second broadcast frequency band is λ _02. When the glass wavelength shortening rate is k (where k = 0.64) and λ _g2 = λ ₀₂ · k,
The independent conductor includes a plurality of linear conductors running in parallel in the second direction,
The length of the first directional component of the short-circuit line connected to the distal end portion closest to the peripheral portion of the vehicle window glass among the distal end portions on the antenna conductor side of the plurality of linear conductors is 0 to The glass antenna for vehicles according to claim 12 which is 0.19 * lambda _g2 . The length of the first directional component of the short-circuit line connected to the distal end portion closest to the peripheral portion of the vehicle window glass among the distal end portions on the antenna conductor side of the plurality of linear conductors is 0 to The glass antenna for vehicles according to claim 12 or 13 which is 25 mm. Having at least one open end that is not connected by the short-circuit wire between at least one tip of the adjacent line conductor of the plurality of line conductors on the antenna conductor side and a pair of line conductors;
The distance of the first directional component of the open end with respect to the distance of the first directional component between the highest and lowest positions of the plurality of filament conductors on the antenna conductor side. The glass antenna for vehicles according to claim 13 or 14 whose sum total is 30% or more. The independent conductor includes a plurality of linear conductors running in parallel in the second direction,
The glass antenna for a vehicle according to any one of claims 9 to 11 , wherein tip portions on the antenna conductor side of adjacent line conductors of the plurality of line conductors are not connected in a direct current manner. The vehicle glass antenna according to any one of claims 1 to 16 , wherein the second direction is a horizontal or substantially horizontal direction when the vehicle window glass is attached to the vehicle. The connecting element, the first direction and extends in a direction opposite to the second starting point points, a vehicle glass antenna according to any one of claims 1 to 17. The vehicle window glass provided with the glass antenna for vehicles as described in any one of Claim 1 to 18 .

Images