JP2018186582A - Antenna device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wide-band antenna device that can be used in a wide frequency range.SOLUTION: An antenna device comprises: a wide-band antenna 10 based on a bow tie antenna that has a first plate-like metal 20 and a second plate-like metal extending in mutually opposite directions on both sides of a power feeding point; and a patch antenna 50 provided at a second portion folded substantially at a right angle from a first portion 21 at the power feeding point side of the first plate-like metal 20. The second portion also serves as a ground plate for the patch antenna 50. The portion including the patch antenna 50 is housed in a radome 60.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an antenna device including a broadband antenna based on a bowtie antenna.

  In recent years, it has been demanded to install a wideband antenna for telematics (hereinafter “TEL”) and an antenna for global navigation satellite system (hereinafter “GNSS”) in a vehicle. .

JP, 2011-193432, A The patent documents 1 are illustrations of a bow tie antenna, and show the composition which aimed at size reduction.

  When the TEL antenna and the GNSS antenna are combined, there has been a problem that it is difficult to control the bandwidth of the TEL antenna and the directivity gain. In addition, studies on improving the broadband characteristics of the TEL antenna have been insufficient.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a broadband antenna device that can be used in a wide frequency range.

The first aspect of the present invention is an antenna device. The antenna device includes a broadband antenna based on a bow tie antenna having a first conductor element and a second conductor element extending in opposite directions with respect to a feeding point,
A broadband antenna circuit board is interposed between the broadband antenna and a coaxial cable that feeds the broadband antenna, and a ground of the broadband antenna circuit board is overlapped and connected to the first or second conductor element. Integrated.

A second aspect of the present invention is an antenna device. The antenna device includes a broadband antenna based on a bow tie antenna having a first conductor element and a second conductor element extending in opposite directions with respect to a feeding point,
The first conductor element and the second conductor element have different shapes and are asymmetrically arranged with respect to the feeding point.

In the first or second aspect, when the three orthogonal axes are the X axis, the Y axis, and the Z axis, respectively,
The first conductor element has a portion extending in the + Z direction from the feeding point and substantially parallel to the XZ plane, and the second conductor element extends in the −Z direction from the feeding point and substantially parallel to the XZ plane. Have
One or both of the first conductor element and the second conductor element is a first portion close to the feeding point;
It is good to have a 2nd part extended from the 1st part so that it may have a field which is not parallel to the 1st part.

  At least one of the first and second conductor elements may have a curved outline that protrudes toward the feeding point so that an opposing space area between the first and second conductor elements is narrowed.

A third aspect of the present invention is an antenna device. The antenna device includes a broadband antenna based on a bow tie antenna having a first conductor element and a second conductor element extending in opposite directions with respect to a feeding point,
At least one of the first and second conductor elements has a contour of a curve that protrudes toward the feeding point so that an opposing space area between the first and second conductor elements is narrowed;
Each of the first conductor element and the second conductor element is a plate metal,
When the three orthogonal axes are the X, Y, and Z axes,
The first conductor element has a portion extending in the + Z direction from the feeding point and substantially parallel to the XZ plane, and the second conductor element extends in the −Z direction from the feeding point and substantially parallel to the XZ plane. Have
One or both of the first conductor element and the second conductor element is a first portion close to the feeding point;
A second portion that is bent from the first portion and extends so as to have a region that is non-parallel to the first portion.

  The second portion may extend from the first portion so as to be substantially parallel to the XY plane or to form an angle of 90 ° or less with the first portion.

  It is good to have the 3rd part extended from the 2nd part so that it may have the field which is not parallel to the 2nd part.

  It should be noted that any combination of the above-described constituent elements, and those obtained by converting the expression of the present invention between methods and systems are also effective as aspects of the present invention.

  According to the present invention, it is possible to realize a broadband antenna device including a bowtie antenna that can be used as a TEL antenna or the like installed in a vehicle. It is also possible to provide a patch antenna that can be used as a GNSS antenna or the like in a part of a wideband antenna based on a bow tie antenna to be combined.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an antenna device according to a first embodiment of the present invention, obliquely viewed from the upper front. The perspective view of a back diagonally lower viewpoint similarly. FIG. 3 is a plan view of the first embodiment. The bottom view. The front view. The rear view. The right side view. The left side view. FIG. 3 is a rear view of the TEL antenna circuit board according to the first embodiment. The perspective view which expands and shows the part which is 1st and 2nd plate-shaped metal of the antenna for TEL in Embodiment 1, and includes a feeding point. FIG. 3 is a bottom view of the GNSS antenna circuit board according to the first embodiment. FIG. 5 is a layout diagram at the time of measurement of antenna gain and the like in the case of the first embodiment. 3 is a graph showing antenna characteristics of the TEL antenna according to Embodiment 1 and frequency characteristics of VSWR. 6 is a graph showing the frequency characteristics of the average gain (dBic) of the θ polarization (vertical polarization) at θ = 90 ° (horizontal plane), which is the antenna characteristics of the TEL antenna in the first embodiment. 3 is a graph showing antenna characteristics of a GNSS antenna that does not include a low-noise amplification unit in Embodiment 1, and shows frequency characteristics of VSWR. Similarly, the graph which shows the frequency characteristic of the axial ratio (dB) of right-handed polarized wave in theta = 0 degree. Similarly, the graph which shows the frequency characteristic of the gain (dBic) of a right-handed polarized wave in theta = 0 degree. Explanatory drawing which shows the example of the shape of the 1st and 2nd conductor element (antenna element) of a bow tie antenna, respectively. FIG. 18 is a graph showing the relationship between VSWR and parameters d / λ (where d = width of each conductor element, λ = wavelength of TEL radio wave) using shapes 1 to 3 of FIG. 17 as parameters. Explanatory drawing which shows the other example of the shape of the 1st and 2nd conductor element of a bow tie antenna, respectively. 20 is a graph showing the relationship between VSWR and d / λ using the shapes 3, 3-1 and 3-2 of FIG. 19 as parameters. The perspective view from the front diagonal upper viewpoint of Embodiment 2 of the antenna device which concerns on this invention. FIG. 6 is a perspective view of a rear oblique lower viewpoint according to the second embodiment. The front view of Embodiment 2. FIG. The rear view. FIG. The bottom view. The right side view. The left side view. The perspective view which expands and shows the part which is 1st and 2nd plate-shaped metal of the antenna for TEL in Embodiment 2, and includes a feeding point. FIG. 10 is a layout diagram at the time of measurement of antenna gain and the like in the case of the second embodiment. 6 is a graph showing the antenna characteristics of the TEL antenna according to Embodiment 2 and showing the frequency characteristics of VSWR. 10 is a graph showing the frequency characteristics of the average gain (dBic) of θ polarization (vertical polarization) at θ = 90 ° (horizontal plane), which is antenna characteristics of the TEL antenna according to the second embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or equivalent component, member, process, etc. which are shown by each drawing, and the overlapping description is abbreviate | omitted suitably. In addition, the embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

  1 to 8 show an embodiment of an antenna device according to the present invention, in which a GNSS antenna as a GNSS antenna is formed on a conductor element (antenna element) of a TEL broadband antenna 10 based on a bowtie antenna (base). The composite antenna apparatus 1 provided with the patch antenna 50 is shown. For convenience of explanation, as shown in FIGS. 1 and 11, an X axis, a Y axis, and a Z axis that are orthogonal to the composite antenna device 1 are defined. In FIG. 11, the angle between the Z axis and the observation point is θ °, and the angle between the intersection of the perpendicular line from the observation point to the XY plane and the origin of the XY plane and the origin is the azimuth angle. Let φ. Here, for convenience of explanation, the description may be made assuming that + Z direction = upward and −Z direction = downward.

  The TEL broadband antenna 10 based on the bow tie antenna includes a first plate metal 20 as a first conductor element and a second plate metal as a second conductor element extending in opposite directions with a feeding point 45 to be described later interposed therebetween. 30 and a TEL antenna circuit board 40 as a broadband antenna circuit board.

  The first plate-shaped metal 20 extends from the feeding point 45 in the + Z direction, is substantially parallel to the XZ plane, and has a first portion 21 having a shape approximating a triangle, semicircle, or semi-ellipse with the feeding point 45 as a vertex. And a second portion 22 that is bent substantially parallel to the XY plane from the first portion 21. Ribs 23 and 24 rising in the + Z direction are formed at both side positions of the second portion 22 that are separated in the Y-axis direction. However, the second portion 22 is bent at a substantially right angle with respect to the first portion 21 from a position one step below the upper edge of the first portion 21, and the rib 23 is configured by the upper side portion of the first portion 21. .

  The second plate-shaped metal 30 has a shape that extends in the −Z direction from the feeding point 45 and is approximately parallel to the XZ plane and approximates a triangle, a semicircle, or a semi-ellipse with the feeding point 45 as a vertex.

  The first plate metal 20 and the second plate metal 30 of the TEL broadband antenna 10 are fixed to a resin radome 60 that transmits radio waves. The TEL antenna circuit board 40 of FIG. 9A is connected to the feeding side of the first plate metal 20 and the second plate metal 30, and the first plate metal 20 and the TEL antenna circuit board 40 are in the radome 60. Is housed in.

As shown in FIG. 9A, the circuit board for TEL antenna 40 for impedance matching has strip-like conductor patterns P ₁ , P ₂ , and P ₃ on the board 40 (the back side of the board is a ground pattern and constitutes a microstrip line. ), Chip capacitors C ₁ , C ₂ , and chip coils L ₁ , L ₂ . A chip coil L ₁ is connected between the strip-shaped conductor patterns P ₁ and P ₂ , and a chip capacitor C ₂ is connected between the strip-shaped conductor patterns P ₂ and P ₃ . 9A of the circuit board for TEL antenna 40 is a ground pattern, the chip capacitor C ₁ is a strip conductor pattern P ₂ , and between the ground patterns, the chip coil L ₂ is a strip conductor pattern P ₃ , a ground pattern. Each connected in between.

The center conductor 47a of the coaxial cable 47 as a feed line for supplying power to the TEL for a broadband antenna 10 is connected to a strip conductor pattern P _1, the outer conductor 47b of the coaxial cable 47 is connected to the ground pattern. That is, the coaxial cable 47 is connected to the power supply side end 20 a of the first plate metal 20 and the power supply side end 30 a of the second plate metal 30 via the matching circuit 41. The feeding-side end 20a of the first plate-shaped metal 20 shown in FIG. 9B is electrically connected so as to overlap the ground pattern on the back surface of the TEL antenna circuit board 40. Further, the feeding-side end portion 30a of the second sheet metal 30 is connected to a strip conductor pattern P ₃ of Figure 9A. Here, the second sheet metal 30 the feeding end 30a and the strip conductor pattern P ₃ and the connection point next feed point 45 in FIG. 9, the center conductor 47a of the coaxial cable 47 and the second sheet metal 30 side The external conductor 47b is electrically connected to the first plate-shaped metal 20 side.

  The patch antenna 50 as the GNSS antenna is provided on the second portion 22 of the first plate metal 20 parallel to the XY plane. The patch antenna 50 includes a patch antenna element 51 provided with a rectangular conductor 52 on a dielectric upper surface, a second portion 22 serving as a ground conductor plate on the bottom surface side of the patch antenna element 51, and a GNSS antenna provided on the lower surface of the second portion 22. Circuit board 55, and these are housed in radome 60. The ribs 23 and 24 on both sides of the second portion 22 have notches facing both side surfaces perpendicular to the Y-axis direction of the patch antenna element 51 so as not to obstruct the passage of the magnetic flux of radio waves received by the patch antenna 50. 23a and 24a are formed, respectively.

As shown in FIG. 10, the circuit board 55 for the GNSS antenna has a strip-like conductor pattern P ₁₁ , P ₁₂ , P ₁₃ , P ₁₄ of the board 55 (the back side of the board is a ground pattern and constitutes a microstrip line); a chip coil _{L 11} connecting the branched one pattern strip conductor pattern _{P 11} and strip conductor pattern _{P 12,} a chip coil _{L 12} connecting the strip conductor pattern _{P 12, P 13,} strip conductor pattern _{P 11} other branched pattern and the strip conductor pattern _{P 14} and chip coil _{L 13} which connects, the chip capacitors _{C 11, C 12, C 13} , C 14, C 15, C 16, strip conductor pattern _{P 12,} It includes a chip resistor _{R 1} between P _14. The back surface of the GNSS antenna circuit board 55 shown in FIG. 10 is a ground pattern, and the chip capacitor C ₁₁ is arranged between one of the striped conductor pattern P ₁₁ and the ground pattern between the chip capacitors C ₁₂ , C ₁₃ is between the strip conductor pattern P ₁₂ and the ground pattern, the chip capacitor C ₁₄ is between the strip conductor pattern P ₁₃ and the ground pattern, and the chip capacitor C ₁₅ is between the other branched pattern of the strip conductor pattern P ₁₁ and the ground pattern. in, the chip capacitor C ₁₆ strip conductor pattern P _14, it is connected between the ground pattern. Transmission line branched one side of the strip conductor pattern P ₁₁ which branches into two transmission paths (chip coil L ₁₁ and the chip capacitor C _11, the portion including the C ₁₂₎ and the other branched side (chip coil L ₁₃ And a portion including chip capacitors C ₁₅ and C ₁₆ ) constitute a coupling circuit 58. The chip coil L ₁₂ , the strip-shaped conductor pattern P ₁₃ , and the chip capacitors C ₁₃ and C ₁₄ constitute a phase adjustment circuit 59. Two feeding pins 53a and 53b connected to the rectangular conductor 52 of the patch antenna element 51 for receiving circularly polarized waves penetrate the patch antenna element 51 and the through holes 22a and 22b (FIG. 9B) of the second portion 22, respectively. Further, it is provided so as to penetrate the circuit board 55 for the GNSS antenna, and in the power feeding section 56, the power feeding pins 53a and 53b are connected to the strip-shaped conductor patterns P ₁₃ and P ₁₄ , respectively. The ground pattern on the back surface of the circuit board 55 for the GNSS antenna is overlapped with and electrically connected to the second portion of the first plate metal 20 so that the first plate metal 20 can connect the ground of the patch antenna 50. Also serves as. The GNSS antenna circuit board 55 may be further provided with a band-pass filter and a low-noise amplification unit, but are omitted in this embodiment.

The center conductor 57a of the coaxial cable 57 as a feed line for feeding the patch antenna 50 is connected to the side of the pattern that are not branched strip conductor pattern P _11, the outer conductor 57b of the coaxial cable 57 is connected to the ground pattern ing. That is, the coaxial cable 57 is electrically connected to the two feeding pins 53 a and 53 b of the patch antenna 50 through the coupling circuit 58 and the phase adjustment circuit 59 on the GNSS antenna circuit board 55. The two feeding pins 53 a and 53 b are connected to the rectangular conductor 52 of the patch antenna element 51.

  In order to prevent unnecessary coupling, a conductor shield case 70 is disposed and fixed on the bottom surface of the substrate 55 so as to cover the lower surface of the circuit substrate 55 for the GNSS antenna.

  In order to prevent leakage current from flowing through the outer conductors of the coaxial cables 47 and 57, magnetic cores 75 and 76 (for example, ferrite cores) are provided on the outer periphery of the coaxial cables 47 and 57 (coaxial cables 47 and 57). Passes through the magnetic cores 75 and 76). The magnetic cores 75 and 76 are also preferably accommodated in the radome 60.

  The TEL broadband antenna 10 based on the bow tie antenna included in the composite antenna device 1 operates in both transmission and reception, and a case in which it operates as a transmission antenna will be described. First, the high-frequency signal propagates through the coaxial cable 47, then propagates through the microstrip line on the TEL antenna circuit board 40, and is finally fed to the first and second plate-like metals 20 and 30 of the TEL broadband antenna 10. , And radiated into the space as radio waves.

  The patch antenna 50 as a GNSS antenna provided in the composite antenna device 1 performs a receiving operation. First, the patch antenna 50 receives the corresponding satellite wave, and then the high-frequency signal propagated from the patch antenna 50 to the GNSS antenna circuit board 55 is converted into a phase adjustment circuit 59 or a coupling circuit 58 (a band-pass filter provided as necessary). And a circuit such as a low noise amplifier), and finally propagates from the circuit board 55 for the GNSS antenna to the coaxial cable 57, and a high frequency signal is derived to the outside.

  FIG. 12 shows the frequency characteristics of VSWR of the TEL broadband antenna 10 based on the bow tie antenna in this embodiment, and a sufficiently low VSWR is realized over a wide frequency band (699 to 3800 MHz) of LTE (Long Term Evolution). is made of. However, this is a case where a coaxial cable having a characteristic impedance of 50Ω is connected.

  When the composite antenna device 1 is arranged as shown in FIG. 11 and the + Z direction of the Z axis is the zenith direction, the TEL broadband antenna 10 has a θ polarization of θ = 90 ° (horizontal plane) as shown in FIG. Average gain increases. The gain deviation at the azimuth angle φ is small.

  FIG. 13 shows the frequency characteristic of the average gain (dBic) of the θ polarization (vertical polarization) at θ = 90 ° (horizontal plane) of the TEL broadband antenna 10, and a sufficient average gain over a desired frequency band in LTE. Is secured. However, the average gain (dBic) is an average value of gain when the azimuth angle φ in FIG. 11 is changed from 0 ° to 360 °.

  FIG. 14 shows the frequency characteristics of the VSWR of the patch antenna 50 as a GNSS antenna that does not include the low-noise amplification unit in the present embodiment, and includes GPS (Global Positioning System; frequency bands 1575.397 to 1576.4443 MHz) and GLONASS. A sufficiently low VSWR can be realized over the frequency band (Global Navigation Satellite System; frequency band 159.807 to 1605.6305 MHz). However, this is a case where a coaxial cable having a characteristic impedance of 50Ω is connected.

  When the composite antenna device 1 is arranged as shown in FIG. 11 and the + Z direction of the Z axis is the zenith direction, the patch antenna 50 as a GNSS antenna is polarized in the right-handed direction in the zenith direction as shown in FIGS. The gain becomes higher.

  FIG. 15 shows the frequency characteristic of the axial ratio (dB) of right-handed polarization at θ = 0 ° of the patch antenna 50 as the GNSS antenna shown in this embodiment, which is sufficiently good in the GPS and GLONASS frequency bands. A reasonable axial ratio is obtained.

  FIG. 16 shows the frequency characteristics of the right-hand polarized wave gain (dBic) at θ = 0 ° of the patch antenna 50 as the GNSS antenna shown in this embodiment, which is sufficiently good in the GPS and GLONASS frequency bands. Gain has been obtained.

  According to the present embodiment, the following effects can be achieved.

(1) A TEL based on a bow tie antenna having a first plate metal 20 as a first conductor element extending in opposite directions with a feeding point interposed therebetween and a second plate metal 30 as a second conductor element. Band antenna 10 is configured, patch antenna 50 as a GNSS antenna is provided on first plate metal 20, and first plate metal 20 is also used as a ground plate for patch antenna 50. A wide band and small composite antenna device can be obtained.

(2) The first plate-like metal 20 of the TEL broadband antenna 10 has a first portion 21 on the power feeding side and a second portion 22 bent at a right angle from the first portion 21. By providing the patch antenna 50, when the main parts of the first and second plate metals 20 and 30 of the TEL broadband antenna 10 are vertically arranged so that vertical polarization can be transmitted and received (+ Z direction of the Z axis) ), The upper surface of the GNSS patch antenna 50 (the surface on which the rectangular conductor 52 is disposed) can be directed in the direction of θ = 0 ° suitable for radio wave reception from a satellite.

  That is, the TEL broadband antenna 10 based on the bow tie antenna has a high average gain of θ polarization (vertical polarization) of θ = 90 ° (horizontal plane) and a small gain deviation at the azimuth angle φ. This is advantageous for communication with a TEL base station when the station direction is unknown in the azimuth angle φ of FIG. The patch antenna 50, which is a GNSS antenna, has a high gain of right-handed polarization in the zenith direction, and thus works advantageously for communication with satellite waves.

(3) Since the ribs 23 and 24 rising in the + Z direction are formed on the second portion 22 of the first plate-like metal 20 at both side positions spaced apart in the Y-axis direction of the patch antenna 50, the first plate-like metal The patch antenna 50 can be contributed to an improvement in sensitivity by increasing the entire area of the patch antenna 50, and the notches 23a and 24a are provided in the portions of the ribs 23 and 24 facing both side surfaces orthogonal to the Y-axis direction of the patch antenna 50. It is possible not to obstruct the passage of the magnetic flux of the received radio wave, and the performance degradation of the patch antenna 50 can be avoided. Further, the resonance frequency of the patch antenna 50 can be adjusted depending on the size of the notches 23a and 24a.

(4) By providing the magnetic cores 75 and 76 on the outer circumferences of the coaxial cables 47 and 57 that respectively feed the TEL broadband antenna 10 and the patch antenna 50, leakage current flows through the outer conductors of the coaxial cables 47 and 57. Can be suppressed.

(5) As can be seen from FIG. 2 and FIG. 6, the first plate metal 20 of the TEL broadband antenna 10 and the circuit board 40 for the TEL antenna are overlapped to ground the first plate metal 20 and the circuit board 40. Is connected and integrated to simplify the structure. In addition, when such a configuration is not used, it is necessary to provide a circuit element including a conductor, such as a substrate, in the vicinity of the outside of the antenna conductor element, which causes a disadvantage that the antenna characteristics are deteriorated due to the influence of the conductor.

  FIG. 17 shows a basic shape (shape 1) and a modification (shapes 2 and 3) of a bow tie antenna having a pair of conductor elements extending in opposite directions with a feeding point interposed therebetween. Here, in order to simplify the analysis, a case will be described in which the pair of conductor elements have the same shape (congruent) and are symmetrically arranged with respect to the feeding point.

  The shape 1 in FIG. 17A is a triangular shape having a feeding point as a vertex, and the shape 2 in FIG. 17B is a contour that is linearly deformed so that two sides sandwiching the vertex of the triangle are convex outward. (In other words, the outline in which the opposing space area between the pair of conductor elements is reduced), the shape 3 in FIG. 5C is a feeding point so that the opposing space area between the pair of conductor elements is reduced. The semicircle-shaped conductor element which has the outline of the curve which protruded convexly toward is shown. Furthermore, a semi-elliptical conductor element can be used. When the facing space area between the pair of conductor elements is small and the capacitance between the conductor elements is large, better band characteristics can be obtained over a wide band.

  In FIG. 17, when the area of a pair of conductor elements is increased, the impedance characteristic caused by the non-similar shape change is sharper when the frequency is changed when the frequency is changed than when the contour is made a straight line. It is easy to suppress various fluctuations.

  FIG. 18 shows the relationship between VSWR using shapes 1 to 3 as parameters and d / λ (where d = width of each conductor element, d / 2 = length of each conductor element, λ = wavelength of TEL radio wave). It is a graph, and it can be seen that VSWR is stable in shape 2 lower than shape 1 and further stable in shape 3 lower than that. However, this is a case where a coaxial cable having a characteristic impedance of 50Ω is connected.

  FIG. 19 shows a configuration in which inductance and capacitance are increased without increasing the height (shapes 3-1 and 3 with respect to shape 3 using a pair of semicircular conductor elements (semicircle having a radius of 2 / d). 2), which can be employed as the conductor element of the TEL broadband antenna 10 of the first embodiment.

  FIG. 19A shows the shape 3, and the pair of conductor elements 80 and 90 facing each other across the feeding point are semicircular. The shape 3-1 in FIG. 19B extends so that one conductor element 90 forms an angle of approximately 90 ° to 90 ° with the semicircular first portion 91 close to the feeding point and the first portion 90. The second portion 92 is present. In the shape 3-2 of FIG. 19C, the other conductor element 80 also extends so as to form an angle of approximately 90 ° to 90 ° from the semicircular first portion 81 close to the feeding point and the first portion 80. The second portion 82 is present.

  FIG. 20 is a graph showing the relationship between VSWR and d / λ using the shapes 3, 3-1 and 3-2 as parameters. The shape of the VSWR is lower than that of the shape 3 in a lower frequency range and is stable. It can be seen that 3-2 is further stable to a lower frequency range. However, this is a case where a coaxial cable having a characteristic impedance of 50Ω is connected.

  FIGS. 21 to 28 show an antenna apparatus 2 according to a second embodiment of the antenna apparatus according to the present invention, which includes a TEL broadband antenna 100 based on a bowtie antenna. For convenience of explanation, an X axis, a Y axis, and a Z axis that are orthogonal to the antenna device 2 are defined as shown in FIGS. In FIG. 29B, the angle between the Z axis and the observation point is θ °, and the angle between the intersection of the perpendicular line from the observation point to the XY plane and the origin of the XY plane and the origin is the azimuth angle. Let φ.

  The TEL broadband antenna 100 based on the bow tie antenna includes a first plate metal 120 serving as a first conductor element and a second plate metal 130 serving as a second conductor element extending in opposite directions with the feeding point 145 interposed therebetween. And a TEL antenna circuit board 40 (same structure as FIG. 9A of the first embodiment) as a broadband antenna circuit board.

  The first plate-like metal 120 extends from the feeding point 145 in the + Z direction, is substantially parallel to the XZ plane, and has a substantially semicircular or substantially semi-elliptical first part 121 having the feeding point 145 as the apex, and the first part. 21 has a second portion 122 bent and extended in the −Y direction so as to be substantially parallel to the XY plane, and a third portion 123 bent and extended in the −Z direction from the second portion.

  The second plate-like metal 130 has a symmetrical structure with the first plate-like metal 120 across the feeding point 145, extends in the −Z direction from the feeding point, and is substantially parallel to the XZ plane, with the feeding point 145 as the apex. A first portion 131 having a shape approximating a semicircle or semi-ellipse, a second portion 132 bent and extended in the −Y direction so as to be substantially parallel to the XY plane from the first portion 131, and And a third portion 133 that is bent in the + Z direction from the two portions and extends.

  The first plate metal 120 and the second plate metal 130 of the TEL broadband antenna 100 are fixed to a resin radome 160 that transmits radio waves. 9A is connected to the feeding side of the first plate metal 120 and the second plate metal 130, and the first and second plate metals 120 and 130 and the TEL antenna circuit board are connected. 40 is accommodated in the radome 160.

  The TEL antenna circuit board 40 for impedance matching is as shown in FIG. 9A of the first embodiment. The matching circuit is mounted on the TEL antenna circuit board 40 through the matching circuit of the TEL antenna circuit board 40. 100 and the coaxial cable 47 are connected. That is, the coaxial cable 47 is connected to the power supply side end 120a of the first plate metal 120 and the power supply side end 130a of the second plate metal 130 of FIG. As can be seen from FIGS. 22 and 24, the first plate metal 120 of the TEL broadband antenna 100 and the circuit board 40 for the TEL antenna are overlapped, and the first plate metal 120 and the ground of the circuit board 40 are connected. Have been integrated.

  In order to suppress leakage current from flowing through the outer conductor of the coaxial cable 47, a magnetic core 75 (for example, a ferrite core) is provided on the outer periphery of the coaxial cable 47. The magnetic core 75 is also preferably housed within the radome 160.

  FIG. 30 shows the frequency characteristics of VSWR of the TEL broadband antenna 100 based on the bow tie antenna in the second embodiment, and a sufficiently low VSWR can be realized over a wide frequency band of LTE. However, this is a case where a coaxial cable having a characteristic impedance of 50Ω is connected.

  When antenna apparatus 2 of Embodiment 2 is arranged as shown in FIG. 29B and the + Z direction of the Z axis is the zenith direction, TEL broadband antenna 100 has θ = 90 ° (horizontal plane) as shown in FIG. The average gain of θ polarization increases. The gain deviation at the azimuth angle φ is small.

  FIG. 31 shows the frequency characteristics of the average gain (dBic) of the θ polarization (vertical polarization) at θ = 90 ° (horizontal plane) of the TEL broadband antenna 100, and a sufficient average gain is ensured over the LTE frequency band. is made of. However, the average gain (dBic) is an average value of gains when the azimuth angle φ in FIG. 29B is changed from 0 ° to 360 °.

  According to the configuration of the antenna device 2 shown in the second embodiment, the first portions 121 and 131 of the first and second plate-like metals 120 and 130 extending on the opposite side across the feeding point 145 are directed toward the feeding point 145. By having a substantially semicircular or substantially semi-elliptical shape having a curved contour bulging in a convex shape, and further having second portions 122 and 132 and third portions 123 and 133 bent from the first portions 121 and 131, Capacitance and inductance can be increased, characteristics can be improved in a lower frequency range, and the profile of the antenna device 2 can be reduced.

  The present invention has been described above by taking the embodiment as an example. However, it is understood by those skilled in the art that various modifications can be made to each component and each processing process of the embodiment within the scope of the claims. By the way. Hereinafter, modifications will be described.

  When the antenna device of each of the above-described embodiments is mounted on a vehicle, the XY plane of FIGS. 1, 11 and 29B is generally arranged on the horizontal plane, and the + Z direction on the Z axis is arranged in the zenith direction. The arrangement of the antenna device is not limited and can be changed according to the application.

  In each of the above embodiments, the case where the plate-like metal as the conductor element of the broadband antenna based on the bow tie antenna is formed by bending the second portion with respect to the first portion is exemplified. It may be formed by bending between the first portion and the second portion. In the case of the second embodiment, the second portion and the third portion may be formed to be curved.

  In the first embodiment, the main part of the conductor element of the broadband antenna 10 based on the bow tie antenna is arranged along the Z-axis direction, and the patch antenna 50 is arranged on a plane substantially orthogonal to the Z-axis. 10 and the arrangement angle of the patch antenna 50 are arbitrary.

  In the second embodiment, the first and second plate-like metals 200 and 300 have substantially the same shape, but one of them may be, for example, the shapes 1 to 3 in FIG.

  The circuit configurations of the TEL antenna circuit board and the GNSS antenna circuit board in each embodiment are merely examples, and the circuit configurations can be changed as appropriate.

DESCRIPTION OF SYMBOLS 1 Composite antenna apparatus 2 Antenna apparatus 10,100 Broadband antenna 20,120 for TEL 1st plate-shaped metal 21,121,131 1st part 22,122,132 2nd part 23,24 Rib 23a, 24a Notch 30,130 1st Two-plate metal 40 TEL antenna circuit board 41 Matching circuits 45 and 145 Feed points 47 and 57 Coaxial cable 50 Patch antenna 51 Patch antenna element 55 GNSS antenna circuit board 60 and 160 Radome 70 Shield case

Claims (3)

A broadband antenna based on a bow tie antenna having a first conductor element and a second conductor element extending in opposite directions across the feed point;
A broadband antenna circuit board is interposed between the broadband antenna and a coaxial cable that feeds the broadband antenna, and a ground of the broadband antenna circuit board is overlapped and connected to the first or second conductor element. An antenna device characterized by being integrated. A broadband antenna based on a bow tie antenna having a first conductor element and a second conductor element extending in opposite directions across the feed point;
The antenna device, wherein the first conductor element and the second conductor element have different shapes and are asymmetrically arranged with respect to the feeding point. A broadband antenna based on a bow tie antenna having a first conductor element and a second conductor element extending in opposite directions across the feed point;
At least one of the first and second conductor elements has a contour of a curve that protrudes toward the feeding point so that an opposing space area between the first and second conductor elements is narrowed;
Each of the first conductor element and the second conductor element is a plate metal,
When the three orthogonal axes are the X, Y, and Z axes,
The first conductor element has a portion extending in the + Z direction from the feeding point and substantially parallel to the XZ plane, and the second conductor element extends in the −Z direction from the feeding point and substantially parallel to the XZ plane. Have
One or both of the first conductor element and the second conductor element is a first portion close to the feeding point;
An antenna device comprising: a second portion that is bent and extends from the first portion so as to have a region that is non-parallel to the first portion.