Antenna device

Abstract

An antenna device provided in a vehicle component, wherein an antenna element connected to a power supply unit includes a main element extending from the power supply unit to an open end via at least one bent portion, and when a narrowest substantially quadrilateral region where the power supply unit and the antenna element are in contact with each other outside the power supply unit and the antenna element is defined as a first region, the length L of a side of the first region in a first direction X is 0.5 times or more and 8 times or less the length L of the first region in a second direction Y . When the element length of the main element is defined as L, the center wavelengths of the first, second, and third frequency bands in air are defined as λ1, λ2, and λ3, and the wavelength shortening ratio of the surrounding medium is defined as k, at least two of the following formulas 1, 2, and 3 are satisfied. 0.09×k×λ1 ≤ L ≤ 0.28×k×λ1 ··· Formula 1; 0.20×k×λ2 ≤ L ≤ 0.62×k×λ2 ··· Formula 2; 0.59×k×λ3 ≤ L ≤ 1.77×k×λ3 ··· Formula 3.

Description

Technical Field

[0001] The present disclosure relates to an antenna device. Background Art

[0002] In recent years, as an antenna device mounted on a vehicle such as a motor vehicle, an antenna device integrated with a composite antenna component capable of receiving signals in a plurality of frequency bands such as AM broadcast waves, FM broadcast waves, terrestrial digital television broadcast waves, and DAB (Digital Audio Broadcasting) has been widely used. For example, a rear spoiler antenna in which a common antenna capable of receiving two types of electric waves in the FM band and the DAB band and an AM antenna capable of receiving electric waves for AM broadcast are provided inside the rear spoiler is known (for example, refer to Patent Document 1).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Laid-Open No. 2018-007223 Summary of the Invention

[0006] Technical Problem to be Solved by the Invention

[0007] However, a conventional common antenna requires a passive element that is capacitively coupled to an antenna component via a capacitive coupling unit, and thus its configuration is relatively complex.

[0008] The present disclosure provides an antenna device capable of receiving electric waves in a plurality of frequency bands with a simple configuration.

[0009] Technical Solution for Solving the Technical Problem

[0010] The present disclosure provides an antenna device,

[0011] which is an antenna device installed in a vehicle component mounted on a vehicle body and capable of receiving electric waves in at least two of a first frequency band, a second frequency band, and a third frequency band, and includes:

[0012] a first power supply unit, and

[0013] a first antenna component connected to the first power supply unit,

[0014] the first antenna component includes a main element extending from the first power supply unit to an open end via at least one bent portion,

[0015] when a narrowest substantially quadrilateral region where the first power supply unit and the first antenna component are in contact with each other outside the first power supply unit and the first antenna component is defined as a first region,

[0016] the length of a side of the first region in a first direction is defined as L X, let the length of the first region in the second direction be L Y When X L Y is 0.5 times or more and 8 times or less of L

[0017] Let the element length of the main element be L, let the center wavelength of the first frequency band in air be λ1, let the center wavelength of the second frequency band in air be λ2, let the center wavelength of the third frequency band in air be λ3, and let the wavelength shortening rate of the surrounding medium be k. It satisfies at least two of Equation 1, Equation 2, and Equation 3.

[0018] 0.09×k×λ1 ≤ L ≤ 0.28×k×λ1 ··· Equation 1

[0019] 0.20×k×λ2 ≤ L ≤ 0.62×k×λ2 ··· Equation 2

[0020] 0.59×k×λ3 ≤ L ≤ 1.77×k×λ3 ··· Equation 3.

[0021] Advantageous Effects of the Invention

[0022] According to the present disclosure, an antenna device capable of receiving radio waves of multiple frequency bands with a simple configuration can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure shows an example diagram of a vehicle component provided with an antenna device of one embodiment and a vehicle body to which the vehicle component is mounted.

[0024] Figure 2 The figure shows a top view of a configuration example of the antenna device of the first embodiment.

[0025] Figure 3 The figure shows a top view of a configuration example of the antenna device of the second embodiment.

[0026] Figure 4 The figure shows a top view of a configuration example of the antenna device of the third embodiment.

[0027] Figure 5 The figure shows a top view of a configuration example of the antenna device of the fourth embodiment.

[0028] Figure 6 The figure shows a top view of a configuration example of the antenna device of the fifth embodiment.

[0029] Figure 7 The figure shows a top view of a configuration example of the antenna device of the sixth embodiment.

[0030] Figure 8 The figure shows a top view of a configuration example of the antenna device of the seventh embodiment.

[0031] Figure 9 The figure shows a top view of a configuration example of the antenna device according to the eighth embodiment.

[0032] Figure 10 The figure shows a top view of a configuration example of the antenna device according to the ninth embodiment.

[0033] Figure 11 The figure shows a top view of a configuration example of the antenna device according to the tenth embodiment.

[0034] Figure 12 The figure shows a top view of a configuration example of the antenna device according to the eleventh embodiment.

[0035] Figure 13 The figure shows an example of the measurement result of the antenna gain of the antenna device according to the second embodiment.

[0036] Figure 14 The figure shows an example of the measurement result of the antenna gain of the antenna devices according to the fourth, fifth, and sixth embodiments.

[0037] Figure 15 The figure shows an example of the measurement result of the antenna gain of the antenna devices according to the eighth and ninth embodiments. Detailed Embodiments

[0038] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In addition, for ease of understanding, the proportions of the respective parts in the drawings may be different from the actual proportions. Deviations within a degree that does not impair the effects of the present invention may exist in the parallel, right-angle, orthogonal, horizontal, vertical, up-down, left-right, etc. directions. In addition, the corner shapes are not limited to right angles and may also be arcuate bows. The X-axis direction, Y-axis direction, and Z-axis direction respectively represent directions parallel to the X-axis, directions parallel to the Y-axis, and directions parallel to the Z-axis. The X-axis direction, Y-axis direction, and Z-axis direction are orthogonal to each other. The XY plane, YZ plane, and ZX plane respectively represent imaginary planes parallel to the X-axis direction and Y-axis direction, imaginary planes parallel to the Y-axis direction and Z-axis direction, and imaginary planes parallel to the Z-axis direction and X-axis direction.

[0039] Figure 1 The figure shows an example diagram of a vehicle member provided with an antenna device according to an embodiment and a vehicle body on which the vehicle member is mounted. The X-axis direction, Y-axis direction, and Z-axis direction respectively correspond to the vehicle width direction, the front-rear direction of the vehicle, and the up-down direction of the vehicle. Figure 1 The illustrated antenna device 100 is an example of an antenna device included in a vehicle member mounted on a vehicle body. Figure 1An example is shown in which an antenna device 100 is mounted on a rear spoiler 1 installed on a vehicle body 2. The rear spoiler 1 is an example of a vehicle component and is a type of aerodynamic kit installed at the rear of the vehicle body 2. The rear spoiler 1 is a resin-made component, but it can also be formed of materials other than resin. The rear spoiler 1 may be equipped with a high-mounted stop lamp 3. The antenna device 100 represents the antenna device in each of the following embodiments.

[0040] Figure 2 The top view of a configuration example of the antenna device according to the first embodiment is shown. The positive Y-axis direction corresponds to the rear of the vehicle, and the X-axis direction corresponds to the vehicle width direction. The first direction corresponds to the positive X-axis direction, and the second direction corresponds to the positive Y-axis direction. The third direction on the opposite side of the second direction corresponds to the negative Y-axis direction, and the fourth direction on the opposite side of the first direction corresponds to the negative X-axis direction. Figure 2 The illustrated antenna device 101 receives radio waves in at least two of the first frequency band, the second frequency band, and the third frequency band.

[0041] For example, the first frequency band and the second frequency band are VHF (Very High Frequency) bands with frequencies of 30 MHz to 300 MHz, and the third frequency band is a UHF (Ultra High Frequency) band with a frequency of 300 MHz to 3 GHz. For example, the first frequency band is set in the frequency band of FM broadcast waves included in the VHF band, the second frequency band is set in the frequency band of DAB Band III included in the VHF band, and the third frequency band is set in the frequency band of terrestrial digital television broadcast waves of 470 MHz to 710 MHz included in the UHF band, for example, 470 MHz to 890 MHz.

[0042] The antenna device 101 includes a power supply unit 31 and antenna elements 10.

[0043] The power supply unit 31 is an example of a first power supply unit and is a power supply point for supplying power to the antenna elements 10. The power supply unit 31 is electrically connected, for example, to the input terminal of an amplifier (not shown) that amplifies the signal received by the antenna elements 10. The signal amplified by the amplifier is supplied to a receiving device (not shown) mounted on the vehicle body. Specific examples of the power supply unit 31 include connectors, electrodes, etc.

[0044] The antenna component 10 is an example of the first antenna component and is connected to the power supply unit 31. The end portion (base end portion) of the antenna component 10 on the power supply unit 31 side is electrically connected to the power supply unit 31 through, for example, solder or a conductive adhesive. The antenna component 10 is a conductor formed in such a way that it can receive radio waves in at least two of the first frequency band, the second frequency band, and the third frequency band, and resonates at the frequencies of each frequency band above the VHF band. The antenna component 10 can be built into the rear spoiler 1 or provided on the outer surface of the rear spoiler 1. The antenna component 10 is a linear conductive member and can be formed, for example, by a wire, a conductive coating, a metal rod, a metal plate, etc.

[0045] When the above high-mounted stop lamp 3 is mounted on the rear spoiler 1, by arranging the antenna component 10 above the high-mounted stop lamp 3, it is possible to suppress a decrease in the reception sensitivity of the antenna component 10 to radio waves. In addition, from the viewpoint of suppressing a decrease in the reception sensitivity of the antenna component 10 to radio waves, the antenna component 10 is preferably arranged so as not to cross the wiring connected to the high-mounted stop lamp 3.

[0046] The part where the antenna component 10 is formed or installed is, for example, a part formed of a dielectric. More specifically, it can be the outer cover of the rear spoiler 1 or a dielectric substrate (not shown) fixed to the outer cover. The antenna component 10 is formed on the dielectric substrate, making it easy to install the antenna component 10 on the rear spoiler 1. The dielectric substrate includes a rigid substrate, a flexible substrate, etc. The antenna component 10 can also be composed of a coated conductor in which a conductor is coated with an insulating material inside an aerodynamic kit such as the rear spoiler 1. At this time, inside the aerodynamic kit, the coated conductor can be fixed by a plurality of dielectrics (for example, groove-shaped snap fits) arranged at intervals, and a part of the coated conductor can also be aerial wiring.

[0047] The antenna component 10 includes a main element 50 that extends from the power supply unit 31 via at least one bending portion ( Figure 2 which is one bending portion 51 in the illustrated example) to the open end 59. The main element 50 has a first element 11 and a second element 12.

[0048] The first element 11 is connected to the power supply unit 31 and extends in a direction away from the power supply unit 31. In this example, it extends linearly from the power supply unit 31 in the first direction to the bending portion 51. The second element 12 extends in a direction away from the power supply unit 31, that is, in a direction different from the direction in which the first element 11 extends. In this example, it extends linearly from the bending portion 51 in the second direction to the open end 59.

[0049] The narrowest approximate quadrilateral (in the XY plane) region where the power supply unit 31 and the antenna component 10 are connected on the outer sides of the power supply unit 31 and the antenna component 10 is defined as the first region 41. The length of the side of the first region 41 in the first direction is set as L X , and the length of the first region in the second direction is set as L Y . At this time, considering that the reception sensitivity of radio waves in multiple frequency bands can be ensured with a simple structure, L X is preferably 0.5 times or more and 8 times or less of L Y , more preferably 0.75 times or more and 6.5 times or less of L Y , and still more preferably 1.5 times or more and 6.5 times or less of L Y . In particular, when the first direction (the direction parallel to the vehicle width direction) is longer than the second direction (the direction parallel to the vehicle longitudinal direction), when the antenna device 101 is mounted on the rear spoiler 1 where the vehicle width direction is longer than the vehicle longitudinal direction, the mounting space (region) can be effectively utilized.

[0050] Let the element length of the main element 50 be L, the wavelength of the radio wave of the center frequency of the first frequency band in the air be λ1, the wavelength of the radio wave of the center frequency of the second frequency band in the air be λ2, the wavelength of the radio wave of the center frequency of the third frequency band in the air be λ3, and the wavelength shortening rate of the surrounding medium be k. At this time, when the element length L satisfies

[0051] 0.09×k×λ1 ≤ L ≤ 0.28×k×λ1 ··· Formula 1

[0052] 0.20×k×λ2 ≤ L ≤ 0.62×k×λ2 ··· Formula 2

[0053] 0.59×k×λ3 ≤ L ≤ 1.77×k×λ3 ··· Formula 3.

[0054] In the case of at least two of them, the reception sensitivity of radio waves in multiple frequency bands can be ensured with a simple structure. The element length L preferably satisfies all three formulas 1, 2, and 3. In addition, the element length L (of the main element 50) represents the conductor length (total length) from the power supply unit 31 to the open end 59, and the same applies to other embodiments described later. The surrounding medium represents the part where the main element 50 is disposed.

[0055] For example, when the first frequency band is the frequency band of FM broadcast waves (76 MHz to 108 MHz), the center wavelength λ1 in the air is 3261 mm. When the second frequency band is the frequency band of DAB Band III (170 MHz to 240 MHz), the center wavelength λ2 in the air is 1463 mm. When the third frequency band is the frequency band of terrestrial digital television broadcast waves (470 MHz to 710 MHz), the center wavelength λ3 in the air is 508 mm. At this time, if k = 1, when the element length L is adjusted to be more than about 300 mm and less than about 900 mm, the antenna gain of the radio waves in these three frequency bands is increased. In addition, among the antenna gains of the radio waves in the three frequency bands exemplified above, the antenna gain of a specified polarization wave can be preferentially evaluated according to the specifications. For example, in the case of FM broadcast waves and terrestrial digital television broadcast waves, the antenna gain of the horizontal polarization wave can be used as the priority index for evaluation. In addition, for example, in the case of DAB BandIII broadcast waves, the antenna gain of the vertical polarization wave can be used as the priority index for evaluation.

[0056] Preferably, when the element length L satisfies

[0057] 0.10×k×λ1≤L≤0.23×k×λ1 ··· Formula 1a

[0058] 0.23×k×λ2≤L≤0.52×k×λ2 ··· Formula 2a

[0059] 0.68×k×λ3≤L≤1.48×k×λ3 ··· Formula 3a

[0060] in at least two of the cases, a higher reception sensitivity for radio waves in multiple frequency bands can be ensured with a simple structure. The element length L more preferably satisfies all three formulas 1a, 2a, and 3a.

[0061] Figure 3 Shown is a top view of a configuration example of the antenna device according to the second embodiment. In the second embodiment, for the same configurations and effects as those in the first embodiment, the description is omitted or simplified by reference to the above description. Figure 3 In the antenna device 102 shown, the shape of the main element 50 is different from that of the antenna device 101 in the first embodiment.

[0062] The antenna component 10 includes a main element 50 that extends from the power supply unit 31 via a plurality of bent portions ( Figure 3 two bent portions 51 and 52 in the example shown) to the open end 59. The main element 50 has a first element 11, a second element 12, and a third element 13.

[0063] The first element 11 is connected to the power supply unit 31 and extends away from the power supply unit 31. In this example, it linearly extends from the power supply unit 31 in the first direction to the bending portion 51. The second element 12 extends away from the power supply unit 31. In this example, it linearly extends from the bending portion 52 in the first direction to the open end 59. The third element 13 connects the end portion of the first element 11 on the side opposite to the power supply unit 31 side (the bending portion 51 in this example) and the end portion of the second element 12 on the power supply unit 31 side (the bending portion 52 in this example). In this example, the third element 13 linearly extends from the bending portion 51 in the second direction to the bending portion 52.

[0064] In the antenna device 102, when the element length L satisfies at least two of the above equations 1, 2, and 3, the reception sensitivity of radio waves in multiple frequency bands can be ensured with a simple configuration. The element length L preferably satisfies all three equations 1, 2, and 3.

[0065] Furthermore, in the antenna device 102, when the element length L satisfies at least two of the above equations 1a, 2a, and 3a, the reception sensitivity of radio waves in multiple frequency bands can be ensured with a simpler configuration and higher sensitivity. The element length L more preferably satisfies all three equations 1a, 2a, and 3a.

[0066] In the antenna device 102, the multiple bending portions of the antenna component 10 are only at two locations, namely the connection portion between the first element 11 and the third element 13, and the connection portion between the second element 12 and the third element 13. Since there are only two bending portions, the antenna device 102 can be realized with a simple configuration.

[0067] In the antenna device 102, when the third element 13 forms an angle (angle α, angle β) within the range of 10° to 170° with respect to the first element 11 and the second element 12, the reception sensitivity of radio waves in multiple frequency bands can be ensured with a simple configuration. In Figure 3 the example shown, the angle α formed by the third element 13 and the first element 11 is 90°, and the angle β formed by the third element 13 and the second element 12 is 90°. Furthermore, the angle α is preferably 30° to 150°, more preferably 60° to 120°. Furthermore, the angle β is preferably 30° to 150°, more preferably 60° to 120°.

[0068] In the antenna device 102, the end portion of the second element 12 on the side opposite to the third element 13 side is the open end 59. Thereby, the reception sensitivity of radio waves in multiple frequency bands can be ensured with a simple configuration.

[0069] Figure 4The top view of the configuration example of the antenna device according to the third embodiment is shown. In the third embodiment, the description of the same configuration and effects as those in the second embodiment is omitted or simplified by reference to the above description. Figure 4 In the antenna device 103 shown, the shape of the main element 50 is different from that of the antenna device 102 of the second embodiment.

[0070] The antenna component 10 includes a main element 50 extending from the power supply unit 31 via a plurality of bent portions ( Figure 4 In the example shown, there are three bent portions 51, 52, 53) to the open end 59. The main element 50 has a first element 11, a second element 12, a third element 13, and a fourth element 14.

[0071] The first element 11 is connected to the power supply unit 31 and extends in a direction away from the power supply unit 31. In this example, it extends linearly from the power supply unit 31 in the first direction to the bent portion 51. The second element 12 extends in a direction away from the power supply unit 31. In this example, it extends linearly from the bent portion 52 in the first direction to the bent portion 53. The third element 13 connects the end portion of the first element 11 on the side opposite to the power supply unit 31 side (the bent portion 51 in this example) and the end portion of the second element 12 on the power supply unit 31 side (the bent portion 52 in this example). In this example, the third element 13 extends linearly from the bent portion 51 in the second direction to the bent portion 5. The fourth element 14 is connected to the end portion of the second element 12 on the side opposite to the power supply unit 31 side (the bent portion 53 in this example). In this example, it extends linearly from the bent portion 53 in the third direction to the open end 59.

[0072] In the antenna device 103, when the element length L of the main element 50 satisfies at least two of the above equations (1), (2), and (3), the reception sensitivity of radio waves in multiple frequency bands can be ensured with a simple configuration. The element length L of the main element 50 preferably satisfies all three equations (1), (2), and (3).

[0073] In addition, in the antenna device 103, when the element length L of the main element 50 satisfies at least two of the above equations (1a), (2a), and (3a), a higher reception sensitivity of radio waves in multiple frequency bands can be ensured with a simple configuration. The element length L of the main element 50 more preferably satisfies all three equations (1a), (2a), and (3a).

[0074] Figure 5 The top view of the configuration example of the antenna device according to the fourth embodiment is shown. In the fourth embodiment, the description of the same configuration and effects as those in the second embodiment is omitted or simplified by reference to the above description. Figure 5 The antenna device 104 shown is different from the antenna device 102 of the second embodiment in that it further has an auxiliary element 60. The antenna component 10 has a main element 50 and an auxiliary element 60.

[0075] Figure 5 The auxiliary element 60 shown is connected to the power supply unit 31. Figure 5 In this case, the auxiliary element 60 has a fifth element 15 and a sixth element 16, and includes an L-shaped element portion. The fifth element 15 is connected to the power supply unit 31 and extends in a direction away from the power supply unit 31. In this example, it extends linearly from the power supply unit 31 in the second direction to the bending portion 54. The sixth element 16 is connected to the fifth element 15 and extends in a direction different from that of the fifth element 15. In this example, it extends linearly from the bending portion 54 in the first direction to the open end 58.

[0076] Since the antenna device 104 has, in addition to the main element 50, an auxiliary element 60 including an L-shaped element portion, the sensitivity of a frequency band with relatively low reception sensitivity can be improved compared to the case where the auxiliary element 60 is not included, and the reception sensitivity of the entire specified frequency band can be increased. In addition, since the auxiliary element 60 is also provided in the antenna devices of the fifth to seventh embodiments described later, the above effects can also be achieved.

[0077] Figure 6 The top view of a configuration example of the antenna device of the fifth embodiment is shown. In the fifth embodiment, the description of the same configuration and effects as those of the fourth embodiment is omitted or simplified by reference to the above description. Figure 6 In the antenna device 105 shown, the shape of the auxiliary element 60 is different from that of the antenna device 104 of the fourth embodiment.

[0078] Figure 6 The auxiliary element 60 shown is connected to a portion of the main element 50 other than the end portion ( Figure 6 in the example shown, it is the middle portion of the first element 11). Figure 6 In this case, the auxiliary element 60 has a fifth element 15 and a sixth element 16, and includes a T-shaped element portion. The fifth element 15 is electrically (DC) connected to the power supply unit 31 and extends in a direction away from the power supply unit 31. In this example, it extends linearly from the middle portion of the first element 11 in the second direction to the bending portion 54. The sixth element 16 is connected to the fifth element 15 and extends in a direction different from that of the fifth element 15. In this example, it bifurcates from the bending portion 54 and linearly extends in the first direction and the fourth direction to the open ends 57 and 58, respectively.

[0079] Since the antenna device 105 has, in addition to the main element 50, an auxiliary element 60 including a T-shaped element portion, the sensitivity of a frequency band with relatively low reception sensitivity can be improved compared to the case where the auxiliary element 60 is not included, and the reception sensitivity of the entire specified frequency band can be increased.

[0080] Figure 7The figure shows a top view of a configuration example of the antenna device according to the sixth embodiment. In the sixth embodiment, for the same configurations and effects as those in the fourth embodiment, the descriptions are omitted or simplified by reference to the above descriptions. Figure 7 In the shown antenna device 106, the shape of the auxiliary element 60 is different from that of the antenna device 104 in the fourth embodiment.

[0081] Figure 7 The shown auxiliary element 60 is connected to the power supply unit 31. Figure 7 In this case, the auxiliary element 60 has a fifth element 15 and a sixth element 16, and includes a T-shaped element portion. The fifth element 15 is connected to the power supply unit 31 and extends in a direction away from the power supply unit 31. In this example, it linearly extends from the power supply unit 31 along the second direction to the open end 58. The sixth element 16 is connected to the fifth element 15 and extends in a direction different from that of the fifth element 15. In this example, it linearly extends from the middle portion different from the open end 58, i.e., the bent portion 54, along the first direction to the open end 57.

[0082] Since the antenna device 106 has, in addition to the main element 50, an auxiliary element 60 including a T-shaped element portion, compared with the case where the auxiliary element 60 is not included, it is possible to improve the sensitivity of the frequency band with relatively low reception sensitivity and improve the reception sensitivity of the entire specified frequency band.

[0083] Figure 8 The figure shows a top view of a configuration example of the antenna device according to the seventh embodiment. In the seventh embodiment, for the same configurations and effects as those in the fourth embodiment, the descriptions are omitted or simplified by reference to the above descriptions. Figure 8 In the shown antenna device 107, the shape of the auxiliary element 60 is different from that of the antenna device 104 in the fourth embodiment.

[0084] Figure 8 The shown auxiliary element 60 is connected to the power supply unit 31. Figure 8 In this case, the auxiliary element 60 has a fifth element 15 and a sixth element 16, and includes an L-shaped element portion. The fifth element 15 is connected to the power supply unit 31 and extends in a direction away from the power supply unit 31. In this example, it linearly extends from the power supply unit 31 along the second direction to the bent portion 54. The sixth element 16 is connected to the fifth element 15 and extends in a direction different from that of the fifth element 15. In this example, it linearly extends from the bent portion 54 along the fourth direction to the open end 58.

[0085] Since the antenna device 107 has, in addition to the main element 50, an auxiliary element 60 including an L-shaped element portion, compared with the case where the auxiliary element 60 is not included, it is possible to improve the sensitivity of the frequency band with relatively low reception sensitivity and improve the reception sensitivity of the entire specified frequency.

[0086] In the fourth embodiment ( Figure 5 ) and the seventh embodiment ( Figure 8 ), the total length of the fifth element 15 and the sixth element 16 constituting the auxiliary element 60 is set to L CL . At this time, when the element length L CL satisfies

[0087] 0.13×k×λ1 ≤ L CL ≤ 0.31×k×λ1 ··· Equation 4

[0088] 0.30×k×λ2 ≤ L CL ≤ 0.69×k×λ2 ··· Equation 5

[0089] 0.88×k×λ3 ≤ L CL ≤ 1.97×k×λ3 ··· Equation 6.

[0090] When at least two of the above equations are satisfied, the reception sensitivity of radio waves in multiple frequency bands can be ensured with a simple configuration. The element length L CL preferably satisfies all three equations 4, 5, and 6.

[0091] Preferably, when the element length L CL satisfies

[0092] 0.15×k×λ1 ≤ L CL ≤ 0.30×k×λ1 ··· Equation 4a

[0093] 0.34×k×λ2 ≤ L CL ≤ 0.65×k×λ2 ··· Equation 5a

[0094] 0.98×k×λ3 ≤ L CL ≤ 1.87×k×λ3 ··· Equation 6a

[0095] When at least two of the above equations are satisfied, the reception sensitivity of radio waves in multiple frequency bands can be ensured with a simpler configuration and higher. The element length L CL more preferably satisfies all three equations 4a, 5a, and 6a.

[0096] When at least two of the above equations 4, 5, and 6 are satisfied, considering that the reception sensitivity of radio waves in multiple frequency bands can be ensured with a simple configuration, the length L6 of the sixth element 16 is preferably 1.25 times or more and 4 times or less, more preferably 1.5 times or more and 3.75 times or less, and further preferably 1.75 times or more and 3.5 times or less of the length L5 of the fifth element 15.

[0097] In the fifth embodiment ( Figure 6 ) and the sixth embodiment ( Figure 7)In [it], the total length of the fifth element 15 and the sixth element 16 that constitute the auxiliary element 60 is set to L CT . At this time, for the element length L CT satisfies

[0098] 0.18×k×λ1≤L CT ≤0.43×k×λ1 ··· Equation 7

[0099] 0.41×k×λ2≤L CT ≤0.96×k×λ2 ··· Equation 8

[0100] 1.18×k×λ3≤L CT ≤2.76×k×λ3 ··· Equation 9.

[0101] In the case of at least two of the above equations, the reception sensitivity of radio waves in multiple frequency bands can be ensured with a simple configuration. The element length L CT preferably satisfies all three equations 7, 8, and 9.

[0102] Preferably, for the element length L CT satisfies

[0103] 0.19×k×λ1≤L CT ≤0.37×k×λ1 ··· Equation 7a

[0104] 0.44×k×λ2≤L CT ≤0.82×k×λ2 ··· Equation 8a

[0105] 1.28×k×λ3≤L CT ≤2.36×k×λ3 ··· Equation 9a

[0106] In the case of at least two of the above equations, the reception sensitivity of radio waves in multiple frequency bands can be ensured with a simpler configuration and higher sensitivity. The element length L CT more preferably satisfies all three equations 7a, 8a, and 9a.

[0107] When at least two of the above equations 7, 8, and 9 are satisfied, considering that the reception sensitivity of radio waves in multiple frequency bands can be ensured with a simple configuration, the length L6 of the sixth element 16 is preferably 2 times or more and 6 times or less the length L5 of the fifth element 15, more preferably 2.2 times or more and 5 times or less, and further preferably 2.5 times or more and 4.3 times or less.

[0108] Figure 9 Shown is a top view of a configuration example of the antenna device according to the eighth embodiment. In the eighth embodiment, for the same configurations and effects as in the first embodiment, the description is omitted or simplified by reference to the above description. Figure 9In the antenna device 108 shown, the shape of the main element 50 is different from that of the antenna device 101 of the first embodiment.

[0109] The antenna component 10 includes a main element 50 extending from the power supply unit 31 to the open end 59 via at least one bent portion ( Figure 9 in the example shown, it is one bent portion 51). The main element 50 is an L-shaped element having a seventh element 17 and an eighth element 18.

[0110] The seventh element 17 is connected to the power supply unit 31 and extends away from the power supply unit 31. In this example, it extends linearly from the power supply unit 31 in the second direction to the bent portion 51. The eighth element 18 is connected to the end of the seventh element 17 on the side opposite to the power supply unit 31 side (the bent portion 51 in this example) and extends in a direction different from the extending direction of the seventh element 17. In this example, it extends linearly from the bent portion 51 in the first direction to the open end 59.

[0111] In the antenna device 108, when the element length L of the main element 50 satisfies at least two of the above formulas 1, 2, and 3, the reception sensitivity of radio waves in multiple frequency bands can be ensured with a simple configuration. The element length L of the main element 50 preferably satisfies all three formulas 1, 2, and 3.

[0112] Furthermore, in the antenna device 108, when the element length L of the main element 50 satisfies at least two of the above formulas 1a, 2a, and 3a, a higher reception sensitivity of radio waves in multiple frequency bands can be ensured with a simple configuration. The element length L of the main element 50 more preferably satisfies all three formulas 1a, 2a, and 3a.

[0113] Figure 10 The figure shows a top view of a configuration example of the antenna device of the ninth embodiment. In the ninth embodiment, for the same configurations and effects as those of the eighth embodiment, the description is omitted or simplified by reference to the above description. Figure 10 The antenna device 109 shown is different from the antenna device 108 of the eighth embodiment in that it further has a ninth element 19. The antenna component 10 has a main element 50 and a ninth element 19.

[0114] The ninth element 19 is connected to the power supply unit 31 or a portion of the main element 50 other than the end portion. In Figure 10 the example shown, it is connected to the middle portion of the seventh element 17. Figure 10 The ninth element 19 shown extends linearly from the middle portion of the seventh element 17 in the first direction to the open end 56. The ninth element 19 is shorter than the eighth element 18, but it may also be the same as or longer than the eighth element 18.

[0115] Since the antenna device 109 has the ninth element 19, compared with the case without the ninth element 19, it can improve the sensitivity of the frequency band with relatively low reception sensitivity and enhance the reception sensitivity of the overall specified frequency band.

[0116] Figure 11 The top view of the configuration example of the antenna device according to the tenth embodiment is shown. In the tenth embodiment, the description of the same configuration and effects as those in the eighth embodiment is omitted or simplified by reference to the above description. Figure 11 The shown antenna device 110 is different from the antenna device 108 of the eighth embodiment in that it also has the ninth element 19. The antenna component 10 has the main element 50 and the ninth element 19.

[0117] The ninth element 19 is connected to the power supply unit 31 or a part of the main element 50 other than the end portion. In Figure 11 the shown example, it is connected to the middle part of the seventh element 17. Figure 11 The shown ninth element 19 linearly extends from the middle part of the seventh element 17 in the fourth direction to the open end 56. The ninth element 19 is shorter than the eighth element 18, but it can also be the same as or longer than the eighth element 18.

[0118] Since the antenna device 110 has the ninth element 19, compared with the case without the ninth element 19, it can improve the sensitivity of the frequency band with relatively low reception sensitivity and enhance the reception sensitivity of the overall specified frequency.

[0119] Figure 12 The top view of the configuration example of the antenna device according to the eleventh embodiment is shown. In the eleventh embodiment, the description of the same configuration and effects as those in the second embodiment is omitted or simplified by reference to the above description. Figure 12 The shown antenna device 111 is different from the antenna device 102 of the second embodiment in that it also has the power supply unit 32 and the antenna component 20.

[0120] The antenna device 111 includes the power supply unit 31, the antenna component 10, the power supply unit 32, and the antenna component 20. In addition, Figure 12 the shown antenna component 10 has the same shape as that in Figure 3 the shown second embodiment, but it can also have the shape of other embodiments.

[0121] The power supply unit 32 is an example of the second power supply unit, which is a power supply point for supplying power to the antenna component 20. The power supply unit 32 is electrically connected to, for example, the input terminal of an amplifier (not shown) that amplifies the signal received by the antenna component 20. The signal amplified by the amplifier is supplied to a receiving device (not shown) mounted on the vehicle body. As a specific example of the power supply unit 32, a connector, an electrode, etc. can be cited. In addition, in the antenna device 111, the power supply unit 32 can be arranged near the power supply unit 31. By bringing the power supply unit 31 and the power supply unit 32 close to each other as in the antenna device 111 shown in Figure 12 , it is possible to easily bundle the wirings connecting these power supply units 31 and 32 to the input terminal of the amplifier (not shown), etc., to simplify the structure, and it is preferable in terms of effective use of space.

[0122] The antenna component 20 is an example of the second antenna component, which is connected to the power supply unit 32. The end portion (base end portion) on the power supply unit 32 side of the antenna component 20 is electrically connected to the power supply unit 32 through, for example, solder or a conductive adhesive. The antenna component 20 is a conductor formed in a manner capable of receiving AM broadcast waves included in the MF (medium frequency) band with a frequency of 300 kHz to 3 MHz. The antenna component 20 can be built into the rear spoiler 1 or provided on the outer surface of the rear spoiler 1. The antenna component 20 is a linear conductive member, and can be formed of, for example, a wire, a conductive coating, a metal rod, a metal plate, etc., or can be a coated conductor in which a conductor is coated with an insulating material.

[0123] The description of the form in which the antenna component 20 is mounted on the rear spoiler 1 is omitted by referring to the above description (of the first embodiment) of the form in which the antenna component 10 is mounted on the rear spoiler 1.

[0124] The narrowest substantially quadrilateral (in the XY plane) region where the power supply unit 32 and the antenna component 20 are in contact with each other outside the power supply unit 32 and the antenna component 20 is defined as the second region 42. In this example, the second region 42 is narrower than the first region 41, but it can also have the same area as the first region 41, or can be wider than the first region 41. In the antenna device 111, if the second region 42 is arranged in the X-axis direction (vehicle width direction) with respect to the first region 41, then when the antenna device 111 is mounted on the rear spoiler 1, for example, the mounting space (region) can be effectively utilized.

[0125] Figure 13 The figure shows an example of the measurement result of the antenna gain of the antenna device (refer to Figure 3 ) of the second embodiment. Figure 13The numerical values in the respective cells shown indicate the average antenna gains of the horizontal polarization wave (H) and the vertical polarization wave (V) for three frequency bands (FM broadcast band, DAB Band III, terrestrial digital television broadcast band (DTV)), respectively. The average antenna gain represents the value obtained by rotating a vehicle equipped with an antenna device on a turntable, calculating the average value Ga of the antenna gains measured at specified angles within 360° in the horizontal plane, and further averaging the average values Ga measured for the specified frequencies within each frequency band. The numerical values marked next to the respective components in the column of the configuration example represent the lengths of the respective components (unit: mm). In addition, although the illustration of the power supply points of the respective components in the column of the configuration example is omitted, each power supply point is arranged at the position shown in the above-described embodiment.

[0126] In addition, the comparative example has an antenna element 71 of an AM antenna, an antenna element 72 of an FM / DAB shared antenna, and a passive element 73, which corresponds to the antenna described in the above-mentioned Patent Document 1. The length of the portion (capacitive coupling portion) of the passive element 73 along the antenna element 72 is 220 mm, and the interval of the capacitive coupling portion is 1 mm. The angles α and β of the antenna device 102A (refer to Figure 3 ) are both formed as 75°, and the angles α and β of the antenna device 102B are both formed as 90°. The antenna gains of DAB Band III and DTV of the antenna device 102A are improved. The antenna gains of the three frequency bands of the antenna device 102B are all improved.

[0127] Figure 14 Shown is a diagram of an example of the measurement results of the antenna gains of the antenna devices of the fourth, fifth, and sixth embodiments (refer to Figure 5 , 6 , 7). Figure 14 The numerical values in the respective cells shown and the meaning of the column of the configuration example are the same as those in the case of Figure 13 . The antenna gains of the three frequency bands of the antenna device 104 are all improved. The antenna gains of the antenna devices 105 and 106, particularly DAB Band III and DTV, are improved.

[0128] Figure 15 Shown is a diagram of an example of the measurement results of the antenna gains of the antenna devices of the eighth and ninth embodiments (refer to Figure 9 , 10 ). Figure 15 The numerical values in the respective cells shown and the meaning of the column of the configuration example are the same as those in the case of Figure 13 . The antenna gains of the three frequency bands of the antenna device 108 are all improved. The antenna gains of the antenna device 109, particularly DAB Band III (vertical polarization wave) and DTV, are improved.

[0129] The above description has been made regarding the embodiments, but the technology of the present disclosure is not limited to the above embodiments. Various modifications and improvements such as combinations or replacements of part or all with other embodiments can be made.

[0130] For example, the antenna device of the present disclosure is not limited to being provided on a resin vehicle member. For example, if it can receive transmitted radio waves with desired sensitivity, it can also be provided on a vehicle member formed of a material other than resin. In addition, the vehicle member on which the antenna device is provided is not limited to an aerodynamic kit such as a rear spoiler, and can also be an exterior component such as a door, a bumper, a roof, an engine hood, or a window glass.

[0131] This international patent application claims the priority based on Japanese Patent Application No. 2020-076121 filed with the Japan Patent Office on April 22, 2020, and incorporates the entire contents of Japanese Patent Application No. 2020-076121 into this patent application.

[0132] Reference Signs

[0133] 1 Rear spoiler

[0134] 2 Vehicle body

[0135] 3 High-mounted stop lamp

[0136] 10 Antenna element

[0137] 11 First element

[0138] 12 Second element

[0139] 13 Third element

[0140] 14 Fourth element

[0141] 15 Fifth element

[0142] 16 Sixth element

[0143] 17 Seventh element

[0144] 18 Eighth element

[0145] 19 Ninth element

[0146] 20 Antenna element

[0147] 31, 32 Power supply unit

[0148] 41 First region

[0149] 42 Second region

[0150] 50 Main element

[0151] 51, 52, 53, 54 Bending portion

[0152] Open ends 56, 57, 58, 59

[0153] Auxiliary element 60

[0154] Antenna elements 71, 72

[0155] Passive element 73

[0156] Antenna devices 101 to 111

Claims

1. An antenna device, which is an antenna device for receiving radio waves in at least two of the first frequency band, the second frequency band, and the third frequency band, and is provided in a vehicle component mounted on a vehicle body, and includes: a first power supply unit, and a first antenna component connected to the first power supply unit, wherein the first antenna component includes a main element extending from the first power supply unit to an open end via at least one bent portion, when a narrowest quadrilateral region where the first power supply unit and the first antenna component are in contact with each other outside the first power supply unit and the first antenna component is defined as a first region, Let the length of the side of the first region in the first direction be L X , and let the length of the first region in the second direction be L Y When this is the case, L X is at least 0.5 times and at most 8 times that of L Y , when the element length of the main element is set as L, the center wavelength of the first frequency band in air is set as λ1, the center wavelength of the second frequency band in air is set as λ2, the center wavelength of the third frequency band in air is set as λ3, and the wavelength shortening rate of the surrounding medium in which the main element is disposed is set as k, it satisfies at least two of Formula 1, Formula 2, and Formula 3: 0.09×k×λ1≤L≤0.28×k×λ1 ··· Formula 1 0.20×k×λ2≤L≤0.62×k×λ2 ··· Formula 2 0.59×k×λ3≤L≤1.77×k×λ3 ··· Formula 3.

2. The antenna device according to claim 1, wherein the first antenna component has: a plurality of the bent portions, a first element connected to the first power supply unit and extending away from the first power supply unit, a second element extending away from the first power supply unit, and a third element connecting an end portion of the first element opposite to the first power supply unit side and an end portion of the second element on the first power supply unit side.

3. The antenna device according to claim 2, wherein, There are only two connection portions of the plurality of bent portions, namely, a connection portion between the first element and the third element and a connection portion between the second element and the third element.

4. The antenna device according to claim 2 or 3, wherein The first element and the second element extend in the first direction.

5. The antenna device according to claim 2, wherein, The third element forms an angle in the range of 10° to 170° with the first element and the second element.

6. The antenna device according to claim 5, wherein, The third element extends in the second direction.

7. The antenna device according to claim 2, wherein, An end portion of the second element opposite to the third element side is an open end.

8. The antenna device according to claim 2, wherein, The first antenna component has a fourth element connected to an end portion of the second element opposite to the first power supply unit side.

9. The antenna device according to claim 8, wherein The fourth element extends in a third direction opposite to the second direction.

10. The antenna device according to claim 1, wherein, The first antenna component has an auxiliary element connected to a portion of the first power supply unit or the main element other than the end portion.

11. The antenna device according to claim 10, wherein, The auxiliary element is connected to the main element.

12. The antenna device according to claim 10, wherein, The auxiliary element has a fifth element extending in the second direction, and a sixth element connected to the fifth element and extending in a direction different from the fifth element.

13. The antenna device according to claim 12, wherein the fifth element extends in the second direction, the sixth element extends in at least one of the first direction and a fourth direction opposite to the first direction.

14. The antenna device according to claim 12, wherein, The auxiliary element includes an L-shaped element portion.

15. The antenna device according to claim 14, wherein, The total length L of the fifth element and the sixth element CL satisfies at least two of Equation 4, Equation 5, and Equation 6: 0.13×k×λ1 ≤ L CL ≤ 0.31×k×λ1 ··· Equation 4 0.30×k×λ2≤L CL ≤0.69×k×λ2 ··· Equation 5 0.88×k×λ3≤L CL ≤1.97×k×λ3 ··· Equation 6 16. The antenna device according to claim 15, wherein, The length L6 of the sixth element is 1.25 times or more and 4 times or less the length L5 of the fifth element.

17. The antenna device according to claim 12, wherein, The auxiliary element includes a T-shaped element portion.

18. The antenna device according to claim 17, wherein, The total length L of the fifth element and the sixth element CT satisfies at least two of Equation 7, Equation 8, and Equation 9: 0.18×k×λ1≤L CT ≤0.43×k×λ1 ··· Equation 7 0.41×k×λ2≤L CT ≤0.96×k×λ2 ··· Equation 8 1.18×k×λ3≤L CT ≤2.76×k×λ3 ··· Equation 9 19. The antenna device according to claim 18, wherein, The length L6 of the sixth element is not less than twice and not more than six times the length L5 of the fifth element.

20. The antenna device according to claim 10, wherein, The auxiliary element has a plurality of open ends.

21. The antenna device according to claim 1, wherein the main element is an L-shaped element, the L-shaped element has: a seventh element connected to the first power supply unit and extending away from the first power supply unit, an eighth element connected to an end portion of the seventh element opposite to the first power supply unit side and extending in a direction different from the extending direction of the seventh element.

22. The antenna device according to claim 21, wherein the seventh element extends in the second direction, the eighth element extends in the first direction.

23. The antenna device according to claim 21 or 22, wherein The first antenna component has a ninth element connected to a part of the first power supply unit or the main element other than the end portion.

24. The antenna device according to claim 23, wherein, The ninth element is connected to the first power supply unit or the seventh element and extends in the first direction or the fourth direction opposite to the first direction.

25. The antenna device according to claim 1, wherein it receives radio waves in the first frequency band, the second frequency band, and the third frequency band, the first frequency band is the frequency band of FM broadcast waves, the second frequency band is the frequency band of DAB BandIII, the third frequency band is the frequency band of terrestrial digital television broadcast waves.

26. The antenna device according to claim 1, wherein it further includes a second power supply unit and a second antenna component connected to the second power supply unit, the second antenna component receives AM broadcast waves.

27. The antenna device according to claim 1, wherein, The vehicle component is made of resin.

28. The antenna device according to claim 1, wherein, The vehicle component is an aerodynamic kit.

Images