JP2012090011A - On-vehicle broadband antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact and low profile on-vehicle broadband antenna whose interferences when integrated with a GPS antenna are reduced and whose antenna characteristics can be adjusted easily.SOLUTION: For on-vehicle broadband in the prevent embodiment, a tip 114 of a power fed element 110 is folded down 180 degrees to an opposite side of a non-power fed element 120 so as to be disposed on a side face 132 of a pedestal 130. Furthermore, a tip 124 of the non-power fed element 120 is folded down 180 degrees to an opposite side of the power fed element 110 so that a folded part 123 is disposed on a side face 133 of the pedestal 130, and the tip 124 also is disposed on a top face 131 of the pedestal 130. That way, the tip 114 of the power fed element 110 and the tip 124 of the non-power fed element 120 are folded down 180 degrees in a direction they are apart from each other, thereby preventing antenna characteristics from being degraded by effects exerted by the tip of either element upon the other element.

Description

  The present invention relates to an in-vehicle broadband antenna applicable to a composite antenna mounted on a vehicle, and more particularly to an in-vehicle broadband antenna that can be integrated with a GPS antenna to form a composite antenna.

  In recent years, devices such as GPS, ETC, and VICS have been mounted on vehicles, and the number of antennas mounted on vehicles has increased accordingly. In order to cope with such an increase in the number of antennas mounted on a vehicle, it is strongly required to reduce the installation space of each antenna as much as possible. Development of composite antennas is ongoing. As a general vehicle-mounted antenna, it is preferable that its dimensions are, for example, 10 cm square or less and a height of several cm or less in order to facilitate arrangement in the vehicle.

  In mobile phones, the use of frequency bands such as the 800 MHz band and the 900 MHz band has good propagation characteristics and a wide communication range. Therefore, the use in this frequency band is also strongly desired as an in-vehicle mobile phone. For this reason, there is a high need for a vehicle-mounted broadband antenna corresponding to this frequency band. However, for example, at 824 MHz, the wavelength is 364 mm, and an antenna with a large size is required. In addition to this, in the vehicle-mounted antenna, in order to reduce the influence of equipment around the installation location, a method of providing a substrate that operates electrically as a ground plate or a substrate having a ground plate, and disposing the antenna element thereon Is used.

  As a small and low-profile antenna that operates on a substrate, for example, an inverted L antenna and an inverted F antenna are known. In these antennas, the length of the antenna element is required to be about 1/4 of the wavelength. When radiating radio waves in a direction parallel to the substrate with an inverted L antenna or an inverted F antenna, the radio waves in the direction parallel to the substrate radiated from the substrate should be actively used by adjusting the arrangement with respect to the substrate. Can widen the frequency band. On the other hand, when a radio wave in a direction orthogonal to the substrate is radiated on the substrate, there is a problem that the frequency band becomes narrow in the inverted L antenna and the inverted F antenna.

  Therefore, as a measure for making it possible to use a wider frequency band, methods using parasitic elements (parasitic elements) are known (Patent Documents 1 and 2). When the parasitic element is arranged in the vicinity of the feeding element, the parasitic element operates at another frequency close to the operating frequency of the feeding element due to the combination of the two. As a result, it is possible to operate in a wide frequency band in which the operating frequencies of the feeding element and the parasitic element are combined.

JP 2004-201278 A JP 2006-238269 A

  However, in-vehicle wideband antennas, which have been made wider by adding parasitic elements to the feed elements, require a relatively large space for arranging the two elements in parallel, and secure a space for mounting in the vehicle. There is a problem that it is difficult to do. Therefore, in order to reduce the installation space of the in-vehicle broadband antenna, it is strongly recommended that the in-vehicle broadband antenna be further reduced in size and height and that the in-vehicle broadband antenna be integrated with the GPS antenna to be mounted as a composite antenna. desired.

  However, in the past, it has been extremely difficult to arrange a feeding element and a parasitic element of a predetermined size in a narrow space without impairing antenna characteristics, and it has been difficult to reduce interference when integrated with a GPS antenna. It was. Furthermore, when the feeding element and the parasitic element are arranged in a narrow space, there arises a problem that adjustment of antenna characteristics becomes difficult.

  The present invention has been made to solve these problems, and provides a small and low-profile in-vehicle broadband antenna in which interference when integrated with a GPS antenna is reduced and antenna characteristics can be easily adjusted. The purpose is to do.

  A first aspect of the in-vehicle broadband antenna of the present invention includes a power feeding element having a radiation portion, and a power feeding element portion and a grounding element portion that are connected to the radiation portion and arranged in a substantially vertical direction, and the power feeding element. A parasitic element having an operating part arranged so as to be connectable, and a parasitic side grounding element part connected to the operating part and arranged to be substantially parallel to the feeding element part and the grounding element part, A substrate having a pedestal having a predetermined height on which the feeding element and the parasitic element are arranged, a wiring part on which at least a wiring pattern connected to the feeding element part is arranged, and a pedestal mounting part on which the pedestal is mounted The power feeding element includes at least a main portion of the radiating portion arranged in the longitudinal direction of the upper surface of the pedestal, and a tip is folded 180 degrees to the opposite side of the parasitic element, Serial parasitic element, and at least a part is arranged substantially parallel to said radiating portion on the upper surface of the pedestal tip of the operation portion is folded back 180 degrees on the opposite side of the feed element.

  Another aspect of the in-vehicle broadband antenna of the present invention is characterized in that an in-vehicle composite antenna is configured in combination with a GPS antenna formed by a patch antenna.

  Another aspect of the in-vehicle broadband antenna according to the present invention is characterized in that the parasitic element is disposed on a side of the pedestal where the GPS antenna is disposed.

  In another aspect of the in-vehicle broadband antenna according to the present invention, the grounding element portion, the feeding element portion, and the non-feeding side grounding element portion are arranged in order from one end on the side surface of the base on the wiring pattern side. It is characterized by that.

  In another aspect of the in-vehicle broadband antenna according to the present invention, a concave portion is formed in a vertical direction on a side surface of the base on the wiring pattern side, and at least the ground element portion and the feeding element portion are arranged in the concave portion. It is characterized by.

  Another aspect of the in-vehicle broadband antenna according to the present invention is characterized in that an impedance adjusting portion of the power feeding element is formed in the concave portion.

  Another aspect of the on-vehicle broadband antenna according to the present invention is characterized in that the parasitic element includes a stub capable of adjusting the magnitude of coupling with the feeder element.

  In another aspect of the in-vehicle broadband antenna according to the present invention, the pedestal is formed in a substantially rectangular parallelepiped shape having four side surfaces, and a part of the feeding element and the parasitic element is disposed on one or more side surfaces. It is characterized by.

  In another aspect of the in-vehicle broadband antenna of the present invention, the substrate is formed in a substantially U-shape including another pedestal mounting portion on the opposite side to the pedestal mounting portion across the wiring portion, A receiving antenna including another pedestal and another feeding element arranged on the other pedestal is mounted on the other pedestal mounting portion to have a diversity configuration.

  ADVANTAGE OF THE INVENTION According to this invention, while being integrated with a GPS antenna, while being able to reduce, it becomes possible to provide a vehicle-mounted wideband antenna that can easily adjust antenna characteristics and is small and low-profile.

1 is a perspective view illustrating a schematic configuration of a vehicle-mounted broadband antenna according to a first embodiment of the present invention. It is the graph which shows the schematic diagram and VSWR characteristic which show the folding | turning direction of each element of the vehicle-mounted broadband antenna of 1st Embodiment. It is the schematic which shows the return | turnback direction of each element of the vehicle-mounted broadband antenna of the comparative example 1, and the graph which shows the VSWR characteristic. It is the schematic which shows the return | turnback direction of each element of the vehicle-mounted broadband antenna of the comparative example 2, and the graph which shows the VSWR characteristic. It is the schematic which shows the folding | turning direction of each element of the vehicle-mounted broadband antenna of the comparative example 3, and the graph which shows the VSWR characteristic. It is a perspective view which shows schematic structure of the vehicle-mounted broadband antenna of 2nd Embodiment of this invention.

  A vehicle-mounted broadband antenna according to a preferred embodiment of the present invention will be described in detail with reference to the drawings. In addition, about each structural part which has the same function, the same code | symbol is attached | subjected and shown for simplification of illustration and description.

(First embodiment)
An in-vehicle broadband antenna according to a first embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a perspective view showing a schematic configuration of a vehicle-mounted broadband antenna according to the present embodiment. FIG. 1 (a) is a perspective view seen from the feeding point side, and FIG. 1 (b) is a perspective view seen from the open end side. FIG.

  The in-vehicle broadband antenna 100 according to this embodiment includes a plate-like or linear feed element 110 and a parasitic element 120 having a substantially constant width, and these are arranged on a substantially rectangular parallelepiped base 130. ing. The power feeding element 110 has a radiation part 111, a power feeding element part 112 connected to the power feeding line, and a grounding element part 113 connected to the ground plane, and is an inverted F antenna. The feed element 110 is not limited to an inverted F antenna, and may be an inverted L antenna, for example. The main part of the radiating part 111 is arranged in the longitudinal direction of the upper surface 131 of the pedestal 130, and the feeding element part 112 and the grounding element part 113 are arranged on the side surface of the pedestal 130. Accordingly, the power feeding element portion 112 and the ground element portion 113 are bent at a part of the power feeding element 110 and are arranged in a substantially vertical direction with respect to the radiating portion 111.

  The parasitic element 120 includes an operation unit 121 arranged to be coupled to the feeding element 110 and a parasitic side grounding element unit 122 connected to the ground plane. The operation unit 121 is disposed in the longitudinal direction of the upper surface 131 of the pedestal 130, and the non-feed side grounding element unit 122 is disposed on the side surface of the pedestal 130. Thereby, the parasitic side grounding element part 122 is also bent at a part of the parasitic element 120 and arranged in a substantially vertical direction with respect to the operating part 121.

  The radiating portion 111 of the power feeding element 110 and the operating portion 121 of the parasitic element 120 each have a capacitive coupling portion disposed in close proximity to each other on the upper surface 131 of the pedestal 130. The antenna characteristics can be adjusted by forming the capacitive coupling portion by bringing the feeding element 110 and the parasitic element 120 close to each other. Further, the feeding element portion 112 and the grounding element portion 113 of the feeding element 110 and the parasitic side grounding element portion 122 of the parasitic element 120 are arranged so as to be substantially parallel on the side surface of the pedestal 130.

  The in-vehicle broadband antenna 100 according to the present embodiment is configured to be used as an in-vehicle composite antenna in combination with a GPS antenna formed by a patch antenna, and can be disposed adjacent to the GPS antenna. The substrate 140 on which the in-vehicle broadband antenna 100 is mounted includes a pedestal mounting portion 141 for mounting the pedestal 130 on one end side of the arrangement region 150 for mounting the GPS antenna, and on the feeding element portion 112 side. The wiring part 142 for arrange | positioning the wiring pattern 142a for connecting at least the electric power feeding element part 112 and the electric power feeding line 160 is provided.

  The board 140 is mounted substantially horizontally on the vehicle, whereby the radiation part 111 and the like are installed substantially horizontally, and the feeding element part 112, the grounding element part 113, and the non-feeding side grounding element part 122 are installed in the vertical direction. The The substrate 140 is electrically operated as a ground plane or is a composite including the ground plane. Alternatively, the base plate of the in-vehicle broadband antenna 100 may be provided on the bottom surface of the base 130.

  In the in-vehicle broadband antenna 100 according to the present embodiment, since the feeding element 110, the parasitic element 120, and the respective element portions are all arranged on the upper surface 131 or the side surface of the pedestal 130, the antenna dimensions are the dimensions of the pedestal 130. Determined. Therefore, when the wavelength corresponding to the lowest operating frequency of the in-vehicle broadband antenna 100 is λ, the longitudinal dimension (maximum dimension) of the pedestal 130 is less than λ / 4, and the maximum width of the pedestal 130 (the upper surface 131) The in-vehicle broadband antenna 100 is reduced in size and height by setting the direction orthogonal to the longitudinal direction) to λ / 10 or less and further the height of the pedestal 130 to about λ / 10.

  In an inverted F antenna, an inverted L antenna, or the like, the element length needs to be approximately λ / 4. However, if the longitudinal dimension of the pedestal 130 is less than λ / 4, the feeding element 110 is disposed only in the longitudinal direction of the pedestal 130. It is not possible to do so, and it is necessary to bend and arrange a part. Similarly, when the parasitic element 120 cannot be provided with a necessary length in the longitudinal direction of the pedestal 130, it is necessary to bend a part thereof.

  As described above, when it is necessary to fold a part of the power supply element 110 or the parasitic element 120 and arrange the pedestal 130 on the pedestal 130, it is difficult to arrange the bent portion on the upper surface 131 because the upper surface 131 of the pedestal 130 is narrow. Become. In addition, there arises a problem that the antenna characteristics are deteriorated depending on the location of the bent portion. In the feeding element 110 and the parasitic element 120, the potential at the tip is maximized at the time of resonance. Therefore, bending the tip and bringing it close to the other element has a strong influence on each other and deteriorates the antenna characteristics. Resulting in.

  For example, if the tip of the power feeding element 110 is bent and brought close to the parasitic element 120, the effect that the parasitic element 120 operates at a frequency in the vicinity of the operating frequency of the power feeding element 110 is reduced. There is a risk that it will not be possible to realize a wide bandwidth.

  Therefore, in the in-vehicle broadband antenna 100 of the present embodiment, the folded portion of one element is bent to the opposite side of the other element. When the leading end portions of both the power supply element 110 and the parasitic element 120 are bent, the respective bent portions are bent so as to be opposite to each other (to be outward). Further, in order to arrange the bent portion on the pedestal 130, the side surface of the arrangement pedestal 130 can be used in addition to the upper surface 131. As side surfaces of the pedestal 130, side surfaces 132, 133, and 134 shown in FIG. 1 can be used. By arranging the folded portion using such a side surface, it is possible to reduce the mutual influence as much as possible as far as possible from the other element.

  In FIG. 1, the front end portion 114 of the power feeding element 110 is folded back 180 degrees on the side opposite to the parasitic element 120 and is disposed on the side surface 132 of the pedestal 130. Further, the leading end portion 124 of the parasitic element 120 is folded back 180 degrees on the side opposite to the feeding element 110, the folded portion 123 is disposed on the side surface 133 of the pedestal 130, and the leading end portion 124 is disposed on the upper surface 131 of the pedestal 130. . In this way, when the front end portion 114 of the feed element 110 and the front end portion 124 of the parasitic element 120 are folded back by 180 degrees in the direction away from each other, each of the front end portions affects the other element, thereby deteriorating the antenna characteristics. It is preventing.

  A description will be given of how the folding directions of the distal end portion 114 of the power feeding element 110 and the distal end portion 124 of the parasitic element 120 affect the characteristics of the in-vehicle broadband antenna 100 using simulation results. FIG. 2 is a diagram showing the characteristics of the on-vehicle broadband antenna 100 of the present embodiment, and FIG. 2A is a schematic diagram showing the folding direction of the feeding element 110 and the parasitic element 120 of the on-vehicle broadband antenna 100. FIG. 4B is a graph showing the VSWR characteristics.

  FIG. 2A shows that the front end portion 114 of the feeding element 110 and the front end portion 124 of the parasitic element 120 are folded back in the direction away from each other (outside). By turning the tip portions 114 and 124 away from each other, a VSWR characteristic as shown in FIG. 2B is obtained, and a good characteristic is obtained in a wide band between the low-side frequency F1 and the high-side frequency F2. I understand that. Here, the low frequency F1 = 880 MHz and the high frequency F2 = 960 MHz.

  In addition, as Comparative Example 1, FIG. 3 shows the antenna characteristics when the feeding element and the parasitic element are made straight without being folded back. FIG. 6A is a schematic diagram showing that both the feeding element 11 and the parasitic element 12 are linear, and FIG. 6B is a graph showing the VSWR characteristics. From the VSWR characteristics shown in FIG. 3B, it can be seen that when the feeding element 11 and the parasitic element 12 are linear, good characteristics can be obtained in a wide band of frequencies F1 to F2. When FIG. 2B, which is the antenna characteristic of the in-vehicle broadband antenna 100 of this embodiment, is compared with FIG. 3B, it can be seen that approximately the same VSWR characteristic is obtained in both cases.

  On the other hand, FIGS. 4 and 5 show simulation results when the folding direction of the feeding element and the parasitic element is different from that of the in-vehicle broadband antenna 100 of the present embodiment. In FIG. 4, as shown in FIG. 4A as Comparative Example 2, both the tip of the feeding element 21 and the tip of the parasitic element 22 are folded leftward, and the VSWR characteristics at that time are shown in FIG. This is shown in b). In FIG. 5, as shown in FIG. 5A as Comparative Example 3, the front end portion of the feeding element 31 and the front end portion of the parasitic element 32 are folded back toward each other in the inner direction, and the VSWR at that time The characteristics are shown in FIG.

  As shown in FIG. 4, when both the front end of the feed element 21 and the front end of the parasitic element 22 are turned leftward, the VSWR characteristic is greatly deteriorated and the operation in the frequency band F1 to F2 cannot be performed. I understand. This indicates that when the leading end of the parasitic element 22 is close to the radiating portion of the feeding element 21, the feeding element 21 is strongly influenced by the leading end of the parasitic element 22 and the VSWR characteristics are greatly deteriorated. ing.

  In addition, as shown in FIG. 5, even when the leading end of the feeding element 31 and the leading end of the parasitic element 32 are folded back toward the inner side, the VSWR characteristics are greatly degraded, and the operation is performed in the frequency band of F1 to F2. It turns out that it becomes impossible. In this case, it is shown that the VSWR characteristic is greatly deteriorated due to the strong influence of each other due to the proximity of the leading end of the feeding element 31 and the leading end of the parasitic element 32 and interference.

  From the above simulation results, it is preferable that the distal end portion 114 of the power feeding element 110 and the distal end portion 124 of the parasitic element 120 are folded back outwardly away from each other in order to reduce the influence on the other element as much as possible. Recognize. Thereby, it is possible to obtain approximately the same VSWR characteristics as when the feeding element 110 and the parasitic element 120 are made straight without being folded back.

  In order to reduce the influence of the folded tip portion on the other element as much as possible, at least one of the tip portion 114 of the feeding element 110 and the tip portion 124 of the non-feeding element 120 is further connected to the side surface in the longitudinal direction of the base 130 ( 132, 134). By disposing at least one of the tip portions 114 and 124 on the side surface in the longitudinal direction of the pedestal 130, the influence on the other element can be further reduced.

  In the in-vehicle broadband antenna 100 of the present embodiment, the front end portion 114 of the power feeding element 110 is disposed on the side surface 132 in the longitudinal direction. In addition, by disposing part of the power feeding element 110 and the parasitic element 120 on the side surface of the pedestal 130, the size of the in-vehicle broadband antenna 100, that is, the size of the pedestal 130 can be reduced. In this embodiment, the front end portion 114 of the power supply element 110 and the folded portion 123 of the parasitic element 120 are arranged on the side surface 132 and the side surface 133 of the pedestal 130, respectively, thereby ensuring the necessary element length in each case. Yes.

  Another factor that affects the antenna characteristics of the in-vehicle broadband antenna 100 according to this embodiment is a mirror image current. In general, in an inverted F antenna or an inverted L antenna that operates on a ground plane, a mirror image current is generated on the ground plane. This mirror image current has a characteristic that it acts so as to cancel out a component in a direction parallel to the substrate (base plate) surface of the current flowing through the element. The effect of such a mirror image current becomes stronger as the distance between the element and the substrate (base plate) becomes smaller.

  In the in-vehicle broadband antenna 100 of this embodiment, at least the main part of the radiating portion 111 of the feed element 110 is disposed on the upper surface 131 of the pedestal 130 having a height of about λ / 10, thereby increasing the distance from the ground plane. This reduces the effect of mirror image current. Further, when a part of the radiating portion 111 is disposed on the side surface of the pedestal, it is preferably disposed above half of the height of the pedestal 130.

  The in-vehicle broadband antenna 100 according to the present embodiment can constitute an in-vehicle composite antenna by arranging a GPS antenna in the arrangement region shown in FIG. When combined with a GPS antenna, it is necessary to reduce as much as possible the deterioration of the antenna characteristics of the in-vehicle broadband antenna 100 due to the influence of the GPS antenna.

  Therefore, in the present embodiment, at least a main part of the power feeding element 110 is arranged on the upper surface 131 of the pedestal 130 having a predetermined height so as to be higher in the vertical direction than the GPS antenna mounted in the arrangement region 150. Thus, the main part of the power feeding element 110 is arranged at a position higher than the GPS antenna, so that interference from the GPS antenna is reduced. In the present embodiment, the height of the pedestal 130 is about λ / 10, which can reduce interference from the GPS antenna.

  Further, it is preferable that the feeding element 110 is arranged on the left side of the pedestal 130 in the drawing far from the GPS antenna installation area 150 and the parasitic element 120 is arranged on the right side of the pedestal 130 near the GPS antenna installation area 150 in the drawing. In the present embodiment, since the tip end portion 114 of the power feeding element 110 is folded back in a direction further away from the GPS antenna installation area 150, the influence from the GPS antenna can be further reduced.

  Further, the power feeding element portion 112 and the grounding element portion 113 of the power feeding element 110 and the power feeding element grounding element portion 122 of the parasitic element 120 are arranged in order from the end side of the pedestal 130, the grounding element portion 113, the power feeding element portion 112, The parasitic element ground element 122 is arranged in this order, and the feeder element 112 is sandwiched between the parasitic element 113 and the parasitic element 122. Impedance adjustment is facilitated by bringing the non-feed side grounding element portion 122 and the feed element portion 112 close to each other.

  In order to further reduce the size of the in-vehicle broadband antenna 100 of the present embodiment, a recess 134a is formed on the side surface 134 of the pedestal 130 on which the feed element portion 112 and the ground element portion 113 are arranged. By forming the concave portion 134a, a connection pad portion for connecting the power feeding element portion 112 and the ground element portion 113 to the substrate 140 can be provided in the concave portion 134a. Thereby, it can prevent or reduce that a connection pad part protrudes from the side surface 134 to a GPS antenna side, and reduces the required space of the board | substrate 140 for mounting the vehicle-mounted broadband antenna 100, especially the wiring part 142. Is possible. In the present embodiment, the concave portion 134a is formed only in the portion where the feeding element portion 112 and the grounding element portion 113 are disposed. However, the present invention is not limited thereto, and for example, the non-feeding side grounding element portion 122 is also included. A recess 134a may be formed.

  In the in-vehicle broadband antenna 100 of the present embodiment, a connection line 115 that connects the power feeding element portion 112 of the power feeding element 110 and the ground element portion 113 is provided, and the power feeding element portion 112, the ground element portion 113, the connection line 115, and the like. Thus, a U-shaped impedance adjusting portion 110a is formed. The impedance adjustment unit 110a is disposed in the recess 134a, and the radiation unit 111 is connected to the connection line 115. In the impedance adjustment unit 110a, the size of the impedance can be adjusted by adjusting the length (height) of the feeding element unit 112 and the grounding element unit 113 and the length of the connection line 115.

  By providing the impedance adjusting unit 110a as described above, it is possible to arrange the feeding element 110 and the parasitic element 120 in a straight line without providing a bent portion or the like for adjusting the impedance. It becomes possible. Further, by providing the impedance adjustment unit 110a, the element position for performing the impedance adjustment becomes clear, and the adjustment becomes easy.

  In the in-vehicle broadband antenna 100 of the present embodiment, the lengths of the tip portions 114 and 124 folded back 180 degrees are adjusted, the coupling (proximity distance) between the elements in each of the feeding element 110 and the parasitic element 120, both The antenna characteristics can be adjusted by adjusting the coupling (proximity distance) between the elements 110 and 120. In order to further facilitate adjustment of the antenna characteristics, a stub for adjusting the distance between the feeding element 110 and the parasitic element 120 can be provided. A stub that protrudes from the parasitic element 120 side to the feeder element 110 side is provided at a coupling portion that is disposed substantially in parallel between the radiating portion 111 of the feeder element 110 and the operating portion 121 of the parasitic element 120, and The antenna characteristics can be easily adjusted by adjusting the width of the stub and the distance from the power feeding element 110.

  As described above, according to the present embodiment, the feeding element 110 and the parasitic element 120 are arranged on the pedestal 130, and the front end portions 114 and 124 are folded back in a direction away from each other, thereby being integrated with the GPS antenna. Thus, it is possible to reduce the interference at the time, and to provide a vehicle-mounted broadband antenna 100 that is easy to adjust the antenna characteristics and is small and low in profile.

(Second Embodiment)
An in-vehicle broadband antenna according to a second embodiment of the present invention will be described below with reference to FIG. FIG. 6 is a perspective view showing a schematic configuration of the in-vehicle broadband antenna according to the present embodiment. FIG. 6A is a perspective view seen from the feeding point side, and FIG. 6B is a perspective view seen from the open end side. FIG.

  In the in-vehicle broadband antenna 200 of the present embodiment, the substrate 240 is formed in a substantially U-shape including another pedestal mounting portion 243 in addition to the pedestal mounting portion 141 and the wiring portion 142. The pedestal mounting portion 141 is mounted with a first antenna portion 201 having a power feeding element 110 and a parasitic element 120 similar to the in-vehicle broadband antenna 100 of the first embodiment, and the pedestal mounting portion 243 has a power feeding element 210. The second antenna unit 202 having the above is mounted. The GPS antenna arrangement area 150 can be provided between the base mounting part 141 and another base mounting part 243.

  In the present embodiment, the first antenna unit 201 operates as a transmission / reception antenna, and the second antenna unit 202 operates as a reception antenna. By making the substrate 240 substantially U-shaped, the distance between the first antenna unit 201 and the second antenna unit 202 is ensured, whereby the diversity of the first antenna unit 201 and the second antenna unit 202 is increased. It is configured. In order to make the distance between the first antenna unit 201 and the second antenna unit 202 as long as possible, the first antenna unit 201 and the second antenna unit 202 are preferably arranged at the ends of the two opposing sides of the substantially U-shaped substrate 240.

  The second antenna unit 202 includes a plate-like or linear feed element 210 having a substantially constant width, and this is arranged on a substantially rectangular parallelepiped base 230. The power feeding element 210 includes a radiation portion 211 and a power feeding element portion 212 connected to the wiring pattern 242a. The main part of the radiating part 211 is arranged in the longitudinal direction of the upper surface 231 of the pedestal 230, and the feeding element part 212 is arranged on the side surface of the pedestal 230 substantially facing the feeding element part 112 of the one antenna part 201. As a result, the power feeding element portion 212 is bent at a part of the power feeding element 210 and disposed in a substantially vertical direction with respect to the radiating portion 211, and is connected to the power feeding line 260 via the wiring pattern 242a.

  Also in the second antenna unit 202, since the radiating unit 211 and the feeding element unit 212 of the feeding element 210 are arranged on the upper surface 231 or the side surface of the pedestal 230, the dimension of the second antenna unit 202 is determined by the dimension of the pedestal 230. . By arranging the radiating portions 211 not only on the upper surface 231 of the pedestal 230 but also on the side surfaces, the longitudinal dimension (maximum dimension) of the pedestal 230 is less than λ / 4, and the maximum width of the pedestal 230 (the longitudinal length of the upper surface 231) (The direction orthogonal to the direction) is λ / 10 or less and the height of the pedestal 230 is about λ / 10, whereby the second antenna unit 202 is reduced in size and height.

  Since the longitudinal dimension of the pedestal 230 is less than λ / 4, the distal end portion 214 is 180 degrees opposite to the first antenna portion 201 in order to arrange the necessary element length of the feed element 210 on the pedestal 230. It is folded and disposed on the side surface 232 of the pedestal 230. As a result, interference with the first antenna unit 201 is reduced as much as possible, and when a GPS antenna is mounted between the first antenna unit 201 and the second antenna unit 202 to form a composite antenna, interference with the GPS antenna is achieved. Can also be reduced. As a result, it is possible to provide a vehicle-mounted broadband antenna 200 having good antenna characteristics due to diversity reception characteristics with the first antenna unit 201.

  In addition, by disposing the main part of the radiating portion 211 of the power feeding element 210 on the pedestal 230 having a height of about λ / 10, the distance from the ground plane is increased to reduce the influence of the mirror image current, and more perpendicular to the GPS antenna. By increasing the direction, the influence from the GPS antenna can be reduced.

  Further, also in the second antenna unit 202, a recess 234a is formed on the side surface 234 of the pedestal 230 where the feeding element unit 212 is disposed, and a connection pad unit for connecting the feeding element unit 212 to the substrate 240 is formed in the recess 234a. It is provided inside. As a result, the connection pad portion can be prevented or reduced from protruding from the side surface 234 toward the first antenna portion 201, and the necessary space for the substrate 240, particularly the wiring portion 142 can be reduced. The wideband antenna 200 can be reduced in size.

  Note that the description in the present embodiment shows an example of the in-vehicle broadband antenna according to the present invention, and the present invention is not limited to this. The detailed configuration and detailed operation of the in-vehicle broadband antenna in the present embodiment can be changed as appropriate without departing from the spirit of the present invention.

100, 200 In-vehicle broadband antenna 110, 210 Feed element 110a Impedance adjustment unit 111 Radiation unit 112 Feed element unit 113 Ground element unit 114, 214 Tip unit 115 Connection line 120 Parasitic element 121 Operation unit 122 Parasitic side ground element unit 123 Folded portion 124 Tip portion 130, 230 Pedestal 131, 231 Upper surface 132, 133, 134, 135, 232, 234 Side surface 134a, 234a Recess 140, 240 Substrate 141 Pedestal mounting portion 142 Wiring portion 142a, 242a Wiring pattern 150 Arrangement region 160, 260 Feeding line 201 First antenna part 202 Second antenna part 243 Another pedestal mounting part

Claims (9)

A feeding element having a radiating part, and a feeding element part and a grounding element part connected to the radiating part and arranged in a substantially vertical direction;
A parasitic part having an operating part arranged to be coupled to the feeding element and a parasitic side grounding element part connected to the operating part and arranged to be substantially parallel to the feeding element part and the grounding element part Elements,
A pedestal having a predetermined height on which the feeding element and the parasitic element are disposed;
A board having at least a wiring part on which a wiring pattern connected to the power feeding element part is disposed, and a pedestal mounting part on which the pedestal is mounted;
The feeding element has at least a main portion of the radiating portion arranged in the longitudinal direction of the upper surface of the pedestal and a tip folded back 180 degrees to the side opposite to the parasitic element,
The on-vehicle element is characterized in that at least a part of the operating part is disposed substantially parallel to the radiating part on the upper surface of the pedestal, and the tip is folded 180 degrees to the opposite side to the feeding element. Wideband antenna. The in-vehicle broadband antenna according to claim 1, wherein the in-vehicle composite antenna is configured in combination with a GPS antenna formed by a patch antenna. The in-vehicle broadband antenna according to claim 2, wherein the parasitic element is disposed on a side of the pedestal where the GPS antenna is disposed. The grounding element portion, the feeding element portion, and the non-feeding side grounding element portion are arranged in order from one end on the side surface of the base on the wiring pattern side. 2. A broadband antenna for vehicle use according to item 1. 5. The recess according to claim 1, wherein a recess is formed in a vertical direction on a side surface of the base on the wiring pattern side, and at least the ground element portion and the power feeding element portion are disposed in the recess. The in-vehicle broadband antenna according to the item. 6. The in-vehicle broadband antenna according to claim 5, wherein an impedance adjusting portion of the power feeding element is formed in the concave portion. The on-vehicle broadband antenna according to any one of claims 1 to 6, wherein the parasitic element includes a stub capable of adjusting a magnitude of coupling with the feeder element. The pedestal is formed in a substantially rectangular parallelepiped shape having four side surfaces, and a part of the feeding element and the parasitic element is disposed on one or more of the side surfaces. The in-vehicle broadband antenna according to any one of the above. The substrate is formed in a substantially U-shape with another pedestal mounting part on the opposite side of the pedestal mounting part across the wiring part,
The receiving antenna comprising another pedestal and another feeding element arranged on the other pedestal is mounted on the other pedestal mounting portion to have a diversity configuration. In-vehicle broadband antenna.

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