WO2012053494A1

WO2012053494A1 - Vehicle-mounted antenna

Info

Publication number: WO2012053494A1
Application number: PCT/JP2011/073872
Authority: WO
Inventors: 青木　一芳; 範行庄司; 磯　洋一; 裕次郎中山; 正弘楠
Original assignee: 古河電気工業株式会社
Priority date: 2010-10-18
Filing date: 2011-10-17
Publication date: 2012-04-26

Abstract

An objective of the present invention is to provide a small, low-profile vehicle-mounted antenna for which interference is reduced when integrated with a GPS antenna and which is amenable to adjustment of antenna characteristics. In addition, an objective of the present invention is to provide a vehicle-mounted antenna for which favorable antenna characteristics can be acquired in either a low-frequency band or a high-frequency band, and which is capable of achieving further saving of space. The distal end (114) of a feed element (110) is folded back 180 degrees to the opposite side of a non-fed element (120). Also, the distal end (124) of the non-fed element (120) is folded back 180 degrees to the opposite side of the feed element (110). Furthermore, the direction of extension of the primary portion of the fH-band-use antenna element (316) and the direction of extension of the primary portion of the fL-band-use antenna element (314) differ by approximately 180 degrees upon the upper surface of a pedestal (330).

Description

Automotive antenna

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

For example, an inverted L antenna and an inverted F antenna are known as small and low profile antennas that operate on a substrate. 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, a method using a parasitic element (parasitic element) is known as a countermeasure for making it possible to use a wider frequency band (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.

In recent years, with the enhancement of functions of vehicles such as automobiles, various devices such as GPS and ETC have been mounted on the vehicle, and the number of antennas mounted on the vehicle increases as the number of mounted devices increases. There is a tendency. In order to cope with such an increase in the number of on-vehicle antennas, development of a composite antenna that integrates a plurality of antennas and a reduction in the size and height of each antenna is in progress.

In recent years, there has been an increasing demand for mounting a telephone antenna for use in a mobile phone or the like on a vehicle, and it is difficult to secure a space for installing a telephone antenna. Is desired. Due to the recent increase in the frequency band used for mobile phones, telephone antennas that support both low frequency bands such as 824 MHz to 960 MHz and high frequency bands such as 1575 MHz (GPS band) and 1710 MHz to 2170 MHz are desired. Yes.

For example, a composite antenna as shown in FIG. 18 has been proposed as a multi-frequency telephone antenna that supports both the low frequency band and the high frequency band. 18A and 18B are perspective views schematically showing a configuration of a conventional composite antenna. FIG. 18A is a perspective view seen from the power feeding side, and FIG. 18B is a perspective view seen from the grounding portion side.

18 (a) and 18 (b), the composite antenna 400 includes a substrate 410 provided on the common ground 401 at a predetermined distance, and a telephone disposed in an L shape on the

edge portions

412 and 413. Antenna unit 420. The telephone antenna unit 420 has a configuration in which a telephone antenna element 430 is formed on the surface of a pedestal 421. The telephone antenna element 430 includes a low frequency band antenna element 431, a high frequency band antenna element 432, and the like. It has

parasitic elements

433 and 434, a power feeding part 435 and a grounding part 436. The telephone antenna 430 is an inverted F-type antenna, and is provided with a grounding part 436 for connecting to the substrate ground 411 from the middle of the low-frequency band antenna element 431. In addition, the power feeding part 435 and the grounding part 436 are provided in the vicinity of the center of the first portion 421a of the base 421, and both the power feeding point 435a and the grounding point 436a are arranged closer to the center than the corner part 414 of the composite substrate 410. Yes. By arranging the low frequency band antenna element 431 and the high frequency band antenna element 432 at the

edge portions

412 and 413 of the substrate ground 411, the usable frequency band is widened, and the low frequency band antenna element 431 and By arranging the high-frequency band antenna elements 432 so as to be orthogonal to each other, it is possible to reduce interference between the low-frequency band antenna elements 431 and the high-frequency band antenna elements 432.

JP 2004-201278 A JP 2006-238269 A JP 2010-171507 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.

Further, when the antenna element for low frequency band and the antenna element for high frequency band are arranged orthogonally, the antenna size becomes large, so that there is a problem that the antenna installation space in the vehicle cannot be reduced. In the future, in order to make it possible to mount the antenna on a vehicle with more functions and lower fuel consumption, it is desired to make the antenna installation space as small as possible while increasing the bandwidth and improving the gain. .

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

Also, an object of the present invention is to provide an in-vehicle antenna that can obtain good antenna characteristics in both the low frequency band and the high frequency band and can realize further space saving.

According to a first aspect of the vehicle-mounted antenna of the present invention, a power feeding element having a radiation portion, a power feeding element portion and a grounding element portion connected to the radiation portion and arranged in a substantially vertical direction, and the power feeding element are coupled. A parasitic element having an operating portion arranged in a possible manner, and a parasitic element grounding element portion connected to the operating portion and arranged to be substantially parallel to the feeding element portion and the grounding element portion; A substrate having a pedestal having a predetermined height on which an element and the parasitic element are disposed, a wiring portion on which a wiring pattern connected to at least the feeding element portion is disposed, and a pedestal mounting portion on which the pedestal is mounted; The 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 back 180 degrees to the side opposite to the parasitic element, Feeding 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 vehicle-mounted antenna of the present invention is characterized in that a vehicle-mounted composite antenna is configured in combination with a GPS antenna formed by a patch antenna.

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

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

According to another aspect of the vehicle-mounted antenna of the present invention, a concave portion is formed in a vertical direction on the side surface of the base on the wiring pattern side, and at least the ground element portion and the feeding element portion are disposed in the concave portion. Features.

Another aspect of the vehicle-mounted antenna of 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 vehicle-mounted antenna according to the present invention is characterized in that the parasitic element includes a stub capable of adjusting a coupling size with the feeding element.

In another aspect of the vehicle-mounted antenna of 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 being.

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

In order to solve the above-described problem, the vehicle-mounted antenna according to the present invention is a vehicle-mounted antenna including a substrate, a pedestal disposed on the substrate, and a power feeding element disposed on the pedestal. The element includes a feed element connected to the substrate and extending in a substantially vertical direction, a low-frequency band antenna element connected to the feed element and extending in a substantially right angle direction, and the feed element. A high frequency band antenna element that is connected and extends in a direction opposite to the extending direction of the low frequency band antenna element, the extending direction of a main portion of the low frequency band antenna element and the high frequency band antenna The extending direction of the main part of the element is different by approximately 180 ° on the upper surface of the pedestal.

The power feeding element further includes a power feeding side grounding element connected to the power feeding element and arranged to face the power feeding element, and the power feeding element and the power feeding side grounding element form a gate-type structure.

Further, the pedestal has a recess on the upper surface, and the feeding element and the feeding-side grounding element having the portal structure are arranged across the recess.

Furthermore, the upper surface of the pedestal is divided into a first plane and a second plane by the recess, and a main part of the low frequency band antenna element is disposed on the first plane, and the high frequency band antenna element The main part is disposed on the second plane.

The vehicle-mounted antenna further includes a parasitic element disposed on the pedestal, and the parasitic element is an operation element disposed on the upper surface of the pedestal so as to be coupled with the low-frequency band antenna element; A non-feed-side grounding element connected to the operating element and disposed substantially parallel to the feeding element, wherein the main part of the operating element is disposed substantially parallel to the main part of the low-frequency band antenna element. The

Further, the parasitic element has a first stub in a main part of the operating element.

Further, the power feeding element has a second stub in a main part of the antenna element for low frequency band.

According to the present invention, it is possible to provide a vehicle-mounted antenna that is reduced in interference when integrated with a GPS antenna, is easy to adjust antenna characteristics, and is small and low-profile.

In addition, according to the present invention, the extending direction of the main part of the low-frequency band antenna element and the extending direction of the main part of the high-frequency band antenna element are configured to differ by approximately 180 ° on the upper surface of the pedestal. Therefore, the interference between the antenna element for the low frequency band and the antenna element for the high frequency band can be greatly reduced, and a sufficient gain and a wide bandwidth of each antenna element can be ensured. In particular, this configuration can realize a wide band of the high-frequency band antenna element, and can improve the gain. In addition, since the extending direction of the main part of both antenna elements differs by approximately 180 °, both antenna elements can be arranged along the edge of one side of the substrate, and space saving can be realized. Become. Therefore, good antenna characteristics can be obtained in both the low frequency band and the high frequency band, and further space saving can be realized. Furthermore, the space can be effectively used three-dimensionally by making the base a concave structure.

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. 1 is a perspective view schematically showing a configuration of a vehicle-mounted antenna according to an embodiment of the present invention. It is the elements on larger scale which show the structure of the board | substrate in FIG. It is sectional drawing which shows schematically the structure of the base by which the electric power feeding element and non-power feeding element in FIG. 1 are arrange | positioned. It is a side view which shows the structure of the electric power feeding element of FIG. 3, a parasitic element, and a base, (a) is the figure seen from the electric power feeding side, (b) shows the figure seen from the grounding part side of the board | substrate. It is the elements on larger scale which show the structure of the vehicle-mounted antenna of FIG. It is a top view which shows the modification of the electric power feeding element in FIG. It is a top view which shows the modification of the parasitic element in FIG. It is a figure which shows the Example of this invention, (a) is the schematic of an antenna structure, (b) is a graph which shows the voltage standing wave ratio (VSWR) characteristic in a high frequency band (GPS band), (c) is a high frequency. It is a figure which shows the gain (GAIN) characteristic in a zone | band (GPS zone). FIG. 9 is a diagram illustrating a GAIN characteristic in a low frequency band in the example of FIG. 8. It is a figure which shows the comparative example of this invention, (a) is the schematic of an antenna structure, (b) is a graph which shows the VSWR characteristic in a high frequency band, (c) is a figure which shows the GAIN characteristic in a high frequency band. FIG. 11 is a diagram illustrating a GAIN characteristic in a low frequency band in the comparative example of FIG. 10. It is the perspective view which shows the structure of the conventional composite antenna roughly, (a) is the perspective view seen from the electric power feeding side, (b) is the perspective view seen from the earthing | grounding part side.

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 has 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 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 of 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 arranged 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 tip end portion 114 of the power feeding element 110 is folded back 180 degrees on the side opposite to the non-power feeding element 120 and 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 front end portion 114 of the power feeding element 110 and the front 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 power supply 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.

Further, as Comparative Example 1, FIG. 3 shows the antenna characteristics when the feeding element and the non-feeding 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 feed 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 portion of the feed element 21 and the front end portion 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 in the inner direction close to each other, the VSWR characteristic is greatly deteriorated and the operation is performed in the frequency band 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. Yes.

As an influence on the antenna characteristics of the in-vehicle broadband antenna 100 according to the present embodiment, there is an effect caused by 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 area 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 the 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 disposed on the left side of the pedestal 130 in the drawing far from the GPS antenna installation region 150 and the parasitic element 120 is disposed on the right side of the pedestal 130 in the drawing near the GPS antenna installation region 150. 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 according to the present embodiment, a concave portion 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 region 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.

In addition, the description in this Embodiment shows an example of the vehicle-mounted broadband antenna which concerns on this invention, and 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.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 7 is a perspective view schematically showing the configuration of the vehicle-mounted antenna according to the embodiment of the present invention.
In FIG. 7, the vehicle-mounted antenna 300 includes a substrate 340, a pedestal 330 disposed on the substrate, a power feeding element 310 disposed on the pedestal, and a parasitic element 320 coupled to the power feeding element. The element 310 and the parasitic element 320 are configured to be disposed on a substantially rectangular parallelepiped base 330. This in-vehicle antenna has a substantially rectangular arrangement region 350 so that a GPS antenna and an ETC antenna can be arranged adjacent to each other, and can be used as an in-vehicle composite antenna in combination with a GPS antenna or the like. It is configured to be possible.

FIG. 8 is a partially enlarged view showing the configuration of the substrate 340 in FIG.
The substrate 340 includes a pedestal mounting portion 341 for mounting the pedestal 330 on one end side of the arrangement region 350, and a wiring portion 342 for arranging a wiring pattern 342a for connecting a feeding element and a feeding line 360 described later. ing. The board 340 is mounted substantially horizontally on the vehicle, whereby the main parts of the low-frequency band antenna element and the high-frequency band antenna element described later are installed substantially horizontally. In addition, the board | substrate 340 may operate | move electrically as a ground plane, and the composite body provided with the ground plane may be sufficient as it.

FIG. 9 is a perspective view schematically showing the configuration of the pedestal 330 on which the feeding element 310 and the parasitic element 320 in FIG. 7 are arranged. 10 is a side view showing the configuration of the feeding element, the parasitic element, and the pedestal of FIG. 9, wherein (a) is a view seen from the feeding side, and (b) is a view seen from the grounding side. .

9 and 10 (a) and 10 (b), the pedestal 330 has a substantially rectangular parallelepiped shape, and serves as a base material that holds the shapes and positions of the feeding element 310 and the non-feeding element. In the present embodiment, a recess 336 is formed on the upper surface of the pedestal 330, and the upper surface is divided by the recess 336 into a first plane 331a and a second plane 331b. The pedestal 330 has side surfaces 332, 333, 334, and 335, and a power feeding element 310 having a substantially constant width is disposed on these upper and side surfaces. The overall dimensions of the pedestal 330 are, for example, 54 mm long, 13 mm wide, and 17 mm high. The low frequency side dimensions of the pedestal 330 are 37 mm in length, 13 mm in width, 17 mm in height, and the high frequency side dimensions are, for example, 11 mm in length, 13 mm in width, and 17 mm in height.

The feed element 310 includes a feed element portion 311 connected to the substrate 340 and extending in a substantially vertical direction, and a high frequency band antenna element connected to the feed element portion 311 and extending in a substantially right angle direction from the feed element portion ( Hereafter referred to as “fH band antenna element”) 316 and a low frequency band element (hereinafter referred to as “fL”) connected to the feed element portion 311 and extending in the direction opposite to the extending direction of the fH band antenna element 316. ”) 314.

The fH band antenna element 316 is bent in a substantially U shape on the second plane 331b, and a main part thereof is disposed substantially parallel to the longitudinal direction of the pedestal 330. The fL band antenna element 314 is bent in a substantially L shape on the first plane 331 a, and a main part thereof is disposed substantially parallel to the longitudinal direction of the pedestal 330. Further, the front end portion 315 of the fL band antenna element 314 is folded 180 degrees with respect to the main part of the fL band antenna element and disposed on the side surface 332. Except for the tip 315 of the fL band antenna element 314, the fH band antenna element 316 and the fL band antenna element 314 are formed to bend on the upper surface of the pedestal 330. Thereby, size reduction of the electric power feeding element 310 is realizable.

The power feeding element 310 includes a power feeding side ground element portion 312 that is connected to the power feeding element portion 311 and is opposed to the power feeding element portion. The power feeding element portion 311 and the power feeding side ground element portion 312 are connected to the gate. It has a mold structure. Thereby, the interference between the fH band antenna element 1316 and the fL band antenna element 314 can be greatly reduced, and the antenna characteristics can be improved. In addition, the power feeding element portion 311 and the power feeding side grounding element portion 312 constituting the gate-type structure are arranged across the recess 336. In the feed element 310, the feed element portion 311, the feed-side ground element portion 312, the fH band antenna element 316, and the fL band antenna element 314 are substantially cross-shaped with the branch portion 313 formed on the bottom surface of the recess 336 as the center. It extends in the direction (FIG. 9). As a result, the fH band antenna element 316 and the fL band antenna element 314 can be easily distributed.

Further, by forming the concave portion 336 in the pedestal 330, the distance between the branch portion 313 and the concave portion 336 side element 316a in the fH band antenna element 316 or the concave portion 336 side element 314a in the branch portion 313 and the fL band antenna element 314 is obtained. (Fig. 10), and interference between the fH band antenna element 316 and the fL band antenna element 314 can be further reduced.

The parasitic element 320 is arranged on the first plane 331 a of the pedestal 330 so as to be electrically coupled to the fL band antenna element 314 and to be substantially parallel to the feeding element 311 connected to the operating element section. And a non-feed-side grounding element portion 321 extending to the grounding point G. The distal end portion 323 of the parasitic element 320 is folded 180 degrees with respect to the main portion of the operating element portion 322 and disposed on the first plane 331a. The main part of the operating element 322 is disposed substantially parallel to the main part of the fL band antenna element 314.

The leading end 323 of the parasitic element 320 is folded back to the side opposite to the folding direction of the leading end 315 of the fL band antenna element 314. In other words, both the

front end portions

323 and 315 are folded back in the direction away from each other (outside). Thereby, by arranging the fL band antenna element 314 and the operating element 322, it is possible to obtain a predetermined amount of coupling and reduce the mutual influence by separating the elements of the

tip portions

323 and 315 as much as possible. In addition, space saving can be realized.

In the feed element 310 configured as described above, in this embodiment, the fH band antenna element 316 is disposed on the opposite side of the feed element 311, that is, the feed point S, with respect to the fL band antenna element 314. Then, the extending direction of the main part of the fH band antenna element 316 and the extending direction of the main part of the fL band antenna element 314 are different by approximately 180 ° on the upper surface of the pedestal 330. Thereby, the interference between the fH band antenna element 316 and the fL band antenna element 314 can be greatly reduced, and the antenna characteristics can be improved. In particular, the gain of the fH band antenna element 316 can be improved.

In the present embodiment, the main parts of the fH band antenna element 316 and the fL band antenna element 314 are arranged on the upper surface of the pedestal 330. The radio wave from the base station is vertical, and in order to transmit and receive this, an antenna having a high vertical polarization GAIN is preferable. In the configuration of this antenna, vertical polarization is more likely to occur as the height from GND (grounding position) is higher (GAIN with respect to vertical polarization is higher). Therefore, if both antenna elements are arranged on the upper surface of the pedestal 330 as much as possible, an antenna having a high vertical polarization (component) GAIN is obtained.

Further, in the case of an L-shaped antenna as in the prior art, the fH band antenna elements and the fL band antenna elements are arranged at substantially right angles, so that these antenna elements are placed at the ends of the two sides of the substrate 340. Need to be placed. On the other hand, by making the extending direction of the main part of the fH band antenna element 316 different from the extending direction of the main part of the fL band antenna element 314 by approximately 180 ° as in the present embodiment, the pedestal 330 is formed in a substantially rectangular parallelepiped. Both the fH band antenna element 316 and the fL band antenna element can be arranged along the edge of one side of the substrate 340. As a result, space saving can be realized, and the degree of freedom of arrangement of the vehicle-mounted antenna is also improved.

By the way, in the manufacturing process of the vehicle-mounted antenna element 300 configured as described above, after mounting the pedestal 330 on which each element is arranged on the substrate 340, each end of the feeding element portion 311 and the non-feeding side grounding element portion 321. The part is joined to a predetermined position of the substrate with solder. At this time, it is necessary to visually check the back fillet at the joint in order to determine whether the joint state is good. However, when the pedestal 330 is disposed close to the solder joint, there is a problem that it is difficult to visually confirm the back fillet. Therefore, the pedestal 330 in this embodiment employs a structure as shown in FIG.

As shown in FIG. 11, the pedestal 330 has a notch 337 at the bottom in the vicinity of the feeding element portion 311 and the non-feeding side grounding element portion 321, and when the pedestal 330 is mounted on the substrate 340, A substantially horizontal through hole 350 is defined between the substrate and the pedestal 330. As a result, the back fillet at the joint between the power feeding element portion 311 and the substrate 340 can be viewed through the through hole 350. Further, the back fillet at the joint between the non-feed-side grounding element portion 321 and the substrate 340 can be visually observed through the through hole 350. Therefore, the operator can easily and surely determine whether the joining state of the feeding point S or the grounding point G is good after the joining work. Further, there is no need to provide a space for viewing the back fillet on the substrate 340, and space saving can be realized. Moreover, since the notch part 337 is provided in the base 330, the base 330 becomes lightweight and the vehicle-mounted antenna 300 can be reduced in weight.

As described above, according to the present embodiment, the extending direction of the main part of the fL band antenna element 314 and the extending direction of the main part of the fH band antenna element 316 are approximately 180 on the upper surface of the pedestal 330. Since they are configured differently, interference between the fL band antenna element 314 and the fH band antenna element 316 can be greatly reduced, and a sufficient gain and a wide bandwidth of each antenna element can be secured. In particular, the fH band antenna element 316 can be widened, and the gain can be improved. Also, since the two main parts of both antenna elements are arranged in a substantially straight line, both the fL band antenna element 314 and the fH band antenna element 316 can be arranged along the edge of one side of the substrate, Space saving can be realized. Therefore, good antenna characteristics can be obtained in both the low frequency band and the high frequency band, and further space saving can be realized. Furthermore, the space can be effectively used three-dimensionally by making the pedestal 330 have a concave structure.

In the present embodiment, the recess 336 is provided on the upper surface of the pedestal 330, but the recess 336 may not be provided. In this case, each element part of the power feeding element part and the power feeding side grounding element part is disposed from the upper surface to the side surface of the pedestal, and the power feeding element part and the power feeding side grounding element part are disposed across the entire pedestal. The effect of the present invention can also be achieved by this configuration.

Further, the shapes of the fL band antenna element 314 and the fH band antenna element 316 are not limited to the present embodiment. The entire fL band antenna element may be substantially linear, or the entire fH band antenna element may be substantially linear. The effect of the present invention can also be achieved by this configuration.

Further, as shown in FIG. 12, the power feeding element 310a may have a stub 361 (second stub) in the main portion of the fL band antenna element 314a on the first plane 331a of the base 330. The stub 361 extends from the main part of the fL band antenna element 314a in a substantially vertical direction, and extends in a substantially vertical direction with respect to the main part of the parasitic element 320a. Thereby, the distance between the feeding element 310a and the parasitic element 320a can be adjusted, and the impedance can be adjusted by changing the electrical coupling state.

Further, as shown in FIG. 13, the parasitic element 320a may have a stub 371 (first stub) in the main portion of the operating element portion 322a in the first plane 331a of the base 330. The stub 371 extends substantially parallel to the main part of the operating element portion 322a, and extends substantially parallel to the main part of the fL band antenna element 314a. Thereby, impedance adjustment becomes possible.

Further, the notch 337 is formed at the bottom in the vicinity of the feeding element 311 and the non-feeding side grounding element 321, but is not limited thereto. As long as the back fillet at the junction between the feeding element portion 311 and the substrate 340 or the back fillet at the junction between the non-feed-side grounding element portion 321 and the substrate 340 can be observed, it can be formed at any location. Well, the notch shape is not limited.

In addition, this embodiment shows an example of the vehicle-mounted antenna which concerns on this invention, and is not limited to this. The detailed configuration, detailed operation, and the like of the integrated antenna in this embodiment can be changed as appropriate without departing from the spirit of the present invention.

Examples of the present invention will be described below.
First, as an embodiment, the feeding element and the parasitic element are arranged as shown in FIG. 14A, and in particular, the main part of the fH band antenna element and the main part of the fL band antenna element in the feeding element are changed by 180 °. A vehicle-mounted antenna is used. In the antenna configuration of FIG. 14A, the voltage standing wave ratio (VSWR) in the high frequency band, the vertical component and horizontal component gain (GAIN) in the high frequency band, and the vertical component in the low frequency band and The gain of the horizontal component was measured to evaluate the antenna characteristics. FIG. 14B shows the VSWR characteristics of the in-vehicle antenna in the high frequency band, FIG. 14C shows the GAIN characteristics of the vertical and horizontal components in the high frequency band, and FIG. 14C shows the GAIN characteristics of the vertical and horizontal components in the low frequency band. Each is shown in FIG.

As a comparative example, the feeding element and the parasitic element are arranged as shown in FIG. 16A. In particular, the main part of the fH band antenna element and the main part of the fL band antenna element in the feeding element are arranged in the same direction. An in-vehicle antenna is used. With the antenna configuration of FIG. 16A, the VSWR in the high frequency band, the GAIN of the vertical and horizontal components in the high frequency band, and the GAIN of the vertical and horizontal components in the low frequency band were measured to evaluate the antenna characteristics. In this comparative example, in order to adjust the frequency and antenna characteristics, a parasitic element having a meander shape was used. FIG. 16B shows the VSWR characteristics of the in-vehicle antenna in the high frequency band, FIG. 16C shows the GAIN characteristics of the vertical and horizontal components in the high frequency band, and FIG. 16C shows the GAIN characteristics of the vertical and horizontal components in the low frequency band. Each is shown in FIG.

Note that, as shown in FIGS. 15 and 17, both the above examples and comparative examples were adjusted so that the GAIN characteristics in the low frequency band were substantially equal.

As a result, in the comparative example, the VSWR greatly changed from about 1 to 5.6 in the frequency band of 1550 to 1600 MHz. In particular, the band where VSWR is 3.0 or less is about 1563 to 1587 MHz, and the band where VSWR is 1.5 or less is about 1571 to 1579 MHz, indicating that the usable band is narrow. The GAIN characteristics were -10 to -3 dBi at 1550 to 1600 MHz and -3.5 to -3.0 dBi at about 1571 to 1579 MHz, indicating a low gain in the usable band.

On the other hand, in the example, the VSWR was about 1.2 to 2.3 in the frequency band of 1550 to 1600 MHz, indicating a substantially stable value. In particular, the band where the VSWR is 1.5 or less is about 1566 to 1592 MHz, and it was found that the usable band is wider than that of the comparative example. In addition, the GAIN characteristic is −3.3 to −2.2 dBi at 1550 to 1600 MHz, particularly −2.3 to −2.1 dBi at about 1566 to 1592 MHz, and it has been found that the gain is sufficient in the usable band. .

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 300 Car-mounted antenna 310 Feeding element 311 Feeding element part 312 Feeding side grounding element part 313 Branching part 31 fH band antenna element 316 fL band antenna element 320 Parasitic element 321 Parasitic element grounding element 330 Base 331a First plane 331b

Second plane

332, 333, 334, 335 Side 336 Recess 337 Notch 340 Substrate 350 Through Hole

Claims

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 arranged, a wiring part on which a wiring pattern connected to at least the feeding element part is arranged, and a pedestal mounting part on which the pedestal is mounted. A substrate, and
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 parasitic element is at least one of the operating portions. The vehicle-mounted antenna is characterized in that the portion is disposed substantially parallel to the radiating portion on the upper surface of the pedestal, and the tip is folded back 180 degrees on the side opposite to the feeding element.
The in-vehicle 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 antenna according to claim 2, wherein the parasitic element is disposed on a side where the GPS antenna is disposed on the pedestal.
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. The vehicle-mounted antenna 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 vehicle-mounted antenna described in the item.
The in-vehicle antenna according to claim 5, wherein an impedance adjustment portion of the power feeding element is formed in the concave portion.
The in-vehicle 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 feeding 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 vehicle-mounted antenna according to any one of claims.
The substrate is formed in a substantially U-shape with another pedestal mounting portion on the opposite side of the pedestal mounting portion across the wiring portion,
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. Vehicle-mounted antenna.
A vehicle-mounted antenna comprising a substrate, a pedestal disposed on the substrate, and a power feeding element disposed on the pedestal,
The feed element includes a feed element connected to the substrate and extending in a substantially vertical direction, a low-frequency band antenna element connected to the feed element and extending in a substantially right-angle direction from the feed element, and the feed A high frequency band antenna element connected to the element and extending in a direction opposite to the extending direction of the low frequency band antenna element;
An in-vehicle antenna, wherein an extending direction of a main part of the low-frequency band antenna element and an extending direction of a main part of the high-frequency band antenna element differ by approximately 180 ° on an upper surface of the pedestal.
The power feeding element further includes a power feeding side grounding element connected to the power feeding element and disposed to face the power feeding element,
The vehicle-mounted antenna according to claim 10, wherein the feeding element and the feeding-side grounding element have a portal structure.
The pedestal has a recess on the top surface,
The vehicle-mounted antenna according to claim 10 or 11, wherein the feeding element and the feeding-side grounding element constituting the gate-type structure are disposed across the recess.
The upper surface of the pedestal is divided into a first plane and a second plane by the recess,
13. The vehicle-mounted antenna according to claim 12, wherein a main part of the low-frequency band antenna element is disposed on the first plane, and a main part of the high-frequency band antenna element is disposed on the second plane. .
Further comprising a parasitic element disposed on the pedestal;
The parasitic element includes an operating element disposed on the upper surface of the pedestal so as to be connectable to the antenna element for a low frequency band, and a parasitic side grounding element connected to the operating element and disposed substantially parallel to the feeding element. And
The in-vehicle antenna according to any one of claims 10 to 13, wherein a main portion of the operating element is disposed substantially parallel to a main portion of the high-frequency band antenna element.
The vehicle-mounted antenna according to claim 14, wherein the parasitic element has a first stub in a main part of the operating element.
The in-vehicle antenna according to any one of claims 10 to 15, wherein the power feeding element has a second stub in a main part of the low-frequency band antenna element.