WO2016175171A1 - Composite antenna device - Google Patents

Abstract

Provided is a composite antenna device that can be reduced in size by contriving the disposition of antenna elements and securing isolation therebetween. The composite antenna device can receive signals of a plurality of frequency bands and comprises a base part 10, a first frequency band element 20 and a second frequency band element 30. The first frequency band element 20 is disposed in a vertical direction when seen from a front surface of the composite antenna device and in a diagonal direction when seen from a side surface of the composite antenna device. The second frequency band element 30 is disposed in a vertical direction when seen from a front surface of the composite antenna device and in a diagonal direction when seen from a side surface of the composite antenna device. The first frequency band element 20 and the second frequency band 30 are disposed so as to extend in a V shape from a first power feeding part 21 and a second power feeding part 31. The second frequency band element 30 is bent midway therealong and has an open end-side part 32 that extends to a prescribed length from the position of the bend.

Description

Compound antenna device

The present invention relates to a composite antenna device, and more particularly to a composite antenna device capable of receiving signals in a plurality of frequency bands.

Conventionally, there are composite antennas that can receive signals in multiple frequency bands. The composite antenna can be designed freely to some extent if there is no particular problem with the space in which the antenna element is placed. There were various restrictions such as unavoidable, and it was difficult to obtain sufficient antenna performance. In recent years, various information devices have been installed in vehicles for safety and comfort. Accordingly, it is necessary to use signals in various frequency bands, and it is necessary to provide antenna elements suitable for each frequency band. However, when the space in the case of the low-profile antenna is small, the antenna elements have to be placed close to each other, and the antenna elements influence each other, and particularly in the AM frequency band, good antenna characteristics. There was a problem of not being able to obtain.

In order to solve such a problem, in the technique disclosed in Patent Document 1, in order to reduce the deterioration of the performance of the first antenna element of the AM / FM antenna as compared with the single antenna element, The top capacity section is provided to increase antenna capacity and suppress performance degradation. In addition, the first antenna element and the Band-III / L-Band second antenna element are electrically cut off using the coil unit, and the top capacitor unit, the first antenna element, and the coil unit resonate in the FM frequency band. The antenna is configured to operate as a non-resonant antenna in the AM frequency band.

JP 2012-199865 A

However, in the technique of the above-mentioned Patent Document 1, it is necessary to open a clearance of 10 mm or more between the first antenna element and the second antenna element in order to achieve isolation between the antenna elements. In addition, Band-III antenna characteristics and FM antenna characteristics are in a trade-off relationship due to isolation. Therefore, both performance improvements have been desired. In recent years, further downsizing of the antenna has been demanded, so that further reduction in installation space has been demanded. At this time, it was more difficult to obtain isolation, and performance degradation could be a problem. In addition, it is conceivable to further increase the size of the top capacitor. However, if the size is increased, there is a problem of isolation between the top capacitor and the Band-III antenna, and there is a problem that the performance of the Band-III antenna is lowered.

In view of such circumstances, the present invention intends to provide a composite antenna device that can be miniaturized by devising the arrangement of antenna elements to ensure isolation.

In order to achieve the above-described object of the present invention, a composite antenna device according to the present invention is connected to a base portion fixed to a vehicle and a first power feeding portion for a first frequency band, and the vehicle is connected to the base portion. In the opposite direction, the first frequency band element and the second frequency band second lower than the first frequency band are arranged in a vertical direction when viewed from the front of the composite antenna device and an oblique direction when viewed from the side. 2 is a second frequency band element that is connected to the power feeding unit and arranged in the vertical direction when viewed from the front of the composite antenna device and in the oblique direction when viewed from the side, in the direction opposite to the vehicle with respect to the base unit. The first frequency band element and the second frequency band element are arranged so as to spread in a V shape from the first power feeding part and the second power feeding part, and the second frequency band element is bent and bent in the middle. From location Having an open end portion that extends up to the length, in which includes the elements for a second frequency band, a.

Here, the open end side portion of the second frequency band element may be bent to the side away from the first frequency band element.

Further, the open end side portion of the second frequency band element may be bent toward the side closer to the first frequency band element.

Further, the open end side portion of the second frequency band element may extend in parallel to the base portion.

Further, the open end side portion of the second frequency band element may be constituted by a capacity loading portion.

The first frequency band element further includes an open end side portion that is bent in the middle of the first frequency band element and extends from the bent position to a predetermined length, and the open end side portion is a second end portion. It may be bent toward the side closer to the frequency band element.

Furthermore, it comprises a substrate erected perpendicularly to the base portion in the direction opposite to the vehicle, and the first frequency band element and the second frequency band element are disposed on the substrate. Also good.

Furthermore, an amplifier circuit for the first frequency band and / or the second frequency band may be provided, and the amplifier circuit may be disposed on the substrate.

In addition, the portion of the first frequency band element and / or the second frequency band element that is arranged so as to spread in a V shape from the first power feeding portion and the second power feeding portion is configured in a coil shape. May be.

Furthermore, a third frequency band element connected to a third power feeding unit for a third frequency band higher than the first frequency band may be provided.

The composite antenna device of the present invention has an advantage that it can be miniaturized by ensuring the isolation by devising the arrangement of the antenna elements.

FIG. 1 is a schematic diagram for explaining a first example of the composite antenna device of the present invention. FIG. 2 is a schematic side view for explaining a second example of the composite antenna device of the present invention. FIG. 3 is a schematic side view for explaining a third example of the composite antenna device of the present invention. FIG. 4 is a schematic diagram for explaining an example in which the composite antenna device of the present invention is realized using a substrate.

Hereinafter, modes for carrying out the present invention will be described together with illustrated examples. FIG. 1 is a schematic diagram for explaining a first example of a composite antenna device of the present invention, FIG. 1 (a) is a side sectional view, and FIG. 1 (b) is a back sectional view. The composite antenna device of the present invention can receive signals in a plurality of frequency bands, and is used for, for example, a vehicle. More specifically, it is used for a low-profile antenna device disposed on a vehicle roof. As shown in the figure, the composite antenna device of the present invention is mainly composed of a base portion 10, a first frequency band element 20, and a second frequency band element 30. Moreover, in the example of illustration, the example applied to the low profile antenna is shown, and it is covered with the cover 1 of the shark fin shape.

The base unit 10 is fixed to the vehicle. For example, the base portion 10 includes a screw boss 11 and the like, and the screw boss 11 is inserted into a hole provided in the vehicle roof and is fixed to the vehicle with a screw. The base portion 10 may be a metal base or a resin base. Further, it may be a composite base of a metal base and a resin base.

The first frequency band of the first frequency band element 20 is a band-III frequency band for digital audio broadcasting (DAB (Digital Audio Broadcasting)), for example. The frequency band of Band-III is, for example, a 174 MHz to 240 MHz band. The first frequency band element 20 is connected to the first power feeding section 21 for the first frequency band. The first frequency band element 20 is arranged in a direction perpendicular to the base portion 10 in the direction opposite to the vehicle, in a vertical direction when viewed from the front of the composite antenna device and in an oblique direction when viewed from the side. The first frequency band element 20 may be rod-shaped or linear, or may be patterned on the substrate by etching or the like. Further, it may be formed in a meander shape or a coil shape. In that case, the axis of the element may be arranged in the vertical direction when viewed from the front and in the oblique direction when viewed from the side.

The second frequency band of the second frequency band element 30 is lower than the first frequency band, for example, a frequency band for the FM frequency band. The FM frequency band is, for example, a 76 MHz to 90 MHz band or an 88 MHz to 108 MHz band. The second frequency band element 30 is connected to the second power feeding section 31. The second frequency band element 30 is arranged in a direction perpendicular to the base portion 10 in the direction opposite to the vehicle and in an oblique direction as viewed from the front and from a side of the composite antenna device. The first frequency band element 20 and the second frequency band element 30 are arranged so as to spread in a V shape from the first power supply unit 21 and the second power supply unit 31. That is, the first power feeding unit 21 and the second power feeding unit 31 are brought close to each other, and the elements are arranged to be away from each other. Further, the second frequency band element 30 is bent halfway and has an open end side portion 32 extending from the bent position to a predetermined length. In the illustrated example, the open end side portion 32 is bent toward the side away from the first frequency band element 20. Moreover, the open end side part 32 showed the example extended in parallel with respect to the base part 10. In FIG. However, the open end side portion 32 may be appropriately inclined according to the shape of the cover 1 or the like. The second frequency band element 30 may also be rod-shaped or linear, or may be patterned on the substrate by etching or the like. Further, it may be formed in a meander shape or a coil shape. In that case, the axis of the element may be arranged in the vertical direction when viewed from the front and in the oblique direction when viewed from the side.

Here, the V-shaped angle of the first frequency band element 20 and the second frequency band element 30 is θ. When θ was changed from 0 ° to 170 °, it was found that isolation was increased as θ was increased. In addition, when the 1st frequency band and the 2nd frequency band were the same frequency, the tendency for isolation to become low was seen. That is, it has been found that the isolation can be achieved as the first frequency band and the second frequency band are different frequencies and as θ is larger. The composite antenna device of the present invention is configured to be a low-profile antenna using such a phenomenon.

The composite antenna device according to the present invention is configured in this way, so that isolation between antenna elements can be ensured. Note that a coil may be appropriately provided between the element and the power feeding unit for impedance adjustment or the like.

Next, another example of the composite antenna device of the present invention will be described. FIG. 2 is a schematic side view for explaining a second example of the composite antenna device of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same parts. In FIG. 2, only the elements are shown, and the base portion and the like are omitted. In the example of FIG. 1, the open end side portion 32 of the second frequency band element 30 is bent to the side away from the first frequency band element 20. However, the present invention is not limited to this, and may be bent toward the side closer to the first frequency band element 20, as shown in FIG.

Also in the example shown in FIG. 2, the first frequency band element 20 is arranged in the direction perpendicular to the vehicle with respect to the base portion 10 in the direction opposite to the vehicle and in the oblique direction as viewed from the side. Has been. In addition, the second frequency band element 30 is disposed in a direction perpendicular to the base portion 10 in the direction opposite to the vehicle and in an oblique direction as viewed from the front and from a side of the composite antenna device. The first frequency band element 20 and the second frequency band element 30 are arranged so as to spread in a V shape from the first power supply unit 21 and the second power supply unit 31. Furthermore, the second frequency band element 30 is bent halfway, and the open end side portion 32 is bent toward the side closer to the first frequency band element 20. That is, the second frequency band element 30 can be disposed so as to be folded back. Thereby, the length of a longitudinal direction can be shortened.

As described above, the second frequency band element 30 can be isolated regardless of which of the open end side portions 32 is bent. Therefore, when the internal space is limited, such as a low-profile antenna. In addition, it can be appropriately arranged according to the space.

Next, another example of the composite antenna device of the present invention will be described. FIG. 3 is a schematic side view for explaining a third example of the composite antenna device of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same parts. In FIG. 3, only the elements are shown, and the base portion and the like are omitted. In the examples of FIGS. 1 and 2, the open end side portion 32 of the second frequency band element 30 is bent. However, the present invention is not limited to this, and the first frequency band element 20 may be bent as shown in FIG. That is, the first frequency band element 20 can be arranged so as to be folded. Thereby, the length in the longitudinal direction can be shortened. Further, the height direction can be shortened.

In the example shown in FIG. 3, the second frequency band element 30 is bent halfway, and the open end side portion 32 is bent toward the side closer to the first frequency band element 20. Further, as different from FIG. 2, the first frequency band element 20 further includes an open end side portion 22 that is bent halfway and extends from the bent position to a predetermined length. It is bent to the side closer to the element 30 for the two frequency bands. Even in such an arrangement, it is possible to achieve isolation as long as the first power supply unit 21 and the second power supply unit 31 are arranged so as to spread in a V shape.

In this way, the open end side portion 32 of the second frequency band element 30 is bent toward the side closer to the first frequency band element 20, and the open end side portion 22 of the first frequency band element 20 is further bent to the second frequency. It is also possible to bend the side closer to the band element 30. That is, further miniaturization is possible by arranging the two elements so as to be folded.

Next, the case where the composite antenna device of the present invention is mounted on a substrate will be described. 4A and 4B are schematic views for explaining an example in which the composite antenna device of the present invention is realized using a substrate. FIG. 4A is a side sectional view and FIG. 4B is a back sectional view. is there. In the figure, the same reference numerals as those in FIG. 3 denote the same parts. Basically, the example shown in FIG. 3 is arranged on a substrate. In the above-described illustrated example, it has been conceptually described that the isolation can be improved by devising the arrangement between the elements, but FIG. 4 illustrates a more specific mounting example. In the illustrated example, the elements are arranged using a substrate. As shown in the figure, the substrate 40 is erected perpendicularly to the base portion 10 in the direction opposite to the vehicle. The first frequency band element 20 and the second frequency band element 30 are formed by patterning on the substrate 40 by etching or the like.

In the illustrated example, an example is shown in which the portion of the first frequency band element 20 arranged so as to spread in a V shape is configured in a coil shape. Specifically, the substrate 40 is a double-sided substrate, and the first frequency band element 20 is patterned so as to be coiled by being spirally connected using the front and back surfaces. At this time, the axis of the coiled portion is arranged in the vertical direction when viewed from the front and in the oblique direction when viewed from the side. The first frequency band element 20 is bent halfway, and the open end side portion extending from the bent position to a predetermined length is constituted by a plate-like pattern 23 in the illustrated example. The plate-like pattern 23 is directed to the side closer to the second frequency band element 30 as a whole. Thus, in the composite antenna device of the present invention, the first frequency band element 20 is not only configured in a rod shape or a linear shape, but may be combined with a coiled pattern or a plate-like pattern as in the illustrated example. In addition, about a coil-shaped pattern, not only what is formed by patterning but the thing using an air core coil may be used.

And in the example of illustration, the example arrange | positioned so that the part arrange | positioned so that it may spread in V shape of the element 30 for 2nd frequency bands was shown in the coil shape. Specifically, the substrate 40 is a double-sided substrate, and the second frequency band element 30 is patterned so as to be coiled by being spirally connected using the front and back surfaces. At this time, the axis of the coiled portion is arranged in the vertical direction when viewed from the front and in the oblique direction when viewed from the side. The second frequency band element 30 is bent halfway, and the open end side portion extending from the bent position to a predetermined length is constituted by a capacity loading portion 33 in the illustrated example. In the illustrated example, the capacity loading portion 33 is configured by an umbrella-type element. This has a top 34 that extends in the longitudinal direction in accordance with the upper edge of the substrate, and a roof-like slope 35 that slopes from the top 34 to both sides. The longitudinal direction of the capacity loading portion 33 is directed to the side closer to the first frequency band element 20. That is, in the illustrated example, the tip (upper side) of the coil-shaped portion of the second frequency band element 30 is connected to the rear side of the capacity loading portion 33 (rear power feeding), so that the first frequency band It is comprised so that it may face in the side which approaches the element 20 for use. In addition, the front end side of the coil-shaped part of the element 30 for 2nd frequency bands may be connected to the front side part of the capacity | capacitance loading part 33. FIG. In this case, the arrangement example shown in FIG. 1 is obtained. In the example shown in FIG. 4, the length in the longitudinal direction can be shortened by being connected to the rear side portion. Note that there is no particular difference in the reception performance of vertically polarized waves even if the capacity loading unit 33 is rear feeding.

As described above, in the composite antenna device of the present invention, the second frequency band element 30 is not only configured in a rod shape or a linear shape, but a coiled pattern or a capacity loading portion may be appropriately combined as shown in the illustrated example. . Further, the capacity loading portion 33 may have a configuration in which a plate-like pattern is arranged on a substrate instead of the umbrella-shaped element as shown in the illustrated example. Further, the present invention is not limited to the combination of the illustrated examples, and can be appropriately combined according to the internal space of the low-profile antenna or the like.

In the illustrated example, an example in which the amplifier circuit 45 is disposed on the substrate 40 is shown. The amplifier circuit 45 amplifies signals for the first frequency band and / or the second frequency band. As described above, the first frequency band element 20 and the second frequency band element 30, and the amplifier circuit 45 for amplifying these signals are all configured on the same substrate 40, so that one main component element is formed. A substrate can be formed. The amplifier circuit 45 may be provided on the base unit 10 side.

Furthermore, in the illustrated example, the example in which the third frequency band element 50 is arranged on the substrate 40 is shown. That is, FIG. 4 shows an example of a composite antenna apparatus that can receive signals in three frequency bands. The third frequency band is a higher frequency band than the second frequency band, for example, the DAB L-Band frequency band. The frequency band of L-Band is, for example, 1.4 GHz band. The third frequency band element 50 is connected to the third power feeding section 51 for the third frequency band. Since the L-Band, which is the third frequency band, has a high frequency and a short element length, the third frequency band element 50 can be appropriately disposed in an empty space on the substrate.

As described above, the composite antenna device according to the present invention can be downsized by devising the arrangement of the antenna elements and ensuring the isolation, so that a large free space can be secured on the base portion 10 as well. . Therefore, for example, as shown in the drawing, a sanitary wave antenna 60 such as a GPS antenna can be installed.

4 shows an example in which the first frequency band element 20 and the second frequency band element 30 are patterned on the substrate 40 by etching or the like, but the present invention is not limited to this. Since the elements for the first frequency band and the elements for the second frequency band may be arranged as shown in the illustrated example, each element can be arranged using a frame base such as an element holder made of resin or the like. It is.

It should be noted that the composite antenna device of the present invention is not limited to the illustrated example described above, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 Base part 11 Screw boss 20 1st frequency band element 21 1st electric power feeding part 22 Open end side part 23 Plate-shaped pattern 30 2nd frequency band element 31 2nd electric power feeding part 32 Open end side part 33 Capacity loading part 34 Top part 35 Inclined part 40 Substrate 45 Amplifier circuit 50 Third frequency band element 51 Third feeding part 60 Sanitary wave antenna

Claims (10)

A composite antenna device capable of receiving signals of a plurality of frequency bands, the composite antenna device comprising:
A base fixed to the vehicle;
It is connected to the first power supply unit for the first frequency band, and is arranged in the vertical direction when viewed from the front of the composite antenna device and in the oblique direction when viewed from the side, in the direction opposite to the vehicle with respect to the base unit. A first frequency band element;
Connected to a second power feeding unit for a second frequency band lower than the first frequency band, and viewed from the front and the side of the composite antenna device in the direction opposite to the vehicle with respect to the base unit. A second frequency band element arranged in an oblique direction, wherein the first frequency band element and the second frequency band element are arranged so as to spread in a V shape from the first power feeding unit and the second power feeding unit. And the second frequency band element having an open end side portion that is bent halfway and extends from the bent position to a predetermined length;
A composite antenna device comprising: 2. The composite antenna device according to claim 1, wherein an open end side portion of the second frequency band element is bent toward a side away from the first frequency band element. 2. The composite antenna device according to claim 1, wherein an open end side portion of the second frequency band element is bent toward a side closer to the first frequency band element. 4. The composite antenna device according to claim 1, wherein an open end side portion of the second frequency band element extends in parallel to the base portion. 5. . 5. The composite antenna device according to claim 1, wherein an open end side portion of the second frequency band element is configured by a capacity loading portion. 6. The composite antenna device according to claim 1, wherein the first frequency band element is an opening in which the first frequency band element is bent halfway and extends from a bent position to a predetermined length. A composite antenna apparatus, further comprising an end portion, wherein the open end portion is bent toward a side closer to the second frequency band element. 7. The composite antenna device according to claim 1, further comprising a substrate erected perpendicularly to the base portion in a direction opposite to a vehicle, and the first frequency. A composite antenna device, wherein a band element and a second frequency band element are disposed on the substrate. 8. The composite antenna device according to claim 7, further comprising an amplifier circuit for a first frequency band and / or a second frequency band, wherein the amplifier circuit is disposed on the substrate. A composite antenna device. 9. The composite antenna device according to claim 1, wherein the first frequency band element and / or the second frequency band element spreads in a V-shape from the first power feeding unit and the second power feeding unit. Thus, the part arrange | positioned in this way is comprised by coil shape, The composite antenna apparatus characterized by the above-mentioned. 9. The composite antenna device according to claim 1, further comprising a third frequency band element connected to a third power feeding unit for a third frequency band higher than the first frequency band. A composite antenna device comprising:

Images