JP2018148334A - Slot antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slot antenna which has simple power feeding structure and can obtain a high antenna gain.SOLUTION: The slot antenna comprises: a plate-like radiation conductor 20 having first and second regions 21 and 22 positioned on both sides through a slot S1; a plate-like reflection conductor 30 arranged in parallel with the radiation conductor 20 so as to overlap with the radiation conductor 20; an electric power feeding conductor 41 that extends vertically to the radiation conductor 20 and is connected to the first region 21 of the radiation conductor 20; and a ground conductor 42 that extends vertically to the radiation conductor 20 and is connected to the second region 22 of the radiation conductor 20. According to the present invention, the electric power feeding conductor 41 and the ground conductor 42 which is vertical to the radiation conductor 20 are used, so that an electric power feeding can be simply and surely performed. Also, an electromagnetic wave radiated onto the reflection conductor 30 is reflected by the reflection conductor 30, and radiated to the opposite side, so that a high antenna gain can be obtained.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a slot antenna.

  As an antenna device using a flat radiation conductor, a slot antenna is widely known in addition to a patch antenna (see Patent Documents 1 and 2). The slot antenna has a structure in which a slot (closed opening) is formed in a flat radiation conductor, and resonates at a desired frequency by adjusting the position and shape of the slot, the position of the feed point, etc. Can do.

JP 2007-336170 A JP-A-9-116311

  However, since the slot antenna described in Patent Document 1 uses a coaxial cable to supply power, the power supply structure is complicated, and it is difficult to apply to a portable electronic device such as a smartphone. It was. Further, the slot antenna described in Patent Document 2 has a problem in that the coupling between the microstrip line and the radiation conductor is weak because power is supplied using the microstrip line. Further, the slot antennas described in Patent Documents 1 and 2 also have a problem that the antenna gain is low.

  Accordingly, an object of the present invention is to provide a slot antenna having a simple feeding structure and capable of obtaining a high antenna gain.

  The slot antenna according to the present invention includes a flat plate-like radiation conductor having first and second regions located on both sides of the slot, and a flat plate-like shape arranged in parallel with the radiation conductor so as to overlap the radiation conductor. A reflective conductor; a feed conductor extending perpendicular to the radiation conductor; connected to the first region of the radiation conductor; and extending perpendicular to the radiation conductor; And a ground conductor connected to the second region.

  According to the present invention, since the feeding conductor and the grounding conductor perpendicular to the radiation conductor are used, simple and reliable feeding can be performed. Moreover, since the electromagnetic wave radiated to the reflective conductor is reflected by the reflective conductor and radiated to the opposite side, it is possible to obtain a higher antenna gain than the conventional slot antenna.

  In the present invention, the power supply conductor may be provided through the reflective conductor. According to this, interference between the feeding conductor and the reflecting conductor can be prevented with a simple structure.

  In the present invention, the ground conductor may be connected to the reflective conductor or may be provided through the reflective conductor. The former is suitable when a ground potential is applied to the reflective conductor, and the latter is suitable when a potential different from the ground potential is applied to the reflective conductor.

  The slot antenna according to the present invention may further include another ground conductor provided on the same plane as the reflective conductor, and an end portion of the ground conductor may be connected to the other ground conductor. According to this, since the reflective conductor and another ground conductor can be formed at the same time, it is possible to give the ground potential to the ground conductor with a simple configuration without increasing the number of manufacturing steps.

  In the present invention, the distance between the radiation conductor and the reflection conductor is preferably ¼ or less of the wavelength of the antenna resonance signal. According to this, the overall thickness can be reduced, and the reflection efficiency by the reflection conductor can be increased.

  The slot antenna according to the present invention further includes a dielectric layer, wherein the radiation conductor is formed on or near one surface of the dielectric layer, and the reflective conductor is formed on or near the other surface of the dielectric layer. It does not matter. According to this, it becomes possible to form a slot antenna on a board itself such as a printed board or an LTCC board.

  The slot antenna according to the present invention further includes a flat plate-like excitation conductor that is positioned on the opposite side of the reflection conductor from the radiation conductor and is disposed in parallel with the radiation conductor so as to overlap the radiation conductor. It doesn't matter. According to this, since the excitation conductor is excited by the radiation conductor, the antenna characteristics can be improved.

  In this case, the excitation conductor may be in a floating state, or a slot may be formed at a position overlapping the slot of the radiation conductor. According to the former, it is possible to widen the antenna band, and according to the latter, it is possible to make a dual band. In the latter case, the excitation conductor has third and fourth regions located on both sides of the slot, and the feed conductor includes the first region of the radiating conductor and the excitation conductor. The ground conductor may be connected to the third region, and the ground conductor may be connected to the second region of the radiation conductor and the fourth region of the excitation conductor. According to this, since the excitation conductor behaves in the same manner as the radiation conductor, it is possible to further improve the antenna characteristics.

  As described above, the slot antenna according to the present invention has a simple feeding structure and can obtain a high antenna gain.

FIG. 1 is a schematic perspective view showing the structure of a slot antenna 10A according to the first embodiment of the present invention. FIG. 2 is a plan view of the slot antenna 10A. 3 is a cross-sectional view taken along line AA in FIG. FIG. 4 is a schematic cross-sectional view for explaining a method of supporting the slot antenna 10A. FIG. 5 is a schematic cross-sectional view for explaining another method of supporting the slot antenna 10A. FIG. 6 is a plan view showing the structure of the slot antenna 10B according to the second embodiment of the present invention. FIG. 7 is a cross-sectional view taken along line BB in FIG. FIG. 8 is a cross-sectional view showing a modification of the slot antenna 10B. FIG. 9 is a schematic perspective view showing the structure of a slot antenna 10C according to the third embodiment of the present invention. FIG. 10 is a cross-sectional view of the slot antenna 10C. FIG. 11 is a schematic perspective view showing the structure of a slot antenna 10D according to the fourth embodiment of the present invention. FIG. 12 is a cross-sectional view of the slot antenna 10D. FIG. 13 is a schematic perspective view showing the structure of a slot antenna 10E according to the fifth embodiment of the present invention. FIG. 14 is a cross-sectional view of the slot antenna 10E.

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

<First Embodiment>
FIG. 1 is a schematic perspective view showing the structure of a slot antenna 10A according to the first embodiment of the present invention. 2 is a plan view of the slot antenna 10A, and FIG. 3 is a cross-sectional view taken along the line AA in FIG.

  As shown in FIGS. 1 to 3, the slot antenna 10 </ b> A according to the present embodiment includes a flat plate-like radiation conductor 20 having an xy plane and a flat plate-like reflection conductor 30 having an xy plane. Although not particularly limited, in this embodiment, the radiation conductor 20 and the reflective conductor 30 have the same planar size, and both are arranged so as to overlap in the z direction.

  A slot S1 extending in the y direction is formed at the center of the radiation conductor 20 in the x direction. The slot S1 is a closed opening, and the first region 21 and the second region 22 located on both sides in the x direction via the slot S1 are connected via the connection portions 23 located at both ends in the y direction of the slot S1. Connected.

  A feeding conductor 41 is connected to the first region 21 of the radiation conductor 20. The power supply conductor 41 serves to supply a transmission signal output from the RF circuit 100 to the first region 21 of the radiation conductor 20 and to supply a reception signal received by the radiation conductor 20 to the RF circuit 100. The power supply conductor 41 extends in the z direction, and in the present embodiment, is connected to the radiation conductor 20 through a through hole 31 in which a part of the reflection conductor 30 is cut out. Thereby, the contact between the feeding conductor 41 and the reflecting conductor 30 is prevented.

  On the other hand, a ground conductor 42 is connected to the second region 22 of the radiation conductor 20. The ground conductor 42 serves to supply a ground potential to the second region 22 of the radiation conductor 20. The ground conductor 42 also extends in the z direction. In the present embodiment, a ground potential is applied to the reflective conductor 30, and the second region 22 of the radiating conductor 20 is connected by connecting the second region 22 of the radiating conductor 20 and the reflective conductor 30 by the ground conductor 42. Is supplied with a ground potential.

  The reflective conductor 30 plays a role of reflecting electromagnetic waves radiated from the radiating conductor 20. That is, from the radiating conductor 20, electromagnetic waves are mainly emitted toward both sides in the z direction, and a part of the electromagnetic waves radiated downward (minus side in the z direction) is reflected by the reflecting conductor 30, and the upper side. Radiated to the positive side in the z direction. Thereby, since the electromagnetic wave radiated | emitted to the upper side (plus side of az direction) is strengthened, an antenna gain improves. In addition, in the present embodiment, since the power supply conductor 41 extending in the z direction is used to directly supply power to the first region 21 of the radiation conductor 20, reliable power supply can be performed with a simple structure. .

  The distance L1 between the radiation conductor 20 and the reflection conductor 30 in the z direction is preferably equal to or less than ¼ of the wavelength of the signal having the antenna resonance frequency. According to this, the overall thickness of the slot antenna 10A can be reduced, and the reflection efficiency by the reflection conductor 30 can be increased. However, if the distance L1 between the radiating conductor 20 and the reflecting conductor 30 is too short, there is a problem in that the radiating conductor and the reflecting conductor are capacitively coupled. It is preferable to set it to 1/10 or more of the signal wavelength. Here, “wavelength” refers to the length of one wavelength in the free space when the space between the radiation conductor 20 and the reflection conductor 30 is a free space, and a dielectric is provided between the radiation conductor 20 and the reflection conductor 30. In the case of intervening, it indicates the length of one wavelength considering the wavelength shortening effect of the dielectric.

  4 and 5 are schematic cross-sectional views for explaining a method of supporting the slot antenna 10A.

  In the example shown in FIG. 4, the dielectric layer 50 is used, the radiation conductor 20 is formed on one surface 50 a of the dielectric layer 50, and the reflective conductor 30 is formed on the other surface 50 b of the dielectric layer 50. The feed conductor 41 and the ground conductor 42 are provided through the dielectric layer 50. As the dielectric layer 50, a part of a circuit board such as a printed board or an LTCC board can be used. In this case, the power supply conductor 41 and the ground conductor 42 are configured by through-hole conductors that penetrate a part of the circuit board. The According to this configuration, the slot antenna 10A can be configured by forming the conductor pattern on the front and back of the dielectric layer 50 and forming the through-hole conductor. Further, the radiating conductor 20 may be formed in the vicinity thereof instead of the one surface 50a, and the reflecting conductor 30 may be formed in the vicinity thereof instead of the other surface 50b.

  In the example shown in FIG. 5, the two supports 51 and 52 facing each other are used, the radiation conductor 20 is formed on the surface of the support 51, and the reflection conductor 30 is formed on the surface of the support 52. The power supply conductor 41 and the ground conductor 42 are provided between the support body 51 and the support body 52, and for example, connection pins or the like can be used. As the supports 51 and 52, a circuit board such as a printed circuit board, a casing of a portable electronic device, or the like can be used. According to such a configuration, it is possible to configure the slot antenna 10A using a space formed inside the portable electronic device.

<Second Embodiment>
FIG. 6 is a plan view showing the structure of the slot antenna 10B according to the second embodiment of the present invention, and FIG. 7 is a sectional view taken along line BB of FIG.

  As shown in FIGS. 6 and 7, the slot antenna 10 </ b> B according to the present embodiment is different in that another through hole 32 is provided in the reflective conductor 30 and a ground conductor 42 is provided through the through hole 32. This is different from the slot antenna 10A according to the first embodiment. Since other configurations are the same as those of the slot antenna 10A according to the first embodiment, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  In the present embodiment, since the ground conductor 42 and the reflective conductor 30 do not come into contact with each other, an arbitrary potential can be applied to the reflective conductor 30. As an example, the power supply potential may be applied to the reflective conductor 30, or a part of the signal wiring formed on the substrate may be used as the reflective conductor 30.

  Further, as shown in FIG. 8 which is a modified example, a notch 32a is provided in the reflective conductor 30, and another ground conductor 42a is provided on the same plane so as not to contact the reflective conductor 30 in a region surrounded by the notch 32a. May be formed. The ground conductor 42 a is provided at a position overlapping the ground conductor 42 in plan view, and is connected to the lower end portion of the ground conductor 42. Thus, if the ground conductor 42a located on the same plane as the reflective conductor 30 is provided, the ground potential can be applied to the ground conductor 42 with a simple configuration without increasing the number of manufacturing steps.

  As illustrated in the present embodiment, it is not essential to apply a ground potential to the reflective conductor 30 in the present invention.

<Third Embodiment>
FIG. 9 is a schematic perspective view showing the structure of a slot antenna 10C according to the third embodiment of the present invention, and FIG. 10 is a cross-sectional view of the slot antenna 10C.

  As shown in FIGS. 9 and 10, the slot antenna 10C according to the present embodiment is different from the slot antenna 10A according to the first embodiment in that an excitation conductor 60 is added. Since other configurations are the same as those of the slot antenna 10A according to the first embodiment, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  The excitation conductor 60 is a flat conductor located on the opposite side of the reflection conductor 30 when viewed from the radiation conductor 20, and the radiation conductor 20 and the reflection conductor 30 are overlapped with the radiation conductor 20 and the reflection conductor 30 in the z direction. Arranged in parallel. That is, the excitation conductor 60 also has an xy plane and has a structure in which the radiation conductor 20 is sandwiched between the excitation conductor 60 and the reflection conductor 30. In the present embodiment, the radiation conductor 20, the reflection conductor 30, and the excitation conductor 60 have the same planar size, and are disposed so as to overlap in the z direction.

  The excitation conductor 60 is in a floating state without being connected to any wiring, and is excited by electromagnetic waves radiated from the radiation conductor 20. As a result, electromagnetic waves are also radiated from the excitation conductor 60, so that the antenna band can be widened. The planar size of the excitation conductor 60 and the distance L2 between the excitation conductor 60 and the radiation conductor 20 may be designed according to the radiation characteristics required for the excitation conductor 60.

<Fourth Embodiment>
FIG. 11 is a schematic perspective view showing the structure of a slot antenna 10D according to the fourth embodiment of the present invention, and FIG. 12 is a sectional view of the slot antenna 10D.

  As shown in FIGS. 11 and 12, the slot antenna 10D according to the present embodiment is different from the slot antenna 10C according to the third embodiment in that the slot S2 is provided in the excitation conductor 60. Since the other configuration is the same as that of the slot antenna 10C according to the third embodiment, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  The slot S2 provided in the excitation conductor 60 is provided at a position overlapping the slot S1 provided in the radiating conductor 20, and has the same shape and size as the slot S1. That is, the slot S2 is a closed opening extending in the y direction, and the third region 61 and the fourth region 62 located on both sides in the x direction via the slot S2 are both ends in the y direction of the slot S2. It is connected via a connection part 63 located at the position.

  With this configuration, the excitation conductor 60 excited by the radiating conductor 20 functions as another slot antenna, so that dual banding can be achieved. The planar size of the excitation conductor 60, the distance L2 between the excitation conductor 60 and the radiation conductor 20, the position, shape, and size of the slot S2 may be designed according to the radiation characteristics required for the excitation conductor 60.

<Fifth Embodiment>
FIG. 13 is a schematic perspective view showing the structure of a slot antenna 10E according to the fifth embodiment of the present invention, and FIG. 14 is a cross-sectional view of the slot antenna 10E.

  As shown in FIGS. 13 and 14, in the slot antenna 10E according to the present embodiment, the first region 21 of the radiating conductor 20 and the third region 61 of the excitation conductor 60 are connected by the feed conductor 41, and the ground conductor 42 is used. The second antenna 22 is different from the slot antenna 10D according to the fourth embodiment in that the second region 22 of the radiating conductor 20 and the fourth region 62 of the excitation conductor 60 are connected. Since other configurations are the same as those of the slot antenna 10D according to the fourth embodiment, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  In the present embodiment, power is directly supplied to the third region 61 of the excitation conductor 60 and a ground potential is directly applied to the fourth region of the excitation conductor 60. For this reason, the excitation conductor 60 is not only excited by the radiation conductor 20, but also functions as another radiation conductor. As a result, the antenna gain can be further increased.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. Needless to say, it is included in the range.

  For example, in each of the above-described embodiments, a single slot antenna has been described. However, a so-called phased array can be configured by arranging a plurality of slot antennas in a line shape or a matrix shape.

10A to 10E Slot antenna 20 Radiating conductor 21 First region 22 Second region 23 Connection portion 30 Reflecting conductor 31, 32 Through hole 32a Notch 41 Feeding conductor 42, 42a Grounding conductor 50 Dielectric layers 50a, 50b Surface 51, 52 support body 60 excitation conductor 61 3rd area | region 62 4th area | region 63 Connection part 100 RF circuit S1, S2 Slot

Claims (11)

A flat plate-like radiation conductor having first and second regions located on both sides of the slot;
A flat reflective conductor disposed in parallel with the radiation conductor so as to overlap the radiation conductor;
A feed conductor extending perpendicular to the radiation conductor and connected to the first region of the radiation conductor;
And a grounding conductor extending perpendicularly to the radiation conductor and connected to the second region of the radiation conductor.   The slot antenna according to claim 1, wherein the feeding conductor is provided so as to penetrate the reflective conductor.   The slot antenna according to claim 1, wherein the ground conductor is connected to the reflective conductor.   The slot antenna according to claim 1, wherein the ground conductor is provided so as to penetrate the reflective conductor.   The slot according to claim 1, further comprising another ground conductor provided on the same plane as the reflective conductor, wherein an end of the ground conductor is connected to the other ground conductor. antenna.   The slot antenna according to any one of claims 1 to 5, wherein a distance between the radiation conductor and the reflection conductor is equal to or less than ¼ of a wavelength of an antenna resonance signal. Further comprising a dielectric layer;
7. The radiating conductor is formed on one surface of the dielectric layer or in the vicinity thereof, and the reflective conductor is formed on the other surface of the dielectric layer or in the vicinity thereof. The slot antenna as described in any one.   The flat excitation conductor further located in the opposite side to the said reflective conductor seeing from the said radiation conductor and arrange | positioned in parallel with the said radiation conductor so that it may overlap with the said radiation conductor is further provided. The slot antenna according to any one of 7.   The slot antenna according to claim 8, wherein the excitation conductor is in a floating state.   The slot antenna according to claim 8, wherein the excitation conductor has a slot formed at a position overlapping the slot of the radiation conductor. The excitation conductor has third and fourth regions located on both sides through the slot,
The feeding conductor is connected to the first region of the radiation conductor and the third region of the excitation conductor;
The slot antenna according to claim 10, wherein the ground conductor is connected to the second region of the radiating conductor and the fourth region of the excitation conductor.

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