JPWO2017141698A1 - Antenna device - Google Patents

Abstract

The patch antenna includes a feeding element and a parasitic element. A feed line feeds the feed element. The feed element and the parasitic element are arranged side by side in a direction parallel to the excitation direction of the feed element. The feed line extends from the feed element in a direction parallel to the excitation direction. In plan view, the parasitic element includes a conductor pattern arranged on both sides of the feeder line, and the conductor pattern and the feeder line do not overlap. With this configuration, it is possible to weaken the electromagnetic coupling between the parasitic element and the feed line and to increase the bandwidth.

Description

  The present invention relates to an antenna device including a patch antenna.

  Patent Document 1 listed below discloses a wide-angle antenna including a feeding element and parasitic elements arranged on both sides thereof. The feeding element and the two parasitic elements are arranged in a direction orthogonal to the excitation direction. The structure of the feed line to the feed element is not shown.

  Patent Document 2 below discloses an antenna device including a feeding element and a plurality of parasitic elements. In this antenna device, a plurality of parasitic elements are arranged on a feeding element and a conductor layer thereon. The feeding element and the parasitic element partially overlap in plan view. The antenna gain can be improved by widening the region surrounding the plurality of parasitic elements.

JP2013-168875A JP 2004-242168 A

  In the wide-angle antenna disclosed in Patent Document 1, in order to prevent the feed line from electromagnetically affecting the parasitic element, the feed line is arranged on a conductor layer different from that of the parasitic element, It is preferable to arrange a ground conductor between the feeding element. For this reason, the number of conductor layers to be formed increases.

  In the antenna device disclosed in Patent Document 2, the antenna gain is improved by arranging a plurality of parasitic elements. Since the resonance point is not increased by the parasitic element, it is not possible to increase the bandwidth.

  An object of the present invention is to provide an antenna device that can weaken electromagnetic coupling between a parasitic element and a feed line and can achieve a wide band.

An antenna device according to a first aspect of the present invention provides:
A patch antenna including a feeding element and a parasitic element;
A feed line that feeds power to the feed element;
The feeding element and the parasitic element are arranged side by side in a direction parallel to the excitation direction of the feeding element,
The feed line extends from the feed element in a direction parallel to the excitation direction,
In plan view, the parasitic element includes a conductor pattern disposed on both sides of the feeder line, and the conductor pattern and the feeder line do not overlap.

  A wide band can be achieved by the double resonance phenomenon of the feeding element and the parasitic element. Since the feeder line and the parasitic line do not overlap, the electromagnetic influence of the feeder line on the parasitic line is reduced.

  In the antenna device according to the second aspect of the present invention, in addition to the configuration of the antenna device according to the first aspect, the feed line is disposed on a conductor layer different from the parasitic element.

  Compared with the case where the feed line and the parasitic element are arranged on the same conductor layer, the distance from the feed line to the parasitic element can be increased. Thereby, the electromagnetic coupling between the feed line and the parasitic element can be further reduced.

  In the antenna device according to the third aspect of the present invention, in addition to the configuration of the antenna device according to the first or second aspect, the feeding element and the parasitic element are arranged on the same conductor layer.

  By disposing the feeding element and the parasitic element on the same conductor layer, it is possible to suppress an increase in the number of layers of the entire conductor layer.

  An antenna device according to a fourth aspect of the present invention includes a ground conductor in addition to the configurations of the first to third antenna devices, and the feed line has the patch antenna and the ground conductor in the thickness direction. It is arranged between.

  A microstrip line is constituted by the feed line and the ground conductor.

  In the antenna device according to the fifth aspect of the present invention, in addition to the configurations of the antenna devices according to the first to fourth aspects, the dimension of the parasitic element in terms of the excitation direction is effective at the operating frequency of the patch antenna. 1/2 of the wavelength.

  Since a double resonance phenomenon due to the feeding element and the parasitic element is likely to occur, a wide band can be achieved.

  In the antenna device according to the sixth aspect of the present invention, in addition to the configuration of the antenna device according to the fourth aspect, the dimension related to the excitation direction of the parasitic element is 1 of the effective wavelength at the operating frequency of the patch antenna. / 4, and one end of the excitation direction is connected to the ground conductor.

  Since a double resonance phenomenon due to the feeding element and the parasitic element is likely to occur, a wide band can be achieved.

  A wide band can be achieved by the double resonance phenomenon of the feeding element and the parasitic element. Since the feeder line and the parasitic line do not overlap, the electromagnetic influence of the feeder line on the parasitic line is reduced.

1A is a plan view of the antenna device according to the first embodiment, and FIGS. 1B and 1C are cross-sectional views taken along one-dot chain lines 1B-1B and 1C-1C in FIG. 1A, respectively. 2A is a plan view of the antenna device according to the second embodiment, and FIG. 2B is a cross-sectional view taken along one-dot chain line 2B-2B in FIG. 2A. 3A and 3B are graphs showing the return loss of the antenna devices according to the comparative example and the second embodiment, respectively. FIGS. 3C and 3D are graphs showing the antenna gains of the antenna devices according to the comparative example and the second embodiment, respectively. is there. FIG. 4 is a plan view of an antenna device to be simulated according to a comparative example. 5A and 5B are plan views of the antenna device according to the third embodiment and its modification, respectively. 6A and 6B are cross-sectional views of an antenna device according to the fourth embodiment and its modification, respectively. 7A is a plan view of the antenna device according to the fifth embodiment, and FIG. 7B is a cross-sectional view taken along one-dot chain line 7B-7B in FIG. 7A. 8A is a plan view of the antenna device according to the sixth embodiment, and FIG. 8B is a cross-sectional view taken along one-dot chain line 8B-8B in FIG. 8A. FIG. 9 is a plan view of the antenna device according to the seventh embodiment.

[Example 1]
With reference to the drawings from FIG. 1A to FIG. 1C, the antenna device according to the first embodiment will be described.

  FIG. 1A is a plan view of the antenna device according to the first embodiment. A patch antenna including a feed element 11 and parasitic elements 12 and 13 and a feed line 14 are formed on the dielectric substrate 10. The feed element 11 has a substantially square or rectangular planar shape. A direction parallel to a pair of sides of a square or rectangle is defined as an x direction, and a direction parallel to the other pair of sides is defined as a y direction.

  The feed line 14 is connected to the feed element 11 at the feed point 15 and feeds the feed element 11. The feeding point 15 is arranged at a position shifted in the x direction from the center of the feeding element 11. The distance from the center of the feeding element 11 to the feeding point 15 is ¼ of the dimension of the feeding element 11 in the x direction. In this case, the x direction corresponds to the excitation direction of the feed element 11. The feed line 14 extends from the feed point 15 in the x direction (a direction parallel to the excitation direction).

  One parasitic element 12, the feeding element 11, and the other parasitic element 13 are arranged in this order in the x direction. One parasitic element 12 is disposed on the opposite side to the direction in which the feeder line 14 extends with respect to the feeder element 11 and has a square or rectangular planar shape having sides parallel to the x direction and the y direction. . The other parasitic element 13 is arranged on the same side as the direction in which the feeder line 14 extends with respect to the feeder element 11.

  The parasitic element 13 includes a pair of conductor patterns obtained by dividing a virtual pattern having the same planar shape as the parasitic element 12 into two by a straight line along the feeder line 14. That is, the parasitic element 13 includes a pair of conductor patterns arranged on both sides of the feeder line 14 in plan view. The pair of conductor patterns does not overlap with the feed line 14. An interval between the pair of conductor patterns is represented by Gy. The dimension of the parasitic element 13 in the y direction is represented by Wy.

  FIG. 1A shows an example in which the feed line 14 is bent in the y direction after passing through the region where the parasitic element 13 is disposed from the feed point 15 and then bent in the x direction. The shape of the feeder line 14 after passing through the region where the parasitic element 13 is disposed is not limited to the shape shown in FIG. 1A. However, the feeder line 14 is disposed so as not to overlap the conductor pattern constituting the parasitic element 13 in plan view.

  The dimension of the feed element 11 in the x direction is ½ of the effective wavelength at the operating frequency. The effective wavelength depends on the dielectric constant of the dielectric substrate 10. The dimension in the y direction of the feed element 11 is also ½ of the effective wavelength at the operating frequency, for example. For example, when the operating frequency is 60 GHz and the relative dielectric constant of the dielectric substrate 10 is about 3, the dimension of the feed element 11 in the x direction is about 1.5 mm.

  The dimension in the x direction of the parasitic elements 12 and 13 is set to about ½ of the effective wavelength at the operating frequency of the patch antenna. As a result, it is possible to achieve a wide band due to the double resonance phenomenon of the feeding element 11 and the parasitic elements 12 and 13. The dimension of the parasitic elements 12 and 13 in the y direction is substantially the same as the dimension of the feeder element 11 in the y direction.

  FIG. 1B is a cross-sectional view taken along one-dot chain line 1B-1B in FIG. 1A. For example, a total of three conductor layers are disposed inside and on the top surface of the dielectric substrate 10. The number of conductor layers can be increased as necessary.

  The feeding element 11 and the parasitic elements 12 and 13 are disposed on the uppermost conductor layer of the dielectric substrate 10. In FIG. 1B, a cross section of the feed element 11 and the parasitic element 12 and a side surface of the parasitic element 13 appear. The feed line 14 is disposed in the second conductor layer from the top. The feed line 14 is connected to the feed element 11 through the conductive via 16. A ground conductor 17 is disposed on the third conductor layer from the top. In this way, the feed line 14 is arranged on a different conductor layer from the parasitic element 13. Further, the feed line 14 is disposed between the patch antenna including the feed element 11 and the parasitic elements 12 and 13 and the ground conductor 17 in the thickness direction. The feed line 14 and the ground conductor 17 constitute a microstrip line.

  FIG. 1C shows a cross-sectional view taken along one-dot chain line 1C-1C in FIG. 1A. The distance in the thickness direction from the upper surface of the feeder line 14 to the lower surface of the parasitic element 13 is represented by T. The feed line 14 is preferably arranged at the center of the gap Gy between the pair of conductor patterns constituting the parasitic element 13. An interval in the y direction from the feeder line 14 to one conductor pattern is represented by My.

  Next, the effect of Example 1 is demonstrated. In Example 1, since the parasitic elements 12 and 13 are loaded on the feeding element 11, it is possible to achieve a wide band due to the double resonance effect.

  Since the feeder line 14 and the parasitic element 13 do not overlap, the electromagnetic influence of the feeder line 14 on the parasitic element 13 is reduced without arranging a ground conductor between the parasitic element 13 and the feeder line 14. can do. Further, the feeding element 11 and the parasitic element 12 are arranged on the same conductor layer. As a result, an increase in the number of conductor layers can be suppressed as compared with the case where both are disposed in different conductor layers.

  In order to reduce the coupling between the feed line 14 and the parasitic element 13, it is preferable to increase the interval My in the y direction from the feed line 14 to one of the conductor patterns. For example, the interval My is preferably 0 or more, and more preferably the interval T in the thickness direction from the upper surface of the feed line 14 to the lower surface of the parasitic element 13.

  However, if the distance My is excessively increased, the area of the conductor pattern constituting the parasitic element 13 is reduced, and the effect of loading the parasitic element 13 on the feeder element 11 is diminished. In order to obtain a sufficient effect of loading the parasitic element 13 on the feeding element 11, the distance Gy between the pair of conductor patterns is preferably set to ½ or less of the dimension Wy in the y direction of the parasitic element 13.

[Example 2]
Next, an antenna device according to Example 2 will be described with reference to FIGS. 2A to 4. Hereinafter, differences from the first embodiment will be described, and description of common configurations will be omitted. In the first and second embodiments, the configurations of the parasitic elements 12 and 13 are different.

  FIG. 2A is a plan view of the antenna device according to the second embodiment. In Example 1, as shown in FIG. 1A, the dimension in the x direction of each of the parasitic elements 12 and 13 was about ½ of the effective wavelength at the operating frequency. In Example 2, the dimension in the x direction of each of the parasitic elements 12 and 13 is about ¼ of the effective wavelength at the operating frequency. In other words, the dimension of each of the parasitic elements 12 and 13 in the x direction is ½ of the dimension of the feeder element 11 in the x direction.

  2B is a cross-sectional view taken along one-dot chain line 2B-2B in FIG. 2A. An end of the parasitic element 12 far from the feeding element 11 is connected to the ground conductor 17 via the conductive via 18. Similarly, the end of the parasitic element 13 far from the feeding element 11 is connected to the ground conductor 17 via the conductive via 19.

  In the second embodiment as well, a wide band can be achieved by the double resonance phenomenon of the feeding element 11 and the parasitic elements 12 and 13. Further, in the second embodiment, similarly to the first embodiment, the influence of the feeder line 14 on the parasitic element 13 can be reduced, and an increase in the number of conductor layers can be suppressed. In addition, in the second embodiment, since the dimensions of the parasitic elements 12 and 13 in the x direction are smaller than those in the first embodiment, it is possible to reduce the size of the patch antenna.

  The effect of the antenna device according to the second embodiment will be described with reference to the drawings from FIG. 3A to FIG. 3D. The return loss and antenna gain of the antenna device according to Example 2 and the antenna device according to the comparative example were calculated by simulation.

The simulation conditions of the antenna device according to Example 2 are as follows.
-The dimension of the feed element 11 in the x direction is 1.5 mm and the dimension in the y direction is 1.4 mm.
・ Dimension of parasitic element 12 in the x direction 0.8 mm, dimension in the y direction 1.4 mm
・ Dimension of parasitic element 13 in x direction 0.8mm
・ Dimension y of parasitic element 13 in the y direction Wy 1.4mm
-Gy 0.3 mm between the pair of conductor patterns of the parasitic element 13
-Distance T 0.05mm from the upper surface of the feed line 14 to the bottom surface of the parasitic element 13
-Distance in the y direction from the feed line 14 to the conductor pattern of the parasitic element 13 My 0.1 mm
The relative dielectric constant of the dielectric substrate 3 3

  FIG. 4 shows a plan view of an antenna device to be simulated according to a comparative example. In the comparative example, the parasitic element 13 is not separated into a pair of conductor patterns, but is constituted by one conductor pattern. For this reason, the feeder line 14 overlaps the parasitic element 13. As a result, compared with the antenna device according to the second embodiment, the electromagnetic influence of the feed line 14 on the parasitic element 13 is increased. Other configurations of the antenna device according to the comparative example are the same as those of the antenna device according to the second embodiment.

  3A and 3B show the return loss of the antenna device according to the comparative example and the example 2, respectively. The horizontal axis represents frequency in the unit “GHz”, and the vertical axis represents return loss in the unit “dB”. As an example, when comparing the frequency bandwidth with a return loss of −10 dB or less, the bandwidth of the antenna device according to the comparative example is about 3 GHz, whereas the bandwidth of the antenna device according to the second embodiment is 5 GHz or more. Recognize. Thus, the operating bandwidth of the antenna device according to the second embodiment is wider than the operating bandwidth of the antenna device according to the comparative example.

  3C and 3D show antenna gains of the antenna devices according to the comparative example and the second embodiment, respectively. The horizontal axis represents frequency in the unit “GHz”, and the vertical axis represents antenna gain in the unit “dBi”. In the antenna device according to the comparative example, the antenna gain is depressed in the vicinity of 61 GHz. On the other hand, in the antenna device according to the second embodiment, this depression is not generated. Thus, the antenna device according to the second embodiment has a higher antenna gain than the antenna device according to the comparative example.

  From the simulations shown in the graphs from FIG. 3A to FIG. 3D, it is possible to confirm the excellent effect of Example 2 over the comparative example. That is, by separating the parasitic element 13 into a pair of conductor patterns, the influence of the feeder line 14 on the parasitic element 13 can be reduced. As a result, the bandwidth of the antenna device can be increased and the antenna gain can be increased.

[Example 3]
Next, an antenna device according to Example 3 will be described with reference to FIGS. 5A and 5B.
FIG. 5A is a plan view of the antenna device according to the third embodiment. In the antenna device according to the third embodiment, one parasitic element 12 (FIG. 1A) of the antenna device according to the first embodiment is not arranged. The patch antenna includes a feed element 11 and a divided parasitic element 13. Other configurations are the same as those of the antenna device according to the first embodiment.

  FIG. 5B shows a plan view of an antenna device according to a modification of the third embodiment. In the antenna device according to the modification of the third embodiment, one parasitic element 12 (FIG. 2A) of the antenna device according to the second embodiment is not arranged. The patch antenna includes a feed element 11 and a divided parasitic element 13. Other configurations are the same as those of the antenna device according to the second embodiment.

  In the antenna device according to the third embodiment and its modification, the same effects as those of the first and second embodiments can be obtained.

[Example 4]
Next, an antenna device according to Example 4 will be described with reference to FIGS. 6A and 6B. Hereinafter, differences from the first embodiment shown in FIGS. 1A and 1B will be described, and descriptions of common configurations will be omitted.

  FIG. 6A is a cross-sectional view of the antenna device according to the fourth embodiment. In Example 1, the feeding element 11 and the parasitic elements 12 and 13 (FIG. 1B) are arranged on the same conductor layer. In Example 4, the feed element 11 is disposed in the uppermost conductor layer, and the parasitic elements 12 and 13 are disposed in the second conductor layer from the top. The feed line 14 and the ground conductor 17 are disposed in the third and fourth conductor layers from the top, respectively.

  FIG. 6B shows a cross-sectional view of an antenna device according to a modification of the fourth embodiment. In this modification, the feed element 11 is arranged in the second conductor layer from the top, and the parasitic elements 12 and 13 are arranged in the uppermost conductor layer. Other configurations are the same as those of the antenna device of the fourth embodiment shown in FIG. 6A.

  Also in the fourth embodiment, the coupling between the two can be reduced without arranging a ground conductor between the feeder line 14 and the parasitic element 13.

[Example 5]
Next, an antenna device according to Example 5 will be described with reference to FIGS. 7A and 7B. Hereinafter, differences from the first embodiment shown in FIGS. 1A and 1B will be described, and descriptions of common configurations will be omitted.

  FIG. 7A is a plan view of the antenna device according to the fifth embodiment, and FIG. 7B is a cross-sectional view taken along one-dot chain line 7B-7B in FIG. 7A. In the fifth embodiment, the feed element 11 and the feed line 14 are arranged on the same conductor layer, for example, the uppermost conductor layer. A ground conductor 17 is disposed on the second conductor layer from the top.

  The conductor pattern constituting the feed element 11 is provided with a recess 11A from the center of one side perpendicular to the x direction toward the center. The planar shape of the recess 11 </ b> A is a square or a rectangle, and the depth (dimension in the x direction) is ¼ of the dimension in the x direction of the feed element 11. The feed line 14 extends in the x direction from the center of the bottom of the recess 11A. A connection point between the feed line 14 and the feed element 11 corresponds to the feed point 15. The feed line 14 passes between a pair of conductor patterns of the parasitic element 13.

  Also in the fifth embodiment, since the feed line 14 and the parasitic element 13 do not overlap with each other, similarly to the first embodiment, the influence of the feed line 14 on the parasitic element 13 can be reduced. Furthermore, in Example 5, since the feed element 11, the parasitic elements 12, 13, and the feed line 14 are arranged in the same conductor layer, the number of conductor layers can be reduced.

[Example 6]
Next, an antenna device according to Example 6 will be described with reference to FIGS. 8A and 8B. Hereinafter, differences from the fifth embodiment illustrated in FIGS. 7A and 7B will be described, and descriptions of common configurations will be omitted.

  FIG. 8A is a plan view of the antenna device according to the sixth embodiment, and FIG. 8B is a cross-sectional view taken along one-dot chain line 8B-8B in FIG. 8A. In Example 5, the feed element 11, the parasitic elements 12, 13, and the feed line 14 are arranged in the same conductor layer. In Example 6, the feeding element 11 and the parasitic elements 12 and 13 are arranged in different conductor layers. The two parasitic elements 12 and 13 are arranged in the same conductor layer, for example, the uppermost conductor layer. The feed element 11 and the feed line 14 are arranged on the same conductor layer, for example, the second conductor layer from the top.

  Also in Example 6, the feed line 14 and the parasitic element 13 do not overlap. For this reason, as in the seventh embodiment, the influence of the feeder line 14 on the parasitic element 13 can be reduced.

[Example 7]
Next, an antenna device according to Example 7 will be described with reference to FIG. Hereinafter, differences from the first embodiment shown in FIGS. 1A and 1B will be described, and descriptions of common configurations will be omitted.

  FIG. 9 is a plan view of the antenna device according to the seventh embodiment. The antenna device according to the seventh embodiment has an array antenna structure including a plurality of patch antennas 20 arranged in the y direction. Each of the patch antennas 20 has the same structure as the patch antenna according to the first embodiment, and includes a feed element 11 and parasitic elements 12 and 13 arranged in the x direction. A plurality of feed lines 14 are connected to the plurality of feed elements 11, respectively.

  Like the antenna device in the seventh embodiment, the array antenna can be configured using the antenna device in the first embodiment. Similarly, an array antenna can be configured by using any one of the antenna devices according to the second to sixth embodiments.

  In the seventh embodiment, each feed line 14 of the patch antenna 20 extends in a direction (x direction) orthogonal to the arrangement direction (y direction) of the patch antenna 20. For this reason, the feed line 14 does not overlap with the parasitic element 13 and also does not overlap with the feed element 11 and the parasitic elements 12 and 13 of the other patch antennas 20. With this configuration, the influence of the feed line 14 on the other patch antennas 20 can be reduced.

  Each of the above-described embodiments is an exemplification, and needless to say, partial replacement or combination of the configurations shown in the different embodiments is possible. About the same effect by the same composition of a plurality of examples, it does not refer to every example one by one. Furthermore, the present invention is not limited to the embodiments described above. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

DESCRIPTION OF SYMBOLS 10 Dielectric board | substrate 11 Feeding element 11A Indentation 12, 13 Parasitic element 14 Feeding line 15 Feeding point 16 Conductive via 17 Grounding conductor 18, 19 Conductive via 20 Patch antenna

Claims (6)

A patch antenna including a feeding element and a parasitic element;
A feed line that feeds power to the feed element;
The feeding element and the parasitic element are arranged side by side in a direction parallel to the excitation direction of the feeding element,
The feed line extends from the feed element in a direction parallel to the excitation direction,
In plan view, the parasitic element includes a conductor pattern disposed on both sides of the feeder line, and the conductor pattern and the feeder line do not overlap with each other.   The antenna apparatus according to claim 1, wherein the feed line is disposed on a conductor layer different from the parasitic element.   The antenna device according to claim 1, wherein the feeding element and the parasitic element are arranged in the same conductor layer. In addition, it has a ground conductor,
The antenna device according to any one of claims 1 to 3, wherein the feed line is disposed between the patch antenna and the ground conductor in a thickness direction.   5. The antenna device according to claim 1, wherein a dimension of the parasitic element in the excitation direction is ½ of an effective wavelength at an operating frequency of the patch antenna.   5. The dimension of the parasitic element in the excitation direction is 1/4 of the effective wavelength at the operating frequency of the patch antenna, and one end of the parasitic element is connected to the ground conductor in the excitation direction. The antenna device described.

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