Antenna equipment, transmitters, and radar

Abstract

To provide an antenna device capable of suppressing interline coupling.SOLUTION: An antenna device includes a dielectric substrate, an antenna pattern formed on a first main surface of the dielectric substrate, and a ground pattern formed on a second main surface of the dielectric substrate. The antenna pattern includes first and second patch antennas adjacent to each other in a first direction, and first and second transmission lines connecting the first and second patch antennas and spaced apart from each other in a second direction orthogonal to the first direction. The first and second transmission lines have spacing in some sections wider than that in other sections.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an antenna device, a transmitter, and a radar.

Background Art

[0002] Patent Documents 1 and 2 disclose a series-fed patch array antenna in which a plurality of patch antennas are arranged in one direction and connected in series.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the antenna device as described above, when connecting patch antennas to each other with a plurality of transmission lines, coupling between the lines becomes a problem.

[0005] The present invention has been made in view of the above problems, and its main object is to provide an antenna device, a transmitter, and a radar capable of suppressing coupling between lines.

Means for Solving the Problems

[0006] To solve the above problems, an antenna device according to one aspect of the present invention comprises a dielectric substrate, an antenna pattern formed on a first main surface of the dielectric substrate, and a ground pattern formed on a second main surface of the dielectric substrate, wherein the antenna pattern comprises first and second patch antennas adjacent to each other in a first direction, and first and second transmission lines that connect the first and second patch antennas and are spaced apart from each other in a second direction perpendicular to the first direction, wherein the spacing between some sections of the first and second transmission lines is wider than the spacing between other sections. This makes it possible to suppress inter-line coupling.

[0007] In the above embodiment, the spacing of the partial section may be wider than the spacing of the section on the first patch antenna side and the spacing of the section on the second patch antenna side. This makes it possible to widen the spacing of the partial section regardless of the connection position of the transmission line to the patch antenna.

[0008] In the above embodiment, the first and second transmission lines may be curved in opposite directions. This makes it possible to suppress unwanted radiation by curving the transmission lines.

[0009] Furthermore, an antenna device according to another aspect of the present invention comprises a dielectric substrate, an antenna pattern formed on a first main surface of the dielectric substrate, and a ground pattern formed on a second main surface of the dielectric substrate, wherein the antenna pattern comprises first and second patch antennas adjacent to each other in a first direction, and first and second transmission lines that connect the first and second patch antennas and are spaced apart from each other in a second direction perpendicular to the first direction, and further comprises an auxiliary ground pattern that suppresses inter-line coupling of the first and second transmission lines. This makes it possible to suppress inter-line coupling.

[0010] In the above embodiment, the auxiliary ground pattern may be placed between the first and second transmission lines. This makes it possible to suppress inter-line coupling.

[0011] In the above embodiment, the auxiliary ground pattern may also be arranged outward in the second direction relative to the first and second transmission lines. This makes it possible to further suppress inter-line coupling.

[0012] In the above embodiment, an auxiliary dielectric substrate covering the first and second transmission lines may be further provided, and the auxiliary ground pattern may be arranged on the main surface of the auxiliary dielectric substrate opposite to the first and second transmission lines. This makes it possible to suppress inter-line coupling.

[0013] Furthermore, a transmitter according to another aspect of the present invention includes the above-described antenna device. This makes it possible to include an antenna device that suppresses inter-line coupling.

[0014] Furthermore, another embodiment of the present invention provides a radar equipped with the above-described antenna device. This makes it possible to provide an antenna device that suppresses inter-line coupling. [Brief explanation of the drawing]

[0015] [Figure 1] This figure shows an example of a radar configuration. [Figure 2] This is a diagram showing an example of the configuration of an antenna device. [Figure 3] This is a magnified view of a portion of Figure 2. [Figure 4] This is a diagram showing an example of the configuration of an antenna device. [Figure 5] This is a magnified view of a portion of Figure 4. [Figure 6] This figure shows an example of a cross-sectional structure. [Figure 7] This is a diagram showing an example of the configuration of an antenna device. [Figure 8] This is a diagram showing an example of the configuration of an antenna device. [Figure 9] This is a diagram showing an example of the configuration of an antenna device. [Figure 10] This figure shows an example of a cross-sectional structure. [Figure 11] This is a diagram showing an example of the configuration of an antenna device. [Figure 12] It is a diagram showing an example of a cross-sectional structure. [Figure 13] It is a diagram showing an example of a cross-sectional structure. [Figure 14] It is a diagram showing a reference example. [Figure 15] It is a diagram showing a reference example.

Mode for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0017] [Radar] FIG. 1 is a block diagram showing a configuration example of a radar 100 according to the present embodiment. The radar 100 is an example of a transmitter according to the present embodiment and includes an antenna device 10 according to the present embodiment. In addition to the antenna device 10, the radar 100 includes a transmission / reception unit 11, a signal processing unit 12, and a control unit 13.

[0018] The transmission / reception unit 11 includes a modulation unit and a magnetron, and intermittently drives the magnetron with a pulse voltage generated by the modulation unit in response to a trigger signal from the signal processing unit to generate a transmission signal. The antenna device 10 transmits the transmission signal from the transmission / reception unit 11 as a radio wave pulse.

[0019] In addition, the antenna device 10 converts the received reflected wave into a reception signal. The reception signal from the antenna device 10 is signal-processed by the signal processing unit 12 through a frequency conversion / amplification circuit and a detection circuit included in the transmission / reception unit 11 and sent to the control unit 13 as a digital signal.

[0020] The radar 100 may be, for example, a marine radar that transmits and receives microwaves, or may be, for example, an in-vehicle radar for obstacle detection or collision prevention that transmits and receives millimeter waves.

[0021] [First Embodiment] FIG. 2 is a plan view showing a configuration example of an antenna device 10A according to the first embodiment. FIG. 3 is a partially enlarged view of FIG. 2.

[0022] The antenna device 10A comprises a dielectric substrate 2, an antenna pattern 30 formed on the first main surface of the dielectric substrate 2 (the surface visible in Figure 2), and a ground pattern 21 (see Figure 6, etc.) formed on the second main surface of the dielectric substrate 2 opposite to the first main surface. The antenna pattern 30 includes a plurality of patch antennas 31-38. The number of patch antennas is not particularly limited.

[0023] Antenna device 10A is a series-fed patch array antenna, in which multiple patch antennas 31-38 are arranged in one direction and connected in series. In the figure, the x-direction is the direction of arrangement of patch antennas 31-34, and the y-direction, which is perpendicular to the x-direction, is the width direction of patch antennas 31-34.

[0024] The antenna pattern 30 is formed, for example, by patterning a metal foil provided on the first main surface of the dielectric substrate 2 using photolithography technology. Therefore, the patch antennas 31-38 and the transmission lines 41, 45, 49, 51, 52, 55, 56, 61-64 connected to them are integrated.

[0025] A feed line 9 is provided at the center of the antenna pattern 30 in the arrangement direction x. There are an even number of patch antennas 31-38, and the feed line 9 is provided between the two central patch antennas 31 and 35. However, the feed line 9 may also be provided at one end of the antenna pattern 30 in the arrangement direction x.

[0026] The patch antennas 31-38 are formed in a rectangular shape and have a width corresponding to half a wavelength of the fundamental frequency used. That is, the width (length y in the width direction) of the patch antennas 31-38 is approximately equal to half a wavelength of the fundamental frequency.

[0027] As shown in Figure 3, the patch antennas 31-38 have a shape that is symmetrical with respect to a center line (line of symmetry) C that passes through the center of the width direction y. In three dimensions, the center line C can also be described as a plane of symmetry perpendicular to the width direction y.

[0028] The patch antennas 31-38 have an input side 7 and an output side 8 that extend in the width direction y and face each other in the arrangement direction x. The input side 7 is the side closer to the feed line 9, and the output side 8 is the side further away from the feed line 9.

[0029] Two transmission lines 41 and 49 are connected to the input side 7 of the patch antenna 31, and two transmission lines 51 and 52 are connected to the output side 8 of the patch antenna 31.

[0030] Transmission line 41 is connected to the first side (upper side in the figure) of the center line C of the input side 7 of the patch antenna 31, and transmission line 49 is connected to the second side (lower side in the figure) of the center line C of the input side 7 of the patch antenna 31, opposite to the first side.

[0031] Transmission line 51 is connected to the first side of the center line C of the output side 8 of the patch antenna 31, and transmission line 52 is connected to the second side of the center line C of the output side 8 of the patch antenna 31, opposite to the first side.

[0032] Two transmission lines 51 and 52 are connected to the input side 7 of the patch antenna 32, and two transmission lines 61 and 62 are connected to the output side 8 of the patch antenna 32.

[0033] Transmission line 51 is connected to the first side of the center line C of the input side 7 of the patch antenna 32, and transmission line 52 is connected to the second side of the center line C of the input side 7 of the patch antenna 32, opposite to the first side.

[0034] Transmission line 61 is connected to the first side of the center line C of the output side 8 of the patch antenna 32, and transmission line 62 is connected to the second side of the center line C of the output side 8 of the patch antenna 32, opposite to the first side.

[0035] In the following description, the shape of the transmission lines 51 and 52 connecting the patch antennas 31 and 32 will be described as an example. Note that other transmission lines 41, 45, 49, 55, 56, 61-68 may have a similar shape, not just transmission lines 51 and 52.

[0036] As shown in the reference examples in Figures 14 and 15, when currents with opposite phases are passed through two transmission lines 51 and 52, the radiated radio waves cancel each other out, thus suppressing unwanted radiation. However, inter-line coupling occurs between transmission lines 51 and 52, and this component may become unwanted radiation, potentially affecting the directional characteristics of the antenna.

[0037] Therefore, in the first embodiment, as shown in Figure 3, the spacing between some sections 515 and 525 of the transmission lines 51 and 52 is made wider than that between other sections 513, 523, 514, and 524, thereby suppressing inter-line coupling.

[0038] Specifically, the transmission lines 51 and 52 have parallel sections 513 and 523 connected to the patch antenna 31, sections 514 and 524 connected to the sections 513 and 523, with the spacing between them gradually increasing as they move toward the patch antenna 32, and parallel sections 515 and 525 connected to the sections 514 and 524, and also connected to the patch antenna 32.

[0039] According to this, the spacing between some sections 515 and 525 of the transmission lines 51 and 52 is wider than that between other sections 513, 514, 523, and 524, which makes it possible to suppress inter-line coupling and reduce unwanted radiation caused by inter-line coupling.

[0040] Furthermore, while there are constraints on the length of the transmission lines 51 and 52, such as being equivalent to one wavelength of the fundamental wave, bending the transmission lines 51 and 52 eliminates the need to make the spacing between the patch antennas 31 and 32 the same as the length of the transmission lines 51 and 52.

[0041] Therefore, it becomes possible to arrange the patch antennas 31 and 32 at appropriate intervals, regardless of the length constraints of the transmission lines 51 and 52. This makes it possible to suppress grating lobes and optimize the beam shape.

[0042] In the illustrated example, the spacing between sections 515 and 525 is increased by bending both transmission lines 51 and 52. However, the method is not limited to this; the spacing may also be increased by bending only one of the transmission lines 51 or 52.

[0043] [Second Embodiment] Figure 4 is a plan view showing an example of the configuration of the antenna device 10B according to the second embodiment. Figure 5 is a partially enlarged view of Figure 4. Figure 6 is a diagram showing an example of the cross-sectional structure when cut along the line VI-VI in Figure 5. For configurations that overlap with the above embodiments, the same numbering may be used to omit detailed explanations.

[0044] As shown in Figure 5, in the second embodiment, the transmission lines 51 and 52 are bent so that their central portions are separated from each other. That is, the spacing between the central sections 515 and 525 of the transmission lines 51 and 52 is wider than the spacing between sections 514 and 524 on the patch antenna 31 side and the spacing between sections 516 and 526 on the patch antenna 32 side.

[0045] More specifically, the transmission lines 51 and 52 have sections 514 and 524 connected to patch antenna 31, where the spacing gradually widens as you move toward patch antenna 32; sections 516 and 526 connected to patch antenna 32, where the spacing gradually widens as you move toward patch antenna 31; and the widest spacing section 515 and 525 interposed between them.

[0046] According to this, the spacing of the central section 515, 525 can be increased compared to the spacing at which the transmission lines 51, 52 are connected to the patch antennas 31, 32. This makes it possible to further suppress inter-line coupling and to increase the degree of freedom in the placement of the patch antennas 31, 32.

[0047] In the second embodiment, sections 515 and 525 were located at the same position in the array direction x, and the transmission lines 51 and 52 were roughly diamond-shaped. However, the embodiment is not limited to this, and as shown in the modified antenna device 10C in Figure 7, sections 515 and 525 may be located at different positions in the array direction x, and the transmission lines 51 and 52 may be roughly parallelogram-shaped.

[0048] [Third Embodiment] Figure 8 is a plan view showing an example configuration of the antenna device 10D according to the third embodiment. For configurations that overlap with the above embodiments, the same number is used, and detailed explanations may be omitted.

[0049] In the third embodiment, the transmission lines 51 and 52 are curved in opposite directions. That is, the transmission lines 51 and 52 are curved in an arc shape as a whole, such that the central sections 515 and 525 are separated from each other in the width direction y.

[0050] According to this, sharp bends in the transmission lines 51 and 52 can be eliminated, making it possible to further suppress unwanted radiation.

[0051] [Fourth embodiment] Figure 9 is a plan view showing an example of the configuration of the antenna device 10E according to the fourth embodiment. Figure 10 is a diagram showing an example of the cross-sectional structure when cut along line XX in Figure 9. For configurations that overlap with the above embodiments, the same number is used to omit detailed explanations.

[0052] In the fourth embodiment, an auxiliary ground pattern 23 is placed between the transmission lines 51 and 52 to suppress inter-line coupling. The auxiliary ground pattern 23 is grounded to a ground pattern 21 on the second main surface of the dielectric substrate 2.

[0053] The auxiliary ground pattern 23 is formed, for example, in a rectangular shape that is long in the arrangement direction x. The auxiliary ground pattern 23 is formed with a gap between it and the patch antennas 31, 32 and the transmission lines 51, 52.

[0054] According to this, by placing the auxiliary ground pattern 23 between the transmission lines 51 and 52, it becomes possible to suppress inter-line coupling and reduce unwanted radiation caused by inter-line coupling.

[0055] Furthermore, the auxiliary ground pattern 23 may be placed not only between transmission lines 51 and 52, but also between transmission lines 41, 45, and 49, between transmission lines 55 and 56, between transmission lines 61 and 62, between transmission lines 63 and 64, between transmission lines 65 and 66, or between transmission lines 67 and 68.

[0056] [Fifth Embodiment] Figure 11 shows an example of the configuration of the antenna device 10F according to the fifth embodiment. Figure 12 shows an example of the cross-sectional structure when cut along the line XII-XII in Figure 11. For configurations that overlap with the above embodiments, the same number is used to omit detailed explanations.

[0057] In the fifth embodiment, an auxiliary ground pattern 25 is also arranged outward in the width direction y relative to the transmission lines 51 and 52. That is, the transmission lines 51 and 52 are sandwiched in the same plane by the auxiliary ground patterns 23 and 25, and are configured as a grounded coplanar line.

[0058] The auxiliary ground pattern 25 is formed, for example, in a rectangular shape that is long in the arrangement direction x. The auxiliary ground pattern 25 is formed with a gap between it and the patch antennas 31, 32 and the transmission lines 51, 52. The auxiliary ground pattern 25 is grounded to the ground pattern 21 on the second main surface of the dielectric substrate 2.

[0059] According to this, by arranging the auxiliary ground pattern 25 outside the width direction y with respect to the transmission lines 51 and 52, it becomes possible to further suppress inter-line coupling and suppress unwanted radiation caused by inter-line coupling.

[0060] Furthermore, the auxiliary ground pattern 25 may be placed not only outside the transmission lines 51 and 52, but also outside the transmission lines 41, 45, and 49, outside the transmission lines 55 and 56, outside the transmission lines 61 and 62, outside the transmission lines 63 and 64, outside the transmission lines 65 and 66, and outside the transmission lines 67 and 68.

[0061] [Sixth Embodiment] Figure 13 shows an example of the cross-sectional structure of the antenna device 10G according to the sixth embodiment. For configurations that overlap with the above embodiments, the same number is used, and detailed explanations may be omitted.

[0062] In the sixth embodiment, an auxiliary dielectric substrate 26 is provided to cover the transmission lines 51 and 52, and an auxiliary ground pattern 27 is provided on the main surface of the auxiliary dielectric substrate 26 opposite to the transmission lines 51 and 52 (the upper main surface in the figure).

[0063] In other words, the transmission lines 51 and 52 are sandwiched between the dielectric substrate 2, the auxiliary dielectric substrate 26, the ground pattern 21, and the auxiliary ground pattern 27, and are configured as triplate lines.

[0064] According to this, by covering the transmission lines 51 and 52 with the auxiliary dielectric substrate 26 and the auxiliary ground pattern 27, it becomes possible to further suppress inter-line coupling and suppress unwanted radiation caused by inter-line coupling.

[0065] Furthermore, the auxiliary dielectric substrate 26 and auxiliary ground pattern 27 can cover not only transmission lines 51 and 52, but also other transmission lines 41, 45, 49, 55, 56, and 61-68. On the other hand, although not shown in the figures, the auxiliary dielectric substrate 26 and auxiliary ground pattern 27 do not cover the patch antennas 31-38 in order to avoid impairing radio wave radiation.

[0066] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications are of course possible for those skilled in the art.

[0067] Although several embodiments have been described above, these embodiments may be combined as appropriate. For example, any of the first to third embodiments relating to the shape of the transmission line may be combined with any of the fourth to sixth embodiments relating to the auxiliary ground pattern. Alternatively, the fourth and sixth embodiments relating to the auxiliary ground pattern may be combined.

[0068] The following lists representative embodiments of the present invention.

[0069] (1) Dielectric substrate and An antenna pattern formed on the first main surface of the dielectric substrate, A ground pattern formed on the second main surface of the dielectric substrate, Equipped with, The aforementioned antenna pattern is First and second patch antennas adjacent to each other in the first direction, The first and second patch antennas are connected by first and second transmission lines that are separated from each other in a second direction perpendicular to the first direction, Equipped with, The first and second transmission lines have some sections with wider spacing than other sections. Antenna device.

[0070] (2) The interval of the aforementioned partial section is wider than the interval of the section on the first patch antenna side than the aforementioned partial section, and wider than the interval of the section on the second patch antenna side than the aforementioned partial section. (1) The antenna device described above.

[0071] (3) The first and second transmission lines are curved in opposite directions. The antenna device described in (1) or (2).

[0072] (4) Dielectric substrate and An antenna pattern formed on the first main surface of the dielectric substrate, A ground pattern formed on the second main surface of the dielectric substrate, Equipped with, The aforementioned antenna pattern is First and second patch antennas adjacent to each other in the first direction, The first and second patch antennas are connected by first and second transmission lines that are separated from each other in a second direction perpendicular to the first direction, Equipped with, The system further includes an auxiliary ground pattern that suppresses inter-line coupling between the first and second transmission lines. Antenna device.

[0073] (5) The auxiliary ground pattern is placed between the first and second transmission lines. (4) The antenna device described above.

[0074] (6) The auxiliary ground pattern is also arranged outward in the second direction relative to the first and second transmission lines. (4) or (5) the antenna device described above.

[0075] (7) The system further comprises an auxiliary dielectric substrate covering the first and second transmission lines, The auxiliary ground pattern is arranged on the main surface of the auxiliary dielectric substrate opposite to the first and second transmission lines. An antenna device as described in any of (4) to (6).

[0076] (8) A transmitter equipped with an antenna device as described in any of (1) through (7).

[0077] (9) A radar equipped with an antenna device as described in any of (1) through (7). [Explanation of Symbols]

[0078] 2 dielectric substrate, 21 ground pattern, 23, 25, 27 auxiliary ground patterns, 30 antenna pattern, 31-38 patch antenna, 41, 45, 49, 51, 52, 55, 56, 61-68 transmission lines, 7 input side, 8 output side, 9 feed line, 10 antenna device, 11 transmitting / receiving unit, 12 signal processing unit, 13 control unit, 100 radar (example of transmitter)

Claims

1. Dielectric substrate and An antenna pattern formed on the first main surface of the dielectric substrate, A ground pattern formed on the second main surface of the dielectric substrate, Equipped with, The aforementioned antenna pattern is First and second patch antennas adjacent to each other in the first direction, The first and second patch antennas are connected by first and second transmission lines that are separated from each other in a second direction perpendicular to the first direction, Equipped with, The first and second transmission lines connect the first and second patch antennas without short-circuiting between them. The first and second transmission lines have some sections with wider spacing than other sections. Antenna device.

2. The spacing of the aforementioned partial section is wider than the spacing of the section on the first patch antenna side than the aforementioned partial section, and wider than the spacing of the section on the second patch antenna side than the aforementioned partial section. The antenna device according to claim 1.

3. The first and second transmission lines are curved in opposite directions. The antenna device according to claim 2.

4. Dielectric substrate and An antenna pattern formed on the first main surface of the dielectric substrate, A ground pattern formed on the second main surface of the dielectric substrate, Equipped with, The aforementioned antenna pattern is First and second patch antennas adjacent to each other in the first direction, The first and second patch antennas are connected by first and second transmission lines that are separated from each other in a second direction perpendicular to the first direction, Equipped with, The system further includes an auxiliary ground pattern that suppresses inter-line coupling between the first and second transmission lines. Antenna device.

5. The auxiliary ground pattern is placed between the first and second transmission lines. The antenna device according to claim 4.

6. The auxiliary ground pattern is also arranged outward in the second direction relative to the first and second transmission lines. The antenna device according to claim 5.

7. The system further comprises an auxiliary dielectric substrate covering the first and second transmission lines, The auxiliary ground pattern is arranged on the main surface of the auxiliary dielectric substrate opposite to the first and second transmission lines. The antenna device according to claim 4.

8. A transmitter comprising the antenna device described in claim 1 or 4.

9. A radar comprising the antenna device according to claim 1 or 4.

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