Array antenna

Abstract

In subterahertz wave antennas, ensure that via conductors are properly positioned. [Solution] The array antenna comprises a substrate, multiple antenna sections arranged in an array, each having a substrate, multiple openings arranged in an array on the substrate, and multiple via conductors formed around each of the multiple openings. Each of the multiple antenna sections radiates radio waves in the subterahertz band. The multiple antenna sections include a first antenna section and a second antenna section. The groups of via conductors arranged in a first direction around the openings of the first antenna section and the openings of the second antenna section include a first via conductor row included in the first antenna section and a second via conductor row included in the second antenna section. The first via conductor row is not shared between the first antenna section and the second antenna section. The second via conductor row is not shared between the first antenna section and the second antenna section. Some of the spacing between via conductors included in the first via conductor row differs from the other spacing.

Description

Technical Field

[0001] The present disclosure relates to array antennas.

Background Art

[0002] Patent Document 1 describes a stacked aperture antenna applicable to high bandwidths.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] The array antenna of the present disclosure includes a plurality of antenna units arranged in an array, each comprising a substrate having a first surface, apertures provided in an array on the first surface of the substrate, and a plurality of via conductors formed around each of the plurality of apertures. Each of the plurality of antenna units radiates radio waves in a sub-terahertz band. The plurality of antenna units includes a first antenna unit, and a second antenna unit adjacent to the first antenna unit in a second direction orthogonal to the first direction on the first surface. In a plan view seen from the direction perpendicular to the first surface, a via conductor group aligned in the first direction around the aperture of the first antenna unit and the aperture of the second antenna unit has a first via conductor row included in the first antenna unit, and a second via conductor row arranged offset in the first direction and the second direction with respect to the first via conductor row and included in the second antenna unit. The first via conductor row is not shared by the first antenna unit and the second antenna unit, the second via conductor row is not shared by the first antenna unit and the second antenna unit, and some of the intervals between the via conductors included in the first via conductor row are different from the other intervals.

Brief Description of the Drawings

[0005] [Figure 1]Figure 1 shows an example of the antenna configuration according to this embodiment. [Figure 2] Figure 2 shows an example of the configuration of the antenna section according to the embodiment. [Figure 3] Figure 3 is a diagram illustrating the arrangement method of via conductors in the antenna section according to a comparative example of the embodiment. [Figure 4] Figure 4 is a diagram illustrating the arrangement method of via conductors in an array antenna according to a comparative example of the embodiment. [Figure 5] Figure 5 is a diagram illustrating the problems of the embodiment. [Figure 6] Figure 6 is a diagram illustrating the problems of the embodiment. [Figure 7] Figure 7 is a diagram illustrating an example of a design rule according to this embodiment. [Figure 8] Figure 8 is a diagram illustrating the arrangement method of via conductors in the antenna section according to the first embodiment. [Figure 9] Figure 9 is a diagram illustrating the arrangement method of via conductors in an array antenna according to the first embodiment. [Figure 10] Figure 10 is a diagram illustrating the reflection characteristics of an array antenna according to the first embodiment. [Figure 11] Figure 11 is a diagram illustrating the radiation pattern of an array antenna according to the first embodiment. [Figure 12] Figure 12 is a diagram illustrating the radiation pattern of an array antenna according to the first embodiment. [Figure 13] Figure 13 is a diagram illustrating the radiation efficiency of an array antenna according to the first embodiment. [Figure 14] Figure 14 is a diagram illustrating the arrangement method of via conductors in the antenna section according to the second embodiment. [Figure 15] Figure 15 is a diagram illustrating the arrangement method of via conductors in an array antenna according to the second embodiment. [Figure 16] Figure 16 is a diagram illustrating the arrangement method of via conductors in the antenna section according to the third embodiment. [Modes for carrying out the invention]

[0006] Embodiments of the present invention will be described in detail below with reference to the attached drawings. However, the present invention is not limited by these embodiments, and in the following embodiments, the same parts are denoted by the same reference numerals to omit redundant explanations.

[0007] In the following explanation, we will establish an XYZ Cartesian coordinate system and describe the positional relationships of each part while referring to this XYZ Cartesian coordinate system. The direction parallel to the X-axis in the horizontal plane will be defined as the X-axis direction, the direction parallel to the Y-axis in the horizontal plane perpendicular to the X-axis will be defined as the Y-axis direction, and the direction parallel to the Z-axis perpendicular to the horizontal plane will be defined as the Z-axis direction. Furthermore, the plane containing the X-axis and Y-axis will be appropriately referred to as the XY plane, the plane containing the X-axis and Z-axis will be appropriately referred to as the XZ plane, and the plane containing the Y-axis and Z-axis will be appropriately referred to as the YZ plane. The XY plane is parallel to the horizontal plane. The XY plane, XZ plane, and YZ plane are orthogonal to each other.

[0008] (antenna) An example of the antenna configuration according to the embodiment will be described using Figure 1. Figure 1 is a diagram showing an example of the antenna configuration according to the embodiment.

[0009] As shown in Figure 1, the antenna 1 includes an antenna section 10 and a feed line 20. The antenna section 10 and the feed line 20 are integrally configured. In the example shown in Figure 1, only one antenna section 10 is shown, but multiple antenna sections 10 can be arranged in an array on the feed line 20.

[0010] Figure 2 shows an example of the configuration of the antenna section according to the embodiment. As shown in Figures 1 and 2, the antenna section 10 includes a dielectric layer 11, an opening 12, a plurality of via conductors 13, a slot 14, and a conductor layer 15.

[0011] Dielectric layer 11 extends in the XY plane. The XY plane is also referred to as the first surface. A plurality of dielectric layers 11 are stacked in the Z-axis direction. In FIG. 2, four dielectric layers, namely dielectric layer 11-1, dielectric layer 11-2, dielectric layer 11-3, and dielectric layer 11-4, are shown as being stacked as the dielectric layers 11, but the present disclosure is not limited to this. The number of stacked dielectric layers 11 may be 3 or less, or 5 or more. Dielectric layer 11 is formed of a dielectric material. Dielectric layer 11 is also referred to as a dielectric substrate. Dielectric layer 11 is a dielectric film. The dielectric layer 11 is, for example, a dielectric film formed of an olefin resin-based film material.

[0012] The opening 12 is provided across the plurality of dielectric layers 11. The opening 12 has a shape having a plurality of curved portions in a plan view of the XY plane. Details of the shape of the opening 12 will be described later. Electromagnetic waves are radiated from the opening 12.

[0013] The plurality of via conductors 13 are formed along the stacking direction of each dielectric layer 11. The plurality of via conductors 13 are formed around the opening 12. The plurality of via conductors 13 are configured to surround the opening 12. The plurality of via conductors 13 are formed of a conductive member. The plurality of via conductors 13 are each electromagnetically connected by the conductor layer 15. The maximum interval between the plurality of via conductors 13 is preferably set to, for example, about 1 / 4 of the wavelength of the radio wave used for communication by the antenna unit 10 so as to prevent leakage of electromagnetic waves.

[0014] The antenna unit 10 can be said to be a box-shaped resonator without a lid. The side wall of the opening 12 of the antenna unit 10 is formed by the plurality of via conductors 13 and the conductor layer 15.

[0015] The slot 14 is provided at least at a position in contact with the feed line 20. In the example shown in FIG. 2, the slot 14 is provided in the dielectric layer 11-4.

[0016] The conductor layer 15 extends in the XY plane. The conductor layer 15 is formed of a metal such as copper, for example. The conductor layer 15 is provided on the upper surface of the antenna unit 10, for example. The conductor layer 15 is provided, for example, between the dielectric layer 11 and another dielectric layer 11 adjacent to the dielectric layer 11.

[0017] The feed path 20 includes a dielectric layer 21, a plurality of via conductors 22, a conductor layer 25, and a slot 24. The feed path 20 transmits electromagnetic waves in the stacking direction (Z-axis direction) of the dielectric layer 21.

[0018] The dielectric layers 21 are stacked in the Z-axis direction. The dielectric layer 21 is formed of a dielectric material. The dielectric layer 21 is formed of the same dielectric material as the dielectric layer 11, for example. The dielectric layer 21 is a dielectric film. A conductor layer formed of a conductive member is provided between the dielectric layers 21.

[0019] The plurality of via conductors 22 are formed along the stacking direction of the dielectric layers 21. The plurality of via conductors 22 are electromagnetically connected to the corresponding plurality of via conductors 13.

[0020] The conductor layer 25 extends in the XY plane. The conductor layer 25 is formed of a metal such as copper, for example. The conductor layer 25 is provided on the upper surface of the feed path 20, for example. The conductor layer 25 is provided, for example, between the dielectric layer 21 and the dielectric layer 11 adjacent to the dielectric layer 21.

[0021] The slot 24 is provided at least at a position in contact with the antenna unit 10.

[0022] The antenna unit 10 and the feed path 20 are electromagnetically connected via the slot 14 and the slot 24.

[0023] [Method for arranging via conductors according to comparative example] (Antenna unit according to comparative example) Using Figure 3, the method of arranging via conductors in the antenna section according to a comparative example of the embodiment will be explained. Figure 3 is a diagram illustrating the method of arranging via conductors in the antenna section according to a comparative example of the embodiment.

[0024] Figure 3 is a top view of the antenna section 10a according to the comparative example, viewed from the direction perpendicular to the XY plane. The comparative example shows a method of arranging multiple via conductors 13 in an antenna section 10a that performs communication using millimeter-wave radio waves. As shown in Figure 3, in the antenna section 10a, multiple via conductors 13 are arranged in a rectangular shape around the opening 12a. In the example shown in Figure 3, the via conductors 13 aligned in the X-axis direction are aligned in a straight line. The via conductors 13 aligned in the Y-axis direction are also aligned in a straight line. In this case, the distance L1 from end to end of the via conductors 13 aligned in the X-axis direction is 6.0 [mm], and the distance L2 from end to end of the via conductors 13 aligned in the Y-axis direction is 5.1 [mm].

[0025] (Array antenna related to comparative example) Using Figure 4, the method for arranging via conductors in an array antenna according to a comparative example of the embodiment will be explained. Figure 4 is a diagram illustrating the method for arranging via conductors in an array antenna according to a comparative example of the embodiment.

[0026] Figure 4 is a top view of an array antenna 100a according to a comparative example, viewed from the direction perpendicular to the XY plane. In the example shown in Figure 4, the array antenna 100a is assumed to have antenna sections 10a-1, 10a-2, 10a-3, and 10a-4 arranged in an array. In the example shown in Figure 4, the distance L3 between antenna sections 10a-1 and 10a-2 aligned in the X-axis direction is 6.0 [mm]. The distance L4 between antenna sections 10a-1 and 10a-3 aligned in the Y-axis direction is 6.0 [mm].

[0027] In the examples shown in Figures 3 and 4, the diameter of the via conductor 13 is 0.07 mm, and the design rule requires a minimum spacing of 0.12 mm between the via conductors 13. In the comparative example, the diameter of the via conductor 13 that can be manufactured and the spacing between the via conductors 13 are smaller than the size of the antenna section 10, making a design closer to the ideal possible.

[0028] (Problems with the embodiment) The problems of the embodiment will be explained using Figures 5 and 6. Figures 5 and 6 are diagrams used to explain the problems of the embodiment.

[0029] Figure 5 is a top view of the antenna section 10b, viewed from the vertical direction of the XY plane, to illustrate the problems of the embodiment. The example shown in Figure 5 illustrates the arrangement of multiple via conductors 13 in the antenna section 10b that performs communication using radio waves in the subterahertz band (100 to 300 GHz band). As shown in Figure 5, in the antenna section 10b, multiple via conductors 13 are arranged in a rectangular shape around the opening 12b.

[0030] The antenna section 10b used in the subterahertz wave band is smaller in size than the antenna section 10a used in the millimeter wave band (see Figure 3). In the antenna section 10b, the diameter of the via conductors 13, the spacing between via conductors 13, and the minimum value of the via land are determined by design rules. Figure 7 is a diagram illustrating an example of the design rules according to the embodiment. Figure 7 shows the arrangement of the via conductors 13 as viewed from the vertical direction of the XY plane. In the example shown in Figure 7, the design rules stipulate that when the substrate of the antenna section 10b is made of resin material, the diameter D1 of the via conductors 13 is 0.07 [mm] or more, the spacing D2 between via conductors 13 is 0.12 [mm] or more, and the distance from the edge of the via conductor 13 to the edge of the via land 16 is 0.04 [mm] or more.

[0031] Returning to Figure 5, as shown in Figure 5, the antenna section 10b includes via conductor group 30b-1, via conductor group 30b-2, via conductor group 40b-1, and via conductor group 40b-2, which are composed of multiple via conductors 13.

[0032] Via conductor group 30b-1 and via conductor group 30b-2 include a plurality of via conductors 13 arranged on a straight line parallel to the X-axis direction. Via conductor group 40b-1 and via conductor group 40b-2 include a plurality of via conductors 13 arranged on a straight line parallel to the Y-axis direction. In the antenna section 10b, the distance L5 from end to end of the via conductors 13 arranged in the X-axis direction is 0.6 [mm], and the distance L2 from end to end of the via conductors 13 arranged in the Y-axis direction is 0.51 [mm]. Even in the subterahertz wave band, a near-ideal design is possible with the antenna section 10b alone. In this disclosure, the example shown in Figure 5 is referred to as the reference position of the via conductors 13.

[0033] Figure 6 is a top view of an array antenna 100b used to illustrate the problem, viewed from the vertical direction of the XY plane. In the example shown in Figure 6, the array antenna 100b is assumed to consist of antenna sections 10b-1, 10b-2, 10b-3, and 10b-4 arranged in an array. The array antenna 100b includes via conductor groups 31b, 32b, 33b, 34b, 41b, 42b, 43b, 44b, 45b, and 46b, each composed of multiple via conductors 13.

[0034] The via conductor group 31b to via conductor group 34b includes multiple via conductors 13 arranged on a straight line parallel to the X-axis direction. The via conductor 13 included in via conductor group 32b and the via conductor 13 included in via conductor group 34b face each other in the Y-axis direction.

[0035] Via conductor groups 41b to 46b have multiple via conductors 13 arranged on a straight line parallel to the Y-axis direction. Each via conductor 13 in via conductor group 42b is shared by antenna section 10b-1 and antenna section 10b-2. Each via conductor 13 in via conductor group 45b is shared by antenna section 10b-3 and antenna section 10b-4.

[0036] In the array antenna 100b, the distance L7 between antenna section 10b-1 and antenna section 10b-2, which are aligned in the X-axis direction, is 0.6 [mm]. The distance L8 between antenna section 10b-1 and antenna section 10b-3, which are aligned in the Y-axis direction, is 0.6 [mm]. In this case, the distance between via conductor 13 included in via conductor group 32b and via conductor 13 included in via conductor group 33b may be 0.09 [mm]. Since the distance between via conductors 13 must be at least 0.12 [mm], the example shown in Figure 6 does not satisfy the design rule, and there are places where the distance between via conductors 13 is smaller than the minimum value. Therefore, in subterahertz wave antennas, it is necessary to devise a method for arranging via conductors 13 so as to satisfy the design rule.

[0037] [First Embodiment] (Antenna section according to the first embodiment) The arrangement method of via conductors in the antenna section according to the first embodiment will be explained using Figure 8. Figure 8 is a diagram illustrating the arrangement method of via conductors in the antenna section according to the first embodiment.

[0038] Figure 8 is a top view of the antenna unit 10 according to the first embodiment, viewed from the direction perpendicular to the XY plane. The first embodiment shows a method of arranging a plurality of via conductors 13 in the antenna unit 10 that performs communication using subterahertz wave band radio waves. As shown in Figure 8, the antenna unit 10 includes via conductor group 30-1, via conductor group 30-2, via conductor group 40-1, and via conductor group 40-2, which are composed of a plurality of via conductors 13. In the example shown in Figure 8, the plurality of via conductors 13 included in via conductor group 30-1 and via conductor group 30-2 are not arranged in a straight line. In Figure 8, the X-axis direction is parallel to the H-plane which is parallel to the magnetic field direction, and the Y-axis direction is parallel to the E-plane which is parallel to the electric field direction. The X-axis direction is also called the first direction, and the Y-axis direction is also called the second direction.

[0039] In via conductor group 30-1, in a plan view of the XY plane, at least some of the via conductors 13 are offset from a single straight line parallel to the X-axis direction. Specifically, via conductors 13-2 and 13-4 are offset from a single straight line in the -Y-axis direction in a plan view of the XY plane. In this case, via conductors 13-1, 13-3, and 13-5 are aligned on the same straight line parallel to the X-axis direction in a plan view of the XY plane. Via conductors 13-2 and 13-4 are aligned on the same straight line parallel to the X-axis direction in a plan view of the XY plane. In other words, via conductor group 30-1 can be said to have multiple via conductor groups aligned on multiple different straight lines parallel to the X-axis direction.

[0040] In via conductor group 30-2, in a plan view of the XY plane, at least some of the via conductors 13 are offset from a single straight line parallel to the X-axis direction. Specifically, via conductors 13-7 and 13-8 are offset in the +Y-axis direction from a single straight line in a plan view of the XY plane. In this case, via conductors 13-6, 13-8, and 13-10 are aligned on the same straight line parallel to the X-axis direction in a plan view of the XY plane. Via conductors 13-7 and 13-9 are aligned on the same straight line parallel to the X-axis direction in a plan view of the XY plane. In other words, via conductor group 30-2 can be said to have multiple via conductor groups aligned on multiple different straight lines parallel to the X-axis direction.

[0041] The via conductor group 40-1 and the via conductor group 40-2 each have a plurality of via conductors 13 arranged on the same straight line parallel to the Y-axis direction.

[0042] The spacing L10 between via conductor 13 in via conductor group 40-1 and via conductor 13 in via conductor group 40-2 is 0.6 [mm]. The spacing L11 between via conductor 13-1 and via conductor 13-6 is 0.48 [mm]. The spacing L12 between via conductor 13-2 and via conductor 13-7 is 0.6 [mm]. Spacings L10, L11, and L12 are set to achieve a desired resonant frequency. In the antenna section 10a, the spacing between each via conductor 13 can be 0.12 [mm] or more. That is, the antenna section 10a can satisfy the design rules.

[0043] In the first embodiment, the opening 12 has a shape having multiple curved sections. The opening 12 has a rotationally symmetric shape in a plan view in the XY plane. The opening 12 is formed by providing curved sections in a rectangular opening. The opening 12 has 12 curved sections, from curved section 15a to curved section 15l.

[0044] Curved section 15a is located on the upper edge of the opening 12. Curved section 15b is located at the upper right corner of the opening 12. Curved sections 15c, 15d, and 15e are located on the right edge of the opening 12. Curved section 15f is located at the lower right corner. Curved section 15g is located on the lower edge of the opening 12. Curved section 15h is located at the lower left corner of the opening 12. Curved sections 15i, 15j, and 15k are located on the left edge of the opening 12. Curved section 15l is located at the upper left corner of the opening 12.

[0045] Curved sections 15a to 15l are curved sections that protrude inward from the opening 12. The opening 12 is shown having 12 curved sections, but this disclosure is not limited thereto. The opening 12 may be provided with curved sections so that the resonant frequency of the antenna section 10 deviates from the initial design value due to the arrangement of the via conductors 13. Each curved section may be provided, for example, so that the opening 12 has a rotationally symmetric shape in a plan view in the XY plane. This makes it possible to satisfy the characteristics of the antenna section 10.

[0046] (Array antenna according to the first embodiment) The arrangement method of via conductors in the array antenna according to the first embodiment will be explained using Figure 9. Figure 9 is a diagram illustrating the arrangement method of via conductors in the array antenna according to the first embodiment.

[0047] Figure 9 is a top view of the array antenna 100 according to the first embodiment, viewed from the vertical direction of the XY plane. In the example shown in Figure 9, the array antenna 100 is assumed to consist of antenna section 10-1, antenna section 10-2, antenna section 10-3, and antenna section 10-4 arranged in an array. Antenna section 10-1 through antenna section 10-4 are each supplied with power from the power supply line 20 (see Figure 1).

[0048] In the example shown in Figure 9, the antenna section 10 is arranged in an array. The array antenna 100 shown in Figure 9 includes via conductor group 31, via conductor group 32, via conductor group 33, via conductor group 34, via conductor group 41, via conductor group 42, via conductor group 43, via conductor group 44, via conductor group 45, and via conductor group 46, each composed of multiple via conductors 13.

[0049] The via conductor group 31 includes via conductors 13-11 to 13-20. In the via conductor group 31, at least some of the via conductors 13 are offset from a single straight line in a plan view of the XY plane. Specifically, via conductors 13-12, 13-14, 13-17, and 13-19 are offset from a single straight line in the -Y direction in a plan view of the XY plane. In this case, via conductors 13-11, 13-13, 13-15, 13-16, 13-18, and 13-20 are aligned on the same straight line parallel to the X direction in a plan view of the XY plane. Via conductors 13-12, 13-14, 13-17, and 13-19 are aligned on the same straight line parallel to the X direction in a plan view of the XY plane. In other words, the via conductor group 31 can be said to have multiple via conductor groups arranged on multiple different straight lines parallel to the X-axis direction.

[0050] The via conductor group 32 includes via conductors 13-21 to 13-30. In the via conductor group 32, at least some of the via conductors 13 are offset from a single straight line in a plan view of the XY plane. Specifically, via conductors 13-22, 13-24, 13-27, and 13-29 are offset from a single straight line in the +Y axis direction in a plan view of the XY plane. In this case, via conductors 13-21, 13-23, 13-25, 13-26, 13-28, and 13-30 are aligned on the same straight line parallel to the X axis in a plan view of the XY plane. Via conductors 13-22, 13-24, 13-27, and 13-29 are aligned on the same straight line parallel to the X axis in a plan view of the XY plane. In other words, the via conductor group 32 can be said to have multiple via conductor groups arranged on multiple different straight lines parallel to the X-axis direction.

[0051] The via conductor group 33 includes via conductors 13-22, 13-24, 13-27, 13-29, 13-31, 13-32, 13-33, 13-34, 13-35, and 13-36. In other words, via conductors 13-22, 13-24, 13-27, and 13-29 are via conductors 13 included in via conductor groups 32 and 33.

[0052] In the via conductor group 33, at least some of the via conductors 13 are offset from a straight line in a plan view of the XY plane. Specifically, via conductors 13-22, 13-24, 13-27, and 13-29 are offset in the -Y direction from a straight line in a plan view of the XY plane. In this case, via conductors 13-22, 13-24, 13-27, and 13-29 are aligned on the same straight line parallel to the X direction in an XY plane view. Via conductors 13-31, 13-32, 13-33, 13-34, 13-35, and 13-36 are aligned on the same straight line parallel to the X direction in a plan view of the XY plane. In other words, the via conductor group 33 can be said to have multiple via conductor groups aligned on multiple different straight lines parallel to the X direction.

[0053] Via conductors 13-21 and 13-31 face each other in the Y-axis direction. Via conductors 13-23 and 13-32 face each other in the Y-axis direction. Via conductors 13-25 and 13-33 face each other in the Y-axis direction. Via conductors 13-26 and 13-34 face each other in the Y-axis direction. Via conductors 13-28 and 13-35 face each other in the Y-axis direction. Via conductors 13-30 and 13-36 face each other in the Y-axis direction.

[0054] The via conductor group 34 includes via conductors 13-37 to 13-46. In the via conductor group 34, at least some of the via conductors 13 are offset from a straight line in a plan view of the XY plane. Specifically, via conductors 13-38, 13-40, 13-43, and 13-45 are offset in the +Y direction from a straight line in a plan view of the XY plane. In this case, via conductors 13-37, 23-39, 13-41, 13-42, 13-44, and 13-46 are aligned on a straight line parallel to the X direction in a plan view of the XY plane. Via conductors 13-38, 13-40, 13-43, and 13-45 are aligned on the same straight line parallel to the X direction in a plan view of the XY plane. In other words, the via conductor group 30-4 can be said to have multiple via conductor groups aligned on multiple different identical straight lines parallel to the X-axis direction.

[0055] Via conductor groups 41 to 46 each have multiple via conductors 13 arranged on the same straight line parallel to the Y-axis. Each via conductor 13 included in via conductor group 42 is shared by antenna section 10-1 and antenna section 10-2. Each via conductor 13 included in via conductor group 45 is shared by antenna section 10-3 and antenna section 10-4. Via conductor group 42 may include multiple via conductors 13 for antenna section 10-1 and multiple via conductors 13 for antenna section 10-2.

[0056] In the example shown in Figure 9, the shortest spacing between adjacent via conductors 13 in the X-axis direction occurs between via conductors 13-15 and 13-16, between via conductors 13-25 and 13-26, between via conductors 13-33 and 13-34, and between via conductors 13-41 and 13-42. The spacing between these via conductors 13 can be set to 0.12 [mm].

[0057] In the example shown in Figure 9, the shortest spacing between adjacent via conductors 13 in the Y-axis direction occurs between via conductor 13-21 and via conductor 13-31, between via conductor 13-23 and via conductor 13-32, between via conductor 13-25 and via conductor 13-33, between via conductor 13-26 and via conductor 13-34, between via conductor 13-28 and via conductor 13-35, and between via conductor 13-30 and via conductor 13-36. The spacing between these via conductors 13 can be set to 0.12 [mm].

[0058] In other words, in the example shown in Figure 9, the spacing between each via conductor 13 can be 0.12 mm or more. That is, the first embodiment can realize an array antenna 100 that satisfies the design rules.

[0059] [Reflective properties] The reflection characteristics of the array antenna according to the first embodiment will be explained using Figure 10. Figure 10 is a diagram illustrating the reflection characteristics of the array antenna according to the first embodiment.

[0060] Figure 10 shows frequency [GHz] on the horizontal axis and the S-parameter S11 (reflection characteristic) [dB] on the vertical axis. A smaller S11 value indicates that the signal has passed through the array antenna 100. Waveform 201 represents the reflection characteristic of the array antenna 100. In the example shown in Figure 10, the operating bandwidth of the array antenna 100 is assumed to be from 250 [GHz] to 300 [GHz].

[0061] As waveform 200 shows, the reflection characteristics of the array antenna 100 are -13 dB or less in the operating bandwidth of 250 GHz to 300 GHz. In other words, the array antenna 100 has good reflection characteristics in the operating bandwidth of 250 GHz to 300 GHz.

[0062] [Radiation pattern] (E-plane radiation pattern) The radiation pattern of the array antenna according to the first embodiment will be explained using Figure 11. Figure 11 is a diagram illustrating the radiation pattern of the array antenna according to the first embodiment.

[0063] Figure 11 shows the radiation angle [degrees] on the horizontal axis and the gain [dB] on the vertical axis. Waveform 202 shows the radiation pattern of the E-plane of the array antenna 100. As shown by waveform 202, in the E-plane, the gain is 3 [dB] or more when the radiation angle is in the range of -90 degrees to 90 degrees. As shown by waveform 202, the array antenna 100 has good radiation characteristics in the E-plane.

[0064] (Emission pattern of the H surface) The radiation pattern of the array antenna according to the first embodiment will be explained using Figure 12. Figure 12 is a diagram illustrating the radiation pattern of the array antenna according to the first embodiment.

[0065] Figure 12 shows the radiation angle [degrees] on the horizontal axis and the gain [dB] on the vertical axis. Waveform 203 represents the radiation pattern of the H-plane of the array antenna 100. As shown by waveform 203, the H-plane radiation pattern has a maximum gain of 5 [dB] when the radiation angle is 0 degrees. As shown by waveform 203, the gain of the H-plane radiation pattern gradually decreases as the radiation angle moves away from 0 degrees. As shown by waveform 203, the array antenna 100 has good radiation characteristics in the H-plane.

[0066] [Radiation efficiency] The radiation efficiency of the array antenna according to the first embodiment will be explained using Figure 13. Figure 13 is a diagram illustrating the radiation efficiency of the array antenna according to the first embodiment.

[0067] Figure 13 shows frequency [GHz] on the horizontal axis and radiation efficiency [%] on the vertical axis. Waveform 204 represents the radiation efficiency of the array antenna 100. As waveform 204 shows, the array antenna 100 exhibits a radiation efficiency of 75% or more in its operating bandwidth of 250 [GHz] to 300 [GHz]. In other words, the array antenna 100 has good radiation characteristics in its operating area.

[0068] [Second Embodiment] (Antenna section according to the second embodiment) The arrangement method of via conductors in the antenna section according to the second embodiment will be explained using Figure 14. Figure 14 is a diagram illustrating the arrangement method of via conductors in the antenna section according to the second embodiment.

[0069] Figure 14 is a top view of the antenna section 10A according to the second embodiment, viewed from the direction perpendicular to the XY plane. The first embodiment shows a method of arranging a plurality of via conductors 13A in the antenna section 10A that performs communication using subterahertz wave band radio waves. As shown in Figure 14, the antenna section 10A includes via conductor group 30A-1, via conductor group 30A-2, via conductor group 40A-1, and via conductor group 40A-2, which are composed of a plurality of via conductors 13A. In the example shown in Figure 14, via conductor group 30A-1 and via conductor group 30A-2 have a plurality of via conductors 13A arranged on the same straight line parallel to the X-axis direction. Via conductor group 40A-1 and via conductor group 40A-2 have a plurality of via conductors 13A arranged on the same straight line parallel to the Y-axis direction.

[0070] In the via conductor group 30A-1, in a plan view of the XY plane, each via conductor 13A is positioned offset from the reference position along the same straight line parallel to the X-axis direction. Specifically, each via conductor 13A included in the via conductor group 30A-1 is positioned offset from the reference position in the -X-axis direction.

[0071] In the via conductor group 30A-2, in a plan view of the XY plane, each via conductor 13A is positioned offset from the reference position along the same straight line parallel to the X-axis direction. Specifically, each via conductor 13A included in the via conductor group 30A-2 is positioned offset from the reference position in the +X-axis direction.

[0072] The via conductor group 40-1A and the via conductor group 40A-2 each have a plurality of via conductors 13A arranged on the same straight line parallel to the Y-axis direction.

[0073] The spacing L20 between via conductor 13 in via conductor group 40A-1 and via conductor 13A in via conductor group 40A-2 is 0.6 [mm]. The spacing L21 between via conductor 13A in via conductor group 30A-1 and via conductor 13A in via conductor group 30A-2 is 0.51 [mm]. In the antenna section 10b, the spacing between each via conductor 13 can be 0.12 [mm] or more. That is, the antenna section 10b can satisfy the design rules.

[0074] In the second embodiment, the opening 12A has a shape having multiple curved sections. The opening 12A has a rotationally symmetric shape in a plan view in the XY plane. The opening 12 is formed by providing curved sections in a rectangular opening. The opening 12A has 12 curved sections, from curved section 15Aa to curved section 15AK.

[0075] Curved sections 15Aa, 15Ab, and 15Ac are located on the upper edge of the opening 12A. Curved sections 15Ad, 15Ae, and 15Af are located on the left edge of the opening 12A. Curved sections 15Ag, 15Ah, and 15Ai are located on the lower edge of the opening 12A. Curved sections 15Aj, 15Ak, and 15Al are located on the left edge of the opening 12A.

[0076] Curved section 15Al from curved section 15Aa is a curved section that protrudes inward from the opening 12A. The opening 12A is shown having 12 curved sections, but the disclosure is not limited thereto. The opening 12A may be provided with curved sections so that the resonant frequency of the antenna section 10A deviates from the initial design value due to the arrangement of the via conductors 13, so that the resonant frequency matches the design value. Each curved section may be provided, for example, so that the opening 12A has a rotationally symmetric shape in a plan view in the XY plane. This makes it possible to satisfy the characteristics of the antenna section 10A.

[0077] (Array antenna according to the second embodiment) The arrangement method of via conductors in the array antenna according to the second embodiment will be explained using Figure 15. Figure 15 is a diagram illustrating the arrangement method of via conductors in the array antenna according to the second embodiment.

[0078] Figure 15 is a top view of the array antenna 100A according to the second embodiment, viewed from the direction perpendicular to the XY plane. In the example shown in Figure 15, the array antenna 100A is assumed to have antenna section 10A-1, antenna section 10A-2, antenna section 10A-3, and antenna section 10A-4 arranged in an array.

[0079] In the example shown in Figure 15, the antenna section 10A is arranged in an array. The array antenna 100A shown in Figure 15 includes via conductor group 31A, via conductor group 32A, via conductor group 33A, via conductor group 34A, via conductor group 41A, via conductor group 42A, via conductor group 43A, via conductor group 44A, via conductor group 45A, and via conductor group 46A, which are composed of multiple via conductors 13A.

[0080] The via conductor group 31A includes via conductors 13A-1 to 13A-8. In a plan view of the XY plane, via conductors 13A-1 to 13A-8 are offset from the reference position along the same straight line parallel to the X-axis direction. Specifically, via conductors 13A-1 to 13A-8 are offset from the reference position in the +X-axis direction.

[0081] The via conductor group 32A includes via conductors 13A-9 to 13A-16. In a plan view of the XY plane, via conductors 13A-9 to 13A-16 are offset from the reference position along the same straight line parallel to the X-axis direction. Specifically, via conductors 13A-9 to 13A-16 are offset from the reference position in the -X-axis direction.

[0082] The via conductor group 33A includes via conductors 13A-17 to 13A-24. In a plan view of the XY plane, via conductors 13A-17 to 13A-24 are offset along the same straight line parallel to the X-axis direction with respect to the reference position. Specifically, via conductors 13A-17 to 13A-24 are offset in the +X-axis direction with respect to the reference position.

[0083] The via conductors 13A-9 to 13-16 and 13A-17 to 13A-24 are offset in opposite directions. Therefore, the via conductors 13A-9 to 13-16 and 13A-17 to 13A-24 are not facing each other in the Y-axis direction.

[0084] The via conductor group 34A includes via conductors 13A-25 to 13A-32. In a plan view of the XY plane, via conductors 13A-25 to 13A-32 are offset along the same straight line parallel to the X-axis direction with respect to the reference position. Specifically, via conductors 13A-25 to 13A-32 are offset in the -X-axis direction with respect to the reference position.

[0085] Via conductor groups 41A to 46A each have multiple via conductors 13A arranged on the same straight line parallel to the Y-axis. Each via conductor 13A included in via conductor group 42A is shared by antenna section 10A-1 and antenna section 10A-2. Each via conductor 13 included in via conductor group 45A is shared by antenna section 10-3 and antenna section 10-4. Via conductor group 42A may include multiple via conductors 13A for antenna section 10A-1 and multiple via conductors 13A for antenna section 10A-2.

[0086] In the example shown in Figure 15, the spacing between each via conductor 13A included in via conductor group 32A and via conductor group 33A tends to be short.

[0087] The spacing between via conductor 13A-10 and via conductor 13A-11, between via conductor 13A-11 and via conductor 13A-12, between via conductor 13A-14 and via conductor 13A-15, between via conductor 13A-15 and via conductor 13A-16, between via conductor 13A-17 and via conductor 13A-18, between via conductor 13A-18 and via conductor 13A-19, and between via conductors 13A-22 and via conductor 13A-23 can be, for example, 160 [μm].

[0088] The spacing between via conductor 13A-9 and via conductor 13A-10, the spacing between via conductor 13A-13 and via conductor 13A-14, the spacing between via conductor 13A-19 and via conductor 13A-20, and the spacing between via conductor 13A-23 and via conductor 13A-24 can be, for example, 146.5 [μm].

[0089] The spacing between via conductor 13A-12 and via conductor 13A-13, and the spacing between via conductor 13A-20 and via conductor 13A-21, can be, for example, 133.5 [μm].

[0090] The spacing between via conductor 13A-10 and via conductor 13A-17, between via conductor 13A-10 and via conductor 13A-18, between via conductor 13A-11 and via conductor 13A-18, between via conductor 13A-11 and via conductor 13A-19, between via conductor 13A-12 and via conductor 13A-19, between via conductor 13A-14 and via conductor 13A-21, between via conductor 13A-14 and via conductor 13A-22, between via conductor 13A-15 and via conductor 13A-22, and between via conductor 13A-15 and via conductor 13A-23, and between via conductor 13A-16 and via conductor 13A-23 can be, for example, 128 [μm].

[0091] The spacing between via conductor 13A-9 and via conductor 13A-17, the spacing between via conductor 13A-12 and via conductor 13A-20, the spacing between via conductor 13A-13 and via conductor 13A-20, the spacing between via conductor 13A-13 and via conductor 13A-21, and the spacing between via conductor 13A-16 and via conductor 13A-24 can be, for example, 120 [μm].

[0092] In other words, in the example shown in Figure 14, the spacing between each via conductor 13 can be 0.12 mm or more. That is, the second embodiment can realize an array antenna 100A that satisfies the design rules.

[0093] [Third Embodiment] (Antenna section according to the third embodiment) The arrangement method of via conductors in the antenna section according to the third embodiment will be explained using Figure 16. Figure 16 is a diagram illustrating the arrangement method of via conductors in the antenna section according to the third embodiment.

[0094] Figure 16 is a top view of the antenna section 10B according to the first embodiment, viewed from the direction perpendicular to the XY plane. The third embodiment shows a method of arranging a plurality of via conductors 13B in an antenna section 10B that communicates using subterahertz wave radio waves, with a substrate made of ceramic. The antenna section 10B includes an opening 12B and a plurality of via conductors 13B formed around the opening 12B. The opening 12B is rectangular, but is not limited to this.

[0095] As shown in Figure 16, at least a portion of the antenna section 10B protrudes toward the opening 12B. Specifically, it includes via conductors 13B-1, 13B-2, 13B-3, and 13B-4. In the third embodiment, the area of ​​the opening 12B is larger than, for example, the opening 12 (see Figure 8) and the opening 12A (see Figure 14). When the antenna section 10B is made of a ceramic substrate, the characteristics can be improved by configuring the antenna section 10B as shown in Figure 16.

[0096] Furthermore, this disclosure can also be structured as follows: (1) A substrate having a first surface, An array of openings is provided on the first surface of the substrate, Multiple via conductors formed around each of the multiple openings, It comprises multiple antenna sections arranged in an array, Each of the multiple antenna sections emits radio waves in the subterahertz band. Each of the aforementioned antenna sections comprises a first antenna section and a second antenna section adjacent to the first antenna section in a second direction perpendicular to the first direction on the first plane. In a plan view taken from the vertical direction of the first surface, the via conductor groups arranged in the first direction around the opening of the first antenna section and the opening of the second antenna section are, The first via conductor array included in the first antenna section, The second via conductor array is arranged offset from the first via conductor array in the first and second directions and is included in the second antenna array, The first via conductor array is not shared between the first antenna section and the second antenna section. The aforementioned second via conductor array is not shared between the aforementioned first antenna section and the aforementioned second antenna section. Some of the spacings between via conductors included in the first via conductor row are different from the other spacings. Array antenna. (2) Some of the spacings between via conductors included in the second via conductor row are different from the other spacings. The array antenna described in (1) above. (3) The plurality of via conductors included in the first via conductor row are arranged in the plan view offset in the first direction with respect to the reference position, The plurality of via conductors included in the second via conductor row are arranged in a plan view so as to be offset in the opposite direction to the plurality of via conductors included in the first via conductor row with respect to the reference position. The array antenna described in (1) or (2) above. (4) The via conductor group is arranged such that, around the first antenna section and the second antenna section, the via conductors constituting the first via conductor row and the via conductors constituting the second via conductor row are alternately arranged along the first direction. The array antenna described in any one of (1) to (3) above. (5) The substrate includes a dielectric resin or ceramic. The array antenna described in any one of (1) to (4) above. (6) The opening has a shape with multiple curved sections in the plan view. The array antenna described in any one of (1) to (5) above. (7) The opening has a rotationally symmetrical shape in the plan view. The array antenna described in any one of (1) to (6) above.

[0097] While embodiments of the present disclosure have been described above, the present disclosure is not limited by the content of these embodiments. Furthermore, the aforementioned components include those that are readily conceivable to those skilled in the art, those that are substantially identical, and those that fall within the so-called equivalent range. Moreover, the aforementioned components can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the embodiments described above. [Explanation of Symbols]

[0098] 1 Antenna 10, 10a, 10b, 10A, 10B Antenna section 100, 100a, 100b, 100A array antenna 11,21 Dielectric layer 12 Openings 13,22 via conductor 14,24 slots 15 Conductor layer 20 Power supply line

Claims

1. A substrate having a first surface, An array of openings is provided on the first surface of the substrate, Multiple via conductors formed around each of the multiple openings, It comprises multiple antenna sections arranged in an array, Each of the multiple antenna sections emits radio waves in the subterahertz band. Each of the aforementioned antenna sections comprises a first antenna section and a second antenna section adjacent to the first antenna section in a second direction perpendicular to the first direction on the first plane. In a plan view taken from the vertical direction of the first surface, the via conductor groups arranged in the first direction around the opening of the first antenna section and the opening of the second antenna section are, The first via conductor array included in the first antenna section, The second via conductor array is arranged offset from the first via conductor array in the first and second directions and is included in the second antenna array, The first via conductor array is not shared between the first antenna section and the second antenna section. The second via conductor array is not shared between the first antenna section and the second antenna section. Some of the spacings between via conductors included in the first via conductor row are different from the other spacings. Array antenna.

2. Some of the spacings between via conductors included in the second via conductor row are different from the other spacings. The array antenna according to claim 1.

3. The plurality of via conductors included in the first via conductor row are arranged in a plan view offset in the first direction with respect to the reference position, The plurality of via conductors included in the second via conductor row are arranged in a plan view so as to be offset in the opposite direction to the plurality of via conductors included in the first via conductor row with respect to the reference position. The array antenna according to claim 2.

4. The via conductor group is arranged such that, around the first antenna section and the second antenna section, the via conductors constituting the first via conductor row and the via conductors constituting the second via conductor row are alternately arranged along the first direction. The array antenna according to claim 1.

5. The substrate includes a dielectric resin or ceramic. The array antenna according to claim 1.

6. The opening has a shape with multiple curved sections in the plan view. The array antenna according to claim 1.

7. The opening has a rotationally symmetrical shape in the plan view. The array antenna according to claim 6.

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