Antenna Module

Abstract

To simplify a configuration of an antenna module capable of radiating beams in a plurality of directions.SOLUTION: An antenna module 1 comprises: a first dielectric layer 11; a second dielectric layer 12 arranged on one side of the first dielectric layer 11; a reflection conductor layer 13 arranged on another side of the first dielectric layer 11; and power feeding parts 14_1 to 14_3, which supply electromagnetic waves of a predetermined wavelength to the first dielectric layer 11. In a plan view, the first dielectric layer 11 has a plurality of regions 11_1 to 11_3 whose dielectric constants differ from one another. The power feeding parts 14_1 to 14_3 are provided in each of the plurality of areas 11_1 to 11_3. Electromagnetic waves 16_1 to 16_3 with tilt angles corresponding to the dielectric constants of the respective regions 11_1 to 11_3 of the first dielectric layer 11 are radiated from a surface of the second dielectric layer 12.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an antenna module. [Background technology]

[0002] In recent years, high-speed, large-capacity communication infrastructure has expanded, and this has led to the development of antenna modules. Patent Document 1 discloses an antenna device that can change the beam direction in the vertical plane of electromagnetic waves radiated from an excitation element.

[0003] The antenna device disclosed in Patent Document 1 has a periodic structure in which a plurality of conductor patterns are arranged in a matrix, and an excitation element. The position of the excitation element is moved vertically or horizontally from the center position of the periodic structure to change the beam direction in the vertical or horizontal plane of the electromagnetic wave radiated from the excitation element, thereby radiating beams in multiple directions. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-114550 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, the technology disclosed in Patent Document 1 radiates beams in multiple directions by moving the position of the excitation element from the center position of the periodic structure and changing the beam direction of the electromagnetic wave radiated from the excitation element.

[0006] However, a movement mechanism is required to move the position of the driven element, which causes a problem that the configuration of the antenna device becomes complicated.

[0007] In view of the above problems, an object of the present disclosure is to simplify the configuration of an antenna module capable of radiating beams in multiple directions. [Means for solving the problem]

[0008] An antenna module according to one aspect of the present disclosure includes a first dielectric layer, a second dielectric layer disposed on one surface of the first dielectric layer, a reflective conductor layer disposed on the other surface of the first dielectric layer, and a power supply section that supplies electromagnetic waves of a predetermined wavelength to the first dielectric layer, wherein, in a plan view, the first dielectric layer has: ratio The first dielectric layer has a plurality of regions with different dielectric constants, and the feeding portion is provided in each of the plurality of regions. ratio An electromagnetic wave having a tilt angle according to the dielectric constant is emitted from the surface of the second dielectric layer.

[0009] In the antenna module, the first dielectric layer may have a plurality of holes, and each of the regions may have a plurality of holes. ratio The dielectric constant may be adjusted by changing the ratio of the volume of the plurality of holes to each of the regions.

[0010] In the antenna module described above, the first dielectric layer may have a plurality of holes extending from the one surface of the first dielectric layer to the other surface thereof, and ratio The dielectric constant may be adjusted by changing the ratio of the volume of the plurality of holes to each of the regions.

[0011] In the antenna module described above, the hole may be cylindrical, and the first dielectric layer may have a thickness of about 100 nm. ratio The effective wavelength considering the dielectric constant is λ e In this case, the pitch of the holes is λ e It may be smaller than / 2.

[0012] In the antenna module described above, the hole may be cylindrical, and ratioThe dielectric constant may decrease as the radius of the plurality of holes increases.

[0013] In the antenna module described above, ratio The higher the dielectric constant, the larger the tilt angle of the electromagnetic wave radiated from the surface of the second dielectric layer may be.

[0014] In the antenna module described above, ratio The dielectric constant of the second dielectric layer ratio It may be smaller than the dielectric constant.

[0015] In the above-mentioned antenna module, ratio The dielectric constant may be 4 to 15.

[0016] In the antenna module described above, ratio The dielectric constant may be 1-3.

[0017] In the above-described antenna module, when the wavelength of the electromagnetic wave is λ, at least one of the width W and the length L of each of the regions of the first dielectric layer may be equal to or greater than λ.

[0018] In the above-described antenna module, in each of the regions of the first dielectric layer, the power supply portion may be arranged at an end opposite to the radiation direction of the electromagnetic waves radiated from the surface of the second dielectric layer.

[0019] In the above-mentioned antenna module, each of the regions of the first dielectric layer may be arranged to extend in a first direction parallel to the one surface of the first dielectric layer and to be aligned in a second direction perpendicular to the one surface of the first dielectric layer and the first direction.

[0020] In the above-described antenna module, the thickness of each of the regions of the first dielectric layer may be the same.

[0021] In the above-described antenna module, the first dielectric layer may include a partition member between each of the regions. [Effects of the Invention]

[0022] The present disclosure simplifies the configuration of an antenna module capable of radiating beams in multiple directions. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a cross-sectional view showing a configuration example of an antenna module according to an embodiment; [Figure 2] 1 is a plan view illustrating a configuration example of an antenna module according to an embodiment; [Figure 3] 1 is a perspective view illustrating a configuration example of an antenna module according to an embodiment; [Figure 4] FIG. 1 is a cross-sectional view showing an antenna module according to a related art. [Figure 5] 1 is a perspective view illustrating a configuration example of an antenna module according to an embodiment; [Figure 6] 1 is a side view illustrating a configuration example of an antenna module according to an embodiment; [Figure 7] FIG. 2 is a bottom view illustrating a configuration example of the antenna module according to the embodiment. [Figure 8] 3 is a plan view illustrating a configuration example of a first dielectric layer included in the antenna module according to the embodiment. FIG. [Figure 9] 10 is a graph showing the relationship between the tilt angle of the beam and the height of the first dielectric layer. [Figure 10] FIG. 10 is a plan view showing another configuration example of the antenna module according to the embodiment. [Figure 11] 10A and 10B are diagrams showing measurement results of the antenna module according to the example. [Figure 12] 10 is a table showing measurement results of the antenna module according to the example. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present disclosure will now be described with reference to the drawings. 1 to 3 are a cross-sectional view, a plan view, and a perspective view, respectively, showing a configuration example of an antenna module according to an embodiment. In this specification, the term "dielectric constant" means "relative dielectric constant."

[0025] As shown in Fig. 1, the antenna module 1 according to this embodiment includes a first dielectric layer 11, a second dielectric layer 12, a reflective conductor layer 13, and a power feeding section 14. The second dielectric layer 12 is disposed on one surface (the surface on the positive side in the z-axis direction) of the first dielectric layer 11. The reflective conductor layer 13 is disposed on the other surface (the surface on the negative side in the z-axis direction) of the first dielectric layer 11. The power feeding section 14 supplies electromagnetic waves of a predetermined wavelength to the first dielectric layer 11. The antenna module 1 according to this embodiment is applicable to a frequency range of, for example, 3 GHz to 300 GHz. For example, it can be applied to the 5G millimeter wave band (24 GHz to 30 GHz), a band of 6 GHz to 24 GHz that is expected to be used in future 6G communications, or a band of 92 GHz to 300 GHz.

[0026] As shown in Fig. 2, the first dielectric layer 11 has a plurality of regions 11_1 to 11_3 having different dielectric constants in a plan view. The power feeding portions 14_1 to 14_3 are provided in each of the plurality of regions 11_1 to 11_3. In the antenna module 1 according to this embodiment, as shown in Fig. 3, the tilt angle θ p Electromagnetic waves having a wavelength of 1000 nm (see FIG. 1) are emitted from the surface of the second dielectric layer 12.

[0027] In this specification, the power feeding portions 14_1 to 14_3 may be collectively referred to as power feeding portion 14. In addition, although this specification describes an example in which first dielectric layer 11 has three regions 11_1 to 11_3, the number of regions provided in first dielectric layer 11 is not limited to three. In other words, first dielectric layer 11 only needs to have two or more regions, and the number of regions can be determined arbitrarily. Details of antenna module 1 according to this embodiment will be described below.

[0028] 2 and 3, the first dielectric layer 11 includes a plurality of regions 11_1 to 11_3 each having a different dielectric constant. Specifically, the first dielectric layer 11 has a dielectric constant of ε r11 In the region 11_1, the dielectric constant is ε r12 and the dielectric constant is ε r13 The first dielectric layer 11 has a region 11_3. The regions 11_1 to 11_3 of the first dielectric layer 11 are provided so as to extend in a first direction (x-axis direction) parallel to the main surface of the first dielectric layer 11 and to be aligned in a second direction (y-axis direction) perpendicular to the main surface of the first dielectric layer 11 and the first direction (x-axis direction).

[0029] As shown in FIGS. 1 and 3, the regions 11_1 to 11_3 of the first dielectric layer 11 each have the same thickness h1. Here, the term "same thickness" includes the case where the regions 11_1 to 11_3 have approximately the same thickness. In other words, if the regions 11_1 to 11_3 are made of different dielectric materials, there may be an error in the thickness of each of the regions 11_1 to 11_3 due to processing accuracy, etc. In this embodiment, the thickness h1 of each of the regions 11_1 to 11_3 of the first dielectric layer 11 may include a variation due to such an error. The variation in the thickness h1 of each of the regions 11_1 to 11_3 may be, for example, about ±5% or about ±10%.

[0030] In this embodiment, partition members may be provided between the respective regions 11_1 to 11_3 of the first dielectric layer 11. By providing the partition members in this manner, it is possible to prevent electromagnetic waves from leaking between the respective regions 11_1 to 11_3. For example, the partition members may be made of a metal material or the like.

[0031] In this embodiment, the dielectric constant of each of the regions 11_1 to 11_3 constituting the first dielectric layer 11 may be adjusted by using a difference in the dielectric constant of the material itself used, or the dielectric constant may be adjusted by using a physical shape. When adjusting the dielectric constant by using a physical shape, for example, a plurality of holes may be formed in the first dielectric layer 11 and the ratio of the volume of the plurality of holes to each of the regions 11_1 to 11_3 may be changed to adjust the dielectric constant of each of the regions 11_1 to 11_3. In this case, the materials constituting each of the regions 11_1 to 11_3 of the first dielectric layer 11 may be the same material. Note that the case of adjusting the dielectric constant by using a plurality of holes will be described later.

[0032] As shown in FIGS. 1 and 3, the second dielectric layer 12 is disposed on the surface on the positive side in the z-axis direction of the first dielectric layer 11. Specifically, the second dielectric layer 12 is provided so as to cover the upper surfaces of the multiple regions 11_1 to 11_3 of the first dielectric layer 11. The dielectric constant of the second dielectric layer 12 is ε r2 and the thickness is h2.

[0033] In this embodiment, the dielectric constant ε of each of the regions 11_1 to 11_3 of the first dielectric layer 11 is r11 ~ε r13 is the dielectric constant ε of the second dielectric layer 12 r2 For example, the dielectric constant ε of each of the regions 11_1 to 11_3 of the first dielectric layer 11 is preferably smaller than r11 ~ε r13 is 1 to 3. The dielectric constant of the second dielectric layer 12 is preferably 4 to 15, more preferably 5 to 10. These numerical values ​​are merely examples, and in this embodiment, the dielectric constant ε of each of the regions 11_1 to 11_3 of the first dielectric layer 11 is r11 ~ε r13 , and the dielectric constant ε of the second dielectric layer 12 r2 may be a dielectric constant other than these.

[0034] For example, the first dielectric layer 11 can be made of a dielectric material such as resin, and the second dielectric layer 12 can be made of a dielectric material such as glass, ceramic, or resin.

[0035] The reflective conductor layer 13 is disposed on the surface of the first dielectric layer 11 on the negative side in the z-axis direction. The reflective conductor layer 13 reflects the electromagnetic waves supplied from the power supply unit 14 to the first dielectric layer 11 at the surface of the first dielectric layer 11 on the negative side in the z-axis direction. This allows the electromagnetic waves supplied from the power supply unit 14 to propagate within the first dielectric layer 11. The reflective conductor layer 13 can be made of a conductive material such as a metal material. Furthermore, for example, if the first dielectric layer 11 and the second dielectric layer 12 are made of a transparent dielectric material and the reflective conductor layer 13 is made of a transparent conductive material, the antenna module 1 can be made into a transparent module. For example, a conductive oxide such as ITO (indium tin oxide) can be used as the transparent conductive material. In terms of antenna performance, it is preferable that the thickness of the reflective conductor layer 13 be 1 μm or more.

[0036] The power supply section 14 supplies electromagnetic waves of a predetermined wavelength to the first dielectric layer 11. For example, the power supply section 14 may be configured by providing an antenna electrode on the bottom surface (the surface on the negative side in the z-axis direction) of the first dielectric layer 11. In this case, the reflective conductor layer 13 and the power supply section 14 (antenna electrode) are configured not to be in electrical contact with each other. For example, an insulating material (such as a PCB (Printed Circuit Board) substrate) may be provided between the reflective conductor layer 13 and the power supply section 14 (antenna electrode). The effective wavelength of the electromagnetic waves is λ e Then, the thickness of the insulating material (PCB substrate) is, for example, λ e / 4 or less, preferably λ e For example, the length of the power supply portion 14 (antenna electrode) in the x-axis direction and the length of the power supply portion 14 in the y-axis direction may be λ e / 2.

[0037] Furthermore, for example, the power supply section 14 may be configured by connecting a waveguide to the bottom surface of the first dielectric layer 11. In this case, an opening 18 is provided in the reflective conductor layer 13 provided on the bottom surface of the first dielectric layer 11 at a portion to which the waveguide is connected (see FIG. 7).

[0038] The antenna module 1 according to this embodiment is a dielectric leaky wave antenna, and the conditions under which electromagnetic waves are radiated from the surface of the second dielectric layer 12 are as follows.

[0039]

number

[0040] where h1 is the thickness of the first dielectric layer 11, ε r1 is the dielectric constant of the first dielectric layer 11, h2 is the thickness of the second dielectric layer 12, ε r2 is the dielectric constant of the second dielectric layer 12, λ0 is the wavelength of the electromagnetic wave supplied from the power supply portion 14 to the first dielectric layer 11, and m and n are positive integers. r1 is the dielectric constant ε of each of the regions 11_1 to 11_3 of the first dielectric layer 11. r11 ~ε r13 It corresponds to.

[0041] In this embodiment, when each parameter satisfies the above conditions, electromagnetic waves are radiated from the surface of the second dielectric layer 12 in the front direction with high gain.

[0042] As shown in FIG. 1, the tilt angle of the electromagnetic wave radiated from the surface of the second dielectric layer 12 is defined as θ p In this case, the tilt angle θ p The conditions for emitting electromagnetic waves with high gain are as follows:

[0043]

number

[0044] In the antenna module 1 according to the present embodiment, the dielectric constant ε of each of the regions 11_1 to 11_3 of the first dielectric layer 11 is r11 ~ε r13 By adjusting the tilt angle θ of the electromagnetic wave emitted from the position corresponding to each of the regions 11_1 to 11_3, p can be determined.

[0045] In this embodiment, the position of the power supply unit 14 may be on the end side of the first dielectric layer 11 (the end side when the first dielectric layer 11 is viewed from above) so that the electromagnetic waves radiated from the surface of the second dielectric layer 12 become tilt beams. That is, depending on the position of the power supply unit 14, the electromagnetic waves radiated from the surface of the second dielectric layer 12 may become conical beams. Here, a conical beam is a beam having a shape obtained by rotating a tilt beam around a central axis. Taking this into consideration, in this embodiment, the power supply units 14_1 to 14_3 are positioned on the end side of each of the regions 11_1 to 11_3 of the first dielectric layer, as shown in FIGS. 2 and 3 . With this configuration, the electromagnetic waves radiated from the surface of the second dielectric layer 12 can become tilt beams.

[0046] For example, in each of the regions 11_1 to 11_3 of the first dielectric layer 11, the feeding portions 14_1 to 14_3 may be arranged at the end opposite to the radiation direction of the electromagnetic waves 16_1 to 16_3 (see FIG. 3) radiated from the surface of the second dielectric layer 12. Specifically, as shown in FIG. 3, in the region 11_2 of the first dielectric layer 11, the radiation direction of the electromagnetic wave 16_2 is the positive side in the x-axis direction, so the feeding portion 14_2 is arranged on the negative side of the region 11_2 in the x-axis direction. Also, in the region 11_3 of the first dielectric layer 11, the radiation direction of the electromagnetic wave 16_3 is the negative side in the x-axis direction, so the feeding portion 14_3 is arranged on the positive side of the region 11_3 in the x-axis direction. Note that the position of the feeding portion 14 in the z-axis direction is not particularly limited. However, for example, when wiring for feeding power to the feeding portion 14 (antenna electrode) is provided on the negative side in the z-axis direction, the feeding portion 14_1 may be arranged near the reflective conductor layer 13 (for example, λ e It is preferable to provide the power supply unit 14 at a frequency of about 1 / 10 or less.

[0047] Fig. 4 is a cross-sectional view showing an antenna module according to the related art. The antenna module 101 shown in Fig. 4 includes first dielectric layers 111_1 to 111_3, a second dielectric layer 112, reflective conductor layers 113_1 to 113_3, and power feeding portions 114_1 to 114_3. For example, if the materials constituting the first dielectric layers 111_1 to 111_3 are made of materials having the same dielectric constant ε r1When the second dielectric layer 112 is made of a material having the above formulas (3) and (4), the tilt angle θ of the electromagnetic wave radiated from the surface of the second dielectric layer 112 is p is adjusted by using the thickness h1 of the first dielectric layer 11. Therefore, in the antenna module 101 shown in FIG. p According to this, the thickness h of the first dielectric layers 111_1 to 111_3 11 ~h 13 However, in this case, it is necessary to adjust the tilt angle θ p The thickness h of the first dielectric layers 111_1 to 111_3 is 11 ~h 13 Since the number of antennas changes, the structure of the antenna module becomes complicated.

[0048] In contrast, in the antenna module 1 according to the present embodiment, as shown in FIGS. 1 and 2, the dielectric constants ε r11 ~ε r13 By adjusting the tilt angle θ of the electromagnetic wave emitted from the position corresponding to each of the regions 11_1 to 11_3, p With this configuration, the thickness of each of the regions 11_1 to 11_3 of the first dielectric layer 11 can be made the same thickness h1, which simplifies the configuration of the antenna module.

[0049] Next, a configuration example of the first dielectric layer 11 included in the antenna module 1 according to this embodiment will be described. Figures 5 to 7 are a perspective view, a side view, and a bottom view, respectively, showing a configuration example of the antenna module according to this embodiment.

[0050] The first dielectric layer 11 shown in Figures 5 and 6 has a plurality of holes 22 extending from one surface of the first dielectric layer 11 to the other surface. That is, the first dielectric layer 11 has a base material 21 and a plurality of holes 22 provided in the base material 21. As shown in Figure 7, an opening 18 is provided in the reflective conductor layer 13 arranged on the bottom surface of the antenna module. A waveguide (not shown) is connected to the opening 18. The electromagnetic wave propagated through the waveguide (not shown) is supplied to the first dielectric layer 11 through the opening 18.

[0051] FIG. 8 is a plan view showing a configuration example of the first dielectric layer included in the antenna module according to this embodiment. As shown in FIG. 8, the dielectric constant of each of the regions 11_1 to 11_3 of the first dielectric layer 11 can be adjusted by changing the volume ratio of the plurality of holes 22_1 to 22_3 (corresponding to the holes 22 shown in FIGS. 5 and 6) in each of the regions 11_1 to 11_3. That is, the dielectric constant of the region 11_1 of the first dielectric layer 11 can be adjusted by changing the volume ratio between the base material 21_1 and the plurality of holes 22_1 in the region 11_1. Furthermore, the dielectric constant of the region 11_2 of the first dielectric layer 11 can be adjusted by changing the volume ratio between the base material 21_2 and the plurality of holes 22_2 in the region 11_2. Furthermore, the dielectric constant of the region 11_3 of the first dielectric layer 11 can be adjusted by changing the volume ratio between the base material 21_3 and the plurality of holes 22_3 in the region 11_3. The base materials 21_1 to 21_3 of the regions 11_1 to 11_3 may be made of the same material or different materials. When made of different materials, the dielectric constant can be adjusted by using two factors: the dielectric constant of the material itself and the ratio of the holes 22 to the base material.

[0052] For example, as shown in Fig. 5, the holes 22 may be cylindrical, and in this case, the dielectric constant of the first dielectric layer 11 can be adjusted by adjusting the radius r of the cylindrical holes 22. Specifically, the dielectric constant of the first dielectric layer 11 decreases as the radius r of the plurality of holes 22 increases, and increases as the radius r of the plurality of holes 22 decreases. In Fig. 5, p indicates the pitch of the holes 22.

[0053] That is, the dielectric constant (effective dielectric constant) ε s is the dielectric constant of the base material, ε m If the dielectric constant of air is 1, it can be expressed by the following equation:

[0054] Effective dielectric constant ε s =(ε m × volume of base material + 1 × volume of hole) / volume of the region of the first dielectric layer

[0055] Here, the dielectric constant of the base material εm is greater than 1, the dielectric constant of each region of the first dielectric layer 11 decreases as the radius r of the hole 22 increases, and increases as the radius r of the hole 22 decreases.

[0056] In the antenna module 1 according to this embodiment, the thickness of each of the regions 11_1 to 11_3 of the first dielectric layer 11 is uniform at h1. Therefore, the tilt angle θ of the electromagnetic wave radiated from the surface of the second dielectric layer 12 is p 8, can be determined by adjusting the effective dielectric constant of each of the regions 11_1 to 11_3 of the first dielectric layer 11, that is, by adjusting the radius r of the holes 22_1 to 22_3 of each of the regions 11_1 to 11_3. s and tilt angle θ p The relationship is expressed by the following equation:

[0057]

number

[0058] From the above formula, the dielectric constant (effective dielectric constant) ε of each of the regions 11_1 to 11_3 of the first dielectric layer 11 is s The higher the tilt angle θ of the electromagnetic wave radiated from the surface of the second dielectric layer 12, the p Conversely, the dielectric constant (effective dielectric constant) ε s The lower the tilt angle θ of the electromagnetic wave radiated from the surface of the second dielectric layer 12, the p becomes smaller.

[0059] In other words, the larger the radius r of the holes 22_1 to 22_3 of each of the regions 11_1 to 11_3 of the first dielectric layer 11, the larger the dielectric constant (effective dielectric constant) ε s Since the tilt angle θ of the electromagnetic wave radiated from the surface of the second dielectric layer 12 is low, p Conversely, the smaller the radius r of the holes 22_1 to 22_3 in each of the regions 11_1 to 11_3 of the first dielectric layer 11, the smaller the dielectric constant (effective dielectric constant) ε sbecomes higher, the tilt angle θ of the electromagnetic wave radiated from the surface of the second dielectric layer 12 becomes p In the configuration example shown in FIG. 8, the radius r of the holes 22_1 to 22_3 of the first dielectric layer 11 decreases in the order of the region 11_1, the region 11_2, and the region 11_3, and therefore the tilt angle θ of the electromagnetic wave decreases in the order of the region 11_1, the region 11_2, and the region 11_3. p becomes larger.

[0060] In this embodiment, the effective wavelength taking into consideration the dielectric constant of each region of the first dielectric layer 11 is defined as λ e In this case, the pitch p of the holes 22 (see FIG. 5) is λ e Preferably it is less than / 2.

[0061] In this embodiment, when the wavelength of the electromagnetic wave is λ, the width W (see FIG. 5) of each region of the first dielectric layer 11 is preferably λ or more, more preferably 3λ / 2 or more, and, taking gain into consideration, even more preferably 2λ or more. On the other hand, if the width W is too large, the aperture efficiency deteriorates (i.e., the portion that does not contribute to radiation increases), so the width W is preferably 8λ or less.

[0062] In this embodiment, when the wavelength of the electromagnetic wave is λ, the length L (see FIG. 5) of each region of the first dielectric layer 11 is preferably λ or more, more preferably 3λ / 2 or more, and, taking the gain into consideration, even more preferably 2λ or more. On the other hand, if the length L is too large, the aperture efficiency deteriorates (i.e., the portion that does not contribute to radiation increases), so the length L is preferably 8λ or less.

[0063] In this embodiment, the distance l shown in FIG. s The distance l (from the end of the second dielectric layer 12 to the opening 18) is preferably 2λ or less, where λ is the wavelength of the electromagnetic wave. By setting the distance l in this range, the generation of a conical beam can be suppressed, and the electromagnetic wave radiated from the surface of the second dielectric layer 12 can be made into a pencil beam. In terms of performance, the distance l s The range is more preferably λ or less. Also, the dimension b of the opening 18 shown in FIG. 7 is set to the value determined by the dielectric constant ε rg ) is the electrical length λ gThen λ g / 2 or more λ g Here, λ g =λ / (ε rg ) 1 / 2 The dimension a of the opening 18 is λ g The value will be smaller than / 2.

[0064] In this embodiment, metal walls may be provided on the side surfaces of the first dielectric layer 11 and the second dielectric layer 12. In this case, the distance l s The minimum value of is 0. In other words, when metal walls are provided on the side surfaces of the first dielectric layer 11 and the second dielectric layer 12, the distance l s Even if the distance l is set to 0, it is possible to suppress the radiation of electromagnetic waves from the side surfaces of the first dielectric layer 11 and the second dielectric layer 12. s The minimum value of is 0. Furthermore, if metal walls are provided on the side surfaces of the first dielectric layer 11 and the second dielectric layer 12, interference with antennas of other beams can be suppressed.

[0065] Figure 9 shows the beam tilt angle θ p 9 is a graph showing the relationship between the effective dielectric constant ε of the first dielectric layer 11 and the height h1 of the first dielectric layer 11. s The figures show the cases where m=1, 2, with m being 1, 1.33, and 2, respectively.

[0066] As shown in FIG. 9, the effective dielectric constant ε s When the value is 1, the beam of mode m=1 (tilt angle θ p = 60°) and the beam of mode m = 2 (tilt angle θ p =0°). In other words, in this case, the electromagnetic wave radiated from the surface of the second dielectric layer 12 is split into two.

[0067] On the other hand, the effective dielectric constant ε of the first dielectric layer 11 s When is 1.33, 2, the tilt angle θ of mode m=1 p = 0~90° and tilt angle θ for mode m=2 p= 0 to 90°, there is no overlapping portion, and therefore only one electromagnetic wave is radiated from the surface of the second dielectric layer 12. Therefore, in this case, it is possible to prevent the beam from splitting into two.

[0068] The effective dielectric constant ε of the first dielectric layer 11 s When considering the range of the maximum tilt angle θ, since m=1 is usually used in the above equation (5), the condition for two beams to be generated is p When m=2, another tilt angle θ p This can be determined by whether or not there is a beam of light. This determination can be made using the following formula:

[0069]

number

[0070] At this time, the maximum ε s is ε r1 Therefore, the dielectric constant ε of the first dielectric layer 11 is r1 is ε r1 >4 / 3sin 2 θ p In this case, the dielectric constant ε of the first dielectric layer 11 is preferably r1 and the dielectric constant ε of the second dielectric layer 12 r2 and ε r1 <ε r2 It is also necessary to satisfy the following.

[0071] Furthermore, when considering the height h1 of the first dielectric layer 11, if holes 22 are provided in the first dielectric layer 11 as shown in FIG. 5, there is a lower limit to the effective dielectric constant that can be realized. In other words, when holes 22 are provided in the first dielectric layer 11, the holes 22 may connect to each other, or strength problems may occur even when the first dielectric layer 11 is produced using a 3D printer. For this reason, the tilt angle θ p Required effective permittivity ε when =0 s The height should be set so that the angle is greater than the lowest achievable value. This allows for a wide beam angle.

[0072] For example, when forming the hole portion 22 by making a hole in the first dielectric layer 11 using a drill, the effective dielectric constant ε s is expressed by the following formula.

[0073]

Equation

[0074] At this time, when setting 0 ≦ r < p / 2 as the condition that the hole portions 22 are not connected to each other, the range of the effective dielectric constant ε s is expressed by the following formula.

[0075]

Equation

[0076] At this time, the range of the height h1 needs to be the following range in order to achieve the tilt angle θ p = 0 in the state where the hole portion 22 is empty.

[0077]

Equation

[0078] In the above description, the case where the hole portion 22 is provided has been described. However, more generally expressed, other than the structure including the hole portion 22, it is as follows.

[0079]

Equation

[0080] According to the present disclosure described above, the configuration of the antenna module capable of radiating beams in a plurality of directions can be simplified.

[0081] FIG. 10 is a plan view showing another configuration example of the antenna module according to the present embodiment. In the present embodiment, as shown in FIG. 10, a plurality of power feeding portions 14a to 14h may be provided in each of the regions 11_1 to 11_3 of the first dielectric layer 11.

[0082] 10, power feeding portions 14a, 14b, and 14c may be provided in region 11_1, power feeding portions 14d and 14e may be provided in region 11_2, and power feeding portions 14f, 14g, and 14h may be provided in region 11_3. Then, by switching the power feeding portion that supplies the electromagnetic waves from among these power feeding portions 14a to 14h, the direction (tilt angle) of the electromagnetic waves radiated from the surface of second dielectric layer 12 can be switched. In other words, in each of regions 11_1 to 11_3 of first dielectric layer 11, the tilt angle θ according to the dielectric constant of each of regions 11_1 to 11_3 of first dielectric layer 11 and the position of power feeding portions 14a to 14h can be changed. p can be emitted from the surface of the second dielectric layer 12.

[0083] In the above configuration example, the dielectric constant of each of the regions 11_1 to 11_3 of the first dielectric layer 11 is adjusted by changing the ratio of the holes 22 formed in each of the regions 11_1 to 11_3. However, in this embodiment, the dielectric constant may be adjusted by adding a mixture to the dielectric material (base material) of each of the regions 11_1 to 11_3 and adjusting the density. The dielectric constant of each of the regions 11_1 to 11_3 may also be adjusted by using two or more types of dielectric materials. The shape of the holes 22 may also be a shape other than a cylindrical shape. The holes 22 do not need to penetrate the first dielectric layer 11, and the depth of the holes 22 may be adjusted to adjust the dielectric constant of each of the regions 11_1 to 11_3. The dielectric constant of each of the regions 11_1 to 11_3 may also be adjusted by adding air bubbles to the dielectric material (base material) of each of the regions 11_1 to 11_3. These are merely examples, and in this embodiment, the dielectric constant of each of the regions 11_1 to 11_3 may be adjusted using methods other than these. [Example]

[0084] Next, an example will be described. As an antenna module according to the example, an antenna module having the configuration shown in FIGS. 5 to 7 was fabricated. In this case, the length L of the first dielectric layer 11 (see FIG. 5) was 240 mm, the width W was 60 mm, and the height h1 was 12.5 mm. High-density polyethylene was used for the first dielectric layer 11. The height h2 (see FIG. 6) of the second dielectric layer 12 was 3.3 mm. The length L and width W (see FIG. 5) of the second dielectric layer 12 were the same as those of the first dielectric layer 11 (length L = 240 mm, width W = 60 mm). A glass plate was used for the second dielectric layer 12. The pitch p of the first dielectric layer 11 was 10 mm, the dimension a of the opening 18 was 10.16 mm, the dimension b was 22.86 mm, and the distance l from the end of the second dielectric layer 12 to the opening 18 was 1. s is the set angle (tilt angle) θ of the emitted electromagnetic wave p When the angle is 0°, it is set to 108.57 mm, and when the angle is set to any other angle, it is set to 8.57 mm.

[0085] In addition, the setting angle (tilt angle) θ of the emitted electromagnetic wave p The effective dielectric constant of the first dielectric layer 11 was determined according to the above. The effective dielectric constant was adjusted by changing the radius r of the hole 22 formed in the first dielectric layer 11.

[0086] Specifically, as shown in the table of FIG. 12, the set angle θ p When the set angle θ is 0°, the radius r of the hole 22 is set to 4.62 mm, and the effective dielectric constant is set to 1.44. p When the set angle θ is 20°, the radius r of the hole 22 is set to 4.31 mm, and the effective dielectric constant is set to 1.56. p When the set angle θ is 40°, the radius r of the hole 22 is set to 3.40 mm, and the effective dielectric constant is set to 1.85. p When the angle is 60°, the radius r of the hole 22 is set to 1.89 mm, and the effective dielectric constant is set to 2.19.

[0087] The beam pattern (gain) was measured when an electromagnetic wave with an operating frequency of 10 GHz was supplied from the power supply 14 to the first dielectric layer 11. The measurement results are shown in Figures 11 and 12. The set angle θ pFor the sample with a setting angle of 0°, the peak angle was 10° and the gain was 11.2dBi. p For a sample with a setting angle of 20°, the peak angle was 12° and the gain was 11.8dBi. p For a sample with a setting angle of 40°, the peak angle was 44° and the gain was 7.2dBi. p In the sample with the effective dielectric constant of the first dielectric layer 11 adjusted, the tilt angle θ of the radiated electromagnetic wave was adjusted. p was able to adjust.

[0088] The present invention has been described above in accordance with the above-mentioned embodiment, but the present invention is not limited to the configuration of the above-mentioned embodiment, and naturally includes various modifications, alterations, and combinations that a person skilled in the art can make within the scope of the invention as defined in the claims of this application. [Explanation of symbols]

[0089] 1 Antenna Module 11 First dielectric layer 11_1, 11_2, 11_3 area 12 Second dielectric layer 13 Reflective conductor layer 14, 14_1, 14_2, 14_3 Power supply unit 16_1, 16_2, 16_3 Electromagnetic waves 21, 21_1, 21_2, 21_3 Base material 22, 22_1, 22_2, 22_3 holes

Claims

1. a first dielectric layer; a second dielectric layer disposed on one surface of the first dielectric layer; a reflective conductor layer disposed on the other surface of the first dielectric layer; a power supply unit that supplies electromagnetic waves of a predetermined wavelength to the first dielectric layer, When viewed in a plan view, the first dielectric layer has a plurality of regions having different dielectric constants, the power supply unit is provided in each of the plurality of regions, an electromagnetic wave having a tilt angle according to the relative dielectric constant of each of the regions of the first dielectric layer is radiated from the surface of the second dielectric layer; Antenna module.

2. The first dielectric layer has a plurality of holes formed therein, the relative dielectric constant of each of the regions is adjusted by changing the ratio of the volume of the plurality of holes to the volume of each of the regions. The antenna module according to claim 1 .

3. the first dielectric layer has a plurality of holes extending from the one surface of the first dielectric layer to the other surface of the first dielectric layer; the relative dielectric constant of each of the regions is adjusted by changing the ratio of the volume of the plurality of holes to the volume of each of the regions. The antenna module according to claim 1 .

4. the hole is cylindrical; The effective wavelength taking into consideration the relative dielectric constant of each of the regions of the first dielectric layer is defined as λ ｅ In this case, the pitch of the holes is λ ｅ / 2 is smaller, The antenna module according to claim 3 .

5. the hole is cylindrical; the relative dielectric constant of the first dielectric layer decreases as the radius of the plurality of holes increases; The antenna module according to claim 3 .

6. 3. The antenna module according to claim 1, wherein the tilt angle of the electromagnetic wave radiated from the surface of the second dielectric layer increases as the relative dielectric constant of each of the regions of the first dielectric layer increases.

7. 3. The antenna module according to claim 1, wherein the dielectric constant of each of the regions of the first dielectric layer is smaller than the dielectric constant of the second dielectric layer.

8. 3. The antenna module according to claim 1, wherein the second dielectric layer has a relative dielectric constant of 4 to 15.

9. 3. The antenna module according to claim 1, wherein the dielectric constant of each of the regions of the first dielectric layer is 1 to 3.

10. 3. The antenna module according to claim 1, wherein, when the wavelength of the electromagnetic wave is λ, at least one of a width W and a length L of each of the regions of the first dielectric layer is λ or more.

11. 3. The antenna module according to claim 1, wherein in each of the regions of the first dielectric layer, the power supply portion is arranged at an end opposite to the radiation direction of the electromagnetic waves radiated from the surface of the second dielectric layer.

12. 3. The antenna module of claim 1, wherein each of the regions of the first dielectric layer extends in a first direction parallel to the one surface of the first dielectric layer and is aligned in a second direction perpendicular to the one surface of the first dielectric layer and the first direction.

13. 3. The antenna module according to claim 1, wherein the thickness of each of the regions of the first dielectric layer is the same.

14. The antenna module according to claim 1 , wherein the first dielectric layer includes a partition member between each of the regions.

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