Antenna device

Abstract

This antenna device comprises: an antenna having a dielectric layer and a conductive layer provided on the dielectric layer; and a guide member having a curved surface. The conductive layer is at least partially guided along the curved surface.

Description

Antenna device

[0001] The present invention relates to an antenna device.

[0002] In recent years, various antenna devices have been developed. An antenna device may include an antenna having a dielectric layer and a conductive layer provided on the dielectric layer.

[0003] Patent Document 1 describes an antenna element. The antenna element includes a dielectric layer and an antenna conductive layer formed on the dielectric layer. The conductive layer has an antenna pattern including a radiator and a transmission line. The antenna pattern is formed in a mesh structure defined by a plurality of conductive lines.

[0004] Patent Document 2 describes an antenna device for a vehicle. The antenna device includes a dielectric plate such as a glass plate for a vehicle, an antenna attached to the dielectric plate, and a transmission line fixed to the dielectric plate.

[0005] Japanese Patent Application Laid-Open No. 2023-535899 International Publication No. 2023 / 176727

[0006] An antenna having a dielectric layer and a conductive layer provided on the dielectric layer may be at least partially bent. When the antenna is at least partially bent, it is necessary to suppress breakage of the conductive layer at the bent portion of the antenna.

[0007] An example of an object of the present invention is to suppress breakage of the conductive layer at the bent portion of an antenna having a dielectric layer and a conductive layer provided on the dielectric layer.

[0008] In an antenna device having a dielectric layer and a conductive layer provided on the dielectric layer, it may be required to facilitate adjustment of the operating frequency band.

[0009] An example of an object of the present invention is to facilitate adjustment of the operating frequency band of an antenna device having a dielectric layer and a conductive layer provided on the dielectric layer.

[0010] In antenna devices having a dielectric layer and a conductive layer provided on the dielectric layer, it is sometimes required to facilitate impedance matching.

[0011] One example of the object of the present invention is to facilitate impedance matching of an antenna device having a dielectric layer and a conductive layer provided on the dielectric layer. Other objects of the present invention will become apparent from the description herein.

[0012] One aspect of the present invention is an antenna device comprising an antenna having a dielectric layer and a conductive layer provided on the dielectric layer, and a guide member having a curved surface, wherein the conductive layer is at least partially guided along the curved surface.

[0013] One aspect of the present invention is an antenna device comprising: an antenna having a dielectric layer and a conductive layer provided on the dielectric layer; and a substrate having a conductive pattern electrically connected to the conductive layer, wherein the conductive pattern is configured to operate at least partially as an antenna.

[0014] One aspect of the present invention is an antenna device comprising an antenna having a dielectric layer and a conductive layer provided on the dielectric layer, wherein the conductive layer includes a plurality of antenna elements arranged asymmetrically with respect to the feed point of the antenna.

[0015] One aspect of the present invention is an antenna device comprising an antenna having a dielectric layer and a conductive layer provided on the dielectric layer, wherein the conductive layer has an antenna element and a transmission line electrically connected to the antenna element, and the width of the transmission line decreases at least partially as it approaches the antenna element.

[0016] According to the above embodiment of the present invention, it is possible to suppress the fracture of the conductive layer in the bent portion of an antenna having a dielectric layer and a conductive layer provided on the dielectric layer.

[0017] According to the above embodiment of the present invention, the operating frequency band of an antenna device having a dielectric layer and a conductive layer provided on the dielectric layer can be easily adjusted.

[0018] According to the above-described embodiment of the present invention, impedance matching of an antenna device having a dielectric layer and a conductive layer provided on the dielectric layer can be facilitated.

[0019] This is an exploded perspective view of the antenna device according to Embodiment 1. This is a schematic plan view showing an example of the microscopic structure of the antenna according to Embodiment 1 at position α in Figure 1. This is a side view of a part of the antenna device according to Embodiment 1. This is a perspective view of the antenna device according to Embodiment 1. This is a perspective view of the antenna device according to Modification 1. This is a graph showing the frequency characteristics of the radiation efficiency of an antenna with an edge pattern and an antenna without an edge pattern. This is a perspective view of the antenna device according to Modification 2, which is used to explain how the antenna elements are positioned at different heights relative to the case using a first spacer, a second spacer, and a connecting block3. This is a perspective view of the antenna device according to Modification 4. This is a perspective view of the antenna device according to Modification 5. This is a perspective view of the antenna device according to Modification 6. This is an exploded perspective view of the antenna device according to Embodiment 2. This is a side view of a part of the antenna device according to Embodiment 2. This is a top view of a part of the antenna device according to Embodiment 2. This is a perspective view of modified versions of the first and second transmission lines. This is a graph showing the frequency characteristics of the radiation efficiency of the substrate according to Embodiment 2 when the antenna is not installed. This is a graph showing the frequency characteristics of the antenna device according to Embodiment 2, in which both the antenna and the substrate are provided. This is a graph showing the frequency characteristics of the radiation efficiency of the antenna device in patterns 1, 2, and 3 of the substrate. This is a graph showing the frequency characteristics of the voltage standing wave ratio (VSWR) of the antenna device in patterns 1, 2, and 3 of the substrate. This is a Smith chart for explaining the impedance matching of the antenna according to Embodiment 2. This is a plan view of the antenna device according to Embodiment 3. This is a side view of a part of the antenna device according to Embodiment 3. This is a graph showing the frequency characteristics of the radiation efficiency of an antenna in which the first antenna element and the second antenna element are arranged asymmetrically, and an antenna in which the first antenna element and the second antenna element are arranged symmetrically.This graph shows the frequency characteristics of the VSWR of an antenna in which the first and second antenna elements are arranged asymmetrically, and an antenna in which the first and second antenna elements are arranged symmetrically.

[0020] Embodiments of the present invention will be described below with reference to the drawings. In all drawings, similar components are denoted by the same reference numerals, and their descriptions are omitted where appropriate.

[0021] Figure 1 is an exploded perspective view of the antenna device 1A according to Embodiment 1. Figure 2 is a schematic plan view showing an example of the microscopic structure of the antenna 10A according to Embodiment 1 at position α in Figure 1. Figure 3 is a side view of a part of the antenna device 1A according to Embodiment 1. Note that in Figure 3, for the sake of clarity, the antenna device 1A is shown as a side view with the substrate 40A and antenna 10A spaced apart from each other. However, in the actual product form of the antenna device 1A, the substrate 40A and antenna 10A are not spaced apart, and the power supply pattern 41A, which is located on the +Z side surface of the substrate 40A, is sandwiched between the dielectric layer 11A and the substrate 40A.

[0022] To explain the directions, we define the X, Y, and Z directions. The Z direction is the height direction of the antenna device 1A. The X direction is one of the horizontal directions perpendicular to the Z direction. The Y direction is one of the horizontal directions perpendicular to both the Z and X directions. In this embodiment, we will explain by assuming that the X direction is the front-back direction, the Y direction is the left-right direction, and the Z direction is the up-down direction. In each figure, the directions indicated by the arrows for the X, Y, and Z axes, respectively, are defined as the front, left, and up directions, respectively. In Figure 2, the white circle with a black dot indicating the Z axis indicates that the Z-axis arrow is pointing towards the front of the page. In Figure 3, the white circle with a black dot indicating the Y axis indicates that the Y-axis arrow is pointing towards the front of the page.

[0023] Unless otherwise specified, the +X side and +X refer to the side indicated by the arrow on the X axis, and the -X side and -X refer to the opposite side of the side indicated by the arrow on the X axis. Unless otherwise specified, the ±X side and ±X refer to both the +X side and the -X side, or both +X and -X. Unless otherwise specified, the +Y side and +Y refer to the side indicated by the arrow on the Y axis, and the -Y side and -Y refer to the opposite side of the side indicated by the arrow on the Y axis. Unless otherwise specified, the ±Y side and ±Y refer to both the +Y side and the -Y side, or both +Y and -Y. Unless otherwise specified, the +Z side and +Z refer to the side indicated by the arrow on the Z axis, and the -Z side and -Y refer to the opposite side of the side indicated by the arrow on the Z axis. Hereafter, unless otherwise specified, ±Z and ±Z refer to both the +Z and -Z sides, or both +Z and -Z.

[0024] The antenna device 1A according to Embodiment 1 will be described with reference to Figure 1, while referring to Figures 2 and 3 as necessary.

[0025] As shown in Figure 1, the antenna device 1A according to Embodiment 1 comprises an antenna 10A, a base 20A, a stopper 30A, a substrate 40A, a cable 50A, a spacer 60A, a case 70A, and a cushion 80A.

[0026] As shown in Figures 1 and 3, the antenna 10A according to Embodiment 1 has a dielectric layer 11A and a conductive layer 12A. As shown in Figure 1, the conductive layer 12A according to Embodiment 1 includes an antenna element 13A and a transmission line 15A. As will be described in detail later, the dielectric layer 11A and the conductive layer 12A are light-transmitting. Therefore, the antenna 10A according to Embodiment 1 can be used as a transparent antenna. In one example, the antenna 10A can be used as a glass antenna that can be attached to glass such as vehicle windows or vending machine windows. In another example, the antenna 10A can operate in the frequency bands of various communication media.

[0027] The dielectric layer 11A is, for example, a resin layer. The dielectric layer 11A has light transmittance and flexibility. The dielectric layer 11A serves as a support layer for the conductive layer 12A. In the example shown in Figure 1, when viewed from the Z direction, the dielectric layer 11A and the conductive layer 12A have substantially the same shape. The shape of the dielectric layer 11A is not limited to the example shown in Figure 1. For example, when viewed from the Z direction, the area of ​​the dielectric layer 11A may be larger than the area of ​​the conductive layer 12A.

[0028] The conductive layer 12A is, for example, a metal layer. As shown in Figures 1 and 3, the conductive layer 12A is provided on the +Z plane side of the dielectric layer 11A. For example, the conductive layer 12A may be formed along the +Z plane of the dielectric layer 11A, or it may be at least partially embedded on the +Z plane side of the dielectric layer 11A. In Figure 1, for illustrative purposes, the conductive layer 12A is shown macroscopically as a layer formed over the entire region enclosed by the outline of the element representing the conductive layer 12A. However, in reality, as shown in Figure 2, when viewed microscopically from the Z direction, the conductive layer 12A is formed in a mesh shape within the region enclosed by the outline of the element representing the conductive layer 12A. Light can pass through the gaps between the mesh shapes formed by the conductive layer 12A. Therefore, the conductive layer 12A has light transmittance. The microscopic structure of the conductive layer 12A is not limited to the example shown in Figure 2.

[0029] As shown in Figures 1 and 3, the conductive layer 12A is provided only on the +Z side of the dielectric layer 11A. Therefore, compared to the case where the conductive layer 12A is provided on both the ±Z sides of the dielectric layer 11A, the light transmittance of the antenna 10A can be maintained and the manufacturing cost of the antenna 10A can be reduced. When the area of ​​the dielectric layer 11A perpendicular to the Z direction is relatively small, the conductive layer 12A may be provided on both the ±Z sides of the dielectric layer 11A in order to achieve sufficient radiation performance of the antenna 10A. When the conductive layer 12A is provided on both the ±Z sides of the dielectric layer 11A, through-holes are required to electrically connect the conductive layers 12A provided on both the ±Z sides of the dielectric layer 11A. However, it can be difficult to provide such through-holes due to the mesh shape of the conductive layer 12A. When the conductive layer 12A is provided on only one side of the dielectric layer 11A in the Z direction, it is not necessary to electrically connect the conductive layers 12A located on both the ±Z sides of the dielectric layer 11A with through-holes.

[0030] The antenna 10A according to Embodiment 1 is configured to operate as a monopole antenna having an antenna element 13A as a radiating element. In the example shown in Figure 1, the antenna element 13A is a self-similar antenna or an antenna similar thereto. A self-similar antenna is an antenna whose shape remains similar even when the scale or size ratio is changed. As shown in Figure 1, viewed from the Z direction, the transmission line 15A extends in the X direction. As shown in Figure 1, the antenna element 13A includes a feed point 17A electrically connected to the +X end of the transmission line 15A. As shown in Figure 1, viewed from the Z direction, the width of the antenna element 13A in the Y direction increases continuously in the -X side portion of the antenna element 13A as it moves away from the feed point 17A toward the +X side. As shown in Figure 1, viewed from the Z direction, the -Y side of the antenna element 13A extends linearly, substantially parallel to the X direction. As shown in Figure 1, when viewed from the Z direction, the +Y side of the antenna element 13A extends in a curved shape in the -X side portion of the antenna element 13A, moving away from the feed point 17A. The shape of the antenna element 13A is not limited to the example shown in Figure 1.

[0031] As shown in Figure 1, the base 20A has a plate 21A, two first claws 22A, and two second claws 23A. The base 20A is, for example, a sheet metal. The plate 21A is positioned substantially perpendicular to the Z direction. The two first claws 22A are bent from both the ±Y sides of the +X side portion of the plate 21A toward the +Z side. The two second claws 23A are bent from both the ±Y sides of the -X side portion of the plate 21A toward the +Z side.

[0032] As shown in Figure 1, the stopper 30A has a block 31A and two arms 32A. The block 31A extends in the Y direction. Two first holes 33A are provided side by side in the Y direction on the +X surface of the block 31A. The two arms 32A extend from both ends of the block 31A on the ±Y side toward the -X side. Two first grooves 34A are provided on the +Y surface of the +Y side arm 32A and on the -Y surface of the -Y side arm 32A. From the viewpoint shown in Figure 1, the first groove 34A provided on the -Y surface of the -Y side arm 32A is located behind the -Y side arm 32A and is not visible. Two second grooves 35A are provided on the -Y surface of the +Y side arm 32A and on the +Y surface of the -Y side arm 32A. From the viewpoint shown in Figure 1, the second groove 35A provided on the -Y surface of the +Y side arm 32A is located behind the +Y side arm 32A and is not visible. When the base 20A and stopper 30A are assembled together, the two first claws 22A are engaged with the two first grooves 34A. The two second claws 23A are engaged with the two second grooves 35A. The two first projections 36A are aligned in the Y direction and protrude from the +Z side from the +Z surface of the two arms 32A.

[0033] The substrate 40A is, for example, a rigid substrate such as a printed circuit board (PCB). As shown in Figure 1, the substrate 40A is positioned substantially perpendicular to the Z direction. In the example shown in Figure 1, when viewed from the Z direction, the substrate 40A has a substantially rectangular shape with a pair of sides substantially parallel to the X direction and another pair of sides substantially parallel to the Y direction. The shape of the substrate 40A is not limited to the example shown in Figure 1.

[0034] As shown in Figure 1, the substrate 40A has a power supply pattern 41A and two ground patterns 42A. The power supply pattern 41A and the two ground patterns 42A are conductive patterns such as metal patterns provided on the +Z side of the substrate 40A. As shown in Figure 1, when viewed from the Z direction, the power supply pattern 41A is located on the +X side of the substrate 40A. As shown in Figure 1, two second holes 43A are provided on both the ±Y sides of the power supply pattern 41A on the +X side of the substrate 40A. As shown in Figure 1, when viewed from the Z direction, the two ground patterns 42A are located side by side in the Y direction on the -X side of the substrate 40A. As shown in Figure 1, the two ground patterns 42A are located between two slits 44A provided side by side in the Y direction on the -X side of the substrate 40A. With the base 20A, stopper 30A, and substrate 40A assembled together, the two first protrusions 36A are inserted into the second hole 43A, and the +Z-side tips of the two second claws 23A pass through the two slits 44A. The +Z-side tips of the two second claws 23A are electrically connected to the two ground patterns 42A by conductivity, such as soldering.

[0035] Cable 50A is a coaxial cable having a core 51A. When the circuit board 40A and cable 50A are assembled together, the +X end of the core 51A and the power supply pattern 41A are electrically connected to each other by conductivity, such as soldering. As shown in Figure 3, when the antenna 10A and circuit board 40A are assembled together, the -X end of the transmission line 15A and the power supply pattern 41A overlap at least partially in the Z direction, with the -Z plane of the -X end of the transmission line 15A and the +Z plane of the power supply pattern 41A being separated from each other in the Z direction. Therefore, the -X end of the transmission line 15A and the power supply pattern 41A are electrically connected to each other non-contact by capacitive coupling. Thus, compared to the case where the -X end of the transmission line 15A and the power supply pattern 41A are electrically connected to each other by conductivity, such as soldering, the electrical connection of the -X end of the transmission line 15A and the power supply pattern 41A can be made easier. The electrical connection between the -X end of the transmission line 15A and the power supply pattern 41A may be a conductive connection such as soldering, rather than capacitive coupling. In Figure 3, for illustrative purposes, the Z-direction dimension of the gap between the -Z plane of the antenna 10A and the +Z plane of the substrate 40A is depicted as wider than the actual gap dimension.

[0036] As shown in Figure 1, the +X side portion of the spacer 60A has a curved surface 61A. As shown in Figure 1, viewed from the Y direction, the curved surface 61A extends toward the -Z side as it moves away from the stopper 30A toward the +X side. As shown in Figure 1, viewed from the Y direction, the curved surface 61A extends in a roughly S-shape such that the tangent plane of the -X side end of the curved surface 61A is substantially perpendicular to the Z direction, and the tangent plane of the +X side end of the curved surface 61A is substantially perpendicular to the Z direction. The shape of the curved surface 61A is not limited to the example shown in Figure 1. The two second protrusions 62A are aligned in the Y direction and protrude toward the -X side from the -X side of the spacer 60A opposite to the curved surface 61A. When the stopper 30A and spacer 60A are assembled together, the two second protrusions 62A are inserted into the two first holes 33A.

[0037] As shown in Figure 1, the case 70A has a roughly rectangular parallelepiped shape with an opening toward the -Z side, having a pair of side walls substantially perpendicular to the X direction, another pair of side walls substantially perpendicular to the Y direction, and a top plate perpendicular to the Z direction. As shown in Figure 1, a notch 71A is provided on the -Z side of the +X side wall of the case 70A. With the antenna 10A, base 20A, stopper 30A, substrate 40A, cable 50A, and spacer 60A assembled together, the case 70A covers the -X end of the transmission line 15A, the base 20A, stopper 30A, substrate 40A, and the +X end of the cable 50A, so that the transmission line 15A is pulled out from the notch 71A, the spacer 60A protrudes toward the +X side from the notch 71A, and the cable 50A is pulled out from the -X side wall of the case 70A. Case 70A covers the substrate 40A with a cushion 80A positioned between the -Z surface of the +Z side top plate of case 70A and the +Z surface of the substrate 40A. The cushion 80A is sandwiched between the -Z surface of the +Z side top plate of case 70A and the +Z surface of the substrate 40A, which suppresses rattling of the substrate 40A. By suppressing rattling of the substrate 40A, fluctuations in the distance in the Z direction between the -X side end of the transmission line 15A and the power supply pattern 41A can be suppressed, and the capacitive coupling between the -X side end of the transmission line 15A and the power supply pattern 41A can be stabilized. The cushion 80A is made of a relatively soft material. Therefore, even if the transmission line 15A and the portion of the dielectric layer 11A that overlaps with the transmission line 15A in the Z direction come into contact with the cushion 80A, damage to the transmission line 15A and the portion of the dielectric layer 11A that overlaps with the transmission line 15A in the Z direction can be suppressed.

[0038] Figure 4 is a perspective view of the antenna device 1A according to Embodiment 1.

[0039] The antenna device 1A according to Embodiment 1 will be described with reference to Figure 4, and with reference to Figure 3 as necessary.

[0040] As shown in Figure 4, when the antenna device 1A is assembled, there is a step in the Z direction between the -X end of the transmission line 15A and the antenna element 13A. Therefore, when the antenna 10A is pulled out from the notch 71A, it is necessary to partially bend the antenna 10A in accordance with the step between the -X end of the transmission line 15A and the antenna element 13A. However, if the antenna 10A is bent with a relatively small radius of curvature, such as by bending it at approximately a right angle between the -X end of the transmission line 15A and the antenna element 13A, it may become difficult to suppress the rupture of the conductive layer 12A in the bent portion of the antenna 10A.

[0041] In Embodiment 1, as shown in Figure 4, the spacer 60A is a guide member that guides the transmission line 15A at least partially between the -X end of the transmission line 15A and the antenna element 13A. Specifically, as shown in Figure 4, the transmission line 15A is guided at least partially along the curved surface 61A between the -X end of the transmission line 15A and the antenna element 13A. The curvature of the curved surface 61A can suppress the bending of the transmission line 15A with a relatively small radius of curvature. In particular, in the example shown in Figure 4, the tangent plane of the -X end of the curved surface 61A and the tangent plane of the +X end of the curved surface 61A are substantially perpendicular to the Z direction. Therefore, compared to the case where the tangent plane of the -X end of the curved surface 61A is oblique to a plane perpendicular to the Z direction, the transmission line 15A can be smoothly guided between the -X end of the curved surface 61A and the -X end of the transmission line 15A. Similarly, compared to the case where the tangent plane of the +X side end of the curved surface 61A is oblique to a plane perpendicular to the Z direction, the transmission line 15A can be smoothly guided between the +X side end of the curved surface 61A and the antenna element 13A. Furthermore, in the example shown in Figure 4, when viewed from the Y direction, the curved surface 61A extends in a substantially S-shaped curve between the -X side end and the +X side end of the curved surface 61A. Therefore, the transmission line 15A can also be smoothly guided between the -X side end and the +X side end of the curved surface 61A. Thus, in Embodiment 1, compared to the case where the transmission line 15A is not guided by the curved surface 61A, the breakage of the conductive layer 12A in the bent portion of the antenna 10A can be suppressed.

[0042] The amount of conductor per unit area constituting the conductive layer 12A may vary depending on the required rigidity of the conductive layer 12A at each position of the antenna 10A. Specifically, the amount of conductor per unit area constituting the portion of the transmission line 15A guided along the curved surface 61A may be greater than the amount of conductor per unit area constituting the antenna element 13A. As shown in Figure 4, the antenna element 13A extends substantially flat in a direction substantially perpendicular to the Z direction. On the other hand, the portion of the transmission line 15A guided along the curved surface 61A is curved along the curved surface 61A. Therefore, compared to the case where the amount of conductor per unit area constituting the portion of the transmission line 15A guided along the curved surface 61A is as small as the amount of conductor per unit area constituting the antenna element 13A, fracture of the portion of the transmission line 15A guided along the curved surface 61A can be suppressed. Furthermore, by partially increasing the amount of conductors per unit area that constitute the portion of the transmission line 15A guided along the curved surface 61A, the light transmittance of the antenna 10A can be maintained more effectively than by increasing the amount of conductors per unit area that constitute the conductive layer 12A over the entire conductive layer 12A. The amount of conductors per unit area that constitute the conductive layer 12A can be adjusted, for example, by adjusting the width, spacing, and other conditions of the multiple intersecting wires in the mesh shape that constitutes the conductive layer 12A, as illustrated in Figure 2.

[0043] Figure 5 is a perspective view of the antenna device 1A according to Modification 1. The antenna device 1A according to Modification 1 is the same as the antenna device 1A according to Embodiment 1, except for the following points.

[0044] As shown in FIG. 5, the antenna 10A according to the first modification has an edge pattern 18A provided along an edge 131A around the Z direction of the antenna element 13A. Hereinafter, as necessary, the region surrounded by the edge 131A of the antenna element 13A is referred to as an enclosed region 132A. The edge pattern 18A is, for example, a conductive pattern such as a metal pattern. Due to the edge pattern 18A, the amount per unit area of the conductor located at the edge 131A of the antenna element 13A is larger than the amount per unit area of the conductor located in the enclosed region 132A of the antenna element 13A.

[0045] In the current distribution generated in the antenna element 13A during the operation of the antenna 10A, a larger current tends to flow at the edge 131A of the antenna element 13A than in the enclosed region 132A of the antenna element 13A. The reason is that in the current distribution generated in the antenna element 13A, generally, the current flows from the edge 131A of the antenna element 13A toward the enclosed region 132A of the antenna element 13A. Therefore, by providing the edge pattern 18A, it is possible to make it easier for a larger current to flow through the edge 131A of the antenna element 13A, and the radiation efficiency of the antenna 10A can be improved. Furthermore, when the edge pattern 18A is provided, the light transmittance of the antenna 10A can be maintained rather than increasing the amount per unit area of the conductor constituting the antenna element 13A over the entire antenna element 13A.

[0046] From the description of the first modification shown in FIG. 5, it can be said that the radiation efficiency of the antenna 10A can be improved by making at least partially different the amount per unit area of the conductor constituting the conductive layer 12A according to the current distribution generated in the antenna element 13A during the operation of the antenna 10A. Specifically, by making the amount per unit area of the conductor constituting the portion where a relatively large current flows in the conductive layer 12A larger than the amount per unit area of the conductor constituting the portion where a relatively small current flows in the conductive layer 12A, it is possible to make it easier for a larger current to flow through the conductive layer 12A, and the radiation efficiency of the antenna 10A can be improved.

[0047] The distribution of the amount per unit area of the conductor constituting the conductive layer 12A is not limited to the example described with reference to FIG. 5. For example, the amount per unit area of the conductor located in the transmission line 15A may be larger than the amount per unit area of the conductor located in the surrounding region 132A. By increasing the amount per unit area of the conductor located in the transmission line 15A, it is possible to facilitate the flow of current through the transmission line 15A and reduce the transmission loss of the transmission line 15A.

[0048] FIG. 6 is a graph showing the frequency characteristics of the radiation efficiency of the antenna 10A provided with the edge pattern 18A and the antenna 10A not provided with the edge pattern 18A. The horizontal axis of the graph shown in FIG. 6 indicates the frequency (unit: MHz). The vertical axis of the graph shown in FIG. 6 indicates the radiation efficiency (unit: dB).

[0049] As shown in FIG. 6, at approximately 500 MHz to approximately 7500 MHz, the radiation efficiency of the antenna 10A provided with the edge pattern 18A is generally higher than the radiation efficiency of the antenna 10A not provided with the edge pattern 18A. From the results shown in FIG. 6, it can be said that the edge pattern 18A can contribute to the improvement of the radiation efficiency of the antenna 10A.

[0050] FIGS. 7 and 8 are perspective views of the antenna device 1A according to Modification 2 for explaining that the antenna element 13A is arranged at different heights with respect to the case 70A by the first spacer 610A, the second spacer 620A, and the connection block 630A. The antenna device 1A according to Modification 2 is the same as the antenna device 1A according to Embodiment 1 except for the following points.

[0051] As shown in FIGS. 7 and 8, the antenna device 1A according to Modification 2 includes a first spacer 610A, a second spacer 620A, and a connection block 630A instead of the spacer 60A according to the embodiment. The first spacer 610A has a first curved surface 611A. The second spacer 620A has a second curved surface 621A. The connection block 630A has a connection surface 631A.

[0052] As shown in Figures 7 and 8, the first spacer 610A protrudes from the notch 71A toward the +X side. The connecting block 630A has two first connecting arms 632A located on both the ±Y sides of the +X side portion of the first spacer 610A, and two second connecting arms 633A located on both the ±Y sides of the second spacer 620A. The +X side portion of the first spacer 610A and the two first connecting arms 632A are attached to each other via a first shaft 612A that protrudes in the Y direction from both the ±Y sides of the +X side portion of the first spacer 610A. In Figures 7 and 8, the first shaft 612A provided on the -Y side of the +X side portion of the first spacer 610A is hidden and not visible by the connecting block 630A. The first spacer 610A and the connecting block 630A are rotatable relative to each other around the first shaft 612A. The second spacer 620A and the two second connecting arms 633A are attached to each other via a second shaft 622A that protrudes in the Y direction from both the ±Y sides of the second spacer 620A. In Figures 7 and 8, the second shaft 622A on the -Y side of the second spacer 620A is hidden and not visible by the connecting block 630A. The second spacer 620A and the connecting block 630A are rotatable relative to each other around the second shaft 622A.

[0053] Similar to Embodiment 1, the transmission line 15A is at least partially guided along the first curved surface 611A, the second curved surface 621A, and the connecting surface 631A between the -X end of the transmission line 15A and the antenna element 13A. As shown in Figures 7 and 8, when the first spacer 610A and the second spacer 620A are connected to each other via the connecting block 630A, the first curved surface 611A, the second curved surface 621A, and the connecting surface 631A are smoothly and continuously curved. Therefore, similar to Embodiment 1, compared to the case where the transmission line 15A is not guided along the first curved surface 611A, the second curved surface 621A, and the connecting surface 631A, the breakage of the conductive layer 12A in the bent portion of the antenna 10A can be suppressed.

[0054] In the second modification, as can be seen from Figures 7 and 8, the height in the Z direction in which the antenna element 13A is positioned can be adjusted by rotating the first spacer 610A and the connecting block 630A around the first axis 612A, and rotating the second spacer 620A and the connecting block 630A around the second axis 622A, thereby adjusting the orientation of the two first connecting arms 632A to the two second connecting arms 633A of the connecting block 630A. In the example shown in Figure 7, the connecting block 630A is positioned approximately parallel to the Z direction from the two first connecting arms 632A to the two second connecting arms 633A. In the example shown in Figure 8, the connecting block 630A is positioned diagonally to the Z direction from the two first connecting arms 632A to the two second connecting arms 633A. Therefore, in the example shown in Figure 8, the antenna element 13A is positioned more towards the +Z side than in the example shown in Figure 7. In other words, in the example shown in Figure 8, the antenna element 13A is positioned at a higher height relative to the case 70A than in the example shown in Figure 7.

[0055] In the modified example 2, the guide member for guiding the transmission line 15A has multiple members, including a first spacer 610A, a second spacer 620A, and a connecting block 630A. By rotating the multiple members while they are connected to each other, the position of the antenna element 13A in the Z direction, that is, the position of the portion of the conductive layer 12A that extends from the guide member in the Z direction, can be adjusted.

[0056] The guide member that guides the transmission line 15A by rotation is not limited to a guide member having multiple members, such as the first spacer 610A, the second spacer 620A, and the connecting block 630A shown in Figures 7 and 8. In one example, a single spacer may rotate as the guide member. In this example, the single spacer may be rotatable around a rotation axis extending in the Y direction to the stopper 30A or a structure equivalent to the stopper 30A in the embodiment. For example, the single spacer and the stopper 30A or a structure equivalent to the stopper 30A are hinged together. By rotating the single spacer, the position of the antenna element 13A in the Z direction, that is, the position of the portion of the conductive layer 12A that extends from the single stopper in the Z direction, can be adjusted.

[0057] Figure 9 is a perspective view of the antenna device 1A according to Modification 3. The antenna device 1A according to Modification 3 is the same as the antenna device 1A according to Embodiment 1, except for the following points.

[0058] The antenna device 1A according to the modified example 3 includes a transparent support 90A that supports the antenna 10A. As shown in Figure 9, the antenna 10A is placed on the +Z side of the transparent support 90A. The transparent support 90A is, for example, an acrylic plate. By supporting the antenna 10A with the transparent support 90A, the strength of the antenna 10A can be improved without impairing the light transmittance of the antenna 10A.

[0059] Figure 10 is a perspective view of the antenna device 1A according to Modification 4. The antenna device 1A according to Modification 4 is the same as the antenna device 1A according to Embodiment 1, except for the following points.

[0060] In the antenna device 1A according to Modification 4, the width of the spacer 60A in the Y direction continuously decreases as it moves away from the notch 71A toward the +X side. Therefore, compared to the case where the width of the spacer 60A in the Y direction is constant regardless of the distance from the notch 71A in the X direction, the space required to arrange the spacer 60A can be reduced.

[0061] Figure 11 is a perspective view of the antenna device 1A according to Modification 5. The antenna device 1A according to Modification 5 is the same as the antenna device 1A according to Embodiment 1, except for the following points.

[0062] The antenna device 1A according to modified example 5 is equipped with a retainer 640A that presses down on the portion of the transmission line 15A that is guided along the curved surface 61A toward the -Z side. By pressing down on this portion of the transmission line 15A with the retainer 640A, rattling of the transmission line 15A can be suppressed. The spacer 60A may also serve as the retainer 640A.

[0063] Figure 12 is a perspective view of the antenna device 1A according to Modification 6. The antenna device 1A according to Modification 6 is the same as the antenna device 1A according to Embodiment 1, except for the following points.

[0064] In the antenna device 1A according to Modification 6, when viewed from the Y direction, the curved surface 61A of the spacer 60A extends toward the +Z side as it moves away from the case 70A toward the +X side. Therefore, the antenna 10A can be pulled out toward the +Z side from the case 70A. In the example shown in Figure 12, the antenna element 13A is arranged substantially perpendicular to the X direction. In Modification 6 as well, the transmission line 15A is at least partially guided along the curved surface 61A of the spacer 60A between the -X end of the transmission line 15A and the antenna element 13A. Therefore, compared to the case where the transmission line 15A is not guided along the curved surface 61A, the breakage of the conductive layer 12A in the bent portion of the antenna 10A can be suppressed.

[0065] Figure 13 is an exploded perspective view of the antenna device 1B according to Embodiment 2. Figure 14 is a side view of a part of the antenna device 1B according to Embodiment 2. Figure 15 is a top view of a part of the antenna device 1B according to Embodiment 2. The antenna device 1B according to Embodiment 2 is the same as the antenna device 1A according to Embodiment 1, except for the following points. Note that in Figure 14, for the sake of clarity, the antenna device 1B is shown as a side view with the substrate 30B and antenna 10B spaced apart from each other. However, in the actual product form of the antenna device 1B, the substrate 30B and antenna 10B are not spaced apart, and the power supply pattern 31B, first ground pattern 32B, first conductive pattern 34B, and second conductive pattern 35B, which are located on the +Z side surface of the substrate 30B, are sandwiched between the dielectric layer 11B and the substrate 30B.

[0066] The antenna device 1B according to Embodiment 2 will be described with reference to Figure 13, and with reference to Figures 14 and 15 as necessary.

[0067] As shown in Figure 13, the antenna device 1B according to Embodiment 2 comprises an antenna 10B, a bottom case 20B, a circuit board 30B, a cable 40B, and a top case 50B.

[0068] As shown in Figures 13 and 14, the antenna 10B according to Embodiment 2 has a dielectric layer 11B and a conductive layer 12B. As shown in Figure 13, the conductive layer 12B includes a first antenna element 13B, a second antenna element 14B, a first transmission line 15B, and a second transmission line 16B. As shown in Figure 13, when viewed from the Z direction, the first antenna element 13B and the second antenna element 14B are located on the +Y side and -Y side of the antenna 10B, respectively, and the first transmission line 15B and the second transmission line 16B are located on the +Y side and -Y side of the antenna 10B, respectively. As will be described in detail later, the dielectric layer 11B and the conductive layer 12B are light-transmitting. Therefore, the antenna 10B according to Embodiment 2 can be used as a transparent antenna. In one example, the antenna 10B can be used as a glass antenna that can be attached to glass such as vehicle windows or vending machine windows. In one example, the antenna 10B can operate in the frequency bands of various communication media.

[0069] The dielectric layer 11B is, for example, a resin layer. The dielectric layer 11B has light transmittance and flexibility. The dielectric layer 11B serves as a support layer for the conductive layer 12B. In the example shown in Figure 13, when viewed from the Z direction, the area of ​​the dielectric layer 11B is larger than the area of ​​the conductive layer 12B. The shape of the dielectric layer 11B is not limited to the example shown in Figure 13. For example, when viewed from the Z direction, the dielectric layer 11B and the conductive layer 12B may have substantially the same shape.

[0070] The conductive layer 12B is, for example, a metal layer. As shown in Figures 13 and 14, the conductive layer 12B is provided on the +Z plane side of the dielectric layer 11B. For example, the conductive layer 12B may be formed along the +Z plane of the dielectric layer 11B, or it may be at least partially embedded on the +Z plane side of the dielectric layer 11B. In Figure 13, for illustrative purposes, the conductive layer 12B is shown macroscopically as a layer formed over the entire region enclosed by the outline of the element representing the conductive layer 12B. However, in reality, similar to the conductive layer 12A described exemplary in Embodiment 1 with reference to Figure 2, when viewed microscopically from the Z direction, the conductive layer 12B is formed in a mesh-like manner within the region enclosed by the outline of the element representing the conductive layer 12B. Therefore, similar to the conductive layer 12A in Embodiment 1, the conductive layer 12B in Embodiment 2 has light transmittance.

[0071] As shown in Figures 13 and 14, the conductive layer 12B is provided only on the +Z side of the dielectric layer 11B. Therefore, compared to the case where the conductive layer 12B is provided on both the ±Z sides of the dielectric layer 11B, the light transmittance of the antenna 10B can be maintained and the manufacturing cost of the antenna 10B can be reduced. When the area of ​​the dielectric layer 11B perpendicular to the Z direction is relatively small, the conductive layer 12B may be provided on both the ±Z sides of the dielectric layer 11B in order to achieve sufficient radiation performance of the antenna 10B. When the conductive layer 12B is provided on both the ±Z sides of the dielectric layer 11B, through-holes are required to electrically connect the conductive layers 12B provided on both the ±Z sides of the dielectric layer 11B. However, it can be difficult to provide such through-holes due to the mesh shape of the conductive layer 12B. If the conductive layer 12B is provided on only one side of the dielectric layer 11B in the Z direction, it becomes unnecessary to electrically connect the conductive layers 12B located on both the ±Z sides of the dielectric layer 11B using through-holes.

[0072] The antenna 10B according to Embodiment 2 is configured to operate as a dipole antenna having a first antenna element 13B and a second antenna element 14B as radiating elements. In the example shown in Figure 13, the first antenna element 13B and the second antenna element 14B are self-similar antennas or similar antennas. In the example shown in Figure 13, the first antenna element 13B and the second antenna element 14B are capable of operating as a bowtie antenna. As shown in Figure 13, the first antenna element 13B and the second antenna element 14B each include a feed point 17B electrically connected to the +X side end of the first transmission line 15B and the second transmission line 16B. As shown in Figure 13, the first antenna element 13B and the second antenna element 14B are arranged substantially symmetrically with respect to an axis passing through the feed point 17B in the X direction. As shown in Figure 13, when viewed from the Z direction, the width of the first antenna element 13B in the X direction increases continuously in the -Y side portion of the first antenna element 13B as it moves away from the feed point 17B toward the +Y side. When viewed from the Z direction, the ±X sides of the first antenna element 13B extend in a curved manner so as they move away from each other in the -Y side portion of the first antenna element 13B as it moves away from the feed point 17B toward the +Y side. When viewed from the Z direction, the shape of the second antenna element 14B is substantially symmetrical to the shape of the first antenna element 13B with respect to an axis passing through the feed point 17B in the X direction. The shapes of the first antenna element 13B and the second antenna element 14B are not limited to the example shown in Figure 13.

[0073] As shown in Figure 13, when viewed from the Z direction, the bottom case 20B has a substantially rectangular shape with a pair of long sides substantially parallel to the X direction and a pair of short sides substantially parallel to the Y direction. A recess 21B is provided on the +Z plane of the bottom case 20B. When the bottom case 20B and the substrate 30B are assembled together, the substrate 30B fits into the recess 21B.

[0074] A spacer 22B is provided on the +X side of the bottom case 20B. In the example shown in Figure 13, the bottom case 20B and the spacer 22B are molded as a single unit. As shown in Figure 13, the +X side portion of the spacer 22B includes a curved surface 23B. As shown in Figure 13, viewed from the Y direction, the curved surface 23B extends toward the -Z side as it moves away from the bottom case 20B toward the +X side. As shown in Figure 13, viewed from the Y direction, the curved surface 23B extends in a roughly S-shape such that the tangent plane at the -X side end of the curved surface 23B is approximately perpendicular to the Z direction, and the tangent plane at the +X side end of the curved surface 23B is approximately perpendicular to the Z direction. The shape of the curved surface 23B is not limited to the example shown in Figure 13.

[0075] The substrate 30B is, for example, a rigid substrate such as a PCB. As shown in Figure 13, the substrate 30B is positioned substantially perpendicular to the Z direction. In the example shown in Figure 13, the substrate 30B has a substantially rectangular shape with a pair of long sides substantially parallel to the X direction and a short side substantially parallel to the Y direction. The shape of the substrate 30B is not limited to the example shown in Figure 13.

[0076] As shown in Figures 13 and 15, the substrate 30B has a power supply pattern 31B, a first ground pattern 32B, a second ground pattern 33B, a first conductive pattern 34B, and a second conductive pattern 35B. The power supply pattern 31B, the first ground pattern 32B, the second ground pattern 33B, the first conductive pattern 34B, and the second conductive pattern 35B are conductive patterns such as metal patterns provided on the +Z side of the substrate 30B. Details of the power supply pattern 31B, the first ground pattern 32B, the second ground pattern 33B, the first conductive pattern 34B, and the second conductive pattern 35B will be described later.

[0077] Cable 40B is a coaxial cable having a core 41B. As shown in Figures 13 and 14, when the substrate 30B and cable 40B are assembled together, cable 40B is attached to the +Z side of the second ground pattern 33B via the first solder 331B, and the core 41B and the power supply pattern 31B are electrically connected to each other via the second solder 311B. In Figures 13 and 14, the first solder 331B is shown as a block in the simulation. In Figures 13 to 15, the second solder 311B is shown as a block in the simulation.

[0078] As shown in Figure 13, the top case 50B has a roughly rectangular parallelepiped shape with an opening toward the -Z side, having a pair of side walls substantially perpendicular to the X direction, another pair of side walls substantially perpendicular to the Y direction, and a top plate perpendicular to the Z direction. As shown in Figure 13, a notch 51B is provided on the -Z side of the +X side wall of the top case 50B. With the antenna 10B, bottom case 20B, substrate 30B, and cable 40B assembled together, the top case 50B covers the -X end of the first transmission line 15B, the -X end of the second transmission line 16B, the bottom case 20B, substrate 30B, and the +X end of the cable 40B, so that the first transmission line 15B and the second transmission line 16B are drawn out from the notch 51B, the spacer 22B protrudes from the notch 51B toward the +X side, and the cable 40B is drawn out from the -X side wall of the top case 50B.

[0079] In Embodiment 2, as in Embodiment 1, when the antenna device 1B is assembled, the first transmission line 15B is at least partially guided along the curved surface 23B between the -X end of the first transmission line 15B and the first antenna element 13B, and the second transmission line 16B is at least partially guided along the curved surface 23B between the -X end of the second transmission line 16B and the second antenna element 14B. Therefore, compared to cases where the first transmission line 15B is not guided along the curved surface 23B, or where the second transmission line 16B is not guided along the curved surface 23B, the breakage of the conductive layer 12B in the bent portion of the antenna 10B can be suppressed.

[0080] The first transmission line 15B, the second transmission line 16B, and the substrate 30B will be further explained with reference to Figures 13 to 15.

[0081] As shown in Figure 15, when viewed from the Z direction, the power supply pattern 31B and the first ground pattern 32B are aligned in the Y direction, with the power supply pattern 31B positioned on the +Y side relative to the first ground pattern 32B and the first ground pattern 32B positioned on the -Y side relative to the power supply pattern 31B. In the example shown in Figure 15, when viewed from the Z direction, the power supply pattern 31B and the first ground pattern 32B have a substantially rectangular shape with a pair of long sides substantially parallel to the X direction and a pair of short sides substantially parallel to the Y direction. The shapes of the power supply pattern 31B and the first ground pattern 32B are not limited to the example shown in Figure 15.

[0082] As shown in Figure 15, when viewed from the Z direction, the second ground pattern 33B is located at the -X side end of the substrate 30B. The power supply pattern 31B and the first ground pattern 32B are integrally formed such that the first ground pattern 32B protrudes toward the +X side from the +X side edge of the power supply pattern 31B.

[0083] As shown in Figure 15, the first conductive pattern 34B and the second conductive pattern 35B are aligned in the Y direction. As shown in Figure 15, the first conductive pattern 34B is located away from the power supply pattern 31B on the +X side. The first conductive pattern 34B is DC-insulated from the power supply pattern 31B, the first ground pattern 32B, the second ground pattern 33B, and the second conductive pattern 35B, but is electrically connected by capacitive coupling. As shown in Figure 15, the second conductive pattern 35B is located away from the first ground pattern 32B on the +X side. The second conductive pattern 35B is DC-insulated from the power supply pattern 31B, the first ground pattern 32B, the second ground pattern 33B, and the first conductive pattern 34B, but is electrically connected by capacitive coupling. In the examples shown in Figures 13 and 15, when viewed from the Z direction, the first conductive pattern 34B and the second conductive pattern 35B have a substantially rectangular shape with a pair of short sides substantially parallel to the X direction and a pair of long sides substantially parallel to the Y direction. The shapes of the first conductive pattern 34B and the second conductive pattern 35B are not limited to the examples shown in Figures 13 and 15.

[0084] As shown in Figure 15, the core 41B of the cable 40B is electrically connected to the -X end of the feed pattern 31B. Therefore, the feed pattern 31B is configured to operate as a monopole antenna when the portion electrically connected to the core 41B of the feed pattern 31B becomes the feed point. Thus, in the antenna device 1B according to Embodiment 2, not only the antenna 10B but also the feed pattern 31B can operate as an antenna. Therefore, by operating the antenna 10B and the feed pattern 31B complementaryly with respect to the operating frequency, the antenna device 1B can be operated over a wide bandwidth. Thus, compared to the case where the feed pattern 31B does not operate as an antenna, it is possible to easily adjust the operating frequency band of the antenna device 1B.

[0085] As shown in Figures 14 and 15, the -Z plane of the -X end of the first transmission line 15B and the +Z planes of the power supply pattern 31B and the first conductive pattern 34B are located apart from each other in the Z direction, while the -X end of the first transmission line 15B and the power supply pattern 31B and the first conductive pattern 34B overlap each other at least partially in the Z direction. Therefore, the -X end of the first transmission line 15B and the power supply pattern 31B and the first conductive pattern 34B are electrically connected to each other non-contactively by capacitive coupling. Thus, compared to the case where the -X end of the first transmission line 15B and the power supply pattern 31B are electrically connected to each other by conduction such as soldering, the electrical connection of the -X end of the first transmission line 15B and the power supply pattern 31B can be made easier. The -X end of the first transmission line 15B and the power supply pattern 31B may be electrically connected to each other by conduction such as soldering. Furthermore, the first conductive pattern 34B can increase the capacitance between the first transmission line 15B and the substrate 30B, enabling the antenna device 1B to operate over a wide bandwidth.

[0086] As shown in Figures 14 and 15, the -Z plane of the -X end of the second transmission line 16B and the +Z planes of the first ground pattern 32B and the second conductive pattern 35B are located apart from each other in the Z direction, while the -X end of the second transmission line 16B and the first ground pattern 32B and the second conductive pattern 35B overlap each other at least partially in the Z direction. Therefore, the -X end of the second transmission line 16B and the first ground pattern 32B and the second conductive pattern 35B are electrically connected to each other non-contactively by capacitive coupling. Thus, compared to the case where the -X end of the second transmission line 16B and the first ground pattern 32B are electrically connected to each other by conduction such as soldering, the electrical connection of the -X end of the second transmission line 16B and the first ground pattern 32B can be made easier. The -X end of the second transmission line 16B and the first ground pattern 32B may be electrically connected to each other by conduction such as soldering. Furthermore, the second conductive pattern 35B can increase the capacitance between the second transmission line 16B and the substrate 30B, enabling the antenna device 1B to operate over a wide bandwidth.

[0087] As shown in Figure 13, the first transmission line 15B and the second transmission line 16B extend in the X direction. As shown in Figure 13, when viewed from the Z direction, the -Y side of the first transmission line 15B and the +Y side of the second transmission line 16B are substantially parallel to the X direction, except for the -X end of the first transmission line 15B and the -X end of the second transmission line 16B. As shown in Figure 13, when viewed from the Z direction, the +Y side of the first transmission line 15B and the -Y side of the second transmission line 16B extend substantially linearly toward each other as they approach the feed point 17B. Therefore, when viewed from the Z direction, the first transmission line 15B and the second transmission line 16B have a substantially tapered shape. Consequently, the width of each of the first transmission line 15B and the second transmission line 16B in the Y direction decreases at least partially as they approach the feed point 17B.

[0088] The characteristic impedance of the two parallel wires of the first transmission line 15B and the second transmission line 16B can be adjusted by the width in the Y direction of each of the first transmission line 15B and the second transmission line 16B. Therefore, in Embodiment 2, the characteristic impedance on the -X side of the first transmission line 15B and the second transmission line 16B can be adjusted by making the width in the Y direction on the -X side of each of the first transmission line 15B and the second transmission line 16B relatively wide to match the impedance on the cable 40B side. Similarly, the characteristic impedance on the +X side of the first transmission line 15B and the second transmission line 16B can be adjusted by making the width in the Y direction on the +X side of each of the first transmission line 15B and the second transmission line 16B relatively narrow to match the impedance on the first antenna element 13B and the second antenna element 14B side. Therefore, compared to the case where the width in the Y direction of each of the first transmission line 15B and the second transmission line 16B is constant regardless of the position of the first transmission line 15B and the second transmission line 16B in the X direction, impedance matching of the antenna device 1B can be made easier.

[0089] As shown in Figure 13, in Embodiment 2, the width in the Y direction of each of the first transmission line 15B and the second transmission line 16B decreases continuously as it approaches the power supply point 17B. In the portion where the width in the Y direction of the first transmission line 15B and the second transmission line 16B changes in a stepwise manner, the characteristic impedance of the first transmission line 15B and the second transmission line 16B also changes in a stepwise manner. In the portion where the characteristic impedance of the first transmission line 15B and the second transmission line 16B changes in a stepwise manner, the input signal is more likely to be reflected due to the stepwise change in characteristic impedance, which can make impedance matching difficult. However, in Embodiment 2, by eliminating the portion where the width in the Y direction of each of the first transmission line 15B and the second transmission line 16B changes in a stepwise manner, the input signal can be made less likely to be reflected, and impedance matching can be made easier.

[0090] Figure 16 is a perspective view of a modified example of the first transmission line 15B and the second transmission line 16B.

[0091] As shown in Figure 16, when viewed from the Z direction, the +Y side of the first transmission line 15B and the -Y side of the second transmission line 16B may extend in a curved shape toward the side approaching each other as they approach the feed point 17B. In the modified example shown in Figure 16, similar to Embodiment 2, the Y-direction widths of the first transmission line 15B and the second transmission line 16B each decrease at least partially as they approach the feed point 17B. Therefore, impedance matching of the antenna 10B can be facilitated compared to the case where the Y-direction widths of the first transmission line 15B and the second transmission line 16B each are constant regardless of their position in the X direction.

[0092] Figure 17 is a graph showing the frequency characteristics of the radiation efficiency of the substrate 30B according to Embodiment 2 when the antenna 10B is not installed. Figure 18 is a graph showing the frequency characteristics of the antenna device 1B according to Embodiment 2 when both the antenna 10B and the substrate 30B are installed. The horizontal axis of the graphs in Figures 17 and 18 represents frequency (unit: MHz). The vertical axis of the graphs in Figures 17 and 18 represents radiation efficiency (unit: dB).

[0093] As shown in Figure 17, even without the antenna 10B installed, the radiation efficiency of the substrate 30B is relatively high in the range of approximately 3500 MHz to approximately 6500 MHz. From the results shown in Figure 17, it can be said that the substrate 30B can contribute to the radiation efficiency in the range of approximately 3500 MHz to approximately 6500 MHz.

[0094] As shown in Figure 18, with both antenna 10B and substrate 30B installed, the radiation efficiency is relatively high in a relatively wide bandwidth of approximately 600 MHz to approximately 6500 MHz. Antenna 10B can be said to contribute to the radiation efficiency from approximately 600 MHz to approximately 3500 MHz. Substrate 30B can be said to contribute to the radiation efficiency from approximately 3500 MHz to approximately 6500 MHz. Therefore, in Embodiment 2, by operating antenna 10B and substrate 30B complementaryly with respect to operating frequency, the antenna device 1B can be operated over a wide bandwidth.

[0095] Figure 19 is a graph showing the frequency characteristics of the radiation efficiency of the antenna device 1B in patterns 1, 2, and 3 of substrate 30B. Figure 20 is a graph showing the frequency characteristics of the voltage standing wave ratio (VSWR) of the antenna device 1B in patterns 1, 2, and 3 of substrate 30B. In the graph shown in Figure 19, the horizontal axis represents frequency (in MHz). In the graph shown in Figure 19, the vertical axis represents radiation efficiency (in dB). In the graph shown in Figure 20, the horizontal axis represents frequency (in MHz). In the graph shown in Figure 20, the vertical axis represents VSWR.

[0096] The pattern 1 of the substrate 30B is similar to the pattern of the substrate 30B according to Embodiment 2, and includes a power supply pattern 31B, a first ground pattern 32B, a second ground pattern 33B, a first conductive pattern 34B, and a second conductive pattern 35B.

[0097] Pattern 2 of substrate 30B is the same as pattern 1 of substrate 30B, except that the first conductive pattern 34B and the second conductive pattern 35B are not provided. The X-direction dimensions of the power supply pattern 31B and the first ground pattern 32B in pattern 2 of substrate 30B are the same as the X-direction dimensions of the power supply pattern 31B and the first ground pattern 32B in pattern 1 of substrate 30B, respectively.

[0098] Pattern 3 of substrate 30B is the same as pattern 1 of substrate 30B, except that the first conductive pattern 34B and the second conductive pattern 35B are not provided, and the X-direction dimensions of the power supply pattern 31B and the first ground pattern 32B are longer than the X-direction dimensions of the power supply pattern 31B and the first ground pattern 32B in pattern 1 of substrate 30B. The power supply pattern 31B of pattern 3 of substrate 30B is extended until the +X-side end of the power supply pattern 31B reaches the same position as the +X-side end of the first conductive pattern 34B in pattern 1 of substrate 30B. The first ground pattern 32B of pattern 3 of substrate 30B is extended until the +X-side end of the first ground pattern 32B reaches the same position as the +X-side end of the second conductive pattern 35B in pattern 1 of substrate 30B.

[0099] A comparison of patterns 1 and 2 on substrate 30B will now be explained. As shown in Figure 19, in the range of approximately 6750 MHz to approximately 7500 MHz, the radiation efficiency of pattern 1 on substrate 30B is generally higher than that of pattern 2 on substrate 30B. As shown in Figure 20, in the range of approximately 6750 MHz to approximately 7500 MHz, the VSWR of pattern 1 on substrate 30B is generally lower than that of pattern 2 on substrate 30B. From the comparison of the results shown in Figures 19 and 20, it can be said that the frequency characteristics of radiation efficiency and VSWR in the range of approximately 6750 MHz to approximately 7500 MHz can be improved by increasing the capacitance between the first transmission line 15B and substrate 30B due to the first conductive pattern 34B, and by increasing the capacitance between the second transmission line 16B and substrate 30B due to the second conductive pattern 35B.

[0100] A comparison of patterns 1 and 3 on substrate 30B will now be explained. As shown in Figure 19, in the range of approximately 4750 MHz to approximately 6500 MHz, the radiation efficiency of pattern 1 on substrate 30B is generally higher than that of pattern 3 on substrate 30B. As shown in Figure 20, in the range of approximately 4750 MHz to approximately 6500 MHz, the VSWR of pattern 1 on substrate 30B is generally lower than that of pattern 3 on substrate 30B. As explained using Figure 17, it can be said that substrate 30B, operating as a monopole antenna, contributes to the radiation efficiency in the range of approximately 3500 MHz to approximately 6500 MHz. Therefore, considering the results shown in Figure 18, a comparison of the results shown in Figures 19 and 20 indicates that, with respect to operating the substrate 30B as a monopole antenna, the length of the feed pattern 31B in the X direction and the length of the first ground pattern 32B in the X direction in pattern 1 of the substrate 30B are more optimized than the length of the feed pattern 31B in the X direction and the length of the first ground pattern 32B in the X direction in pattern 3 of the substrate 30B.

[0101] Figure 21 is a Smith chart illustrating the impedance matching of antenna 10B according to Embodiment 2. The numerical values ​​on the horizontal axis passing through the center of the circle in the Smith chart of Figure 21 represent the real part of the complex reflection coefficient, while the numerical values ​​around the circle in the Smith chart of Figure 21 represent the imaginary part of the complex reflection coefficient.

[0102] The Smith chart shown in Figure 21 shows the impedance of the first antenna element 13B and the second antenna element 14B, expressed relative to 50Ω. In the Smith chart shown in Figure 21, the impedances of the first antenna element 13B and the second antenna element 14B are 116Ω at 617MHz at the point indicated by "1" enclosed in an inverted triangle, 153Ω at 2000MHz at the point indicated by "2" enclosed in an inverted triangle, and 115Ω at 5000MHz at the point indicated by "3" enclosed in an inverted triangle. From the Smith chart shown in Figure 21, the characteristic impedance of the first antenna element 13B and the second antenna element 14B is between 75Ω and 200Ω, so it is necessary to adjust it for the impedance of cable 40B.

[0103] Figure 22 is a plan view of the antenna device 1C according to Embodiment 3. Figure 23 is a side view of a part of the antenna device 1C according to Embodiment 3. In Figure 23, the white circle with an X indicating the Y axis indicates that the Y-axis arrow is pointing towards the back of the page. The antenna device 1C according to Embodiment 3 is the same as the antenna device 1B according to Embodiment 2, except for the following points. Note that in Figure 23, for the sake of clarity, the antenna device 1C is shown as a side view with the substrate 20C and antenna 10C spaced apart from each other, but in the actual product form of the antenna device 1C, the substrate 20C and antenna 10C are not spaced apart.

[0104] As shown in Figure 22, the antenna device 1C according to Embodiment 3 comprises an antenna 10C, a substrate 20C, and a cable 30C. As shown in Figure 23, the antenna 10C according to Embodiment 3 has a dielectric layer 11C and a conductive layer 12C.

[0105] As shown in Figure 22, the conductive layer 12C includes a first antenna element 13C and a second antenna element 14C. As shown in Figure 22, the antenna 10C defines a slot 18C that separates the first antenna element 13C and the second antenna element 14C from each other. As shown in Figure 22, a substantially circular cavity 19C is provided at the -X side base end of the slot 18C. The conductive layer 12C is not provided in the slot 18C or the cavity 19C. As shown in Figure 22, the substrate 20C has a feed line 21C. The feed line 21C is a conductive pattern such as a metal pattern provided on the +Z side of the substrate 20C. The cable 30C is attached to the +Z side of the -X end of the substrate 20C via a third solder 201C. The core 31C of the cable 30C and the -X end of the feed line 21C are electrically connected to each other via a fourth solder 211C. In Figure 23, the third solder 201C is shown as a simulated block. In Figures 22 and 23, the fourth solder 211C is shown as a simulated block.

[0106] In Embodiment 3, the first antenna element 13C and the second antenna element 14C are configured to operate as a tapered slot antenna with the portion of the feed line 21C in the slot 18C that overlaps with the feed point 17C in the Z direction. As shown in Figure 23, the +Z plane of the antenna 10C and the -Z plane of the substrate 20C are located apart from each other in the Z direction. Therefore, the feed line 21C and the first antenna element 13C and the second antenna element 14C are electrically connected to each other without contact. Thus, compared to the case where the feed line 21C and the first antenna element 13C and the second antenna element 14C are electrically connected to each other by conductivity such as soldering, the electrical connection between the feed line 21C and the first antenna element 13C and the second antenna element 14C can be made easier.

[0107] As shown in Figure 22, the first antenna element 13C and the second antenna element 14C are arranged asymmetrically with respect to an axis passing through the feed point 17C in the X direction. In the example shown in Figure 22, the first antenna element 13C and the second antenna element 14C form a self-similar antenna or an antenna similar thereto. As shown in Figure 22, the widths of the first antenna element 13C and the second antenna element 14C increase continuously as they move away from the feed point 17C. In the example shown in Figure 22, the length L1 in the X direction of the +Y side end of the first antenna element 13C is less than the length L2 in the X direction of the -Y side end of the second antenna element 14C. In the example shown in Figure 22, the length of the first antenna element 13C in the Y direction is less than the length of the second antenna element 14C in the Y direction.

[0108] In Embodiment 3, by making the shapes of the first antenna element 13C and the second antenna element 14C different from each other, the operating frequency bands of the first antenna element 13C and the second antenna element 14C can be made different from each other. Therefore, by operating the first antenna element 13C and the second antenna element 14C complementaryly with respect to their operating frequencies, the antenna device 1C can be operated over a wide bandwidth. Consequently, compared to the case where the first antenna element 13C and the second antenna element 14C are arranged substantially symmetrically with respect to the feed point 17C, the adjustment of the operating frequency band of the antenna device 1C can be made easier. Furthermore, by appropriately asymmetrically arranging the first antenna element 13C and the second antenna element 14C with respect to the feed point 17C, compared to the case where the first antenna element 13C and the second antenna element 14C are arranged substantially symmetrically with respect to the feed point 17C, the characteristics of the antenna 10C can be maintained or improved while reducing the area of ​​the antenna 10C.

[0109] In Embodiment 3, the conductive pattern on the substrate 20C may function as an antenna, similar to Embodiment 2. By operating the antenna 10C and the substrate 20C complementaryly with respect to the operating frequency, the antenna device 1C can be operated over a wide bandwidth. Therefore, compared to the case where the substrate 20C does not function as an antenna, it is possible to easily adjust the operating frequency band of the antenna device 1C.

[0110] Figure 24 is a graph showing the frequency characteristics of the radiation efficiency of an antenna 10C in which the first antenna element 13C and the second antenna element 14C are arranged asymmetrically, and an antenna 10C in which the first antenna element 13C and the second antenna element 14C are arranged symmetrically. Figure 25 is a graph showing the frequency characteristics of the VSWR of an antenna 10C in which the first antenna element 13C and the second antenna element 14C are arranged asymmetrically, and an antenna 10C in which the first antenna element 13C and the second antenna element 14C are arranged symmetrically. In the graph shown in Figure 24, the horizontal axis represents frequency (unit: MHz). In the graph shown in Figure 24, the vertical axis represents radiation efficiency (unit: dB). In the graph shown in Figure 25, the horizontal axis represents frequency (unit: MHz). In the graph shown in Figure 25, the vertical axis represents VSWR.

[0111] Unless otherwise specified, an asymmetric antenna 10C refers to an antenna 10C in which the first antenna element 13C and the second antenna element 14C are arranged asymmetrically. Unless otherwise specified, a symmetric antenna 10C refers to an antenna 10C in which the first antenna element 13C and the second antenna element 14C are arranged symmetrically.

[0112] In Figures 24 and 25, the shape of the asymmetric antenna 10C is as follows: The length L1 in the X direction of the +Y end of the first antenna element 13C is 50.00 mm. The length L2 in the X direction of the -Y end of the second antenna element 14C is 90.00 mm. The length L3 in the Y direction between the +Y end of the first antenna element 13C and the -Y end of the second antenna element 14C is 140.50 mm.

[0113] In Figures 24 and 25, the shape of the symmetrical antenna 10C is as follows: The length L1 in the X direction of the +Y end of the first antenna element 13C and the length L2 in the X direction of the -Y end of the second antenna element 14C are 99.42 mm. The length L3 in the Y direction between the +Y end of the first antenna element 13C and the -Y end of the second antenna element 14C is 150.50 mm.

[0114] As shown in Figure 25, the frequency characteristics of the VSWR of the asymmetric antenna 10C and the VSWR of the symmetric antenna 10C are equivalent. As shown in Figure 24, the radiation efficiency of the asymmetric antenna 10C is higher than that of the symmetric antenna 10C over almost the entire range from approximately 1000 MHz to approximately 7500 MHz. From the comparison of the lengths L1, L2, and L3 of the asymmetric antenna 10C and the symmetric antenna 10C described above, the dimensions of the asymmetric antenna 10C are smaller than those of the symmetric antenna 10C. Therefore, by arranging the first antenna element 13C and the second antenna element 14C asymmetrically with respect to the feed point 17C, it is possible to maintain the frequency characteristics of the VSWR of the antenna 10C and further improve the frequency characteristics of the radiation efficiency of the antenna 10C while reducing the area of ​​the antenna 10C.

[0115] The embodiments of the present invention have been described above with reference to the drawings, but these are merely examples of the present invention, and various other configurations can also be adopted.

[0116] This specification provides antenna devices in the following embodiments: (Embodiment 1.1) In embodiment 1, the antenna device comprises an antenna having a dielectric layer and a conductive layer provided on the dielectric layer, and a guide member having a curved surface, wherein the conductive layer is at least partially guided along the curved surface.

[0117] The "guide member" corresponds to the "spacer" in the above-described embodiment.

[0118] According to the above-described embodiment, compared to the case where the conductive layer is not guided by a curved surface, the fracture of the conductive layer in the bent portion of the antenna can be suppressed.

[0119] (Aspect 1.2) In aspect 1.2, the amount of conductor per unit area constituting the portion of the conductive layer guided along the curved surface is greater than the amount of conductor per unit area constituting the other portion of the conductive layer that extends substantially flat.

[0120] According to the above-described embodiment, compared to the case where the amount of conductor per unit area constituting the portion guided along the curved surface of the conductive layer is as small as the amount of conductor per unit area constituting the other portions of the conductive layer that extend substantially flat, it is possible to suppress the fracture of the portion guided along the curved surface of the conductive layer.

[0121] (Aspect 1.3) In aspect 1.3, the curved surface of the guide member extends in an S-shaped curve.

[0122] According to the above-described embodiment, the conductive layer can be guided smoothly.

[0123] (Aspect 1.4) In aspect 1.4, the guide member rotates.

[0124] According to the above embodiment, the position of the portion of the conductive layer that is pulled out from the guide member can be adjusted by rotating the guide member and adjusting the orientation of the guide member.

[0125] (Aspect 1.5) In aspect 1.5, the guide member has a plurality of members.

[0126] The "multiple components" correspond to the "first spacer," "second spacer," and "connecting block" in the above-described embodiment.

[0127] According to the above embodiment, by rotating the multiple members while they are connected to each other, the position of the portion drawn out from the guide member of the conductive layer can be adjusted.

[0128] (Aspect 1.6) In aspect 1.6, the antenna device comprises an antenna having a dielectric layer and a conductive layer provided on the dielectric layer, wherein the amount of conductor per unit area constituting the conductive layer differs at least partially depending on the current distribution generated in the conductive layer when the antenna is operating.

[0129] According to the above embodiment, by partially increasing the amount of conductor per unit area that constitutes the portion of the conductive layer through which a relatively large current flows in the current distribution generated in the conductive layer during antenna operation, it is possible to make it easier for a larger current to flow through the conductive layer, thereby improving the radiation efficiency of the antenna.

[0130] (Aspect 1.7) In aspect 1.7, the amount per unit area of ​​the conductor located at least a portion of the edge of the antenna is greater than the amount per unit area of ​​the conductor located in the portion enclosed by the edge of the antenna.

[0131] According to the above-described embodiment, it is possible to facilitate the flow of a larger current through the edge of the conductive layer.

[0132] According to this specification, antenna devices in the following embodiments are provided: (Embodiment 2.1) In embodiment 2.1, the antenna device comprises an antenna having a dielectric layer and a conductive layer provided on the dielectric layer, and a substrate having a conductive pattern electrically connected to the conductive layer, wherein the conductive pattern is configured to operate at least partially as an antenna.

[0133] The "conductive pattern" corresponds to the "power supply pattern" in the above-described embodiment.

[0134] According to the above embodiment, by operating the antenna and the conductive pattern complementaryly with respect to the operating frequency, the antenna device can be operated over a wide bandwidth. Therefore, compared to the case where the conductive pattern does not act as an antenna, it is possible to easily adjust the operating frequency band of the antenna device.

[0135] (Aspect 2.2) In aspect 2.2, the conductive layer and the conductive pattern are electrically connected to each other in a non-contact manner.

[0136] According to the above-described embodiment, the electrical connection between the conductive layer and the conductive pattern can be made easier compared to the case where the conductive layer and the conductive pattern are electrically connected to each other by conduction such as soldering.

[0137] (Aspect 2.3) In aspect 2.3, the substrate further has other conductive patterns electrically connected to the conductive pattern by capacitive coupling, and the conductive layer and the other conductive patterns are electrically connected to each other by capacitive coupling.

[0138] According to the above-described embodiment, the capacitance between the conductive layer and the substrate can be increased, and the antenna device can be operated over a wide bandwidth.

[0139] (Aspect 2.4) In aspect 2.4, the conductive layer includes a plurality of antenna elements arranged asymmetrically with respect to the feed point of the antenna.

[0140] According to the above embodiment, by operating multiple asymmetrically arranged antenna elements complementaryly, the antenna device can be operated over a wide bandwidth. Therefore, compared to the case where multiple antenna elements are symmetrically arranged, it is possible to easily adjust the operating frequency band of the antenna device.

[0141] (Aspect 2.5) In aspect 2.5, the antenna device comprises an antenna having a dielectric layer and a conductive layer provided on the dielectric layer, wherein the conductive layer includes a plurality of antenna elements arranged asymmetrically with respect to the feed point of the antenna.

[0142] According to the above embodiment, by operating multiple asymmetrically arranged antenna elements complementaryly, the antenna device can be operated over a wide bandwidth. Therefore, compared to the case where multiple antenna elements are symmetrically arranged, it is possible to easily adjust the operating frequency band of the antenna device.

[0143] (Aspect 2.6) Aspect 2.6 further comprises a substrate having a conductive pattern that is electrically connected to the conductive layer in a non-contact manner.

[0144] According to the above-described embodiment, the electrical connection between the conductive layer and the conductive pattern can be made easier compared to the case where the conductive layer and the conductive pattern are electrically connected to each other by conduction such as soldering.

[0145] According to this specification, antenna devices in the following embodiments are provided: (Embodiment 3.1) In embodiment 3.1, the antenna device comprises an antenna having a dielectric layer and a conductive layer provided on the dielectric layer, wherein the conductive layer has an antenna element and a transmission line electrically connected to the antenna element, and the width of the transmission line decreases at least partially as it approaches the antenna element.

[0146] According to the above embodiment, the characteristic impedance of the transmission line on the side away from the antenna element can be adjusted by making the width of the transmission line on the side away from the antenna element relatively wider to match the impedance on the side away from the antenna element. According to the above embodiment, the characteristic impedance of the transmission line on the side where the antenna element is located can be adjusted by making the width of the transmission line on the side where the antenna element is located relatively narrow to match the impedance on the side where the antenna element is located. Therefore, impedance matching of the antenna device can be made easier compared to the case where the width of the transmission line is constant regardless of the position of the transmission line.

[0147] (Aspect 3.2) In aspect 3.2, the width of the transmission line decreases at least partially and continuously as it approaches the antenna element.

[0148] According to the above-described embodiment, by eliminating the portion where the width of the transmission line changes in a stepped manner, the input signal can be made less susceptible to reflection, and impedance matching can be made easier.

[0149] (Aspect 3.3) In aspect 3.3, the conductive layer comprises a plurality of antenna elements and a plurality of transmission lines.

[0150] According to the above-described embodiment, impedance matching of the antenna device can be easily performed for multiple antenna elements and multiple transmission lines.

[0151] (Aspect 3.4) In aspect 3.4, the conductive layer is provided on only one of the two surfaces of the dielectric layer.

[0152] According to the above embodiment, compared to the case where the conductive layer is provided on both sides of the dielectric layer, the light transmittance of the antenna can be maintained and the cost of the antenna can be reduced.

[0153] This application claims priority based on Japanese Patent Application No. 2024-190155, No. 2024-190156, and No. 2024-190157, filed on 29 October 2024, and incorporates all disclosures thereof herein.

[0154] 1A, 1B, 1C Antenna device, 10A, 10B, 10C Antenna, 11A, 11B, 11C Dielectric layer, 12A, 12B, 12C Conductive layer, 13A Antenna element, 13B, 13C First antenna element, 131A Edge, 132A Surrounding region, 14B, 14C Second antenna element, 15A Transmission line, 15B First transmission line, 16B Second transmission line, 17A, 17B, 17C Feed point, 18A Edge pattern, 18C Slot, 19C Cavity, 20A Base, 20B Bottom case, 20C Substrate, 201C Third solder, 21A Plate, 21B Recess, 21C Feed line, 211C Fourth solder, 22A First claw, 22B Spacer, 23A Second claw, 23B curved surface, 30A stopper, 30B circuit board, 30C cable, 31A block, 31B power supply pattern, 311B second solder, 31C core, 32A arm, 32B first ground pattern, 33A first hole, 33B second ground pattern, 331B first solder, 34A first groove, 34B first conductive pattern, 35A second groove, 35B second conductive pattern, 36A first projection, 40A circuit board, 40B cable, 41A power supply pattern, 41B core, 42A ground pattern, 43A second hole, 44A slit, 50A cable, 50B top case, 51A core, 51B notch, 60A spacer, 61A curved surface, 610A first spacer, 611A first curved surface, 612A First axis, 62A Second projection, 620A Second spacer, 621A Second curved surface, 622A Second axis, 630A Connecting block, 631A Connecting surface, 632A First connecting arm, 633A Second connecting arm, 640A Retainer, 70A Case, 71A Notch, 80A Cushion, 90A Transparent support

Claims

1. An antenna device comprising: an antenna having a dielectric layer and a conductive layer provided on the dielectric layer; and a guide member having a curved surface, wherein the conductive layer is at least partially guided along the curved surface.

2. The antenna device according to claim 1, wherein the amount per unit area of ​​conductors constituting the portion of the conductive layer guided along the curved surface is greater than the amount per unit area of ​​conductors constituting the other portion of the conductive layer extending substantially flat.

3. The antenna device according to claim 1 or 2, wherein the curved surface of the guide member extends in an S-shaped curve.

4. The antenna device according to claim 1 or 2, wherein the guide member rotates.

5. The antenna device according to claim 1 or 2, wherein the guide member has a plurality of members.

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