Antenna boards, antenna devices, and electronic components

Abstract

This invention provides an antenna substrate that can reduce reflection loss regardless of the position of the radiating element. [Solution] The antenna substrate 10 comprises a substrate body 11 having a first surface 11A, a ground layer 12 disposed on the first surface 11A, and a radiating element 14 disposed on the first surface 11A at a distance from the ground layer 12. The ground layer 12 includes a first portion 12A and a second portion 12B arranged in a direction parallel to the X direction. The first portion 12A includes a first outer edge portion E1a which is part of the outer edge of the first portion 12A, is located on the Y direction side, and a part of it extends along a direction parallel to the X direction. The second edge E1a2 of the first outer edge portion E1a is located on the -X direction side with respect to the first edge E1a1 of the first outer edge portion E1a and on the -Y direction side with respect to the first edge E1a1.

Description

Technical Field

[0006] , , , ,

[0001] The present disclosure relates to an antenna substrate, an antenna device, and an electronic component.

Background Art

[0002] As one of the wireless communication technologies, Ultra Wide Band (hereinafter referred to as UWB) is known. In UWB, for example, wireless communication using a wide bandwidth of 500 MHz or more is performed.

[0003] As an antenna suitable for UWB, that is, an antenna that can be used in a wide band, a monopole antenna including a plate-like radiation element having a portion that widens as it moves away from the feeding point and the ground plane is known. The portion that widens as it moves away from the feeding point and the ground plane serves to make the input impedance of the radiation element substantially constant over a wide band.

[0004] Patent Document 1 describes an antenna device including a substrate body, a ground layer, a first radiation element, and an antenna element as the monopole antenna as described above. The ground layer and the first radiation element are formed on the substrate body. The antenna element is mounted on the substrate body. Further, the antenna element includes a second radiation element connected to the first radiation element.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Here, we focus on the arrangement of the radiating element. In the course of research conducted by the inventors of this application, it was found that if there is a corner of the ground layer near the radiating element, the reflection loss (negative value) of the radiating element can be reduced. The corner of the ground layer is, for example, near the corner of the substrate body. Therefore, by arranging the radiating element near the corner of the substrate body, it is possible to reduce the reflection loss of the radiating element and increase the radiation efficiency of the radiating element. However, depending on the shape of the substrate body, it was sometimes not possible to realize a configuration in which the radiating element is arranged near the corner of the substrate body.

[0007] The present disclosure aims to provide an antenna substrate, an antenna device, and an electronic component that can reduce reflection loss regardless of the position of the radiating element.

[0008] An antenna substrate according to one aspect of this disclosure comprises a substrate body, a ground layer made of a conductor and disposed on the surface of the substrate body, and a radiating element made of a conductor and disposed on the surface of the substrate body at a distance from the ground layer on one side in a first direction. The ground layer includes a first portion and a second portion aligned in a second direction, with a portion of the ground layer having a boundary that overlaps with a hypothetical straight line passing through the center of the radiating element in a second direction perpendicular to the first direction and extending in the first direction. The first portion is located on one side in the second direction with respect to the boundary. The second portion is located on the other side in the second direction with respect to the boundary. The first portion includes an outer edge portion which is part of the outer edge of the first portion and is located on one side in the first direction and a portion thereof extends along the second direction. The outer edge portion has a first edge and a second edge. The second edge is located on one side in the second direction with respect to the first edge and on the other side in the first direction with respect to the first edge.

[0009] An antenna device relating to one aspect of this disclosure comprises an antenna substrate and a passive element mounted on the antenna substrate. The antenna substrate further comprises a feed line. The passive element is electrically connected to a radiating element and the feed line.

[0010] An electronic component relating to one aspect of this disclosure comprises an antenna substrate of this disclosure and an element having a ground terminal. The ground terminal is electrically connected to the ground layer. [Effects of the Invention]

[0011] According to one aspect of this disclosure, it becomes possible to realize antenna substrates, antenna devices, and electronic components that can reduce reflection loss regardless of the position of the radiating element. [Brief explanation of the drawing]

[0012] [Figure 1] This is a plan view showing an antenna device according to the first embodiment. [Figure 2] This is a plan view showing an antenna substrate according to the first embodiment. [Figure 3] This is a plan view showing an antenna substrate according to the first embodiment. [Figure 4] This is a plan view showing an enlarged portion of the antenna substrate according to the first embodiment. [Figure 5] This is a perspective view showing the antenna element and its surroundings in an antenna device according to the first embodiment. [Figure 6] This is a plan view showing the antenna element and its surroundings in an antenna device according to the first embodiment. [Figure 7] This is a perspective view showing the inside of the antenna element in the first embodiment. [Figure 8] This is a plan view showing the line portion of the antenna element and its surroundings in the first embodiment. [Figure 9] This is a plan view showing an antenna device for a comparative example. [Figure 10] This is a characteristic diagram showing the frequency characteristics of the reflection loss of the comparative example model. [Figure 11] This is a characteristic diagram showing the frequency characteristics of the reflection loss of the model in the first embodiment. [Figure 12] This is a plan view showing an electronic component according to the first embodiment. [Figure 13] It is a plan view showing an antenna substrate according to a second embodiment. [Figure 14] It is a characteristic diagram showing the frequency characteristics of the reflection loss of the model of the second embodiment. [Figure 15] It is a plan view showing an antenna substrate according to a third embodiment. [Figure 16] It is a characteristic diagram showing the frequency characteristics of the reflection loss of the model of the third embodiment.

Embodiments for Carrying Out the Invention

[0013] [First Embodiment] Hereinafter, the first embodiment of the present disclosure will be described in detail with reference to the drawings. First, referring to FIGS. 1 to 4, an outline of the configuration of the antenna device according to the present embodiment will be described. FIG. 1 is a plan view showing the antenna device according to the present embodiment. FIG. 2 is a plan view showing the antenna substrate according to the present embodiment. FIG. 3 is a plan view showing the antenna substrate according to the present embodiment. FIG. 4 is a plan view showing an enlarged part of the antenna substrate according to the present embodiment.

[0014] The antenna device 1 according to the present embodiment includes an antenna substrate 10 according to the present embodiment and a passive element 20. The passive element 20 is mounted on the antenna substrate 10. The passive element 20 will be described in detail later.

[0015] As shown in FIGS. 1 and 2, the antenna substrate 10 includes a substrate body 11. The substrate body 11 is made of a dielectric material. As the dielectric material, for example, resin, glass, ceramic or a composite material is used. The composite material may include one or more of resin, glass, and ceramic. The substrate body 11 has a first surface 11A and a second surface 11B facing each other. FIG. 2 shows the antenna substrate 10 as viewed from the first surface 11A side. FIG. 3 shows the antenna substrate 10 as viewed from the second surface 11B side.

[0016] Here, as shown in Figures 1 to 4, we define the X, Y, and Z directions. The X, Y, and Z directions are orthogonal to each other. In this embodiment, the Z direction is perpendicular to the first surface 11A of the substrate body 11 and is the direction from the second surface 11B toward the first surface 11A. The X and Y directions are parallel to the first surface 11A. Furthermore, the direction opposite to the X direction is defined as the -X direction, the direction opposite to the Y direction is defined as the -Y direction, and the direction opposite to the Z direction is defined as the -Z direction.

[0017] Hereafter, a position at the end of the Z-direction relative to a given reference point will be referred to as "upwards," and a position opposite to "upwards" relative to a given reference point will be referred to as "downwards." Furthermore, a direction parallel to both the X-direction and the -X-direction will simply be referred to as "the direction parallel to the X-direction," a direction parallel to both the Y-direction and the -Y-direction will simply be referred to as "the direction parallel to the Y-direction," and a direction parallel to both the Z-direction and the -Z-direction will simply be referred to as "the direction parallel to the Z-direction."

[0018] A direction parallel to the Y direction or the -Y direction corresponds to the “first direction” in this disclosure. A direction parallel to the X direction or the -X direction corresponds to the “second direction” in this disclosure. In this embodiment in particular, the Y direction corresponds to “one of the first directions” in this disclosure, the -Y direction corresponds to “the other of the first directions” in this disclosure, the -X direction corresponds to “one of the second directions” in this disclosure, and the X direction corresponds to “the other of the second directions” in this disclosure.

[0019] The antenna substrate 10 further includes a ground layer 12, a feed line 13, and a radiating element 14. Each of the ground layer 12, the feed line 13, and the radiating element 14 is made of a conductor and is arranged on the first surface 11A of the substrate body 11, which is the surface of the substrate body 11.

[0020] As shown in Figures 1, 2, and 4, the feed line 13 is a transmission line having a predetermined length. The ground layer 12 is spaced apart from the feed line 13. The radiating elements 14 are spaced apart from the ground layer 12 and the feed line 13 on the Y-direction side (one side of the first direction).

[0021] In the examples shown in Figures 1 and 2, the feed line 13 extends in a direction parallel to the Y direction. The feed line 13 and the radiating element 14 are arranged in this order in the Y direction.

[0022] The feed line 13 includes a first connection part 13C and a second connection part 13P. The first connection part 13C is located near the end of the feed line 13 that is closest to the radiating element 14. In the examples shown in Figures 1 and 2, the first connection part 13C is located near the end of the feed line 13 in the Y direction.

[0023] The second connection point 13P is located near the end of the feed line 13 that is furthest from the radiating element 14. In the example shown in Figures 1 and 2, the second connection point 13P is located near the -Y end of the feed line 13. The second connection point 13P corresponds to the feed point connected to the radiating element 14, and other feed lines, such as cables or wires, that do not constitute the antenna substrate 10 are connected to it. For convenience, the second connection point 13P is hatched in Figures 1 and 2.

[0024] The radiating element 14 may include a width-changing portion 14A whose dimensions in the direction parallel to the X direction increase as it moves away from the power supply line 13. The planar shape (shape viewed from the Z direction) of the width-changing portion 14A is, for example, a trapezoid. The radiating element 14 may further include a constant-width portion 14B connected to the Y-direction end of the width-changing portion 14A. In Figures 1 and 2, the boundary between the width-changing portion 14A and the constant-width portion 14B is shown by a dotted line. The dimensions of the constant-width portion 14B in the direction parallel to the X direction are constant or approximately constant regardless of the position in the Y direction. Note that the configuration of the radiating element 14 is not limited to the examples shown in Figures 1 and 2. For example, the radiating element 14 may not include the constant-width portion 14B, and the entirety may be a width-changing portion 14A. Alternatively, the radiating element 14 may not include the width-changing portion 14A, and the entirety may be a constant-width portion 14B.

[0025] As shown in Figures 2 and 3, the antenna substrate 10 further includes a ground layer 15, a plurality of through-holes 16, and support parts 17 and 18. The ground layer 15 is made of a conductor and is located on the second surface 11B. The plurality of through-holes 16 penetrate the substrate body 11 and electrically connect the ground layer 12 and the ground layer 15. In Figure 4, the plurality of circles all represent through-holes 16.

[0026] The support parts 17 and 18 are made of conductors and are arranged on the first surface 11A of the substrate body 11. Support part 17 is positioned at a distance from the first connection part 13C in the -X direction. Support part 18 is positioned at a distance from the first connection part 13C in the X direction. The portion of the power supply line 13 sandwiched between support parts 17 and 18 may have a smaller dimension in the direction parallel to the X direction than the portion not sandwiched between support parts 17 and 18.

[0027] Next, the configuration of the ground layer 12 will be described in detail with reference to Figures 1 and 2. The ground layer 12 includes a first portion 12A and a second portion 12B. The first portion 12A and the second portion 12B are aligned in a direction parallel to the X direction. In Figure 1, the boundary between the first portion 12A and the second portion 12B is shown by a dotted line. The first portion 12A is located on the -X side (one side of the second direction) relative to the above boundary. The second portion 12B is located on the X side (the other side of the second direction) relative to the above boundary. In the example shown in Figure 1, the above boundary extends in a direction parallel to the Y direction. In Figure 2, the symbol L indicates a virtual straight line that intersects the above boundary and extends in a direction parallel to the Y direction. The virtual straight line L passes through the center of the radiating element 14 in the direction parallel to the X direction (second direction) and extends in the direction parallel to the Y direction (first direction). The above boundary, which is part of the ground layer 12, overlaps with the virtual line L.

[0028] Each of the first portion 12A and the second portion 12B may have a rectangular planar shape overall. In this embodiment in particular, the first portion 12A and the second portion 12B are asymmetrical with respect to the imaginary straight line L shown in Figure 2. The planar shape of the first portion 12A is a deformed rectangle, with a notch provided at the corners located at both the Y-direction and X-direction ends, shaped to follow the power supply line 13, and another notch provided at the corners located at both the Y-direction and -X-direction ends. In this embodiment in particular, the shape of the other notches is rectangular or substantially rectangular.

[0029] The planar shape of the second portion 12B is a deformed rectangle, with notches provided at the corners located at both the Y-direction end and the -X-direction end, shaped to follow the power supply line 13. Furthermore, the second portion 12B has a shape such that when folded around a virtual straight line L, a portion of it does not overlap with the first portion 12A. The aforementioned portion of the second portion 12B, when folded around the virtual straight line L, overlaps with the region of the first portion 12A where other notches are formed.

[0030] The outer edge (outer edge of the planar shape) of the first portion 12A includes a first outer edge portion E1a located on the Y direction side (one side of the first direction), a second outer edge portion E1b located on the -X direction side, a third outer edge portion E1c located on the -Y direction side, and a fourth outer edge portion E1d adjacent to the power supply line 13 at a distance from it.

[0031] The first outer edge portion E1a extends in part along a direction parallel to the X direction (the second direction). The second outer edge portion E1b may extend along a direction parallel to the Y direction. The third outer edge portion E1c may extend along a direction parallel to the X direction. Furthermore, the second outer edge portion E1b and the third outer edge portion E1c may coincide with the outer edge of the substrate body 11 when viewed from the Z direction.

[0032] The outer edge (outer edge of the planar shape) of the second portion 12B includes a first outer edge portion E2a located on the Y-direction side, a second outer edge portion E2b located on the X-direction side, a third outer edge portion E2c located on the -Y-direction side, and a fourth outer edge portion E2d adjacent to the power supply line 13 at a distance from it.

[0033] The first outer edge portion E2a and the third outer edge portion E2c may each extend along a direction parallel to the X direction. The second outer edge portion E2b may extend along a direction parallel to the Y direction. Furthermore, the second outer edge portion E2b and the third outer edge portion E2c may coincide with the outer edge of the substrate body 11 when viewed from the Z direction.

[0034] One end of the third outer edge portion E1c and one end of the third outer edge portion E2c are connected at the boundary between the first portion 12A and the second portion 12B. One end of the fourth outer edge portion E1d and one end of the fourth outer edge portion E2d are connected at the boundary between the first portion 12A and the second portion 12B. The power supply line 13 is located between the fourth outer edge portion E1d and the fourth outer edge portion E2d. The fourth outer edge portions E1d and E2d have a shape that is aligned with the power supply line 13.

[0035] Next, with reference to Figures 1 and 2, the first outer edge portion E1a of the first portion 12A will be described in detail. A portion of the first outer edge portion E1a has a shape along the other notches mentioned above, namely, notches located at the -X end and the Y end of the planar shape of the first portion 12A. In this embodiment in particular, the notches are step-shaped notches.

[0036] The first portion 12A has a first edge E1a1 and a second edge E1a2, which are parts of the first outer edge portion E1a, and a third edge E1a3, which is the other part of the first outer edge portion E1a and connects the first edge E1a1 and the second edge E1a2. The second edge E1a2 is located on the -X side (one side of the second direction) relative to the first edge E1a1 and on the -Y side (the other side of the first direction) relative to the first edge E1a1.

[0037] The first edge E1a1 extends along a direction parallel to the X direction. One end of the first edge E1a1, i.e., the end located at the X-direction end of the first edge E1a1, is connected to the fourth outer edge portion E1d. In a direction parallel to the Y direction, the first edge E1a1 may be located at the same or approximately the same position as the first outer edge portion E2a of the outer edge of the second portion 12B.

[0038] The second edge E1a2 extends along a direction parallel to the X direction. However, as long as the second edge E1a2 extends overall in a direction parallel to the X direction, at least a portion of it may extend in a direction inclined to the direction parallel to the X direction. One end of the second edge E1a2, i.e., the end of the second edge E1a2 in the -X direction, is connected to the second outer edge portion E1b.

[0039] One end of the second edge E1a2 may be located at the outer edge of the substrate body 11. That is, one end of the second edge E1a2 may overlap with the outer edge of the substrate body 11 when viewed from the Z direction.

[0040] The third edge E1a3 is connected to the other end of the first edge E1a1, i.e., the end of the first edge E1a1 located at the -X direction, and to the other end of the second edge E1a2, i.e., the end of the second edge E1a2 located at the X direction. The third edge E1a3 extends along a direction parallel to the Y direction (the first direction). However, as long as the third edge E1a3 extends overall in a direction parallel to the Y direction, at least a portion of it may extend in a direction inclined with respect to the direction parallel to the Y direction.

[0041] The portion of the second edge E1a2 other than one end, as well as the first and third edges E1a1 and E1a3, are positioned so as not to overlap with the outer edge of the substrate body 11 when viewed from the Z direction.

[0042] In this embodiment, one end of the second edge E1a2 coincides with the end of the first outer edge portion E1a, which is located at the -X direction end of the first outer edge portion E1a. Here, the other end of the first edge E1a1 is referred to as the first end of the first edge E1a1, and the aforementioned end of the first outer edge portion E1a is referred to as the second end of the first outer edge portion E1a. The first end of the first edge E1a1 is located at the -X direction end of the first edge E1a1. In Figure 2, the symbol Dx indicates the distance between the first end of the first edge E1a1 and the second end of the first outer edge portion E1a in the direction parallel to the X direction (second direction). The symbol Dy indicates the distance between the first edge E1a1 and the second edge E1a2 in the direction parallel to the Y direction (first direction). The distance Dy may be smaller than the distance Dx.

[0043] Furthermore, the spacing Dy may be smaller or larger than the dimension of the power supply line 13 in the direction parallel to the Y direction. In the former case, the second edge E1a2 may be positioned between the first edge E1a1 and the second connection part 13P in the direction parallel to the Y direction.

[0044] Furthermore, in Figure 2, the symbol Ra indicates a region on the surface of the substrate body 11 that is on the Y-direction side of the second edge E1a2. The area of ​​the first portion 12A in region Ra is smaller than the area of ​​the second portion 12B in region Ra.

[0045] Next, the ground layer 15 will be described with reference to Figure 3. The ground layer 15 includes a first portion 15A and a second portion 15B. The first portion 15A and the second portion 15B are aligned parallel to the X direction. In Figure 3, the boundary between the first portion 15A and the second portion 15B is shown by a dotted line. The first portion 15A is located on the -X side of the boundary. The second portion 15B is located on the X side of the boundary.

[0046] The planar shape of the first portion 15A is the same as or nearly the same as the planar shape of the first portion 12A of the ground layer 12, except for the portion near the feed line 13. The planar shape of the second portion 15B is the same as or nearly the same as the planar shape of the second portion 12B of the ground layer 12, except for the portion near the feed line 13. Parts of each of the first portion 15A and the second portion 15B may overlap with the feed line 13 when viewed from the Z direction.

[0047] Next, other components of the antenna device 1 will be described with reference to Figures 5 to 8. Figure 5 is a perspective view showing the passive element 20 and its surroundings. Figure 6 is a plan view showing the passive element 20 and its surroundings. Figure 7 is a perspective view showing the inside of the passive element 20. Figure 8 is a plan view showing the line portion 24 of the passive element 20 and its surroundings. The passive element 20 may be an antenna element provided with a radiating element, a circuit element provided with at least one of an inductor and a capacitor, or a composite element provided with at least one of an inductor and a capacitor in addition to a radiating element. The following explanation will take the case where the passive element 20 is an antenna element as an example.

[0048] The passive element 20 has an element body 21 and an outer surface. The element body 21 is composed of a laminate including a plurality of stacked dielectric layers and a plurality of conductors (a plurality of conductor layers and a plurality of through-holes). Each of the plurality of dielectric layers may be composed of a dielectric material with a relative permittivity greater than that of the dielectric material constituting the substrate body 11. For example, ceramic is used as the dielectric material of the element body 21.

[0049] As shown in Figure 5, the element body 21 has, for example, a rectangular parallelepiped shape. In this case, the outer surface of the element body 21 includes a top surface 21A, a bottom surface, and four sides 21C, 21D, 21E, and 21F. The top surface 21A is located at the Z-direction end of the element body 21. The bottom surface is located at the -Z-direction end of the element body 21. The bottom surface is the surface facing the antenna substrate 10. Side 21C is located at the -Y-direction end of the element body 21. Side 21D is located at the Y-direction end of the element body 21. Side 21E is located at the -X-direction end of the element body 21. Side 21F is located at the X-direction end of the element body 21.

[0050] The passive element 20 further includes terminals T1, T2, T3, T4, T5, and T6 arranged on the outer surface of the element body 21. Terminals T1, T3, and T4 are arranged from the top surface 21A through the side surface 21C to the bottom surface. Terminal T3 is located on the -X side relative to terminal T1. Terminal T4 is located on the X side relative to terminal T1. Terminals T2, T5, and T6 are arranged from the top surface 21A through the side surface 21D to the bottom surface. Terminal T5 is located on the -X side relative to terminal T2. Terminal T6 is located on the X side relative to terminal T2.

[0051] As shown in Figure 6, the passive element 20 is mounted on the antenna substrate 10 such that terminal T1 is connected to the feed line 13 and terminal T2 is connected to the radiating element 14. When the passive element 20 is mounted on the antenna substrate 10, terminal T1 is connected to the first connection part 13C, terminal T3 is connected to the support part 17, terminal T4 is connected to the support part 18, and terminals T5 and T6 are connected to the radiating element 14.

[0052] As shown in Figure 7, the passive element 20 further includes a radiating element 22 made of a conductor and provided within the element body 21. The radiating element 22 electrically connects terminals T1 and T2. The radiating element 22 also includes a main conductor layer 23, a line portion 24, connecting conductor layers 371 and 381, and through-holes 36T1, 37T1, 38T1, and 38T2.

[0053] The main conductor layer 23 has an end located on the side surface 21C that is in contact with the terminal T1. The main conductor layer 23 also includes a width-changing portion in which the dimension in the direction parallel to the X direction increases as it moves away from the terminal T1. The planar shape of the width-changing portion is, for example, trapezoidal. The Y-direction end of the main conductor layer 23 is separated from the side surface 21D and faces it.

[0054] As shown in Figures 7 and 8, the line portion 24 is composed of a single conductor layer located below the main conductor layer 23. The line portion 24 has a first end located on the side 21D and in contact with the terminal T2, and a second end located on the opposite side of the first end. The line portion 24 also has a shape that revolves around an axis C extending in the Z direction.

[0055] The connecting conductor layers 371 and 381 are located near the side surface 21D. Furthermore, the connecting conductor layer 371 is positioned between the main conductor layer 23 and the line portion 24 in a direction parallel to the Z-direction. The connecting conductor layer 381 is positioned between the main conductor layer 23 and the connecting conductor layer 371 in a direction parallel to the Z-direction.

[0056] Through-hole 36T1 connects the portion of the track section 24 near the second end to the connecting conductor layer 371. Through-hole 37T1 connects the connecting conductor layer 371 to the connecting conductor layer 381. Through-holes 38T1 and 38T2 are spaced apart in a direction parallel to the X direction and connect the connecting conductor layer 381 to the main conductor layer 23.

[0057] Terminal T1 is electrically connected to terminal T2 via the main conductor layer 23, through holes 38T1, 38T2, connecting conductor layer 381, through hole 37T1, connecting conductor layer 371, through hole 36T1, and line portion 24.

[0058] Terminals T3, T4, T5, and T6 are not connected to any conductors within the element body 21.

[0059] Next, the operation and effects of the antenna substrate 10 according to this embodiment will be described. In this embodiment, the first outer edge portion E1a of the first portion 12A of the ground layer 12 has a first edge E1a1 and a second edge E1a2. The second edge E1a2 is located on the -X direction side with respect to the first edge E1a1 and on the -Y direction side with respect to the first edge E1a1. As a result, according to this embodiment, the reflection loss can be reduced regardless of the position of the radiating elements 14 and 22. The effects of this will be explained below with reference to the results of simulations.

[0060] The simulation uses the comparative example model and the first embodiment model. The comparative example model is the comparative example antenna device model. The first embodiment model is the antenna device 1 according to this embodiment.

[0061] Now, with reference to Figure 9, the configuration of the comparative example antenna device 101 will be described. Figure 9 is a plan view showing the comparative example antenna device 101. The comparative example antenna device 101 includes a comparative example ground layer 112 instead of the ground layer 12 in this embodiment. The configuration of the comparative example ground layer 112 is basically the same as that of the ground layer 12. That is, the comparative example ground layer 112 includes a first portion 12A and a second portion 12B, similar to the ground layer 12. However, in the comparative example, the outer edge of the first portion 12A includes an outer edge portion E101a instead of the first outer edge portion E1a in this embodiment.

[0062] The outer edge portion E101a extends in a direction parallel to the X direction. Furthermore, the outer edge portion E101a connects the second outer edge portion E1b and the fourth outer edge portion E1d. The outer edge portion E101a substantially corresponds to the edge obtained by extending the first edge E1a1 in this embodiment to the second outer edge portion E1b. The other configurations of the comparative antenna device are the same as those of antenna device 1.

[0063] In the simulation, the dimensions of the substrate body 11 in the direction parallel to the Y direction were set to 48 mm in both the comparative example model and the first embodiment model, and the dimensions of the substrate body 11 in the direction parallel to the X direction were set to 23 mm. In addition, in the simulation, the distance Dx between the first end of the first edge E1a1 and the second end of the first outer edge portion E1a in the direction parallel to the X direction was set to 10 mm, and the distance Dy between the first edge E1a1 and the second edge E1a2 in the direction parallel to the Y direction was set to 8 mm.

[0064] Furthermore, in the simulation, the comparative model and the first embodiment model were designed so that the bandwidth BW of the antenna device 101 in the comparative model and the antenna device 1 in the first embodiment model, respectively, were between 6.2 GHz and 8.3 GHz. Then, the frequency characteristics of the reflection loss of the radiating elements 14 and 22 were determined for each of the comparative model and the first embodiment model.

[0065] Figure 10 is a characteristic diagram showing the frequency characteristics of the reflection loss of the comparative example model. Figure 11 is a characteristic diagram showing the frequency characteristics of the reflection loss of the model of the first embodiment. In Figures 10 and 11, the horizontal axis represents frequency, and the vertical axis represents reflection loss. In Figures 10 and 11, the frequency region enclosed by the two dashed lines represents the bandwidth BW. From Figures 10 and 11, it can be seen that the model of the first embodiment has a smaller reflection loss compared to the comparative example model.

[0066] During the research conducted by the inventors of the present invention, it was found that reflection loss can be reduced when the corners of the ground layer 12 (112) are located near the radiating elements 14 and 22. The corners of the ground layer 12 (112) are, for example, near the corners of the substrate body 11. Therefore, by arranging the radiating elements 14 and 22 near the corners of the substrate body 11, reflection loss can be reduced. However, in the comparative example, the radiating elements 14 and 22 are not located near the corners of the substrate body 11, but rather near the center of the substrate body 11 in a direction parallel to the X direction. Therefore, in the comparative example, reflection loss cannot be reduced.

[0067] In contrast, according to this embodiment, the first edge E1a1 and the second edge E1a2 allow for the presence of a corner of the ground layer 12 near the radiating elements 14 and 22. In other words, according to this embodiment, a configuration can be substantially achieved in which the radiating elements 14 and 22 are positioned near the corner of the ground layer 12, regardless of their actual positions. As a result, according to this embodiment, reflection loss can be reduced regardless of the positions of the radiating elements 14 and 22.

[0068] Next, with reference to Figure 12, the electronic component 1A according to this embodiment will be described. Figure 12 is a plan view showing the electronic component 1A. The electronic component 1A comprises an antenna device 1 and an element 50. As mentioned above, since the antenna device 1 comprises an antenna substrate 10, it can also be said that the electronic component 1A comprises the antenna substrate 10 and the element 50.

[0069] Element 50 may be any active element such as a transistor or semiconductor IC, or any passive element such as an inductor or capacitor. Furthermore, element 50 may constitute part of any circuit. Note that the number of elements 50 is not limited to one; there may be multiple elements.

[0070] Element 50 has a ground terminal 50a. The ground terminal 50a is electrically connected to the ground layer 12. The ground terminal 50a may be connected to the ground layer 12 at a position away from the radiating elements 14 and 22. In the example shown in Figure 12, the ground terminal 50a is connected to the second portion 12B of the ground layer 12. However, the ground terminal 50a may be connected to the first portion 12A of the ground layer 12. Furthermore, element 50 may have other terminals that are electrically connected to the second connection portion 13P of the power supply line 13.

[0071] In electronic component 1A, the ground layer 12 can be used as the ground layer for element 50. As a result, according to this embodiment, electronic component 1A can be made smaller compared to the case where a separate ground layer for element 50 is provided in addition to the ground layer 12.

[0072] [Second Embodiment] Next, a second embodiment of the present disclosure will be described. First, with reference to Figure 13, the differences between the configuration of the antenna substrate 10 according to this embodiment and that of the first embodiment will be described. Figure 13 is a plan view showing the configuration of the antenna substrate 10 according to this embodiment.

[0073] In this embodiment, the shape of the first outer edge portion E1a of the first portion 12A of the ground layer 12 differs from that of the first embodiment. Specifically, in this embodiment, the third edge E1a3 of the first outer edge portion E1a extends along directions inclined with respect to the direction parallel to the X direction and the direction parallel to the Y direction. The distance between the third edge E1a3 and the fourth outer edge portion E1d in the direction parallel to the X direction decreases as it approaches the radiating element 14.

[0074] The planar shape of the first part 12A is a deformed rectangle, with a notch provided at the corners located at both the Y-direction and X-direction ends, shaped to follow the power supply line 13, and another notch provided at the corners located at both the Y-direction and -X-direction ends. In this embodiment, the other notch is trapezoidal in shape.

[0075] The other configurations of the antenna substrate 10 according to this embodiment are the same as those of the first embodiment.

[0076] Next, an example of the characteristics of the antenna device according to this embodiment, obtained by simulation, will be described. The antenna device according to this embodiment comprises an antenna substrate 10 according to this embodiment and a passive element 20 (antenna element) which is a passive element 20 described in the first embodiment and includes a radiating element 22 provided within the element body 21. Although not shown, the passive element 20 is mounted on the antenna substrate 10 according to this embodiment, similar to the first embodiment.

[0077] The simulation uses the model of the second embodiment. The model of the second embodiment is a model of the antenna device according to this embodiment. In the simulation, the dimensions of the substrate body 11 in the direction parallel to the Y direction are set to 48 mm, and the dimensions of the substrate body 11 in the direction parallel to the X direction are set to 23 mm. In addition, in the simulation, the distance Dx between the first end of the first edge E1a1 and the second end of the first outer edge portion E1a in the direction parallel to the X direction is set to 10 mm, the distance Dy between the first edge E1a1 and the second edge E1a2 in the direction parallel to the Y direction is set to 8 mm, and the dimensions of the second edge E1a2 in the direction parallel to the X direction are set to 4.8 mm.

[0078] Furthermore, in the simulation, the model of the second embodiment was designed so that the bandwidth BW of the antenna device in the second embodiment model is 6.2 GHz to 8.3 GHz. Then, the frequency characteristics of the reflection loss of the radiating elements 14 and 22 were determined.

[0079] Figure 14 is a characteristic diagram showing the frequency characteristics of the reflection loss of the model of the second embodiment. In Figure 14, the horizontal axis represents frequency, and the vertical axis represents reflection loss. Also in Figure 14, the frequency region enclosed by the two dashed lines represents the bandwidth BW. From Figure 14, it can be seen that the antenna device according to this embodiment has sufficient characteristics to function as an antenna device in practical terms.

[0080] Other configurations, operations, and effects in this embodiment are the same as those in the first embodiment.

[0081] [Third Embodiment] Next, a third embodiment of the present disclosure will be described. First, with reference to Figure 15, the differences between the configuration of the antenna substrate 10 according to this embodiment and that of the first embodiment will be described. Figure 15 is a plan view showing the configuration of the antenna substrate 10 according to this embodiment.

[0082] In this embodiment, the planar shape of the first portion 12A of the ground layer 12 differs from that of the first embodiment. Specifically, in this embodiment, the planar shape of the first portion 12A is a deformed rectangle, with notches provided at the corners located at both the Y-direction and X-direction ends, shaped to follow the power supply line 13, and a slit extending from the end located at the Y-direction end of the rectangle in a direction parallel to the Y-direction. The slit may, at least a portion of it, extend in a direction inclined with respect to the direction parallel to the Y-direction, as long as it extends in a direction parallel to the Y-direction overall.

[0083] Furthermore, in this embodiment, the shape of the first outer edge portion E1a differs from that of the first embodiment. Specifically, in this embodiment, the dimensions of the second edge E1a2 of the first outer edge portion E1a differ from those of the first embodiment. Also, one end of the second edge E1a2 is not connected to the second outer edge portion E1b.

[0084] Furthermore, the first outer edge portion E1a includes the first to third edges E1a1, E1a2, and E1a3, as well as a fourth edge E1a4 and a fifth edge E1a5. One end of the fourth edge E1a4 is connected to one end of the second edge E1a2. One end of the fifth edge E1a5 is connected to the other end of the fourth edge E1a4. The other end of the fifth edge E1a5 is connected to the second outer edge portion E1b.

[0085] The fourth edge E1a4 extends along a direction parallel to the Y direction. The length of the fourth edge E1a4 is the same as or approximately the same as the length of the third edge E1a3. Note that each of the third edge E1a3 and the fourth edge E1a4 may have at least a portion of them extending in a direction inclined with respect to the direction parallel to the Y direction, as long as they extend overall along a direction parallel to the Y direction.

[0086] The fifth edge E1a5 extends along a direction parallel to the X direction. The position of the fifth edge E1a5 in the direction parallel to the Y direction is the same as or approximately the same as the position of the first edge E1a1 in the direction parallel to the Y direction. The other end of the fifth edge E1a5 may be located at the outer edge of the substrate body 11. That is, the other end of the fifth edge E1a5 may overlap with the outer edge of the substrate body 11 when viewed from the Z direction. In addition, as long as the fifth edge E1a5 extends overall in a direction parallel to the X direction, at least a part of it may extend in a direction inclined with respect to the direction parallel to the X direction.

[0087] The other configurations of the antenna substrate 10 according to this embodiment are the same as those of the first embodiment.

[0088] Next, an example of the characteristics of the antenna device according to this embodiment, obtained by simulation, will be described. The antenna device according to this embodiment comprises an antenna substrate 10 according to this embodiment and a passive element 20 described in the first embodiment. Although not shown, the passive element 20 is mounted on the antenna substrate 10 according to this embodiment, similar to the first embodiment.

[0089] The simulation uses the model of the third embodiment. The model of the third embodiment is a model of the antenna device according to this embodiment. In the simulation, the dimensions of the substrate body 11 in the direction parallel to the Y direction are set to 48 mm, and the dimensions of the substrate body 11 in the direction parallel to the X direction are set to 23 mm. In addition, in the simulation, the distance Dx between the first end of the first edge E1a1 and the second end of the first outer edge portion E1a in the direction parallel to the X direction is set to 9 mm, the distance Dy between the first edge E1a1 and the second edge E1a2 in the direction parallel to the Y direction is set to 6 mm, and the dimensions of the second edge E1a2 in the direction parallel to the X direction are set to 0.5 mm.

[0090] Furthermore, in the simulation, the model of the third embodiment was designed so that the bandwidth BW of the antenna device in the model of the third embodiment is 6.2 GHz to 8.3 GHz. Then, the frequency characteristics of the reflection loss of the radiating elements 14 and 22 were determined.

[0091] Figure 16 is a characteristic diagram showing the frequency characteristics of the reflection loss of the model of the third embodiment. In Figure 16, the horizontal axis represents frequency, and the vertical axis represents reflection loss. Also in Figure 16, the frequency region enclosed by the two dashed lines represents the bandwidth BW. From Figure 16, it can be seen that the antenna device according to this embodiment has sufficient characteristics to function as an antenna device in practical terms.

[0092] Other configurations, operations, and effects in this embodiment are the same as those in the first embodiment.

[0093] This disclosure is not limited to the embodiments described above, and various modifications are possible. For example, the planar shape of the first portion 12A of the ground layer 12 is arbitrary and not limited to the examples shown in each embodiment, as long as the requirements of the claims are met. Also, the shape of each edge is not limited to a straight line, but may include curves.

[0094] As described above, the antenna substrate of this disclosure comprises a substrate body, a ground layer made of a conductor and disposed on the surface of the substrate body, and a radiating element made of a conductor and disposed on the surface of the substrate body at a distance from the ground layer on one side in a first direction. The ground layer includes a first portion and a second portion aligned in a second direction, with a portion of the ground layer having a boundary that overlaps with a hypothetical straight line passing through the center of the radiating element in a second direction perpendicular to the first direction and extending in the first direction. The first portion is located on one side in the second direction with respect to the boundary. The second portion is located on the other side in the second direction with respect to the boundary. The first portion includes an outer edge portion which is part of the outer edge of the first portion and is located on one side in the first direction and a portion thereof extends along the second direction. The outer edge portion has a first edge and a second edge. The second edge is located on one side in the second direction with respect to the first edge and on the other side in the first direction with respect to the first edge. Therefore, reflection losses can be reduced regardless of the position of the radiating element.

[0095] In the antenna substrate of this disclosure, one end of the second edge may be located at the outer edge of the substrate body. In this case, the reflection loss can be further reduced.

[0096] Furthermore, in the antenna substrate of this disclosure, the first edge may have a first end located at one end of the first edge in the second direction. The outer edge portion may have a second end located at one end of the outer edge portion in the second direction. The distance between the first edge and the second edge in the first direction may be smaller than the distance between the first end and the second end in the second direction. In this case, the area of ​​the ground layer can be secured while reducing reflection loss, thereby expanding the area that can be used as the ground layer for elements mounted on the antenna substrate.

[0097] Furthermore, in the antenna substrate of this disclosure, the first portion may further have a third edge connecting the first edge and the second edge. The third edge may extend along the first direction. The third edge may be located on one side of the second direction with respect to the radiating element. In this case, reflection loss can be further reduced, and an area that can be used as a ground layer for elements mounted on the antenna substrate can be secured.

[0098] Furthermore, in the antenna substrate of this disclosure, the first portion and the second portion may be asymmetrical when a virtual straight line is drawn around them. In this case, the area of ​​the ground layer can be secured while reducing reflection loss, thereby expanding the area that can be used as the ground layer for elements mounted on the antenna substrate.

[0099] Furthermore, in the antenna substrate of this disclosure, the area of ​​the first portion in the region on the surface of the substrate body located on one side of the second edge in the first direction may be smaller than the area of ​​the second portion in that region. In this case, the area of ​​the ground layer can be secured while reducing the reflection loss, thereby expanding the area that can be used as the ground layer for elements mounted on the antenna substrate.

[0100] Furthermore, in the antenna substrate of this disclosure, the second portion may have a shape such that when folded around a virtual straight line, a part of it does not overlap with the first portion. In this case, the area of ​​the ground layer can be secured while reducing reflection loss, thereby expanding the area that can be used as the ground layer for elements mounted on the antenna substrate.

[0101] Furthermore, the antenna substrate of this disclosure may further include a feed point electrically connected to a radiating element. The second edge may be positioned between the first edge and the feed point in the first direction. In this case, the area of ​​the ground layer can be secured while reducing reflection loss, thereby expanding the area that can be used as the ground layer for elements mounted on the antenna substrate.

[0102] The antenna device of this disclosure comprises an antenna substrate and a passive element mounted on the antenna substrate. The antenna substrate further comprises a feed line. The passive element is electrically connected to the radiating element and the feed line. Therefore, an antenna device with reduced reflection loss can be realized.

[0103] The electronic component of this disclosure comprises an antenna substrate and an element having a ground terminal. The ground terminal is electrically connected to the ground layer. Therefore, the ground layer of the antenna substrate can be used as the ground layer of the element. [Explanation of Symbols]

[0104] 1…Antenna device, 1A…Electronic component, 10…Antenna substrate, 11…Substrate body, 11A…First surface, 11B…Second surface, 12…Ground layer, 12A…First part, 12B…Second part, 13…Feed line, 13C…First connection part, 13P…Second connection part, 14…Radiating element, 14A…Width-changing part, 14B…Constant width part, 15…Ground layer, 16…Through hole, 17,18…Support part, 20…Passive element , 21...element body, 21A...top surface, 21C~21F...side surface, 22...radiating element, 23...main conductor layer, 24...line portion, 50...element, 50a...ground terminal, E1a...first outer edge portion, E1a1...first edge, E1a2...second edge, E1a3...third edge, E1b...second outer edge portion, E1c...third outer edge portion, E1d...fourth outer edge portion, L...virtual straight line, Ra...region, T1~T6...terminals.

Claims

1. The main circuit board and A ground layer made of a conductor and disposed on the surface of the substrate body, The system comprises a radiating element made of a conductor, which is arranged on the surface of the substrate body at a distance from the ground layer on one side in a first direction, The ground layer includes a first portion and a second portion aligned in the second direction, with a portion of the ground layer having a boundary that overlaps with a virtual straight line passing through the center of the radiating element in a second direction perpendicular to the first direction and extending in the first direction, The first portion is positioned on one side of the boundary in the second direction, The second portion is positioned on the other side of the boundary in the second direction, The first portion includes an outer edge portion which is part of the outer edge of the first portion and is located on one side in the first direction and a portion of which extends along the second direction, The aforementioned outer edge portion has a first edge and a second edge, An antenna substrate wherein the second edge is located on one side of the second direction relative to the first edge and on the other side of the first direction relative to the first edge.

2. The antenna substrate according to claim 1, wherein one end of the second edge is located at the outer edge of the substrate body.

3. The first edge has a first end located at one end of the first edge in the second direction, The outer edge portion has a second end located at one end in the second direction of the outer edge portion, The antenna substrate according to claim 1, wherein the distance between the first edge and the second edge in the first direction is smaller than the distance between the first end and the second end in the second direction.

4. The antenna substrate according to claim 1, wherein the first portion further has a third edge connecting the first edge and the second edge.

5. The antenna substrate according to claim 4, wherein the third edge extends along the first direction.

6. The antenna substrate according to claim 4, wherein the third edge is located on one side in the second direction with respect to the radiating element.

7. The antenna substrate according to claim 1, wherein the first portion and the second portion are asymmetrical when the imaginary straight line is centered.

8. The antenna substrate according to claim 1, wherein the area of ​​the first portion in the region on the surface of the substrate body that is on one side of the second edge in the first direction is smaller than the area of ​​the second portion in the region.

9. The antenna substrate according to claim 1, wherein the second portion has a shape such that when folded back around the imaginary straight line, a part of it does not overlap with the first portion.

10. Furthermore, the radiating element is provided with a power supply point that is electrically connected to it. The antenna substrate according to claim 1, wherein the second edge is positioned between the first edge and the feed point in the first direction.

11. An antenna substrate according to any one of claims 1 to 10, The antenna substrate is equipped with a passive element, The aforementioned antenna board further includes a feed line, The passive element is electrically connected to the radiating element and the feed line in an antenna device.

12. An antenna substrate according to any one of claims 1 to 10, The element comprises a ground terminal, The aforementioned ground terminal is an electronic component electrically connected to the ground layer.

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