Antenna

Abstract

This antenna is provided with: a dielectric substrate; a feed conductor portion provided on the dielectric substrate; a linear or band-shaped first conductor portion which is provided on a substrate surface of the dielectric substrate, is connected to the feed conductor portion, and has one end that is an open end; and a linear or band-shaped second conductor portion having a first end and a second end opposite the first end. The first end is connected to an intermediate portion between both ends of the first conductor portion, the second end is an open end, and the second conductor portion protrudes from the intermediate portion.

Description

antenna

[0001] This application claims priority to Japanese Patent Application No. 2022-166185, filed on October 17, 2022, and incorporates by reference all of the contents of said Japanese application.

[0002] In recent years, with the miniaturization of electronic devices, antennas mounted on the substrate surface of a dielectric substrate are often used. Examples of antennas mounted on the substrate surface include inverted-L antennas, inverted-F antennas, meander-line antennas, etc. (See, for example, Patent Document 1.) The antennas have a linear or band-shaped conductor portion that functions as an antenna element.

[0003] JP 2011-142542 A

[0004] The antenna according to an embodiment includes a power supply conductor provided on the dielectric substrate, a linear or strip-shaped first conductor provided on a substrate surface of the dielectric substrate, connected to the power supply conductor and having one open end, and a linear or strip-shaped second conductor having a first end and a second end opposite the first end. The first end is connected to an intermediate portion between both ends of the first conductor, and the second end is an open end. The second conductor protrudes from the intermediate portion.

[0005] FIG. 1 is a perspective view showing an example of an antenna according to a first embodiment. FIG. 2 is an enlarged view of a main portion of a first surface of the antenna. FIG. 3 shows a view of the antenna as viewed from above and a cross-sectional view of a main portion of the antenna. FIG. 4 is a perspective view showing an example of an antenna according to a second embodiment. FIG. 5 is a side view of the antenna according to the second embodiment and a view of the antenna as viewed from above. FIG. 6 is a perspective view showing an example of an antenna according to a third embodiment. FIG. 7 is an enlarged view of a main portion of the antenna and a cross-sectional view of a main portion of the antenna. FIG. 8 is a perspective view of an antenna according to a fourth embodiment. FIG. 9 is an enlarged view of a main portion of a first surface of an antenna according to a fifth embodiment. FIG. 10 is a cross-sectional view of a main portion of an antenna according to a sixth embodiment. FIG. 11 is a perspective view of an antenna according to a seventh embodiment. FIG. 12 is a diagram showing a modified example of a connection mode between a first conductor and a second conductor. FIG. 13 is a perspective view of an antenna according to an eighth embodiment. FIG. 14 shows a view of the antenna according to the eighth embodiment as viewed from above and a cross-sectional view of a main portion of the antenna. FIG. 15 is a perspective view of a second end of a second conductor according to a modification of the eighth embodiment. FIG. 16 is a cross-sectional view of a main portion of an antenna according to another modification of the eighth embodiment. FIG. 17 is a diagram illustrating a modification of the connection between the first conductor and the second conductor. FIG. 18 is a diagram illustrating another modification of the connection between the first conductor and the second conductor. FIG. 19 is a diagram illustrating radiation patterns of vertically polarized components and horizontally polarized components of Example 1 and Comparative Example 1 in the X-Y plane. FIG. 20 is a diagram illustrating radiation patterns of vertically polarized components and horizontally polarized components of Example 1 and Comparative Example 1 in the Y-Z plane. FIG. 21 is a diagram illustrating radiation patterns of vertically polarized components and horizontally polarized components of Example 1 and Comparative Example 1 in the X-Z plane. FIG. 22 is a diagram illustrating radiation patterns of vertically polarized components and horizontally polarized components of Example 2 and Comparative Example 1 in the X-Y plane. FIG. 23 is a diagram illustrating radiation patterns of vertically polarized components and horizontally polarized components of Example 2 and Comparative Example 1 in the Y-Z plane. Fig. 24 is a diagram showing radiation patterns of vertically polarized wave components and horizontally polarized wave components in the X-Z plane for Example 2 and Comparative Example 1. Fig. 25 is a diagram showing radiation patterns of vertically polarized wave components and horizontally polarized wave components in the X-Y plane for Example 3 and Comparative Example 2.FIG. 26 is a diagram showing the radiation patterns of the vertically polarized wave component and the horizontally polarized wave component in the Y-Z plane for Example 3 and Comparative Example 2. FIG. 27 is a diagram showing the radiation patterns of the vertically polarized wave component and the horizontally polarized wave component in the X-Z plane for Example 3 and Comparative Example 2. FIG. 28 is a diagram showing the radiation patterns of the vertically polarized wave component and the horizontally polarized wave component in the X-Y plane for Example 4 and Comparative Example 2. FIG. 29 is a diagram showing the radiation patterns of the vertically polarized wave component and the horizontally polarized wave component in the Y-Z plane for Example 4 and Comparative Example 2. FIG. 30 is a diagram showing the radiation patterns of the vertically polarized wave component and the horizontally polarized wave component in the X-Z plane for Example 4 and Comparative Example 2. FIG. 31 is a diagram showing the relationship between the gain difference Δ of the vertically polarized wave component in the X-Y plane and the length H of the second conductor 14. FIG. 32 is a diagram showing the relationship between the gain difference Δ of the horizontally polarized wave component in the X-Y plane and the length H of the second conductor 14. FIG. 33 is a diagram showing the relationship between the gain difference Δ of the vertically polarized wave component in the Y-Z plane and the length H of the second conductor 14. Fig. 34 is a diagram showing an example of a conventional inverted-F antenna, and Fig. 35 is a diagram showing radiation patterns of vertically polarized wave components and horizontally polarized wave components of the conventional inverted-F antenna.

[0006] [Problem to be Solved by the Present Disclosure] Figure 34 is a diagram showing an example of a conventional inverted-F antenna. In Figure 34, three mutually orthogonal directions are defined as the X direction, Y direction, and Z direction. One of the X directions is defined as the X1 direction, and the direction opposite to the X1 direction is defined as the X2 direction. One of the Y directions is defined as the Y1 direction, and the direction opposite to the Y1 direction is defined as the Y2 direction. One of the Z directions is defined as the Z1 direction, and the direction opposite to the Z1 direction is defined as the Z2 direction.

[0007] In FIG. 34 , the inverted-F antenna 100 has a dielectric substrate 102 , an antenna element 104 , a power supply conductor portion 106 , a short-circuit conductor portion 108 , a first ground conductor portion 109 , and a second ground conductor portion 110 .

[0008] Since the antenna element 104 of the inverted-F antenna 100 is mounted on the surface of the substrate, the gain of the polarized wave component orthogonal to the surface of the substrate may be significantly reduced.

[0009] For example, as shown in FIG. 34, when the dielectric substrate 102 is arranged perpendicular to the horizontal X-Y plane, FIG. 35 shows the radiation patterns of the vertically polarized component and the horizontally polarized component of the inverted-F antenna 100. (a) in FIG. 35 shows the vertically polarized component (V in the figure) and the horizontally polarized component (H in the figure) in the X-Y plane in FIG. 34. (b) in FIG. 35 shows the vertically polarized component (V in the figure) and the horizontally polarized component (H in the figure) in the Y-Z plane in FIG. 34. (c) in FIG. 35 shows the vertically polarized component (V in the figure) and the horizontally polarized component (H in the figure) in the X-Z plane in FIG. 34. In (a) in FIG. 35, "0" indicates the X1 direction, and "90" indicates the Y1 direction. In (b) in FIG. 35, "0" indicates the Z1 direction, and "90" indicates the Y1 direction. In FIG. 35(c), "0" indicates the Z1 direction, and "90" indicates the X1 direction.

[0010] Looking at Figure 35, the horizontally polarized component (H) in the X-Y plane has partial drops in the X1 and X2 directions. The vertically polarized component (V) in the Y-Z plane has partial drops in the Z1 and Z2 directions. In particular, the gain of the horizontally polarized component (H) in the X-Z plane is extremely low in all directions. Thus, in the inverted-F antenna 100, a decrease is observed in the gain of the polarized component orthogonal to the substrate surface, and in the gain of the polarized component orthogonal to the substrate surface. This decrease in the gain of the polarized component orthogonal to the substrate surface is observed not only in inverted-F antennas, but also in the above-mentioned inverted-L antennas and meander line antennas that are mounted on the substrate surface.

[0011] An object of the present disclosure is to provide a technique capable of suppressing a decrease in the gain of a polarization component orthogonal to the substrate surface.

[0012] [Effects of the Present Disclosure] According to the present disclosure, it is possible to suppress a decrease in the gain of the polarization component orthogonal to the substrate surface.

[0013] [Description of the embodiment of the present disclosure] First, the contents of the embodiment will be listed and described. [Outline of the embodiment]

[0014] (1) An embodiment of the antenna includes a power supply conductor provided on the dielectric substrate, a linear or strip-shaped first conductor provided on a substrate surface of the dielectric substrate, connected to the power supply conductor and having one open end, and a linear or strip-shaped second conductor having a first end and a second end opposite the first end. The first end is connected to an intermediate portion between both ends of the first conductor, and the second end is an open end. The second conductor protrudes from the intermediate portion.

[0015] According to the above configuration, since the second conductor protrudes from the intermediate portion of the first conductor, the second conductor can excite a polarization component that intersects with the substrate surface, which can suppress a decrease in gain of the polarization component that is orthogonal to the substrate surface and can compensate for the polarization component that would otherwise experience a decrease in gain if only the first conductor were used.

[0016] (2) In the antenna of (1) above, the dielectric substrate preferably has a retaining hole into which the first end is inserted. In this case, it is easy to hold the second conductor portion protruding from the intermediate portion. (3) Furthermore, in the antenna of (2) above, the intermediate portion may have a through hole into which the first end is inserted. In this case, the second conductor portion can be held by the retaining hole even when it protrudes from the surface of the first conductor portion opposite the surface facing the dielectric substrate.

[0017] (4) In the antenna of (1), the first end portion preferably includes a plate-shaped base conductor portion that is disposed along the intermediate portion. In this case, the first end portion and the intermediate portion can be easily connected by arranging the base conductor portion facing the intermediate portion.

[0018] (5) The antenna of (4) preferably further includes an insulating adhesive layer provided between the base conductor and the intermediate portion. In this case, the insulating adhesive layer can fix the intermediate portion and the second conductor to each other while capacitively coupling them.

[0019] (6) In the antennas described in (1) to (5) above, it is preferable that the second end portion includes a plate-shaped conductor portion along an intersecting plane that intersects with the longitudinal direction of the second conductor portion. In this case, an appropriate capacitance component can be imparted to the second end portion, and even if the length of the second conductor portion is shortened, a decrease in the gain of the polarization component perpendicular to the substrate surface can be suppressed, as in the case of a second conductor portion that does not include a plate-shaped conductor portion. As a result, the entire antenna can be made smaller.

[0020] (7) In the antennas described in (1) to (6) above, it is preferable that the ratio of the longitudinal dimension of the second conductor portion to the longitudinal dimension of the first conductor portion is 0.36 or more and 1.2 or less. If the ratio is less than 0.36, the effect of suppressing the decrease in gain of the polarization component orthogonal to the substrate surface may not be sufficiently obtained. If the ratio is greater than 1.2, the effect of suppressing the decrease in gain of the polarization component orthogonal to the substrate surface may vary, and a stable effect may not be obtained. By setting the ratio to 0.36 or more and 1.2 or less, the decrease in gain of the polarization component orthogonal to the substrate surface can be effectively suppressed.

[0021] (8) In the antennas described above in (1) to (7), the first conductor may form an inverted-F antenna element. In this case, the antenna can function as an inverted-F antenna.

[0022] (9) In the antennas described above in (1) to (8), the first conductor may form an inverted-L antenna element. In this case, the antenna can function as an inverted-L antenna.

[0023] (10) In the antennas described above in (1) to (9), the first conductor portion may have a meander line structure. In this case, the antenna can function as a meander line antenna.

[0024] [Details of the Embodiments] Preferred embodiments will now be described with reference to the drawings. At least some of the embodiments described below may be combined in any desired manner. [Regarding the First Embodiment] FIG. 1 is a perspective view showing an example of an antenna according to the first embodiment. This antenna 1 is, for example, an antenna used for wireless LAN communication. The antenna 1 is an antenna configured by a conductor pattern formed on a substrate of an electronic device having a wireless LAN communication function. In the following description, three mutually orthogonal directions in each drawing are referred to as the X direction, the Y direction, and the Z direction. As shown in FIG. 1 , one of the X directions is referred to as the X1 direction, and the opposite direction of the X1 direction is referred to as the X2 direction. One of the Y directions is referred to as the Y1 direction, and the opposite direction of the Y1 direction is referred to as the Y2 direction. One of the Z directions is referred to as the Z1 direction, and the opposite direction of the Z1 direction is referred to as the Z2 direction.

[0025] Fig. 2 is an enlarged view of a main portion of the first surface 1a of the antenna 1. The first surface 1a is the surface of the antenna 1 facing the Y1 direction. As shown in Figs. 1 and 2, the antenna 1 includes a dielectric substrate 2, a first ground conductor 4, a second ground conductor 6, a feed conductor 8, a first conductor 10, a short-circuit conductor 12, and a second conductor 14.

[0026] In this embodiment, the X-Y plane is a horizontal plane. The Z1 direction is the upward direction, and the Z2 direction is the downward direction. In this embodiment, the antenna 1 is installed so that the first surface 1a is parallel to the X-Z plane, as shown in FIG. 1. That is, the antenna 1 is installed so that the first surface 1a is perpendicular to the horizontal plane. The antenna 1 is also arranged so that the first conductor 10 is positioned upward (Z1 direction).

[0027] The dielectric substrate 2 is a substrate on which the first conductor 10, the short-circuit conductor 12, etc. are mounted. The dielectric substrate 2 is a rigid substrate, but a flexible substrate can also be used. Examples of materials for the dielectric substrate 2 include polyimide resin, epoxy resin, PPE resin, and fluororesin.

[0028] The first ground conductor 4 is a conductor pattern mounted on the first substrate surface 2a. The conductor pattern is made of a conductor such as copper. The first substrate surface 2a is the surface of the dielectric substrate 2 facing the first surface 1a of the antenna 1. The second ground conductor 6 is a conductor pattern mounted on the second substrate surface 2b. The second substrate surface 2b is the surface of the dielectric substrate 2 facing the second surface 1b of the antenna 1. The second surface 1b is the surface of the antenna 1 facing in the Y2 direction.

[0029] The first ground conductor 4 and the second ground conductor 6 are mounted on the first surface 1a and the second surface 1b within a range other than a rectangular portion along the edge of the dielectric substrate 2 in the Z1 direction. Therefore, the first substrate surface 2a has a first region 2a1 and a second region 2a2. The first region 2a1 is a region covered by the first ground conductor 4. The second region 2a2 is a region on the first substrate surface 2a other than the first region 2a1. The second substrate surface 2b has a third region 2b1 and a fourth region 2b2. The third region 2b1 is a region covered by the second ground conductor 6. The fourth region 2b2 is a region on the second substrate surface 2b other than the third region 2b1.

[0030] The first conductor 10, the short-circuit conductor 12, and the power supply conductor 8 are conductor patterns mounted in the second region 2a2 on the first substrate surface 2a. As shown in FIG. 2 , the first ground conductor 4 has a slit 4b. The slit 4b extends in the Z2 direction from the edge 4a of the first ground conductor 4. The edge 4a is aligned along the X direction. The slit 4b is provided at the center of the edge 4a in the X direction. Note that the slit 4b may be provided at a position offset from the center of the first surface 1a in the X direction. The first ground conductor 4 is not provided in the portion of the slit 4b on the first substrate surface 2a. Therefore, the portion of the first substrate surface 2a where the slit 4b is located is the second region 2a2.

[0031] A plurality of vias 19 are provided on both sides of the slit 4b in the X direction. The plurality of vias 19 are columnar members made of a conductor such as copper that penetrate the dielectric substrate 2. One end of each of the plurality of vias 19 is connected to the second ground conductor 6. The other end of each of the plurality of vias 19 is connected to the first ground conductor 4. As a result, the plurality of vias 19 connect the second ground conductor 6 and the first ground conductor 4. The plurality of vias 19 are arranged side by side along the slit 4b. In this embodiment, the connection between the via 19 and the first ground conductor 4 means that the via 19 and the first ground conductor 4 are electrically connected. The electrical connection between the via 19 and the first ground conductor 4 includes not only direct contact between the via 19 and the first ground conductor 4 or conduction between the via 19 and the first ground conductor 4 via another conductor, but also high-frequency connection between the via 19 and the first ground conductor 4 due to capacitive coupling between them. The same applies to "connection" between conductors in the following description.

[0032] The power supply conductor 8 passes through the slit 4b and is connected to the first conductor 10. The power supply conductor 8 extends in the Z direction. The power supply conductor 8 includes a first power supply line 8a and a second power supply line 8b. The first power supply line 8a is the portion of the power supply conductor 8 that is provided within the slit 4b. A small gap is provided between both edges of the first power supply line 8a in the X direction and the edge of the first ground conductor 4 at the slit 4b. The first power supply line 8a, together with the first ground conductors 4 located on both sides of the first power supply line 8a, forms a coplanar line. The first power supply line 8a has a power supply point 8a1. The power supply point 8a1 is provided at the end of the first power supply line 8a in the Z2 direction. A signal source S, such as a communication module for wireless LAN communication, is connected to the power supply point 8a1. The communication module has a function of processing high frequency signals transmitted and received by the antenna 1 .

[0033] The second feed line 8b is a portion of the feed conductor portion 8 other than the first feed line 8a, and is a portion ranging from the edge portion 4a to the first conductor portion 10. An end portion 8b1 of the second feed line 8b is connected to the first conductor portion 10. As a result, the feed conductor portion 8 including the feed point 8a1 is connected to the first conductor portion 10. Therefore, a high-frequency signal applied to the feed point 8a1 is applied to the first conductor portion 10.

[0034] As described above, the first conductor portion 10 and the short-circuit conductor portion 12 are conductor patterns mounted in the second region 2a2. As shown in Fig. 2, the first conductor portion 10 is strip-shaped and extends along the X direction. In the second region 2a2, the first conductor portion 10 is disposed opposite the edge portion 4a with a predetermined gap therebetween.

[0035] The term "strip-like" refers to a shape that has a constant width and a thickness smaller than the width, such as a band or belt, and in this specification refers to a long, thin rectangular shape such as the first conductor 10 or the power supply conductor 8. The term "linear" refers to a shape that has approximately the same dimensions in directions perpendicular to each other in a cross section perpendicular to the longitudinal direction, and in this specification refers to a cylindrical shape such as the second conductor 14, or a quadrangular prism with a substantially square cross section. The first conductor 10 may be linear.

[0036] One end 10a of the first conductor portion 10 is an open end. Meanwhile, a short-circuit conductor portion 12 is connected to the other end 10b of the first conductor portion 10. The short-circuit conductor portion 12 is strip-shaped. The short-circuit conductor portion 12 extends along the Z2 direction from the edge of the first conductor portion 10 on the Z2 direction side. The short-circuit conductor portion 12 connects the other end 10b of the first conductor portion 10 to the first ground conductor portion 4. Furthermore, the power supply conductor portion 8 is connected between one end 10a and the other end 10b of the first conductor portion 10 in the longitudinal direction. In this way, the first conductor portion 10 has one end 10a which is an open end, and the power supply conductor portion 8 is connected between the one end 10a and the other end 10b of the first conductor portion 10. In other words, the first conductor portion 10 constitutes an inverted-F antenna element, and the antenna 1 functions as an inverted-F antenna.

[0037] The second conductor portion 14 is provided on the first conductor portion 10. As shown in FIG. 1, the second conductor portion 14 protrudes from the first conductor portion 10 in the Y2 direction. FIG. 3 shows a view of the antenna 1 as viewed from above and a cross-sectional view of a main portion of the antenna 1. (a) in FIG. 3 is a view of the antenna 1 as viewed from the Z1 direction (top side). As shown in (a) in FIG. 3 and FIG. 1, the second conductor portion 14 (its main body) is a solid linear (cylindrical) member made of a conductor such as copper. The second conductor portion 14 protrudes from an intermediate portion 10c of the first conductor portion 10. The intermediate portion 10c is a portion of the first conductor portion 10 located between one longitudinal end 10a and the other longitudinal end 10b. The second conductor portion 14 has a first end portion 14a and a second end portion 14b. The second end 14b is the end opposite to the first end 14a in the longitudinal direction of the second conductor portion 14. The first end 14a is connected to a predetermined position in the intermediate portion 10c. Therefore, a high-frequency signal applied to the feeding point 8a1 is applied to the second conductor portion 14 via the first conductor portion 10. The second end 14b is an open end.

[0038] As shown in FIG. 2 , the connection position of the second conductor portion 14 in the X direction is a position on the intermediate portion 10c that is a distance L2 away from the edge of the first conductor portion 10 on the X1 direction side. In other words, the distance L2 is the distance along the X direction from the center of the second conductor portion 14 to the edge of the first conductor portion 10 on the X1 direction side. The connection position of the second conductor portion 14 in the Z direction is the center of the first conductor portion 10 in the Z direction. Note that the connection position of the second conductor portion 14 in the Z direction may be shifted from the center of the first conductor portion 10 in the Z direction. In this embodiment, the connection position of the second conductor portion 14 and the connection position of the power supply conductor portion 8 are the same in the X direction. That is, the connection position of the second conductor portion 14 in the X direction is the center of the power supply conductor portion 8 in the X direction.

[0039] 3(b) shows the first end 14a of the second conductor portion 14 in a cross section along the X-Y plane of the antenna 1. The first conductor portion 10 and the second conductor portion 14 are fused together by, for example, welding, brazing, soldering, or the like. The tip of the first end 14a of the second conductor portion 14 abuts against the first surface 10s1 of the first conductor portion 10. Therefore, the second conductor portion 14 protrudes from the first surface 10s1. The first surface 10s1 is the surface of the first conductor portion 10 that contacts the dielectric substrate 2.

[0040] The dielectric substrate 2 has a retaining hole 30. The retaining hole 30 penetrates the dielectric substrate 2 in the Y direction to connect the first substrate surface 2a and the second substrate surface 2b. The second conductor portion 14 is inserted into the retaining hole 30. The second conductor portion 14 passes through the retaining hole 30. The inner peripheral surface of the retaining hole 30 and the outer peripheral surface of the second conductor portion 14 are in contact with each other. This allows the retaining hole 30 to hold the first end portion 14a of the second conductor portion 14. The retaining hole 30 makes it easy to hold the second conductor portion 14 protruding from the first conductor portion 10. An adhesive layer may be formed between the inner peripheral surface of the retaining hole 30 and the outer peripheral surface of the first end portion 14a to fix the second conductor portion 14 to the dielectric substrate 2.

[0041] Here, the second conductor 14 protrudes from the intermediate portion 10c in a direction perpendicular to the substrate surfaces 2a and 2b. Therefore, the second conductor 14 can excite a polarization component that intersects with the substrate surfaces 2a and 2b. As a result, it is possible to suppress a decrease in gain of the polarization component that is perpendicular to the substrate surfaces 2a and 2b, and to compensate for the polarization component that would experience a decrease in gain if only the first conductor 10 were used.

[0042] More specifically, according to the antenna 1 of this embodiment, it is possible to suppress the partial drop in gain observed in the horizontally polarized component in the X-Y plane and the vertically polarized component in the Y-Z plane, as shown in Figure 35, and the decrease in gain of the horizontally polarized component in the X-Z plane.

[0043] Furthermore, in this embodiment, since the second conductor 14 (the main body thereof) is cylindrical, it is possible to excite electromagnetic field components uniformly around the side surface of the second conductor 14 .

[0044] Furthermore, since the second conductor portion 14 in this embodiment protrudes from the intermediate portion 10c in a direction perpendicular to the substrate surfaces 2a and 2b, the decrease in gain of the polarization component perpendicular to the substrate surfaces 2a and 2b can be more effectively suppressed.

[0045] The length L1 of the first conductor portion 10 in the X direction, the distance L2 along the X direction from the edge of the first conductor portion 10 on the X1 direction side to the center of the second conductor portion 14, the width of the first conductor portion 10 in the Z direction, the widths of the short-circuit conductor portion 12 in the X direction and the Z direction, the length H of the second conductor portion 14 (the height from the tip of the second end portion 14b to the first surface 10s1), and the diameter of the second conductor portion 14 are set appropriately according to the frequency of the high-frequency signal applied to the feed point 8a1 and the polarization characteristics of the antenna 1, taking into consideration the thickness of the dielectric substrate 2, the relative dielectric constant, the thickness of each conductor portion, etc.

[0046] The length H of the second conductor portion 14 preferably satisfies the following condition. That is, the ratio of the longitudinal dimension (length H) of the second conductor portion 14 to the longitudinal dimension (length L1) of the first conductor portion 10 is preferably 0.36 or more and 1.2 or less. If the ratio is less than 0.36, the effect of suppressing the decrease in gain of the polarization component orthogonal to the substrate surface may not be sufficiently obtained. If the ratio is greater than 1.2, the effect of suppressing the decrease in gain of the polarization component orthogonal to the substrate surface may vary, and a stable effect may not be obtained. By setting the ratio to 0.36 or more and 1.2 or less, the decrease in gain of the polarization component orthogonal to the substrate surface can be effectively suppressed.

[0047] [Second Embodiment] Fig. 4 is a perspective view showing an example of an antenna according to a second embodiment. This embodiment differs from the first embodiment in that the second conductor 14 has a plate-shaped conductor 20. The plate-shaped conductor 20 is a circular plate-shaped member made of a conductor such as copper.

[0048] FIG. 5 shows a side view of the antenna 1 according to the second embodiment and a view of the antenna 1 as viewed from above. (a) in FIG. 5 shows a view of the antenna 1 as viewed from the Y2 direction. (b) in FIG. 5 shows a view of the antenna 1 as viewed from the Z1 direction. The second conductor 14 includes the above-described plate-shaped conductor 20 and a main body 22. The main body 22 is a solid linear (cylindrical) member made of a conductor such as copper. One end 22a of the main body 22 constitutes the first end 14a of the second conductor 14. Therefore, the one end 22a is connected to the intermediate portion 10c. The plate-shaped conductor 20 is fixed to the tip of the other end 22b of the main body 22. Therefore, the second end 14b of the second conductor 14 includes the other end 22b and the plate-shaped conductor 20.

[0049] The first surface 20a and the second surface 20b of the plate-shaped conductor portion 20 are parallel to the XZ plane. Therefore, the first surface 20a and the second surface 20b are along an intersecting plane that intersects with the longitudinal direction of the second conductor portion 14. The first surface 20a is the surface of the plate-shaped conductor portion 20 that faces the Y2 direction. The second surface 20b is the surface of the plate-shaped conductor portion 20 that faces the Y1 direction.

[0050] The other end 22b is butted against the center of the second surface 20b of the plate-shaped conductor portion 20. The other end 22b and the plate-shaped conductor portion 20 are fused together by, for example, welding or brazing. In this way, the other end 22b of the main body portion 22 and the plate-shaped conductor portion 20 are connected to each other.

[0051] In this embodiment, since the second end 14b of the second conductor 14 includes the plate-like conductor 20, an appropriate capacitance component can be imparted to the second end 14b, and even if the length H of the second conductor 14 is shortened, a decrease in the gain of the polarization component orthogonal to the substrate surface can be suppressed, as in the case of the second conductor 14 not including the plate-like conductor 20. As a result, the entire antenna 1 can be made smaller.

[0052] The diameter D of the plate-shaped conductor portion 20 (the area of ​​the first surface 20a and the second surface 20b), the thickness of the plate-shaped conductor portion 20, and the length H of the second conductor portion 14 are set appropriately according to the dimensions of each of the other parts, the frequency of the high-frequency signal applied to the feed point 8a1, and the polarization characteristics of the antenna 1.

[0053] [Regarding the Third Embodiment] Fig. 6 is a perspective view showing an example of an antenna according to the third embodiment. Fig. 7 is an enlarged view of a main part of the antenna 1 and a cross-sectional view of a main part of the antenna 1. (a) in Fig. 7 shows a main part of the first surface 1a of the antenna 1. (b) in Fig. 7 shows a cross-section taken along line B-B in (a). This embodiment differs from the first embodiment in that the first conductor 10 has a meander line structure.

[0054] 7, the other end 10b of the first conductor portion 10 is connected to the other end 8a2 of the first feed line 8a. This connects the feed point 8a1 of the feed conductor portion 8 and the first conductor portion 10 to each other. For this reason, the feed conductor portion 8 of this embodiment does not have a second feed line 8b.

[0055] As described above, the first conductor portion 10 has a meander-line structure. Therefore, the antenna 1 functions as a meander-line antenna. A meander-line structure is a structure in which a linear or strip-shaped conductor meanders. As shown in FIG. 7A , the intermediate portion 10c of the first conductor portion 10 includes a plurality of first lines 26 parallel to the Z direction and a plurality of second lines 28 parallel to the X direction. The plurality of first lines 26 are arranged at equal intervals in the X direction. The plurality of second lines 28 connect the ends of a pair of adjacent first lines 26 among the plurality of first lines 26. This gives the first conductor portion 10 a meander-line structure. The overall length of the first conductor portion 10 (the overall length at the center in the width direction) is set appropriately depending on the frequency of the high-frequency signal applied to the feed point 8a1.

[0056] The second conductor portion 14 is provided on a line 26a of the plurality of first lines 26. The line 26a is a line connected to the first feeder line 8a of the plurality of first lines 26. The distance L6 is the distance along the Z direction from the edge of the intermediate portion 10c on the Z1 side, excluding the line 26a, to the edge on the Z2 side. The distance L7 is the distance from the edge of the intermediate portion 10c on the Z2 side, excluding the line 26a, to the edge 4a of the first ground conductor portion 4. The distance L4 is the distance along the Z direction from the edge of the first conductor portion 10 on the Z1 side to the center of the second conductor portion 14. The distance L5 is the spacing between a pair of adjacent first lines 26 of the plurality of first lines 26. The distance L5 does not include the width of the first lines 26.

[0057] Although the present embodiment illustrates the case where the second conductor portion 14 is provided on the line 26a, the second conductor portion 14 may be provided in a portion of the intermediate portion 10c (the plurality of first lines 26 and the plurality of second lines 28) other than the line 26a. The second conductor portion 14 is preferably provided in a portion of the intermediate portion 10c closer to the power supply conductor portion 8, such as the line 26a.

[0058] 7(b), the first end 14a of the second conductor portion 14 is connected to the intermediate portion 10c of the first conductor portion 10. The first conductor portion 10 and the second conductor portion 14 are welded together. The second conductor portion 14 protrudes from the line 26a in the Y2 direction. In other words, the second conductor portion 14 protrudes from the first surface 10s1.

[0059] In this embodiment, too, it is possible to suppress a decrease in the gain of the polarization component orthogonal to the substrate surface. Note that the distances L4, L5, L6, and L7, the width in the X direction of the first line 26, the width in the Z direction of the second line 28, the length H of the second conductor portion 14 (the height from the tip of the second end portion 14 b to the first surface 10s1), and the diameter of the second conductor portion 14 are set appropriately in accordance with the frequency of the high-frequency signal applied to the feed point 8a1 and the polarization characteristics of the antenna 1, taking into consideration the thickness of the dielectric substrate 2, the relative dielectric constant, the thickness of each conductor portion, and the like.

[0060] [Regarding the Fourth Embodiment] Fig. 8 is a perspective view of an antenna 1 according to a fourth embodiment. This embodiment differs from the third embodiment in that the second conductor portion 14 includes a plate-shaped conductor portion 20. The plate-shaped conductor portion 20 is provided at the second end portion 14b of the second conductor portion 14. The configuration of the plate-shaped conductor portion 20 is the same as that of the second embodiment shown in Fig. 6. In this case, too, the length H of the second conductor portion 14 can be shortened compared to a second conductor portion 14 that does not include the plate-shaped conductor portion 20.

[0061] [Regarding the Fifth Embodiment] Fig. 9 is an enlarged view of a main portion of the first surface 1a of the antenna 1 according to the fifth embodiment. This embodiment differs from the first embodiment in that it does not include a short-circuit conductor 12 and the first conductor 10 is formed in an L-shape. In other words, the antenna 1 of this embodiment functions as an inverted L-shaped antenna. Therefore, the first conductor 10 of this embodiment constitutes an inverted L-shaped antenna element.

[0062] 9, the intermediate portion 10c of the first conductor 10 includes a main body portion 10c1 extending in the X direction and a bent portion 10c2 extending in the Z direction. The main body portion 10c1 connects one end 10a to the bent portion 10c2. The bent portion 10c2 connects the other end 10b to the main body portion 10c1. The second conductor 14 is provided on the main body portion 10c1.

[0063] The other end 10b of the first conductor portion 10 is connected to the other end 8a2 of the first feed line 8a, thereby connecting the feed point 8a1 of the feed conductor portion 8 and the first conductor portion 10. For this reason, the feed conductor portion 8 of this embodiment does not have a second feed line 8b.

[0064] In this embodiment, too, it is possible to suppress a decrease in the gain of the polarization component orthogonal to the substrate surface. Note that, although the present embodiment illustrates the case where the second conductor 14 is provided in the main body 10c1, the second conductor 14 may be provided in the bent portion 10c2.

[0065] 10 is a cross-sectional view of a main part of the antenna 1 according to the sixth embodiment. This embodiment differs from the first embodiment in that the second conductor 14 protrudes from the first conductor 10 in the Y1 direction.

[0066] As shown in FIG. 10 , the second conductor portion 14 is inserted into the retaining hole 30 and the through hole 32. The through hole 32 penetrates the intermediate portion 10c of the first conductor portion 10 so as to connect the first surface 10s1 and the second surface 10s2. The second surface 10s2 is the surface opposite the first surface 10s1. The inner diameter of the through hole 32 is approximately the same as the inner diameter of the retaining hole 30. Furthermore, the center of the inner circumferential surface of the through hole 32 and the center of the inner circumferential surface of the retaining hole 30 are aligned with each other. In this embodiment, the retaining hole 30 is a bottomed hole that opens only to the first substrate surface 2a. Therefore, when the first end portion 14a of the second conductor portion 14 is inserted into the retaining hole 30, it is easy to position the second conductor portion 14 relative to the dielectric substrate 2.

[0067] The first end 14a of the second conductor 14 is inserted into the holding hole 30 and the through hole 32. In this state, the first conductor 10 and the second conductor 14 are fused together by, for example, welding, brazing, soldering, or the like.

[0068] In this manner, in the present embodiment, the intermediate portion 10c has the through hole 32 into which the first end portion 14a is inserted. This allows the second conductor portion 14 to be held by the holding hole 30 even when the second conductor portion 14 protrudes from the second surface 10s2 of the first conductor portion 10 opposite to the first surface 10s1.

[0069] Seventh Embodiment Fig. 11 is a perspective view of an antenna 1 according to a seventh embodiment. This embodiment differs from the sixth embodiment in that the second conductor 14 has a spiral shape.

[0070] The second conductor 14 of this embodiment is obtained by forming a wire made of a conductor into a spiral shape. In this case, too, it is possible to suppress a decrease in the gain of the polarization component perpendicular to the substrate surface.

[0071] [Regarding Modifications of the Connection between the First Conductor 10 and the Second Conductor 14] Fig. 12 is a diagram showing modifications of the connection between the first conductor 10 and the second conductor 14. Fig. 12 shows a case in which the second conductor 14 protrudes in the Y2 direction from the first conductor 10. The modification shown in Fig. 12 (a) differs from the first embodiment in that the second conductor 14 is inserted into a through hole 32.

[0072] The through hole 32 of the intermediate portion 10c penetrates the intermediate portion 10c of the first conductor portion 10 so as to connect the first surface 10s1 and the second surface 10s2. The inner diameter of the through hole 32 is larger than the outer diameter of the first end portion 14a of the second conductor portion 14. An annular welded portion 50 is provided between the inner circumferential surface of the through hole 32 of the intermediate portion 10c and the outer circumferential surface of the first end portion 14a of the second conductor portion 14.

[0073] The welded portion 50 is formed, for example, from solder. The welded portion 50 is formed as follows: First, the first end 14a of the second conductor portion 14 is inserted into the holding hole 30 and the through hole 32, and the second conductor portion 14 is fixed to the dielectric substrate 2. At this time, the position in the Y direction of the end face 14a1 of the first end 14a is aligned with the position in the Y direction of the second surface 10s2 of the first conductor portion 10. Next, the welded portion 50 is formed by pouring molten solder into the annular space between the inner circumferential surface of the through hole 32 and the outer circumferential surface of the first end 14a.

[0074] In this modification, the first conductor 10 and the second conductor 14 are connected by a welding portion 50 interposed between the inner peripheral surface of the through hole 32 and the outer peripheral surface of the first end portion 14 a. The second conductor 14 is held and fixed to the dielectric substrate 2 by the holding hole 30 and the welding portion 50.

[0075] The modified example shown in FIG. 12( b ) differs from the first embodiment in that the first end 14 a of the second conductor 14 slightly protrudes from the second surface 10 s 2 of the first conductor 10 .

[0076] In this modification, the second conductor 14 is also inserted into the retaining hole 30 and the through hole 32. The inner diameter of the through hole 32 is approximately the same as the inner diameter of the retaining hole 30. Furthermore, the center of the inner peripheral surface of the through hole 32 and the center of the inner peripheral surface of the retaining hole 30 are aligned with each other. Therefore, the inner peripheral surface of the through hole 32 is in contact with the outer peripheral surface of the first conductor 10.

[0077] A welded portion 52 is provided on the second surface 10s2 of the first conductor portion 10. The welded portion 52 is formed, for example, from solder. The welded portion 52 is formed to cover the outer surface of the first end portion 14a protruding from the second surface 10s2 and its periphery. The welded portion 52 connects the first conductor portion 10 and the second conductor portion 14. The second conductor portion 14 is held and fixed to the dielectric substrate 2 by the holding hole 30 and the welded portion 52.

[0078] Although Figure 12 shows a case where the second conductor portion 14 protrudes from the first conductor portion 10 in the Y2 direction, even when the second conductor portion 14 protrudes from the first conductor portion 10 in the Y1 direction, the first conductor portion 10 and the second conductor portion 14 can be connected in a configuration similar to that shown in Figure 12.

[0079] 12(a), the position in the Y direction of the end face 14a1 of the first end portion 14a is aligned with the position in the Y direction of the second surface 10s2 of the first conductor portion 10, but the second conductor portion 14 can be arranged to protrude in the Y1 direction from the second surface 10s2 of the first conductor portion 10. In this way, the configuration shown in FIG. 12(a) can connect the first conductor portion 10 and the second conductor portion 14 while allowing the second conductor portion 14 to protrude in the Y1 direction from the first conductor portion 10.

[0080] 12(b), the first end 14a protruding from the second surface 10s2 is covered with the welded portion 52, but the second conductor 14 can be made to protrude in the Y1 direction from the welded portion 52. As a result, the configuration shown in FIG. 12(b) allows the second conductor 14 to protrude in the Y1 direction from the first conductor 10 while connecting the first conductor 10 and the second conductor 14.

[0081] The modification shown in FIG. 12 is shown as a modification of the first embodiment, but it can also be applied to each of the above-described embodiments that use the linear second conductor 14 .

[0082] [Regarding the Eighth Embodiment] Fig. 13 is a perspective view of an antenna 1 according to the eighth embodiment. Fig. 14 shows a view of the antenna 1 according to the eighth embodiment as viewed from above and a cross-sectional view of a main portion of the antenna 1. (a) in Fig. 14 is a view of the antenna 1 as viewed from the Z1 direction side. This embodiment differs from the first embodiment in that the second conductor 34 is strip-shaped. This embodiment also differs from the first embodiment in that the second conductor 34 protrudes in the Y1 direction.

[0083] The second conductor 34 includes a main body 42, a plate-shaped conductor 40, and a base-end conductor 41. In this embodiment, the second conductor 34 is formed by bending both ends of a band-shaped conductor member at right angles. Therefore, the main body 42 is band-shaped. The plate-shaped conductor 40 and the base-end conductor 41 are rectangular plate-shaped. The main body 42, the plate-shaped conductor 40, and the base-end conductor 41 have the same width dimension in the Z direction. The Z-direction width dimension of the main body 42, the plate-shaped conductor 40, and the base-end conductor 41 is equal to or less than the Z-direction width dimension of the first conductor 10.

[0084] 14A, the base-end conductor 41 is connected to one end 42a of the main body 42. The plate-shaped conductor 40 is connected to the other end 42b of the main body 42. The second end 34b of the second conductor 34 includes the other end 42b and the plate-shaped conductor 40. The plate-shaped conductor 40 extends from the other end 42b along the X1 direction. As described above, when the second end 34b includes the plate-shaped conductor 40, the length of the second conductor 34 along the Y direction can be made shorter than the length of the second end 34b when the second end 34b does not include the plate-shaped conductor 40.

[0085] The first end 34a of the second conductor 34 includes one end 42a and a base conductor 41. The base conductor 41 extends from the one end 42a in the X1 direction. The base conductor 41 is fixed to the intermediate portion 10c. As a result, the second conductor 34 (main body 42) protrudes in the Y1 direction from the first conductor 10. The base conductor 41 is arranged along the intermediate portion 10c. In other words, the base conductor 41 faces the intermediate portion 10c.

[0086] 14(b) shows the first end 34a of the second conductor 34 in a cross section along the XY plane of the antenna 1. The base end conductor 41 has a first surface 41a facing the first conductor 10. The first surface 41a faces the second surface 10s2. The first surface 41a faces the opposite side of the main body 42.

[0087] An insulating adhesive layer 43 is provided between the first surface 41a and the second surface 10s2. The insulating adhesive layer 43 is interposed between the first surface 41a and the second surface 10s2 and fixes the base conductor 41 to the second surface 10s2. The insulating adhesive layer 43 is made of, for example, an insulating resin. The insulating adhesive layer 43 is formed using an insulating resin adhesive, double-sided tape, or the like. The base conductor 41 and the first conductor 10 are connected at high frequencies. In other words, the base conductor 21 and the first conductor 10 are capacitively coupled. As a result, a high-frequency signal applied to the feeding point 8a1 is transmitted between the first conductor 10 and the base conductor 41 and applied to the second conductor 34. The area of ​​the first surface 41a, the thickness of the insulating adhesive layer 43, the dielectric constant of the insulating adhesive layer 43, etc. are set appropriately depending on the frequency of the high-frequency signal applied to the feed point 8a1 and the polarization characteristics of the antenna 1.

[0088] In this embodiment, the first end 34a of the second conductor 34 includes a plate-shaped base conductor 41 that fits along the intermediate portion 10c. Therefore, by arranging the base conductor 41 facing the intermediate portion 10c, the first end 34a of the second conductor 34 can be easily connected to the intermediate portion 10c. Furthermore, in this embodiment, an insulating adhesive layer 43 is provided between the base conductor 41 and the intermediate portion 10c. Therefore, the intermediate portion 10c and the second conductor 34 can be fixed to each other while being capacitively coupled. Furthermore, in this embodiment, the second conductor 34 includes a strip-shaped main body 42. Therefore, the second conductor 34 can be easily processed into a desired shape, for example, by bending one end of the strip-shaped conductor member to provide the base conductor 41 at one end 42a of the main body 42.

[0089] FIG. 15 is a perspective view of the second end 34b of the second conductor 34 according to a modification of the eighth embodiment. In the eighth embodiment, the plate-shaped conductor 40 is rectangular. However, as shown in FIG. 15(a), the plate-shaped conductor 40 may also have a circular shape. In the modification shown in FIG. 15(a), the main body 42 and the plate-shaped conductor 40 are formed by bending a single conductor plate. Therefore, the other end 42b of the main body 42 is connected to the edge of the plate-shaped conductor 40.

[0090] 15(b), the plate-shaped conductor portion 40 may include a bent portion 40a and a plate-shaped portion 40b. The bent portion 40a is provided by bending a single conductor plate, as in the plate-shaped conductor portion 40 of the eighth embodiment, and is connected to the other end 42b. The plate-shaped portion 40b has a circular shape. The bent portion 40a and the plate-shaped portion 40b are fixed to each other, for example, by welding, brazing, soldering, or the like, or by an adhesive layer made of insulating resin or the like. The bent portion 40a is fixed to approximately the center of the plate-shaped portion 40b.

[0091] According to this modification, when a plate-shaped second conductor 34 is employed, it is easy to change the shape and area of ​​the plate-shaped conductor 40. The modification shown in Fig. 15 is also applicable to the eighth embodiment and another modification of the eighth embodiment shown in Fig. 16.

[0092] 16 is a cross-sectional view of a main part of the antenna 1 according to another modification of the eighth embodiment. In the eighth embodiment, the second conductor 34 protrudes in the Y1 direction. In contrast, in this modification, the second conductor 34 protrudes in the Y2 direction.

[0093] 16 , this modification has a land portion 46 and a via 48. The land portion 46 is a conductor pattern and is provided on the second substrate surface 2b of the dielectric substrate 2. The via 48 penetrates the dielectric substrate 2. The via 48 connects the intermediate portion 10c of the first conductor portion 10 and the land portion 46.

[0094] The base conductor portion 41 of the second conductor portion 34 is fixed to the land portion 46 via the insulating adhesive layer 43. Therefore, a high-frequency signal applied to the feeding point 8a1 is transmitted to the base conductor portion 41 via the first conductor portion 10, the via 48, and the land portion 46, and then applied to the second conductor portion 34.

[0095] 17A and 17B are diagrams showing modified examples of the connection between the first conductor portion 10 and the second conductor portion 34. The modified example shown in Fig. 17A differs from the eighth embodiment in that the second conductor portion 34 is inserted into the retaining hole 60 and the through hole 62.

[0096] The retaining hole 60 penetrates the dielectric substrate 2 along the Y direction to connect the first substrate surface 2a and the second substrate surface 2b. The retaining hole 60 is a hole with a rectangular cross-section corresponding to the cross-sectional shape of the second conductor portion 34. The inner surface of the retaining hole 60 and the outer surface of the second conductor portion 34 are in contact with each other. This allows the retaining hole 60 to hold the second conductor portion 34. The through hole 62 penetrates the intermediate portion 10c of the first conductor portion 10 to connect the first surface 10s1 and the second surface 10s2. The cross-sectional shape of the through hole 62 is substantially the same as the cross-sectional shape of the retaining hole 60. Furthermore, the contour of the inner surface of the through hole 62 and the contour of the inner surface of the retaining hole 60 are substantially the same. As described above, the second conductor portion 34 is inserted into the retaining hole 60 and the through hole 62. The main body portion 42 of the second conductor portion 14 passes through the retaining hole 60 and the through hole 62.

[0097] The plate-like conductor portion 40 and the base conductor portion 41 of this modified example extend in the X2 direction relative to the main body portion 42. The base conductor portion 41 protrudes from the second surface 10s2. The base conductor portion 41 also extends along the second surface 10s2 of the first conductor portion 10. The second surface 41b of the base conductor portion 41 is in contact with the second surface 10s2 of the first conductor portion 10.

[0098] A welded portion 64 is provided on the second surface 10s2 of the first conductor 10. The welded portion 64 is formed, for example, from solder. The welded portion 64 is formed so as to cover the outer surface of the base conductor 41 protruding from the second surface 10s2 and its periphery. The welded portion 64 connects the first conductor 10 and the second conductor 34. The second conductor 34 is held and fixed to the dielectric substrate 2 by the holding hole 60 and the welded portion 64.

[0099] The second conductor portion 34 of this modified example is provided on the dielectric substrate 2 as follows. First, a strip-shaped material that is the material for the second conductor portion 34 is inserted into the holding hole 60 and the through-hole 62. Next, both ends of the strip-shaped material are bent to provide the plate-shaped conductor portion 40 and the base conductor portion 41. At this time, the end on the base conductor portion 41 side is made to protrude from the second surface 10s2 of the first conductor portion 10 by the length required for the base conductor portion 41, and the protruding portion is bent along the second surface 10s2. The bent portion becomes the base conductor portion 41. Next, a welded portion 64 is provided on the second surface 10s2 along which the base conductor portion 41 is provided. In this manner, the second conductor portion 34 of this modified example is provided on the dielectric substrate 2.

[0100] The modified example shown in (b) of Figure 17 differs from the eighth embodiment in that the second conductor portion 34 is inserted into the retaining hole 60 and the through hole 62, and in that the second conductor portion 34 protrudes from the first conductor portion 10 in the Y1 direction.

[0101] In this embodiment, the base conductor portion 41 protrudes from the second substrate surface 2b. The base conductor portion 41 is aligned with the second substrate surface 2b of the dielectric substrate 2. The second surface 41b of the base conductor portion 41 is in contact with the second substrate surface 2b.

[0102] The welded portion 66 in this embodiment is formed to cover the outer surface of the main body portion 42 of the second conductor portion 34 protruding from the second surface 10s2 and its periphery. The first conductor portion 10 and the second conductor portion 34 are connected by the welded portion 66. The second conductor portion 34 is held and fixed to the dielectric substrate 2 by the holding hole 60 and the welded portion 64.

[0103] The second conductor portion 34 of this modified example is provided on the dielectric substrate 2 as follows. First, a strip-shaped material that is the material for the second conductor portion 34 is inserted into the holding hole 60 and the through-hole 62. Next, both ends of the strip-shaped material are bent to provide the plate-shaped conductor portion 40 and the base conductor portion 41. At this time, the end on the base conductor portion 41 side is made to protrude from the second substrate surface 2b by the length required for the base conductor portion 41, and the protruding portion is bent along the second substrate surface 2b. This bent portion becomes the base conductor portion 41. Next, a welded portion 64 is provided on the second surface 10s2 from which the main body portion 42 protrudes. In this manner, the second conductor portion 34 of this modified example is provided on the dielectric substrate 2.

[0104] 18 is a diagram showing another modified example of the connection between the first conductor 10 and the second conductor 34. The modified example shown in FIG. 18 differs from the modified example shown in FIG. 17 in that the X-direction dimensions of the retaining hole 60 and the through hole 62 are expanded. In this modified example, the X-direction dimensions of the retaining hole 60 and the through hole 62 are larger than at least one of the X-direction dimensions of the plate-shaped conductor 40 and the X-direction dimension of the base-end conductor 41. Therefore, in this modified example, both ends of a strip-shaped material that is the material for the second conductor 34 are bent to provide the plate-shaped conductor 40 and the base-end conductor 41, and the second conductor 34 can be inserted into the retaining hole 60 and the through hole 62.

[0105] 18 , the base conductor portion 41 of the second conductor portion 34 inserted into the retaining hole 60 and the through-hole 62 protrudes from the second surface 10s2 and is aligned with the second surface 10s2 of the first conductor portion 10. The second surface 41b of the base conductor portion 41 is in contact with the second surface 10s2 of the first conductor portion 10. The weld portion 66 is formed to cover the outer surface of the main body portion 42 of the second conductor portion 34 protruding from the second surface 10s2 and its periphery. This connects the first conductor portion 10 and the second conductor portion 34. The second conductor portion 34 is held and fixed to the dielectric substrate 2 by the retaining hole 60 and the weld portion 64.

[0106] 18 shows the case where the second conductor 34 protrudes in the Y2 direction from the first conductor 10, but the second conductor 34 can be made to protrude in the Y1 direction from the first conductor 10 by abutting the plate conductor 40 in FIG. 18 against the second substrate surface 2b and separating the base conductor 41 in FIG. 18 from the first conductor 10. In this case, the base conductor 41 in FIG. 18 functions as a plate conductor, and the plate conductor 40 in FIG. 18 functions as a base conductor. When the base conductor 41 in FIG. 18 functions as a plate conductor and the plate conductor 40 in FIG. 18 functions as a base conductor, the welded portion 64 is formed to cover the outer surface and the periphery of the main body 42 of the second conductor 34 protruding from the second surface 10s2.

[0107] In the present modified example, the second conductor 34 having the plate-like conductor portion 40 and the base-end conductor portion 41 can be inserted into the holding hole 60 and the through-hole 62, so that the second conductor 34 can be easily provided on the dielectric substrate 2. Furthermore, since the protrusion direction can be selected from either the Y1 direction or the Y2 direction by using the same configuration of the second conductor 34, the dielectric substrate 2, etc., it is possible to reduce costs.

[0108] [Regarding other variations] In the above embodiments 1-7, an example was given of using a solid linear member made of a conductor as the second conductor portion 14 (main body portion 22), but the second conductor portion 14 can also be configured to have a hollow rod-shaped member and a conductive film provided on the surface of this member and connected to the first conductor portion 10.

[0109] Although the plate-shaped conductor 20 of the second and fourth embodiments and the plate-shaped conductor 40 of the eighth embodiment are illustrated as having a circular shape, they may have a shape other than a circle, such as a polygon. However, from the viewpoint of uniformly exciting electromagnetic field components around the plate-shaped conductors 20 and 40, it is preferable that the plate-shaped conductors 20 and 40 be circular.

[0110] In the second, fourth, and eighth embodiments, the plate-shaped conductor portion 20 (40) is fixed in a state in which it abuts against the other end 22b (42b) of the main body portion 22 (42). However, if the plate-shaped conductor portion 20 (40) has a hole, the plate-shaped conductor portion 20 (40) may be fixed to the other end 22b (42b) with the other end 22b (42b) inserted into the hole. In this case, the other end 22b (42b) may penetrate the plate-shaped conductor portion 20 (40). This allows the plate-shaped conductor portion 20 (40) to be moved along the main body portion 22 (42) and the mounting position of the plate-shaped conductor portion 20 (40) in the longitudinal direction of the main body portion 22 (42) to be adjusted.

[0111] The above-described embodiments can be combined as appropriate. For example, in the sixth embodiment, when the antenna 1 has the second conductor 14 protruding from the first conductor 10 in the Y1 direction, the second conductor 14 may have the plate-like conductor 20.

[0112] In the seventh embodiment, the case where the second conductor 14 having a spiral shape protrudes in the Y1 direction from the first conductor 10 has been exemplified. However, the second conductor 14 having a spiral shape may protrude in the Y2 direction from the first conductor 10.

[0113] In addition, in the eighth embodiment, an example was given of a case where a second conductor section 34 made of a rectangular plate-shaped member is provided on the first conductor section 10 that constitutes the inverted F-type antenna element, but a second conductor section 34 made of a rectangular plate-shaped member may also be provided on the first conductor section 10 that has a meander line structure.

[0114] Furthermore, in each embodiment, the combinations applicable to the first conductor section 10 constituting the inverted F-type antenna element are also applicable to the first conductor section 10 constituting the inverted L-type antenna element shown in the fifth embodiment.

[0115] Furthermore, in the above-described embodiments, the second ground conductor 6 is provided on the second substrate surface 2b. However, the second ground conductor 6 may not be provided on the second substrate surface 2b. In this case, the multiple vias 19 connecting the second ground conductor 6 and the first ground conductor 4 are not required. Furthermore, in the above-described embodiments, the second conductors 14, 34 protrude from the intermediate portion 10c in a direction perpendicular to the substrate surfaces 2a, 2b. However, the second conductors 14, 34 may protrude in a direction intersecting the substrate surfaces 2a, 2b as long as they protrude from the intermediate portion 10c.

[0116] In the first and sixth embodiments, the cylindrical second conductor 14 is inserted into the holding hole 30, but the strip-shaped second conductor 14 may be inserted into the holding hole. In this case, the holding hole is rectangular to match the shape of the second conductor 14.

[0117] [Verification Test 1] Next, verification test 1, which was conducted to examine the effects of antenna 1, will be described. As a test method, a model of antenna 1 was constructed, and the directional characteristics of antenna 1 were determined by computer simulation using the model. The frequency of the high-frequency signal targeted by antenna 1 was 2.45 GHz. In verification test 1, the following four examples and two comparative examples were used as test subjects, and the radiation patterns of the vertically polarized component and the horizontally polarized component were determined and compared to verify the effects of antenna 1. The thicknesses of the first ground conductor 4, the second ground conductor 6, the power supply conductor 8, the first conductor 10, and the short-circuit conductor 12 were each set to 36 μm.

[0118] Example 1 The antenna 1 shown in the first embodiment was constructed as a model for Example 1. That is, in Example 1, an antenna 1 having a second conductor portion 14 that does not include a plate-like conductor portion 20 was verified. The dimensions of each portion of the first conductor portion 10 and the second conductor portion 14 were set as follows: Length L1: 27 mm Distance L2: 11 mm Width of the first conductor portion 10 in the Z direction: 3 mm Width of the short-circuit conductor portion 12 in the X direction: 4 mm Width from the edge of the first conductor portion 10 in the Z1 direction to the edge 4a of the first ground conductor portion 4: 8 mm Diameter of the second conductor portion 14: 0.3 mm Length H of the second conductor portion 14: 30 mm

[0119] Example 2 The antenna 1 shown in the second embodiment was constructed as a model of Example 2. That is, in Example 2, an antenna 1 having a second conductor 14 including a plate-shaped conductor 20 was verified. The length H of the second conductor 14 was set to 20 mm. The diameter D of the plate-shaped conductor 20 was set to 10 mm. The model of Example 2 was set to be the same as the model of Example 1, except that the second conductor 14 had the plate-shaped conductor 20 and the length H was 20 mm.

[0120] Example 3 The antenna 1 having the meander line structure shown in the third embodiment was constructed as a model for Example 3. That is, in Example 3, an antenna 1 having a second conductor portion 14 that does not include a plate-like conductor portion 20 was verified. The dimensions of each portion of the first conductor portion 10 and the second conductor portion 14 were set as follows: Total length of first conductor portion 10: 186.5 mm Distance L4: 3.25 mm Distance L5: 1.0 mm Distance L6: 10 mm Distance L7: 0.75 mm Width of first line 26 in the X direction: 0.5 mm Width of second line 28 in the Z direction: 0.5 mm Diameter of second conductor portion 14: 0.3 mm Length H of second conductor portion 14: 30 mm

[0121] Example 4 The antenna 1 having the meander line structure shown in the fourth embodiment was constructed as a model of Example 4. That is, in Example 4, an antenna 1 having a second conductor 14 including a plate-shaped conductor 20 was verified. The length H of the second conductor 14 was set to 20 mm. In addition, the diameter D of the plate-shaped conductor 20 was set to 10 mm. The model of Example 4 was set to be the same as the model of Example 3, except that the second conductor 14 had the plate-shaped conductor 20 and the length H was 20 mm.

[0122] Comparative Example 1 A model of Comparative Example 1 was constructed by removing the second conductor 14 from the antenna 1 shown in the first embodiment.

[0123] Comparative Example 2 A model of Comparative Example 2 was constructed by removing the second conductor portion 14 from the antenna 1 shown in the third embodiment.

[0124] Comparison between Example 1 and Comparative Example 1 Figure 19 is a diagram showing the radiation patterns of the vertically polarized wave component and the horizontally polarized wave component of Example 1 and Comparative Example 1 in the XY plane. In Figure 19, the solid line indicates the radiation pattern of Example 1. The dashed line indicates the radiation pattern of Comparative Example 1. In Figure 19, "0" indicates the X1 direction, and "90" indicates the Y1 direction.

[0125] As shown in Figure 19, there is no significant difference between Example 1 and Comparative Example 1 in terms of the vertical polarization component in the X-Y plane. Furthermore, no reduction in gain is observed in either Example 1 or Comparative Example 1. On the other hand, for the horizontal polarization component, a partial drop in gain is observed along the X direction in Comparative Example 1. In contrast, it can be seen that the partial drop in gain observed in Comparative Example 1 is suppressed in Example 1.

[0126] Fig. 20 is a diagram showing radiation patterns of vertically polarized wave components and horizontally polarized wave components in the YZ plane for Example 1 and Comparative Example 1. Fig. 21 is a diagram showing radiation patterns of vertically polarized wave components and horizontally polarized wave components in the XZ plane for Example 1 and Comparative Example 1.

[0127] 20 and 21, the solid line indicates the radiation pattern of Example 1. The dashed line indicates the radiation pattern of Comparative Example 1. In Fig. 20, "0" indicates the Z1 direction, and "90" indicates the Y1 direction. In Fig. 21, "0" indicates the Z1 direction, and "90" indicates the X1 direction.

[0128] As shown in Figure 20, there is no significant difference between Example 1 and Comparative Example 1 in terms of the horizontally polarized component in the YZ plane. Furthermore, no reduction in gain is observed in either Example 1 or Comparative Example 1. On the other hand, for the vertically polarized component, a partial drop in gain is observed along the Z direction in Comparative Example 1. In contrast, it can be seen that the partial drop in gain observed in Comparative Example 1 is suppressed in Example 1.

[0129] As shown in Figure 21, there is no significant difference between Example 1 and Comparative Example 1 in terms of the vertical polarization component in the X-Z plane. Furthermore, no significant decrease in gain is observed in either Example 1 or Comparative Example 1. On the other hand, for the horizontal polarization component, the gain appears extremely low across all directions in Comparative Example 1. In contrast, it can be seen that the decrease in gain across all directions observed in Comparative Example 1 is suppressed in Example 1.

[0130] Comparison between Example 2 and Comparative Example 1 Fig. 22 is a diagram showing the radiation patterns of vertically polarized wave components and horizontally polarized wave components of Example 2 and Comparative Example 1 in the XY plane. Fig. 23 is a diagram showing the radiation patterns of vertically polarized wave components and horizontally polarized wave components of Example 2 and Comparative Example 1 in the YZ plane. Fig. 24 is a diagram showing the radiation patterns of vertically polarized wave components and horizontally polarized wave components of Example 2 and Comparative Example 1 in the XZ plane. The display methods of Figs. 22 to 24 are the same as those of Figs. 19 to 21.

[0131] It can be seen that the partial drop in gain that appears in the horizontally polarized wave component in the X-Y plane and the vertically polarized wave component in the Y-Z plane is suppressed in Example 2 as in Example 1. Furthermore, in Example 2, the decrease in gain across all directions that appears in the horizontally polarized wave component in the X-Z plane is also suppressed.

[0132] Comparison between Example 3 and Comparative Example 2 Figure 25 is a diagram showing the radiation patterns of vertically polarized wave components and horizontally polarized wave components of Example 3 and Comparative Example 2 in the XY plane. Figure 26 is a diagram showing the radiation patterns of vertically polarized wave components and horizontally polarized wave components of Example 3 and Comparative Example 2 in the YZ plane. Figure 27 is a diagram showing the radiation patterns of vertically polarized wave components and horizontally polarized wave components of Example 3 and Comparative Example 2 in the XZ plane. The display methods of Figures 25 to 27 are the same as those of Figures 19 to 21.

[0133] It can be seen that in Example 3 as well, the partial drop in gain that appears in the horizontal polarization component in the X-Y plane and the vertical polarization component in the Y-Z plane, as well as the decrease in gain across all directions that appears in the horizontal polarization component in the X-Z plane, are suppressed.

[0134] Comparison between Example 4 and Comparative Example 2 Figure 28 is a diagram showing the radiation patterns of vertically polarized wave components and horizontally polarized wave components of Example 4 and Comparative Example 2 in the XY plane. Figure 29 is a diagram showing the radiation patterns of vertically polarized wave components and horizontally polarized wave components of Example 4 and Comparative Example 2 in the YZ plane. Figure 30 is a diagram showing the radiation patterns of vertically polarized wave components and horizontally polarized wave components of Example 4 and Comparative Example 2 in the XZ plane. The display methods of Figures 28 to 30 are the same as those of Figures 19 to 21.

[0135] It can be seen that in Example 4 as well, the partial drop in gain that appears in the horizontally polarized component in the X-Y plane and the vertically polarized component in the Y-Z plane, as well as the decrease in gain across all directions that appears in the horizontally polarized component in the X-Z plane, are suppressed.

[0136] These results demonstrate that the gain reduction of the polarization component orthogonal to the substrate surface can be suppressed. More specifically, it can be confirmed that the partial drop in gain observed in the horizontal polarization component in the X-Y plane and the vertical polarization component in the Y-Z plane, as well as the gain reduction of the horizontal polarization component in the X-Z plane, can be suppressed.

[0137] [Regarding Verification Test 2] Next, verification test 2, which was conducted to evaluate the length H of the second conductor portion 14 of the antenna 1, will be described. The test method involved setting multiple values ​​for the length H of the second conductor portion 14, determining the polarization characteristics for each of the multiple set values, and evaluating the relationship between the length H of the second conductor portion 14 and the polarization characteristics. In verification test 2, the gain difference Δ (minimum value - maximum value) between the minimum and maximum gain values ​​in the polarization characteristics of the X-Y plane and the Y-Z plane was determined, and the relationship between the gain difference Δ and the length H was determined. The gain difference Δ indicates the degree of partial drop in gain in the polarization characteristics. It can be said that the closer the gain difference Δ is to 0, the smaller the partial drop. In verification test 2, Examples 5, 6, and 7 below were tested.

[0138] Example 5: The model was set to be the same as Example 1, except that the length H of the second conductor 14 was changed within a range of 0 to 120 mm. In Example 5, an antenna 1 having a second conductor 14 that does not include a plate-like conductor 20 was verified.

[0139] Example 6 The model was set to be the same as Example 2, except that the length H of the second conductor 14 was changed within a range of 0 to 120 mm and the diameter D of the plate-shaped conductor 20 was set to 6 mm. In Example 6, an antenna 1 having a second conductor 14 including a plate-shaped conductor 20 was verified.

[0140] Example 7: The model was set to be the same as that of Example 2, except that the length H of the second conductor 14 was changed within a range of 0 to 120 mm. In Example 6, an antenna 1 having a second conductor 14 including a plate-like conductor 20 with a larger diameter than that of Example 6 was verified.

[0141] Fig. 31 is a diagram showing the relationship between the gain difference Δ of the vertical polarization component in the XY plane and the length H of the second conductor 14. Fig. 32 is a diagram showing the relationship between the gain difference Δ of the horizontal polarization component in the XY plane and the length H of the second conductor 14. Fig. 33 is a diagram showing the relationship between the gain difference Δ of the vertical polarization component in the YZ plane and the length H of the second conductor 14.

[0142] The vertical axis in Figures 31 to 33 represents the gain difference Δ for each polarization component. The horizontal axis in Figures 31 to 33 represents the length H of the second conductor 14. In Figures 31 to 33, line g5 represents the gain difference Δ for Example 5. Line g6 represents the gain difference Δ for Example 6. Line g7 represents the gain difference Δ for Example 7.

[0143] Looking at line g5 in Fig. 31, in the range of length H from 0 mm to 30 mm, the gain difference Δ gradually approaches 0 as length H increases. Looking at line g6 in Fig. 31, in the range of length H from 0 mm to 30 mm, the gain difference Δ approaches 0 most when length H is about 18 mm. Looking at line g7 in Fig. 31, in the range of length H from 0 mm to 30 mm, the gain difference Δ approaches 0 most when length H is 12 mm. When each of lines g5, g6, and g7 approaches 0 most, the gain difference Δ is around -10 dB.

[0144] These results show that the length H of the second conductor portion 14 in Examples 6 and 7, in which the gain difference Δ approaches zero, is smaller than the length H of the second conductor portion 14 in Example 5, in which the gain difference Δ approaches zero. In other words, the length H, which can effectively suppress a partial drop in the vertical polarization characteristics, is reduced by providing the plate-like conductor portion 20 in the second conductor portion 14. Similar results are also obtained in Figures 32 and 33.

[0145] From these results, it can be seen that by including the plate-shaped conductor portion 20 in the second conductor portion 14, the length H of the second conductor portion 14 can be made shorter than the length H of the second conductor portion 14 that does not include the plate-shaped conductor portion 20.

[0146] Furthermore, from the above results, it can be seen that the length H at which partial drops in the vertical polarization characteristics can be effectively suppressed is reduced by increasing the diameter D of the plate-like conductor portion 20. From these results, it can be seen that the length H of the second conductor portion 14 can be reduced by increasing the diameter D of the plate-like conductor portion 20 of the second conductor portion 14.

[0147] 31 to 33, when the length H of the second conductor portion 14 is less than 10 mm, the gain difference Δ tends to deviate significantly from 0. When the length H of the second conductor portion 14 is greater than 30 mm, the gain difference Δ tends to vary significantly. When the length H of the second conductor portion 14 is 10 mm, the ratio of the length H to the longitudinal dimension (length L1) of the first conductor portion 10 is 0.37. When the length H of the second conductor portion 14 is 30 mm, the ratio of the length H to the longitudinal dimension (length L1) of the first conductor portion 10 is 1.1. In other words, as shown in FIGS. 31 to 33, it can be seen that the reduction in gain of the polarization component orthogonal to the substrate surface can be effectively suppressed when the ratio of the longitudinal dimension (length H) of the second conductor portion 14 to the longitudinal dimension (length L1) of the first conductor portion 10 is in the range of 0.36 to 1.2.

[0148] [Others] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the meaning described above, and is intended to include meanings equivalent to the claims and all modifications within the scope of the claims.

[0149] REFERENCE SIGNS LIST 1 Antenna 1a First surface 1b Second surface 2 Dielectric substrate 2a First substrate surface 2a1 First region 2a2 Second region 2b Second substrate surface 2b1 Third region 2b2 Fourth region 4 First ground conductor portion 4a Edge portion 4b Slit 6 Second ground conductor portion 8 Power supply conductor portion 8a First feed line 8a1 Feed point 8a2 Other end 8b Second feed line 8b1 End portion 10 First conductor portion 10a One end 10b Other end 10c Intermediate portion 10c1 Main body portion 10c2 Bent portion 10s1 First surface 10s2 Second surface 12 Short-circuit conductor portion 14 Second conductor portion 14a First end portion 14a1 End face 14b Second end portion 19 Via 20 Plate-shaped conductor portion 20a First surface 20b Second surface 21 Base end conductor portion 22 Main body portion 22a One end 22b Other end 26 First line 26a Line 28 Second line 30 Retaining hole 32 Through hole 34 Second conductor portion 34a First end 34b Second end 40 Plate-shaped conductor portion 40a Bent portion 40b Plate-shaped portion 41 Base end conductor portion 41a First surface 41b Second surface 42 Main body portion 42a One end 42b Other end 43 Insulating adhesive layer 46 Land portion 48 Via 50 Welded portion 52 Welded portion 60 Retaining hole 62 Through hole 64 Welded portion 66 Welded portion D Diameter L2 Distance L4 Distance L5 Distance L6 Distance L7 Distance S Signal source g5 Diagram g6 Diagram g7 Diagram 100 Inverted-F antenna 102 Dielectric substrate 104 Antenna element 106 Power supply conductor portion 108 Short-circuit conductor portion 109 First ground conductor portion 110 Second ground conductor portion

Claims

1. A dielectric substrate; A power supply conductor portion provided on the dielectric substrate; a first conductor portion having a linear or strip shape and provided on a substrate surface of the dielectric substrate, the first conductor portion being connected to the power supply conductor portion and having one open end; a linear or strip-shaped second conductor portion having a first end and a second end opposite to the first end; Equipped with the first end is connected to a middle portion between both ends of the first conductor portion, the second end is an open end; The second conductor portion protrudes from the intermediate portion. antenna.

2. The dielectric substrate has a holding hole into which the first end is inserted.

2. The antenna of claim 1.

3. The intermediate portion has a through hole into which the first end portion is inserted.

3. The antenna of claim 2.

4. The first end portion includes a plate-shaped base conductor portion along the intermediate portion.

2. The antenna of claim 1.

5. The insulating adhesive layer is provided between the base conductor portion and the intermediate portion.

5. The antenna of claim 4.

6. The second end portion includes a plate-shaped conductor portion along a crossing plane that crosses a longitudinal direction of the second conductor portion. An antenna according to any one of claims 1 to 5.

7. A ratio of a longitudinal dimension of the second conductor portion to a longitudinal dimension of the first conductor portion is equal to or greater than 0.36 and is equal to or less than 1.

2. An antenna according to any one of claims 1 to 5.

8. The first conductor portion constitutes an inverted-F antenna element. An antenna according to any one of claims 1 to 5.

9. The first conductor portion constitutes an inverted L-shaped antenna element. An antenna according to any one of claims 1 to 5.

10. The first conductor portion has a meander line structure. An antenna according to any one of claims 1 to 5.