Antenna element, antenna substrate, and antenna module

Abstract

This antenna element comprises a first dielectric, a second dielectric, a ground conductor, a feeding conductor plate, and a parasitic conductor plate. The ground conductor, the feeding conductor plate, and the parasitic conductor plate are positioned in sequence. The ground conductor and the feeding conductor plate are positioned opposite each other with the first dielectric therebetween. The feeding conductor plate and the parasitic conductor plate are positioned opposite each other with the second dielectric therebetween. The antenna element is provided with a protruding conductor protruding from the feeding conductor plate toward the ground conductor.

Description

[Technical Field]

[0001] The present disclosure relates to an antenna element, an antenna substrate, and an antenna module. [Background technology]

[0002] Patent Document 1 discloses, as a wideband antenna element, a microstrip antenna having a conductor plate and a ground conductor that face each other with a dielectric sandwiched therebetween. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 55-93305 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for antennas with wider bandwidth characteristics. An object of the present disclosure is to provide an antenna element, an antenna substrate, and an antenna module with wider bandwidth characteristics. [Means for solving the problem]

[0005] The antenna element according to the present disclosure comprises: The antenna includes a first dielectric, a second dielectric, a ground conductor, a power-feeding conductor plate, and a non-power-feeding conductor plate, the ground conductor, the power-supply conductor plate, and the parasitic conductor plate are arranged in this order; The ground conductor and the power supply conductor plate are positioned opposite to each other with the first dielectric interposed therebetween, the feeding conductor plate and the non-feeding conductor plate are positioned opposite each other with the second dielectric interposed therebetween, a protruding conductor protruding from the power supply conductor plate toward the ground conductor; 、 In a planar perspective view, the feeding conductor plate has a first side and a second side that intersect with a resonance direction, In a planar perspective view, the center of an end face of the protruding conductor facing the ground conductor is located inward from the first side and within a distance L1 from the first side, and / or inward from the second side and within the distance L1 from the second side, The distance L1 is 0.1 times the effective wavelength corresponding to the maximum frequency of the transmission frequency band. do.

[0006] The antenna substrate according to the present disclosure comprises: having a plurality of antenna elements; Each of the plurality of antenna elements is the antenna element described above.

[0007] The antenna module according to the present disclosure comprises: The antenna substrate; an integrated circuit; Equipped with. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide an antenna element, an antenna substrate, and an antenna module having wider bandwidth characteristics. [Brief explanation of the drawings]

[0009] [Figure 1A] FIG. 1 is a perspective view showing an antenna element according to a first embodiment of the present disclosure. [Figure 1B] FIG. 1 is a plan view showing an antenna element according to a first embodiment of the present disclosure. [Figure 2A] FIG. 2 is a longitudinal cross-sectional view taken along line AA in FIG. 1B. [Figure 2B] FIG. 2 is a longitudinal cross-sectional view taken along line BB in FIG. 1B. [Figure 3] 4 is a graph showing the return loss of the antenna element according to the first embodiment and comparative examples 1 to 3. [Figure 4A] FIG. 10 is a diagram showing a first modification in which the position of the protruding conductor is changed in a direction perpendicular to the resonance direction. [Figure 4B] FIG. 10 is a diagram showing a second modification in which the position of the protruding conductor is changed in a direction perpendicular to the resonance direction. [Figure 4C] FIG. 10 is a diagram showing a third modification in which the position of the protruding conductor is changed in a direction perpendicular to the resonance direction. [Figure 4D] FIG. 10 is a diagram showing a fourth modification in which the position of the protruding conductor is changed in a direction perpendicular to the resonance direction. [Figure 5]10 is a graph showing the return loss of the antenna elements of Modifications 1 to 4. [Figure 6A] FIG. 10 is a diagram showing a fifth modification in which the position of the protruding conductor is changed in the resonance direction. [Figure 6B] FIG. 10 is a diagram showing a sixth modification in which the position of the protruding conductor is changed in the resonance direction. [Figure 6C] FIG. 10 is a diagram showing a seventh modification in which the position of the protruding conductor is changed in the resonance direction. [Figure 7A] 10 is a graph showing the relationship between the position of the protruding conductor in the resonance direction and the pole frequency, showing the relationship between the position and the lower pole frequency. [Figure 7B] 10 is a graph showing the relationship between the position in the resonance direction of the protruding conductor and the pole frequency, showing the relationship between the position and the higher pole frequency. [Figure 7C] 10 is a graph showing the relationship between the position in the resonance direction of the protruding conductor and the pole frequency, and also showing the relationship between the position and the bandwidth between two pole frequencies. [Figure 8A] FIG. 10 is a plan view showing an antenna element according to a second embodiment. [Figure 8B] FIG. 10 is a perspective view showing an antenna element according to a second embodiment. [Figure 8C] FIG. 10 is a longitudinal sectional view showing an antenna element according to a second embodiment. [Figure 9] 10 is a graph showing the relationship between plate width and lower pole frequency. [Figure 10A] FIG. 13 is a diagram showing an eighth modification of the second embodiment. [Figure 10B] FIG. 13 is a diagram showing a ninth modification of the second embodiment. [Figure 10C] FIG. 16 is a diagram showing a tenth modification of the second embodiment. [Figure 11] 13 is a graph showing the return loss of the antenna elements of Modifications 8 to 10. [Figure 12A] FIG. 1 is a perspective view illustrating an antenna substrate and an antenna module according to an embodiment of the present disclosure. [Figure 12B] 1 is a longitudinal cross-sectional view illustrating an antenna substrate and an antenna module according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings.

[0011] (Embodiment 1) FIG. 1A is a perspective view showing an antenna element according to a first embodiment of the present disclosure. FIG. 1B is a plan view showing an antenna element according to the first embodiment of the present disclosure. FIG. 2A is a longitudinal cross-sectional view taken along line AA in FIG. 1B. FIG. 2B is a longitudinal cross-sectional view taken along line BB in FIG. 1B. In the following description, the Z direction in the drawings is defined as a vertically downward direction, and the X and Y directions perpendicular to the Z direction are defined as horizontal directions. The Z direction is a direction perpendicular to the top surface of the feed conductor plate 22, and the X and Y directions are directions along the top surface of the feed conductor plate 22 and are perpendicular to each other. The up, down, left, and right directions in this specification may differ from the up, down, left, and right directions when the antenna element 1 is in use.

[0012] The antenna element 1 of the first embodiment includes a dielectric substrate 10, a feeding conductor plate 22, a parasitic conductor plate 23, a ground conductor 21, a feeding conductor 24, and a protruding conductor 25 located on the dielectric substrate 10.

[0013] The ground conductor 21, the feeding conductor plate 22, and the parasitic conductor plate 23 are positioned in that order. The ground conductor 21 and the feeding conductor plate 22 are positioned opposite each other with a partial layer of the dielectric substrate 10 (i.e., the dielectric layer 11a as the first dielectric) sandwiched between them. The feeding conductor plate 22 and the parasitic conductor plate 23 are positioned opposite each other with a partial layer of the dielectric substrate 10 (i.e., the dielectric layer 11b as the second dielectric) sandwiched between them.

[0014] In a planar perspective, the ground conductor 21 may have a larger area than the power-feeding conductor plate 22 and the parasitic conductor plate 23. In a planar perspective, the power-feeding conductor plate 22 and the parasitic conductor plate 23 may be rectangular. A planar perspective means a perspective seen downward.

[0015] The feed conductor 24 is connected to the feed conductor plate 22. The feed conductor 24 may be connected to a position offset from the center of the feed conductor plate 22 in one direction. In FIGS. 1 and 2 , the feed conductor 24 is connected to a position offset in the X direction from the center of the feed conductor plate 22. The feed conductor 24 may extend from below the ground conductor 21 to the feed conductor plate 22 via the through-hole 21 a in the ground conductor 21. The feed conductor 24 may transmit power corresponding to a transmission signal to the feed conductor plate 22. Alternatively, the feed conductor 24 may transmit a signal received by the antenna element 1.

[0016] The material of the dielectric substrate 10 may be ceramic, such as an aluminum oxide sintered body, a glass ceramic sintered body, a mullite sintered body, or an aluminum nitride sintered body, or may be resin. The dielectric substrate 10 may have a laminated structure and may have multiple (e.g., four) dielectric layers 11a and 11b. A ground conductor 21 may be located on the lower surface of the lower dielectric layer 11a, a feed conductor plate 22 may be located between the two middle dielectric layers 11a and 11b, and a parasitic conductor plate 23 may be located on the upper surface of the uppermost dielectric layer 11b. A dielectric layer may be further located below the ground conductor 21.

[0017] The power-feeding conductor plate 22 and the parasitic conductor plate 23 may be metallized conductor films. The power-feeding conductor 24 and the protruding conductor 25 may be via conductors solidified during firing of the dielectric substrate 10. When the dielectric substrate 10 is a resin substrate, the power-feeding conductor plate 22 and the parasitic conductor plate 23 may be copper foil, and the power-feeding conductor 24 and the protruding conductor 25 may be conductors filled by plating in via holes in the resin substrate.

[0018] According to the antenna element 1 having the above configuration, high-frequency power is fed to the feed conductor plate 22 via the feed conductor 24, causing resonance in the feed conductor plate 22 and outputting radio waves from the feed conductor plate 22. Furthermore, vibration of the electric field is transmitted from the feed conductor plate 22 to the parasitic conductor plate 23, causing resonance in the parasitic conductor plate 23 and outputting radio waves from the parasitic conductor plate 23. The resonant frequency of the parasitic conductor plate 23 is set to be higher than the resonant frequency of the feed conductor plate 22. With this setting, as shown in FIG. 3, wideband characteristics with low loss can be obtained in the band around the lower pole frequency p1 (see FIG. 3) corresponding to the resonant frequency of the feed conductor plate 22, the band around the higher pole frequency p2 (see FIG. 3) corresponding to the resonant frequency of the parasitic conductor plate 23, and the band between the pole frequencies p1 and p2.

[0019] <Protruding conductor> The protruding conductor 25 protrudes from the power supply conductor plate 22 toward the ground conductor 21. The protruding direction may be the Z direction (i.e., the vertical direction), or may be a direction including one or both of the X and Y directions as long as it includes a Z-direction component. The protruding conductor 25 may be a rod-like body extending in the protruding direction, such as a cylindrical or polygonal prism shape. The protruding conductor 25 may have a shape whose thickness does not change in the protruding direction, or a shape whose thickness changes, such as tapering or expanding at the end. The protruding conductor 25 may have a shape that extends straight in the vertical direction, or a shape that has a curved portion in the horizontal direction. Having the protruding conductor 25 be cylindrical and straight facilitates the molding process of the protruding conductor 25, and can distribute stress between the protruding conductor 25 and the dielectric substrate 10, thereby improving the strength around the protruding conductor 25.

[0020] The cross-sectional shape and dimensions of the protruding conductor 25 may be the same as or different from those of the power supply conductor 24. If they are the same, it is easier to form the protruding conductor 25 and the power supply conductor 24 in a common process. The cross-sectional shape and dimensions refer to a cross section along the horizontal direction.

[0021] The length of the protruding conductor 25 (i.e., the vertical dimension) may be any length as long as it does not come into contact with the ground conductor 21. The length of the protruding conductor 25 may be equal to or greater than one-fourth of the distance between the power supply conductor plate 22 and the ground conductor 21 (i.e., the length between the opposing surfaces). This length enhances the effect of increasing the capacitance of the power supply conductor plate 22, which will be described later. When the dielectric substrate 10 has a laminated structure, the tip of the protruding conductor 25 may be located between the dielectric layers 11a. For example, when two dielectric layers 11a of the same thickness are present between the ground conductor 21 and the power supply conductor plate 22, the protruding conductor 25 may have a length that is half the distance between the ground conductor 21 and the power supply conductor plate 22. Positioning the tip of the protruding conductor 25 between multiple dielectric layers 11a facilitates the molding process of the protruding conductor 25.

[0022] The protruding conductor 25 may have a surface, i.e., an end face E25, at the end facing the ground conductor 21. The end face E25 may be parallel to the top surface of the ground conductor 21 or may be inclined relative to the top surface. The presence of the end face E25 allows electric charge to be stored on the end face E25, thereby enhancing the effect of increasing the capacitance of the power supply conductor plate 22 (described later). The end face E25 of the protruding conductor 25 refers to the surface of the protruding conductor 25 that appears when the dielectric substrate 10 is viewed from the ground conductor 21 side in the -Z direction (i.e., from above), assuming that the dielectric substrate 10 is transparent, and the acute angle between the Z axis and the perpendicular to the surface is less than 30 degrees. The center of the end face E25 refers to the intersection of a line that bisects the area of ​​the end face E25 in the X direction and a line that bisects the area of ​​the end face E25 in the Y direction in a planar perspective view. Here, the X direction refers to the direction of the line segment connecting the edge of the power supply conductor plate 22 and the power supply conductor 24 at the shortest distance. When the end face E25 includes a plurality of discontinuous end faces, the center of the end face E25 exists in each of the plurality of end faces and is defined based on each of the end faces.

[0023] The antenna element 1 may have a plurality of protruding conductors 25. The spacing between the plurality of protruding conductors 25 may be equal to or greater than the thickness (i.e., width) of one protruding conductor 25. Such spacing allows the strength of the portions of the dielectric substrate 10 located between the plurality of protruding conductors 25 to be maintained.

[0024] In a planar perspective, the end face E25 of the protruding conductor 25 may be positioned so as not to protrude beyond the power supply conductor plate 22 (see FIG. 1B). In other words, in a planar perspective, the entire end face E25 of the protruding conductor 25 may be positioned within the area surrounded by the outer edge of the power supply conductor plate 22. Here, the area surrounded by the outer edge of the power supply conductor plate 22 corresponds to the area occupied by the power supply conductor plate 22 if the power supply conductor plate 22 does not have a notch such as a slit, and corresponds to the area including the power supply conductor plate 22 and the notch if the power supply conductor plate 22 has a notch such as a slit. With the above configuration, as will be described in the section "Regarding Protrusion of the Plate-Like Body" below, lower return loss and wider bandwidth characteristics can be obtained.

[0025] The power supply conductor 24 may be connected at a position offset from the center of the power supply conductor plate 22. Resonance in the power supply conductor plate 22 occurs in a direction connecting the center of the power supply conductor plate 22 and the center of the connection position (i.e., the feed point) of the power supply conductor 24. In FIGS. 1A, 1B, 2A, and 2B, the power supply conductor 24 is connected at a position offset in the X direction from the center of the power supply conductor plate 22. Therefore, the X direction is the resonance direction of the power supply conductor plate 22, and the Y direction is a direction perpendicular to the resonance direction. The power supply conductor plate 22 may have a first side s1 and a second side s2 that intersect (e.g., are substantially perpendicular to) the resonance direction in a planar perspective view. The first side s1 is closer to the power supply conductor 24 than the second side s2.

[0026] In a planar perspective view, the center of the end face E25 of the protruding conductor 25 may be located in at least one of regions R1 and R2 in FIG. 1B. Regions R1 and R2 are shaded in FIG. 1B. Region R1 corresponds to a region located inside the power supply conductor plate 22 from the first side s1 and within a distance L1 from the first side s1. Region R2 corresponds to a region located inside the power supply conductor plate 22 from the second side s2 and within a distance L1 from the second side s2. Distance L1 is 0.1 times the effective wavelength λ corresponding to the maximum frequency in the transmission frequency band. Distance L1 may also be expressed as ¼ of the dimension L0 of the power supply conductor plate 22 in the X direction. This configuration achieves wider bandwidth antenna characteristics, as will be described in the section "Arrangement of the protruding conductor in the resonance direction" below.

[0027] 1B, the antenna element 1 may have four protruding conductors 25, which may be located at the four corners of the feed conductor plate 22 in a planar perspective view. Here, the corners may refer to areas including the corners of the feed conductor plate 22, among the areas obtained by dividing the feed conductor plate 22 into four equal parts in the X direction and in the Y direction. This configuration allows the spacing between the multiple protruding conductors 25 to be increased, thereby reducing the occurrence of weak parts in the dielectric substrate 10. Furthermore, by locating the protruding conductors 25 in both areas R1 and R2, the antenna characteristics can be significantly broadened.

[0028] <Effect of protruding conductor> Fig. 3 is a graph showing the return loss of the antenna element according to embodiment 1 and comparative examples 1 to 3. The return loss in Fig. 3 is the result of a simulation.

[0029] The protruding conductor 25 acts to increase the capacitance between the feeder conductor plate 22 and the ground conductor 21 without changing the dimensions of the feeder conductor plate 22 in a planar perspective. Therefore, the resonant frequency of the feeder conductor plate 22 becomes lower than when the protruding conductor 25 is not present. On the other hand, the protruding conductor 25 does not significantly affect the resonant frequency of the parasitic conductor plate 23. Therefore, the lower pole frequency p1 of the antenna element 1 can be set to a lower value without changing the higher pole frequency p2, thereby broadening the antenna characteristics.

[0030] The characteristics of Comparative Example 1 in FIG. 3 show the characteristics of an antenna element 1 having the same configuration as that of the antenna element 1 of Embodiment 1, except that the protruding conductor 25 is not provided. As can be seen from a comparison between the characteristics of Comparative Example 1 and the characteristics of Embodiment 1, the presence of the protruding conductor 25 causes the lower pole frequency p1 to be lower than the pole frequency p1a when the protruding conductor 25 is not provided. On the other hand, the higher pole frequency p2 does not change significantly. Therefore, a wider bandwidth is achieved in Embodiment 1.

[0031] The characteristics of Comparative Example 2 in FIG. 3 show characteristics in which the lower pole frequency p1 is adjusted by adjusting the patch size. The patch size refers to the size of the power supply conductor plate 22 and the parasitic conductor plate 23. In Comparative Example 2, the size of the power supply conductor plate 22 is adjusted. As shown by comparing the characteristics of Comparative Example 2 with those of Embodiment 1, adjusting the size of the power supply conductor plate 22 allows the lower pole frequency p1 to be adjusted to a value similar to that of Embodiment 1. However, when the lower pole frequency p1 is adjusted by adjusting the patch size, the area of ​​the power supply conductor plate 22 changes relatively between the parasitic conductor plate 23 and the ground conductor 21. This affects the capacitance between the parasitic conductor plate 23 and the ground conductor 21, resulting in increased reflection loss near the higher pole frequency p2. On the other hand, when the lower pole frequency p1 is reduced by using the protruding conductor 25 as in Embodiment 1, the area of ​​the power supply conductor plate 22 is not restricted, and the area of ​​the power supply conductor plate 22 can be set to improve the characteristics of the power supply conductor plate 22 and the parasitic conductor plate 23. Therefore, in the first embodiment, in addition to the broadband characteristics, the return loss at the higher pole frequency p2 is reduced, and a high antenna gain is obtained.

[0032] The characteristics of Comparative Example 3 in FIG. 3 show the characteristics of a configuration in which the protruding conductor is provided on the ground conductor 21, not on the power supply conductor plate 22. That is, the configuration of Comparative Example 3 includes a protruding conductor protruding from the ground conductor 21 toward the power supply conductor plate 22, but does not include the protruding conductor 25 on the power supply conductor plate 22. The other configurations are the same as those of Embodiment 1. As shown by comparing the characteristics of Comparative Example 3 and Embodiment 1, the protruding conductor of the ground conductor 21 not only increases the capacitance of the power supply conductor plate 22, but also increases the capacitance of the parasitic conductor plate 23. Therefore, the higher pole frequency p2c is shifted to a lower value, reducing the effect of bandwidth broadening. On the other hand, by providing the protruding conductor 25 on the power supply conductor plate 22 as in Embodiment 1, the higher pole frequency p2 is less affected, and the lower pole frequency p1 can be lowered. This achieves broadband antenna characteristics.

[0033] <Arrangement of protruding conductors in the direction perpendicular to the resonance direction> 4A to 4D are diagrams respectively showing Modifications 1 to 4 in which the position of the protruding conductor is changed in a direction perpendicular to the resonance direction. In FIGS. 4A to 4D, components above the feed conductor plate 22 are omitted. In the above diagrams, the Y direction corresponds to the direction perpendicular to the resonance direction. FIG. 5 is a graph showing the return loss of the antenna elements of Modifications 1 to 4. FIG. 5 shows the results of a simulation.

[0034] As described above, the power supply conductor 24 may be connected to a position offset from the center of the power supply conductor plate 22. Resonance in the power supply conductor plate 22 occurs in the direction connecting the center point of the power supply conductor plate 22 and the center of the connection position (i.e., the feed point) of the power supply conductor 24. In Figures 4A to 4D, the X direction is the resonance direction of the power supply conductor plate 22, and the Y direction is the direction perpendicular to the resonance direction.

[0035] Antenna elements 1A to 1D of Modifications 1 to 4 of this embodiment have the same configuration as that of Embodiment 1, except for the number and arrangement of the protruding conductors 25. Each of antenna elements 1A to 1D has one protruding conductor 25. The protruding conductors 25 have the same size, shape, and position in the X direction.

[0036] In a planar perspective, the protruding conductor 25 of Modification 1 is located at an end in the Y direction of the power supply conductor plate 22. In a planar perspective, the protruding conductors 25 of Modifications 2 and 3 are located between the center and the end in the Y direction of the power supply conductor plate 22. In a planar perspective, the protruding conductor 25 of Modification 4 is located at the center in the Y direction of the power supply conductor plate 22.

[0037] The return loss of the antenna elements 1A to 1D of Modifications 1 to 4 has the same characteristics as shown in Fig. 5. From the results of Fig. 5, it can be deduced that even if the position of the protruding conductor 25 is different in the direction orthogonal to the resonance direction (i.e., the Y direction), it is possible to achieve a broadband antenna characteristic.

[0038] Regarding the position of the protruding conductor 25, the main factors that affect the antenna characteristics are the position of the end face E25 of the protruding conductor 25 on the ground conductor 21 side and the connection position of the protruding conductor 25 to the feed conductor plate 22. Therefore, the above fact derived from Figure 5 can be rephrased as follows: In planar perspective, even if the position of the end face E25 of the protruding conductor 25 on the ground conductor 21 side varies in the direction perpendicular to the resonance direction within the feed conductor plate 22, it is possible to achieve broadband antenna characteristics. Alternatively, even if the connection position of the protruding conductor 25 to the feed conductor plate 22 varies in the direction perpendicular to the resonance direction, it is possible to achieve broadband antenna characteristics.

[0039] <Arrangement of protruding conductors in the resonance direction> 6A to 6C are diagrams showing Modifications 5 to 7 in which the position of the protruding conductor is changed in the resonance direction. In Figs. 6A to 6C, components above the power supply conductor plate 22 are omitted. In the above diagrams, the X direction corresponds to the resonance direction.

[0040] As described above, the power supply conductor plate 22 may have a first side s1 and a second side s2 that intersect (for example, are substantially perpendicular to) the resonance direction in a planar perspective view. The first side s1 is closer to the power supply conductor 24 than the second side s2.

[0041] Antenna elements 1E to 1G of modified examples 5 to 7 of this embodiment have the same configuration as embodiment 1, except for the number and arrangement of the protruding conductors 25. Each of the antenna elements 1E to 1G has two protruding conductors 25. All of the protruding conductors 25 have the same size and shape. In each of the antenna elements 1E to 1G, the two protruding conductors 25 are located at both ends in the Y direction.

[0042] The dimensions of the feed conductor plate 22 may be set to be proportional to the effective wavelength (i.e., wavelength in the dielectric) λ of the transmission frequency band of the antenna elements 1E to 1G. In this embodiment, the maximum frequency of the transmission frequency band is 71 [GHz], the relative dielectric constant of the dielectric substrate 10 is 5.7, the effective wavelength λ is 1.77 [mm], and the dimension of the feed conductor plate 22 in the X direction is 0.7 [mm].

[0043] The two protruding conductors 25 in Fig. 6A are located at the ends of the power supply conductor plate 22 in the X direction (i.e., the ends closer to the power supply conductors 24) in a planar perspective view. This position corresponds to a position −0.3 mm (see Fig. 6B) along the X direction, with the center of the power supply conductor plate 22 as the origin. Here and hereinafter, the positions of the protruding conductors 25 are represented by the positions of the center points of the protruding conductors 25.

[0044] 6B are located at the middle in the X direction of the power supply conductor plate 22 in a planar perspective view. This position corresponds to a position −0.2 mm along the X direction, with the center of the power supply conductor plate 22 being the origin.

[0045] 6C are located at opposite ends of the power supply conductor plate 22 in the X direction (i.e., the ends farther from the power supply conductor 24) in a planar perspective view. These positions correspond to positions +0.3 mm (see FIG. 6B) along the X direction, with the center of the power supply conductor plate 22 being the origin.

[0046] 7A to 7C are graphs showing the relationship between the position of the protruding conductor in the resonance direction and the pole frequency. FIG. 7A shows the relationship between the position and the lower pole frequency, FIG. 7B shows the relationship between the position and the higher pole frequency, and FIG. 7C shows the relationship between the position and the bandwidth between the two pole frequencies. The pole frequencies in FIGS. 7A and 7B were extracted from characteristic lines obtained by simulating the frequency characteristics of return loss for multiple additional antenna elements in addition to antenna elements 1E to 1G of Modifications 5 to 7. The additional antenna elements are configured such that the positions of the two protruding conductors 25 in the X direction are −0.1 mm, 0 mm, +0.1 mm, and +0.2 mm (see FIG. 6B). The bandwidth between the pole frequencies in FIG. 7C is the value obtained by subtracting the lower pole frequency from the higher pole frequency.

[0047] The antenna characteristics can be made broadband by widening the two pole frequencies of the return loss (see pole frequencies p1 and p2 in FIG. 3). As shown in FIG. 7C, there is a correlation between the position of the protruding conductor 25 in the X direction and the bandwidth between the pole frequencies. From the results in FIG. 7C, it can be deduced that the antenna characteristics can be made broadband by positioning the center of the protruding conductor 25 in either region R1 or R2 (see FIGS. 6B and 7C). Regions R1 and R2 are shaded in FIGS. 6B and 7C.

[0048] Here, region R1 corresponds to a region located inside the power supply conductor plate 22 from the first side s1 and within a distance L1 from the first side s1. Region R2 corresponds to a region located inside the power supply conductor plate 22 from the second side s2 and within a distance L1 from the second side s2. Distance L1 is 0.1 times the effective wavelength λ corresponding to the maximum frequency in the transmission frequency band. In other words, distance L1 can be expressed as ¼ of the dimension L0 of the power supply conductor plate 22 in the X direction.

[0049] Regarding the position of the protruding conductor 25, the main factors that affect the antenna characteristics are the position of the end face E25 of the protruding conductor 25 on the ground conductor 21 side and the connection position of the protruding conductor 25 to the feed conductor plate 22. Therefore, the above fact derived from FIG. 7C can be restated as follows: In planar perspective, the antenna characteristics can be made wider band by positioning the center of the end face E25 of the protruding conductor 25 on the ground conductor 21 side in either region R1 or R2. Alternatively, the antenna characteristics can be made wider band by positioning the center of the connection position of the protruding conductor 25 to the feed conductor plate 22 in either region R1 or R2.

[0050] (Embodiment 2) Fig. 8A is a plan view showing an antenna element according to embodiment 2. Fig. 8B is a perspective view showing the antenna element according to embodiment 2. Fig. 8C is a longitudinal sectional view showing the antenna element according to embodiment 2. The configuration above the feed conductor plate 22 is omitted in Figs. 8A and 8B. The antenna element 1H according to embodiment 2 has the same configuration as embodiment 1, except that the shape of the protruding conductor 25H is different.

[0051] The protruding conductor 25H has a rod-shaped member 25Ha extending from the power supply conductor plate 22 toward the ground conductor 21, and a plate-shaped member 25Hb connected to the rod-shaped member 25Ha and extending in a direction intersecting the protruding direction of the protruding conductor 25H. The rod-shaped member 25Ha may be configured to extend in a direction perpendicular to the plate surface of the power supply conductor plate 22. The plate-shaped member 25Hb may be connected to the tip of the rod-shaped member 25Ha. In this configuration, the end face E25 of the protruding conductor 25H corresponds to the lower surface of the plate-shaped member 25Hb (i.e., the plate surface facing the ground conductor 21). The plate-shaped member 25Hb may be configured to extend along the upper surface of the ground conductor 21.

[0052] The plate-shaped body 25Hb may be a metallized conductive film. The rod-shaped body 25Ha may be a via conductor solidified when the dielectric substrate 10 is fired. Alternatively, when the dielectric substrate 10 is a resin substrate, the plate-shaped body 25Hb may be copper foil, and the rod-shaped body 25Ha may be a conductor filled in a via hole of the resin substrate by plating. The rod-shaped body 25Ha may be the same as the protruding conductor 25 of the first embodiment. The plate-shaped body 25Hb may be located between the two dielectric layers 11a, 11a.

[0053] 8A, the width of plate-like body 25Hb in the X direction in planar perspective may be equal to the diameter of rod-like body 25Ha (for example, the width in the X direction in the case of a rectangle), and the width in the Y direction may be greater than the diameter of rod-like body 25Ha. Alternatively, the width of plate-like body 25Hb in the X direction in planar perspective may be greater than the diameter of rod-like body 25Ha, and the width in the Y direction may be equal to or greater than the diameter of rod-like body 25Ha. The area of ​​plate-like body 25Hb in planar perspective (i.e., the area extending in the X and Y directions) may be greater than the area of ​​the end face of rod-like body 25Ha in planar perspective.

[0054] <Size of plate-shaped object> FIG. 9 is a graph showing the relationship between plate width and lower pole frequency.

[0055] Varying the width, i.e., area, of plate-like body 25Hb changes the capacitance between ground conductor 21 and feed conductor plate 22, and the pole frequency p1 (see FIG. 3) with lower return loss also changes. FIG. 9 shows the lower pole frequency obtained by simulation for antenna elements with different Y-direction widths Wy (see FIG. 8A) of plate-like body 25Hb and identical other components. The results in FIG. 9 show that a larger area of ​​plate-like body 25Hb reduces the lower pole frequency p1, thereby enabling antenna characteristics to be broader in bandwidth.

[0056] On the other hand, in the characteristic curve of the return loss (see Figure 3), if the higher pole frequency p2 is almost constant and the lower pole frequency p1 becomes too low, the amount of rise in the band q3 (see Figure 3) between the two pole frequencies p1 and p2 increases, and the return loss in this band q3 therefore increases.

[0057] Therefore, the size of the plate-shaped body 25Hb may be adjusted within a range in which the return loss in the band q3 is a desired value (for example, −10 dB or less). By adjusting the size, it is possible to achieve a wideband antenna characteristic that provides a desired gain even in the intermediate band q3.

[0058] <Length of rod> A change in the length Lz of the rod-shaped member 25Ha (see FIG. 8C) affects the characteristic curve of the return loss in the same way as a change in the width Wy of the plate-shaped member 25Hb. This is because, if the rod-shaped member 25Ha is longer and the distance between the tip of the protruding conductor 25H and the ground conductor 21 is narrower, the capacitance between the ground conductor 21 and the power supply conductor plate 22 increases, just as when the width Wy of the plate-shaped member 25Hb is longer. The same is true for a configuration that does not have the plate-shaped member 25Hb (i.e., the configuration of embodiment 1).

[0059] Therefore, the length Lz of the rod-shaped body 25Ha (or the length of the protruding conductor 25 in the first embodiment) may also be adjusted within a range in which the return loss in the intermediate band q3 is a desired value. By adjusting it, it is possible to realize a wideband antenna characteristic in which a desired gain can be obtained even in the intermediate band q3.

[0060] <About protrusion of plate-shaped objects> 10A to 10C show a modified example of the second embodiment. 8 , modified example 9 and variations 10 10A to 10C do not show the configuration above the feed conductor plate 22. Fig. 11 is a graph showing the return loss of the antenna elements of Modifications 8 to 10.

[0061] The antenna element 1I of Modification 8 has the same configuration as that of Embodiment 2 except that the plate-like body 25Ib is square in planar perspective. In planar perspective, the entire plate-like body 25Ib is located within an area surrounded by the outer edge of the feed conductor plate 22.

[0062] In the antenna elements 1J and 1K of Modifications 9 and 10, in a planar perspective view, portions of the plate-like bodies 25Jb and 25Kb are positioned beyond the area surrounded by the outer edge of the feed conductor plate 22. The plate-like body 25Jb of Modification 9 has the same shape and size as the plate-like body 25Ib of Modification 8. The plate-like body 25Kb of Modification 10 is larger in size than the plate-like body 25Ib of Modification 8, and has a larger area positioned beyond the area surrounded by the outer edge of the feed conductor plate 22 (i.e., the amount of protrusion).

[0063] The results in Figure 11 show that, in a planar perspective view, by ensuring that the plate-shaped body 25Ib (or the end face E25 of the protruding conductor 25I on the ground conductor 21 side) does not protrude from the power supply conductor plate 22, antenna characteristics with a wider bandwidth and lower reflection loss can be obtained.

[0064] <Connection between a plate-shaped body and multiple rod-shaped bodies> Figure 8 A When the width Wy of the plate-like member 25Hb is increased, it becomes possible to connect multiple rod-like members 25Ha to one plate-like member 25Hb. However, when multiple spaced-apart rod-like members 25Ha are connected to one plate-like member 25Hb, a loop-shaped current path is formed that connects the power supply conductor plate 22, one rod-like member 25Ha, the plate-like member 25Hb, and the other rod-like member 25Ha. The loop-shaped current path affects the resonance mode of the power supply conductor plate 22, making it difficult to achieve a wide bandwidth of the antenna characteristics.

[0065] Therefore, one plate-shaped member 25Hb may be connected to only one rod-shaped member 25Ha. This configuration makes it possible to achieve a wider bandwidth of the antenna characteristics.

[0066] (Antenna board and antenna module) Fig. 12A is a perspective view showing an antenna substrate and an antenna module according to an embodiment of the present disclosure, Fig. 12B is a longitudinal cross-sectional view showing an antenna substrate and an antenna module according to an embodiment of the present disclosure, and Fig. 12B is a cross-section taken along line BB in Fig. 12A.

[0067] The antenna substrate 110 of this embodiment includes a plurality of antenna elements 1. The antenna element 1 is the antenna element 1 of the above-described embodiment 1, but may be replaced with the antenna element 1H of embodiment 2 or the antenna elements 1A to 1G and 1I of modifications 1 to 8. The plurality of antenna elements 1 may be arranged vertically and horizontally in a matrix or the like on a large dielectric substrate 10 for an array, or may be arranged in any other manner.

[0068] The antenna substrate 110 may have an electrode 130 to which an integrated circuit 200 that outputs a transmission signal and / or inputs a reception signal is connected, and a transmission line 120 that transmits a signal between the electrode 130 and each antenna element 1. A part of the transmission line 120 may be the feed conductor 24 of each antenna element 1.

[0069] The antenna substrate 110 may be equipped with a filter circuit that extracts signals in a desired frequency band from signals on the transmission path 120 .

[0070] The antenna module 100 of this embodiment includes an antenna substrate 110 and an integrated circuit 200. The integrated circuit 200 may be bonded to the side of the antenna substrate 110 opposite to the side emitting radio waves.

[0071] The antenna substrate 110 and antenna module 100 of this embodiment enable either or both of wideband radio wave transmission and radio wave reception. Furthermore, because wideband radio wave transmission is possible, it is easy to add a phase difference to the transmitted radio waves between the multiple antenna elements 1. Adding a phase difference enables beamforming, in which the radio waves are shaped into a beam and output at a desired angle. Therefore, the antenna substrate 110 and antenna module 100 of this embodiment have the advantage of easily realizing beamforming.

[0072] The above describes the embodiments of the present disclosure. However, the antenna element, antenna substrate, and antenna module of the present disclosure are not limited to the above embodiments. For example, the planar shapes of the power-fed conductor plate and the parasitic conductor plate may be polygonal shapes other than rectangular, or shapes that include curved outlines. Furthermore, one or both of the power-fed conductor plate and the parasitic conductor plate may have slits. Furthermore, the dielectric substrate may have spaces such as air gaps between the ground conductor and the power-fed conductor plate, and between the power-fed conductor plate and the parasitic conductor plate. Other details shown in the embodiments may be modified as appropriate without departing from the spirit of the invention. [Industrial Applicability]

[0073] The present disclosure can be used for an antenna element, an antenna substrate, and an antenna module. [Explanation of symbols]

[0074] 1. 1A~1K antenna elements 10 Dielectric substrate 11a Dielectric layer (first dielectric) 11b Dielectric layer (second dielectric) 21 Grounding conductor 22 Power supply conductor plate 23 Parasitic conductor plate 24 Power supply conductor 25, 25H, 25I protruding conductor 25Ha, 25Ia rod-shaped 25Hb, 25Ib plate E25 end face R1, R2 area s1 First side s2 Second side 100 Antenna Module 110 Antenna board 120 Transmission Line 130 electrodes 200 Integrated Circuits p1 Lower pole frequency p2 higher pole frequency

Claims

1. The antenna includes a first dielectric, a second dielectric, a ground conductor, a feed conductor plate, and a parasitic conductor plate, the ground conductor, the power-supply conductor plate, and the parasitic conductor plate are arranged in this order; The ground conductor and the power supply conductor plate are positioned opposite to each other with the first dielectric interposed therebetween, the feeding conductor plate and the parasitic conductor plate are positioned opposite each other with the second dielectric interposed therebetween, a protruding conductor protruding from the power supply conductor plate toward the ground conductor, In a planar perspective view, the feeding conductor plate has a first side and a second side that intersect with a resonance direction, In a planar perspective view, a center of an end face of the protruding conductor facing the ground conductor is located inward from the first side and within a distance L1 from the first side, and / or inward from the second side and within the distance L1 from the second side, The distance L1 is 0.1 times the effective wavelength corresponding to the maximum frequency of the transmission frequency band. Antenna element.

2. The protruding conductor has a rod-shaped body extending in a protruding direction. The antenna element of claim 1 .

3. A coil having four of the protruding conductors, In a planar perspective view, the power supply conductor plate has a rectangular shape, and the four protruding conductors are located at four corners of the power supply conductor plate, respectively. The antenna element of claim 1 .

4. The protruding conductor further includes a plate-like member connected to the rod-like member and extending in a direction intersecting the protruding direction.

3. The antenna element of claim 2.

5. In a planar perspective view, the entire end surface of the protruding conductor on the ground conductor side is located within an area surrounded by an outer edge of the power supply conductor plate.

3. The antenna element according to claim 1 or 2.

6. In planar perspective, the plate-like body is located within an area surrounded by the outer edge of the power supply conductor plate.

5. The antenna element of claim 4.

7. having a plurality of antenna elements; An antenna substrate, wherein each of the plurality of antenna elements is the antenna element according to claim 1 .

8. The antenna substrate according to claim 7; an integrated circuit; An antenna module comprising:

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