Antenna element and antenna device

Abstract

To provide an antenna device which is small size and is capable of communicating by a dual band and an antenna element that is used in the same.SOLUTION: An antennal element 20 comprises an upper conductor 221, first lower conductors 241, second lower conductors 243, first leg parts 223, second leg parts 225, and power supply parts 227. The upper conductor 221 has a central part 231, an annular part 233 and connection parts 235. The annular part 233 surrounds the central part 231 seamlessly. The connection parts 235 connect the central part 231 to the annular part 233. The first leg parts 223 are extended from the central part 231, and the second leg parts 225 are extended from the annular part 233. The first lower conductors 241 and the second lower conductors 243 are formed independently from each other and are arranged away from the upper conductor 221 in a vertical direction. The first lower conductors 241 are connected to the first leg parts 223, and the second lower conductors 243 are connected to the second leg parts 225. The power supply part 227 is extended from the upper conductor 221.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an antenna element and an antenna device including the same. [Background technology]

[0002] Patent Document 1 discloses an antenna device including an antenna element made of a metal plate. The antenna device of Patent Document 1 is said to be smaller in size than a planar antenna device including a ceramic substrate.

[0003] Referring to Figure 25, the antenna device 90 disclosed in Patent Document 1 comprises a dielectric substrate 92, an antenna element 95 consisting of a metal plate arranged at a predetermined interval from the dielectric substrate 92, a plurality of leg pieces 952 extending from the antenna element 95 toward the dielectric substrate 92, a chip capacitor 94 electrically connected to the leg pieces 952 and the dielectric substrate 92, and a resin insert member 96 inserted between the dielectric substrate 92 and the antenna element 95. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-193204 A Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, there has been a need for an antenna device that is not only small but also capable of communicating in dual bands.

[0006] SUMMARY OF THE PRESENT EMBODIMENTS In view of the above, an object of the present invention is to provide an antenna device which is small and capable of communicating in dual bands, and an antenna element used therein. [Means for solving the problem]

[0007] The present invention provides a first antenna element that constitutes an antenna device by being provided on a ground conductor via a dielectric, the antenna element includes an upper conductor, at least one first lower conductor, at least one second lower conductor, at least one first leg, at least one second leg, and at least one feed; the upper conductor has a central portion, an annular portion, and a connecting portion; the annular portion is spaced apart from the central portion and seamlessly surrounds the central portion; the connecting portion connects the central portion and the annular portion, the at least one first leg extends from the central portion; the at least one second leg extends from the annular portion; the at least one first lower conductor is spaced apart from the upper conductor in the vertical direction and is connected to the at least one first leg; the at least one second lower conductor is separate from and spaced apart from the at least one first lower conductor; the at least one second lower conductor is spaced apart from the upper conductor in the vertical direction and is connected to the at least one second leg portion; The at least one feed portion extends from the upper conductor. An antenna element is provided.

[0008] In addition, the present invention provides a first antenna element as a second antenna element, The at least one power supply unit includes two power supplies, Two imaginary lines connecting the center of the central portion and the two power supply portions form an angle of 90 degrees in a plan view. An antenna element is provided.

[0009] Furthermore, the present invention provides a third antenna element, which is a first antenna element, the at least one first lower conductor and the at least one first leg are equal in number and connected one-to-one; The at least one second lower conductor and the at least one second leg are equal in number and connected to each other in a one-to-one manner. An antenna element is provided.

[0010] Furthermore, the present invention provides a fourth antenna element, which is the third antenna element, the at least one first lower conductor comprises four first lower conductors; The at least one second lower conductor comprises four second lower conductors. An antenna element is provided.

[0011] Furthermore, the present invention provides a fifth antenna element, which is a first antenna element, the upper conductor extends in a plane intersecting the up-down direction, The upper conductor, the at least one first leg, the at least one second leg, and the at least one power supply portion are formed of a single metal plate. An antenna element is provided.

[0012] Furthermore, the present invention provides a sixth antenna element, which is a first antenna element, the upper conductor extends in a plane intersecting the up-down direction, The upper conductor, the at least one first lower conductor, the at least one second lower conductor, the at least one first leg, the at least one second leg, and the at least one power supply portion are formed of a single metal plate. An antenna element is provided.

[0013] Furthermore, the present invention provides a first antenna device including any one of first to sixth antenna elements; A ground conductor; a dielectric interposed between the antenna element and the ground conductor; An antenna device comprising: Effect of the Invention

[0014] In the antenna element according to the present invention, the first lower conductor and the second lower conductor each form a capacitor together with the upper conductor, which allows the antenna element to be miniaturized, and also allows an antenna device including such an antenna element to be miniaturized.

[0015] In particular, the shape and size of the second lower conductor affect the setting of the two frequencies of the first and second resonances, and the shape and size of the first lower conductor affect only the frequency of the first resonance. Therefore, the first and second resonances can be set to desired frequencies by determining the shapes and sizes of the first and second lower conductors. In other words, an antenna element for an antenna device capable of communication in dual bands can be obtained. [Brief description of the drawings]

[0016] [Figure 1] 1 is a perspective view showing an antenna device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a top view showing the antenna device of FIG. [Diagram 3] 2 is a side view showing the antenna device of FIG 1, illustrating an enlarged view of a part of the second leg and its surroundings. [Figure 4] 2 is a perspective view showing an upper element included in an antenna element used in the antenna device of FIG. 1. [Diagram 5] FIG. 5 is a top view showing the upper element of FIG. 4. [Figure 6] FIG. 5 is a rear view showing the upper element of FIG. 4. [Figure 7] 2 is a perspective view showing a dielectric substrate used in the antenna device of Fig. 1. A lower element included in the antenna element used in the antenna device is provided on the upper surface of the dielectric substrate. [Figure 8] FIG. 8 is a top view showing the dielectric substrate of FIG. [Figure 9] FIG. 8 is a rear view showing the dielectric substrate of FIG. [Figure 10] 1 is a perspective view showing an antenna device according to a first embodiment of the present invention. [Figure 11] FIG. 11 is a top view showing the antenna device of FIG. [Figure 12] FIG. 11 is a side view showing the blackout device of FIG. [Figure 13] FIG. 4 is a schematic diagram showing a first modified example of an antenna device according to the present invention. [Figure 14] FIG. 11 is a schematic diagram showing a second modified example of the antenna device according to the present invention. [Figure 15] FIG. 11 is a schematic diagram showing a third modified example of the antenna device according to the present invention. [Figure 16] FIG. 11 is a schematic diagram showing a fourth modified example of an antenna device according to the present invention. [Figure 17] FIG. 4 is a schematic diagram showing a first modified example of a slot formed in an antenna element according to the present invention. [Figure 18] FIG. 11 is a schematic diagram showing a second modified example of a slot formed in an antenna element according to the present invention. [Figure 19] FIG. 11 is a schematic diagram showing a third modified example of a slot formed in an antenna element according to the present invention. [Figure 20] FIG. 11 is a schematic diagram showing a fourth modified example of a slot formed in an antenna element according to the present invention. [Figure 21] FIG. 11 is a schematic diagram showing a fifth modified example of a slot formed in an antenna element according to the present invention. [Figure 22] FIG. 13 is a schematic diagram showing a sixth modified example of a slot formed in an antenna element according to the present invention. [Diagram 23] FIG. 13 is a schematic diagram showing a seventh modified example of a slot formed in an antenna element according to the present invention. [Figure 24] FIG. 13 is a schematic diagram showing an eighth modified example of a slot formed in an antenna element according to the present invention. [Diagram 25]FIG. 1 is a perspective view showing an antenna device described in Patent Document 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] (First embodiment) 1 to 3, an antenna device 10 according to a first embodiment of the present invention includes an antenna element 20, a dielectric substrate 30, and a ground conductor 40. In other words, the antenna element 20 is provided on the ground conductor 40 via the dielectric substrate (dielectric) 30 to form the antenna device 10.

[0018] 4 and 7, the antenna element 20 has an upper element 22 and a lower element 24. In the vertical direction, the upper element 22 is located above the lower element 24. In this embodiment, the vertical direction is the Z direction. The +Z direction is upward, and the -Z direction is downward.

[0019] As shown in FIGS. 4 to 6, the upper element 22 includes an upper conductor 221, at least one first leg 223, at least one second leg 225, and at least one feeding portion 227.

[0020] As shown in FIGS. 7 and 8, the lower element 24 includes at least one first lower conductor 241 and at least one second lower conductor 243.

[0021] As can be seen from Fig. 4 to Fig. 6, in this embodiment, the upper element 22 is made of a single metal plate. In other words, the upper conductor 221, at least one first leg 223, at least one second leg 225, and at least one power supply part 227 are made of a single metal plate. In detail, the upper element 22 is integrally formed by stamping and bending a single metal plate. However, the present invention is not limited to this. The upper element 22 may be made of a plurality of metal plates. Alternatively, the upper element 22 may be formed by laser direct structuring (LDS).

[0022] 5, in this embodiment, the number of first legs 223 and the number of second legs 225 are each four. Also, in this embodiment, the number of power feeding units 227 is two. In other words, in this embodiment, at least one power feeding unit 227 includes two power feeding units 227. However, the present invention is not limited to this. The numbers of first legs 223, second legs 225, and power feeding units 227 can be set arbitrarily.

[0023] As can be seen from FIG. 8, in this embodiment, the lower element 24 includes a first lower conductor 241 and a second lower conductor 243. The first lower conductor 241 and the second lower conductor 243 are provided on the upper surface of the dielectric substrate 30. The first lower conductor 241 and the second lower conductor 243 may be formed by etching a conductor layer formed on the upper surface of the dielectric substrate 30. Alternatively, the first lower conductor 241 and the second lower conductor 243 may be formed by attaching a conductor plate or conductor film having a predetermined shape to the upper surface of the dielectric substrate 30. However, the present invention is not limited to this. At least a part of the lower element 24 may be formed integrally with the upper element 22 using the same material as the upper element 22. In addition, the first lower conductor 241 and the second lower conductor 243 do not have to be on the same plane perpendicular to the vertical direction. In other words, the first lower conductor 241 and the second lower conductor 243 may be at different positions in the vertical direction. In this case, the first lower conductor 241 and the second lower conductor 243 may partially overlap in a plan view. However, the first lower conductor 241 and the second lower conductor 243 must be electrically separated from each other.

[0024] As can be understood from FIG. 2, FIG. 5 and FIG. 8, the first lower conductors 241 correspond to the first legs 223, respectively. In other words, the at least one first lower conductor 241 and the at least one first leg 223 are the same in number. In this embodiment, the number of the first lower conductors 241 is four. In other words, the at least one first lower conductor 241 includes four first lower conductors 241. Also, the second lower conductors 243 correspond to the second legs 225, respectively. In other words, the at least one second lower conductor 243 and the at least one second leg 225 are the same in number. In this embodiment, the number of the second lower conductors 243 is four. In other words, the at least one second lower conductor 243 includes four second lower conductors 243. However, the present invention is not limited thereto. The number of first lower conductors 241 can be set arbitrarily as long as it is the same as the number of first legs 223. Moreover, the number of second lower conductors 243 can be set arbitrarily as long as it is the same as the number of second legs 225.

[0025] 7 and 8, at least one power supply pad 32 is further provided on the upper surface of the dielectric substrate 30. The power supply pads 32 correspond to the power supply portions 227, respectively. In this embodiment, the number of power supply pads 32 is two. The power supply pad 32 is connected to a power supply line (not shown) provided on the lower surface of the dielectric substrate 30 through a via that passes through the dielectric substrate 30 in the vertical direction.

[0026] 3, the ground conductor 40 is disposed directly below the dielectric substrate 30. In other words, the antenna device 10 is mounted on the ground conductor 40. A circuit board having conductor layers formed on the entire upper and lower surfaces of an insulating substrate can be used as the ground conductor 40. In this case, the conductor layer on the upper surface and the conductor layer on the lower surface are preferably connected to each other using vias or the like.

[0027] 3 and 9, in this embodiment, a ground layer 245 is formed on the lower surface of the dielectric substrate 30 so as to cover almost the entire surface thereof. The ground conductor 40 disposed under the dielectric substrate 30 is electrically connected to the ground layer 245. However, the present invention is not limited to this. The dielectric substrate 30 does not necessarily have to have the ground layer 245.

[0028] 5, in this embodiment, the outer shape of the upper conductor 221 is substantially square in plan view. However, the present invention is not limited to this. The outer shape of the upper conductor 221 does not have to be substantially square in plan view. However, in order for the antenna device 10 to perform communication using circularly polarized waves, it is preferable that the outer shape of the upper conductor 221 has substantially n-fold symmetry in plan view. Here, n is a multiple of 4 (the same applies below).

[0029] 5, the upper conductor 221 has a central portion 231, an annular portion 233, and a connecting portion 235. The central portion 231 is a portion that includes the center of the upper conductor 221 in a plan view. The annular portion 233 is a portion that follows the outer edge of the upper conductor 221. The connecting portion 235 is a portion that connects the central portion 231 and the annular portion 233. However, the boundary between the central portion 231 and the connecting portion 235, and the boundary between the annular portion 233 and the connecting portion 235 are not clearly defined.

[0030] As shown in FIG. 5, in this embodiment, the outer shape of the central portion 231 is a square that is approximately similar to the outer shape of the upper conductor 221 in a plan view. In this embodiment, the annular portion 233 has an approximately square frame shape that follows the outer shape of the upper conductor 221. In a plan view, the annular portion 233 is located outside and away from the central portion 231, and surrounds the central portion 231 without any breaks. In this embodiment, the number of the connecting portions 235 is four. The connecting portions 235 correspond to the four corners of the central portion 231, respectively, and also correspond to the four corners of the annular portion 233, respectively. Each of the connecting portions 235 connects the corresponding corner of the central portion 231 to the corresponding corner of the annular portion 233.

[0031] As can be seen from Fig. 5 and Fig. 6, in this embodiment, the central portion 231, the annular portion 233, and the connecting portion 235 are located on a plane intersecting the vertical direction. In other words, the upper conductor 221 extends in a plane intersecting the vertical direction. In this embodiment, the upper conductor 221 extends in a plane perpendicular to the vertical direction. However, the present invention is not limited to this. The annular portion 233 may not be located partially on the plane on which the central portion 231 and the connecting portion 235 are located.

[0032] As shown in Figs. 4 to 6, the first leg 223 extends from the central portion 231. In this embodiment, the first leg 223 extends outward in a plan view. More specifically, each of the first leg 223 extends outward in the horizontal direction from any of the four sides of the central portion 231, extends diagonally downward, and further extends outward in the horizontal direction. In this embodiment, each of the first leg 223 extends in either the front-rear direction or the lateral direction. In this embodiment, the front-rear direction is the X direction, and the lateral direction is the Y direction. Moreover, the +X direction is the front, and the -X direction is the rear.

[0033] As shown in FIG. 4 to FIG. 6, the second leg 225 extends from the annular portion 233. In this embodiment, the second leg 225 extends outward from the outer edge of the annular portion 233 in a plan view. In detail, each of the second legs 225 extends outward in the horizontal direction from any of the four corners of the annular portion 233, extends diagonally downward, and further extends outward in the horizontal direction. In this embodiment, the direction in which the second leg 225 extends is the outward direction in the diagonal direction of the upper conductor 221. However, the present invention is not limited to this. The second leg 225 may extend from the inner edge of the annular portion 233 in a plan view. In that case, the second leg 225 may extend inward of the annular portion 233 in a plan view, or may extend outward of the annular portion 233.

[0034] 4 to 6, power supply portion 227 extends from upper conductor 221. In the present embodiment, power supply portion 227 extends from two connecting portions 235 adjacent to each other in the front-rear direction. However, the present invention is not limited to this. Power supply portion 227 may extend from center portion 231.

[0035] 5, two imaginary lines connecting the center of central portion 231 and two power feed portions 227 form an angle of 90 degrees in a plan view. This makes it possible to realize communication using circularly polarized waves by a two-point feeding method using antenna device 10.

[0036] As shown in Figs. 7 and 8, the first lower conductors 241 are arranged at a distance from each other in the center of the dielectric substrate 30. The first lower conductors 241 are arranged in a four-fold symmetry with respect to the center of the dielectric substrate 30 in a plan view. In the present embodiment, the shape of each of the first lower conductors 241 is a nonagon that is line-symmetric with respect to a straight line. However, the present invention is not limited to this. The shape of each of the first lower conductors 241 can be set arbitrarily. However, it is preferable that the first lower conductors 241 are formed in approximately n-fold symmetry with respect to the center of the dielectric substrate 30 in a plan view.

[0037] 1 to 3, each of the first lower conductors 241 is connected to a corresponding first leg 223. In other words, the first lower conductors 241 are connected to the first leg 223 in a one-to-one relationship. Due to the presence of the first leg 223, the first lower conductors 241 are spaced apart from the upper conductor 221 in the up-down direction.

[0038] As shown in Figs. 7 and 8, the second lower conductors 243 are disposed at the corners of the dielectric substrate 30. Each of the second lower conductors 243 is separate from the first lower conductors 241 and is separated from all of the first lower conductors 241. In this embodiment, the shape of the second lower conductors 243 is a square in a plan view. However, the present invention is not limited to this. The shape of each of the second lower conductors 243 can be set arbitrarily. However, it is preferable that the second lower conductors 243 are formed with approximately n-fold symmetry with respect to the center of the dielectric substrate 30 in a plan view.

[0039] 1 to 3, each of the second lower conductors 243 is connected to a corresponding second leg 225. In other words, the second lower conductors 243 are connected to the second leg 225 in a one-to-one relationship. Due to the presence of the second leg 225, the second lower conductors 243 are spaced apart from the upper conductor 221 in the up-down direction.

[0040] 7 and 8, each of the power supply pads 32 is disposed on a diagonal line of the dielectric substrate 30. Each of the power supply pads 32 is located between two adjacent first lower conductors 241. The two power supply pads 32 are located on a straight line in the front-rear direction with one first lower conductor 241 between them.

[0041] In the antenna device 10 shown in Fig. 1 to Fig. 3, the first lower conductor 241 and the second lower conductor 243 each form a capacitor together with the upper conductor 221. That is, the presence of the first lower conductor 241 and the second lower conductor 243 affects the resonance frequency of the antenna device 10. More specifically, the presence of the first lower conductor 241 and the second lower conductor 243 lowers the resonance frequency compared to when they are not present. In other words, the presence of the first lower conductor 241 and the second lower conductor 243 makes it possible to miniaturize the antenna element 20 having a predetermined resonance frequency, thereby making it possible to miniaturize the antenna device 10.

[0042] 1 to 3, each of the first lower conductor 241 and the second lower conductor 243 forms a capacitor together with the ground conductor 40. Instead of this capacitor, a capacitor element such as a chip capacitor may be connected between each of the first lower conductor 241 and the second lower conductor 243 and the ground conductor 40.

[0043] The antenna device 10 shown in Fig. 1 to Fig. 3 has a first resonant frequency and a second resonant frequency higher than the first resonant frequency. The shape and size of the second lower conductor 243 affect the setting of both the first resonant frequency and the second resonant frequency. On the other hand, the shape and size of the first lower conductor 241 affect only the setting of the first resonant frequency. Therefore, by determining the shapes and sizes of the first lower conductor 241 and the second lower conductor 243, the first resonant frequency and the second resonant frequency can be set to desired frequencies, respectively. That is, an antenna element 20 and an antenna device 10 capable of communication in dual bands can be obtained.

[0044] 1 to 3 employs a two-point power supply system. In detail, a first input signal is input to one of the power supply pads 32, and a second input signal having a phase difference of 90 degrees from the first input signal is input to the other of the power supply pads 32, thereby enabling the antenna element 20 to perform communication using highly circularly polarized waves. In order to achieve communication using highly circularly polarized waves, it is preferable that the outer shape of the upper conductor 221, the arrangement of the first lower conductor 241, and the arrangement of the second lower conductor 243 are substantially n-rotationally symmetric.

[0045] (Second embodiment) 10 to 12, an antenna device 10A according to the second embodiment of the present invention includes an antenna element 20A, a dielectric substrate 30A, and a ground conductor 40A. The antenna device 10A is basically configured similarly to the antenna device 10 according to the first embodiment.

[0046] As can be seen from Fig. 10 to Fig. 12, the antenna element 20A includes an upper conductor 221A, at least one first leg 223A, at least one second leg 225A, at least one power supply 227A, at least one first lower conductor 241A, and at least one second lower conductor 243A. In this embodiment, the antenna element 20A is made of a single metal plate. Similarly to the upper conductor 221 of the first embodiment, the upper conductor 221A includes a central portion 231A, an annular portion 233A, and a connecting portion 235A.

[0047] 10 to 12, in this embodiment, the number of first legs 223A, second legs 225A, first lower conductors 241A and second lower conductors 243A is four, and in this embodiment, the number of power feeding parts 227A is two.

[0048] 10 to 12, the antenna element 20A is mounted on the upper surface of a dielectric substrate 30A. A ground conductor 40A is provided on the lower surface of the dielectric substrate 30A. With this configuration, the antenna device 10A operates in the same manner as the antenna device 10 according to the first embodiment.

[0049] According to this embodiment, it is possible to reduce the size of the antenna element 20A and the antenna device 10A. Also, according to this embodiment, it is possible to obtain the antenna element 20A and the antenna device 10A capable of communicating in dual bands. Since the first lower conductor 241A and the second lower conductor 243A are integrated into the antenna element 20A, it is possible to prevent a decrease in the positional accuracy of the first lower conductor 241A and the second lower conductor 243A relative to the upper conductor 221, which depends on the mounting accuracy.

[0050] The present invention has been described above by way of examples, but the present invention is not limited to the above-described examples, and various modifications and changes are possible without departing from the spirit and scope of the present invention.

[0051] (First Modification) Referring to FIG. 13, the antenna element 20B comprises an upper conductor 221B, at least one first lower conductor 241B, at least one second lower conductor 243B, at least one first leg 223B, at least one second leg 225B, and at least one power supply portion 227B.

[0052] 13, the antenna element 20B is disposed above the ground conductor 40B and spaced apart from the ground conductor 40B to form an antenna device 10B. The antenna element 20B and the ground conductor 40B are fixed to each other by a support member (not shown). Air exists between the antenna element 20B and the ground conductor 40B as a dielectric. Thus, in the antenna device of the present invention, the dielectric may be air.

[0053] (Second Modification) 14, the antenna device 10C is configured by disposing the antenna element 20B above and away from the ground conductor 40B. In the vertical direction, a dielectric 34 is filled between the first lower conductor 241B or the second lower conductor 243B and the ground conductor 40B. As the dielectric 34, various resins such as epoxy resin and Teflon (registered trademark) can be used. Thus, in the antenna device of the present invention, the dielectric does not need to be a rigid substrate.

[0054] (Third Modification) 15, the antenna device 10D is configured by disposing the antenna element 20B above the ground conductor 40B and away from the ground conductor 40B. In the vertical direction, a space between the upper conductor 221B of the ground conductor 40B and the ground conductor 40B is filled with a dielectric 34. Various resins such as epoxy resin and Teflon (registered trademark) can be used as the dielectric 34. In this way, in the antenna device of the present invention, the dielectric may be filled not only between the antenna element 20B and the ground conductor 40B but also inside the antenna element 20B.

[0055] (Fourth Modification) 16, the antenna device 10E is configured by disposing the antenna element 20B above the ground conductor 40B and away from the ground conductor 40B. In the vertical direction, a dielectric 34 is filled in a space between the upper conductor 221B of the ground conductor 40B and the first lower conductor 241B or the second lower conductor 243B. In addition, in the vertical direction, air exists as a dielectric between the first lower conductor 241B or the second lower conductor 243B and the ground conductor 40B. In this way, in the antenna device of the present invention, the dielectric may be filled only inside the antenna element 20B.

[0056] (Slot Variations) When the upper element 22 or the antenna element 20A is manufactured using a single metal plate, the first leg 223 or 223A and the power feeder 227 or 227A are cut and raised. At that time, a slot (opening) is necessarily formed in the upper conductor 221 or 221A. The shape of the slot can be set arbitrarily, for example, as shown in Fig. 17 to Fig. 24. However, it is preferable that the shape of the upper conductor and the shape and arrangement of the slot have n-fold symmetry in order to realize communication by circular polarization.

[0057] 17, four first slots 261 and two second slots 263 are formed in the upper conductor 221C. The first slots 261 and the second slots 263 are each rectangular in shape. The first slots 261 correspond to, for example, the first leg portions 223 of the first embodiment. The second slots 263 correspond to, for example, the power supply portions 227 of the first embodiment.

[0058] 18, two third slots 265 are further formed compared to upper conductor 221C in FIG. 17. Third slots 265 are dummy slots that do not correspond to either first leg 223 or power feeding portion 227 of the first embodiment. By forming the dummy slots, the shape of upper conductor 221C in FIG. 18 has four-fold symmetry. This makes it possible to obtain circularly polarized waves with high circularity.

[0059] As shown in FIG. 19 or 20, the shape of the first slot 261 may be hexagonal.

[0060] In each of the upper conductors 221C in Fig. 17 to Fig. 20, each of the first slots 261 is disposed between the center and a side of the upper conductor 221C, and each of the second slots 263 is disposed between the center and a corner of the upper conductor 221C. However, as shown in Fig. 21 to Fig. 24, each of the first slots 261 may be disposed between the center and a corner of the upper conductor 221C, and each of the second slots 263 may be disposed between the center and a side of the upper conductor 221C. Also, as shown in Fig. 23 or 24, the shape of the first slots 261 may be octagonal.

[0061] 17 to 24, none of the first slot 261, the second slot 263, and the third slot 265 extends to the center or to the outer edge of the upper conductor 221C. Therefore, each of the upper conductors 221C shown in Fig. 17 to 24 has a central portion 231C, an annular portion 233C surrounding it without interruption, and a connecting portion 235C connecting the central portion 231C and the annular portion 233C. [Explanation of symbols]

[0062] 10, 10A, 10B, 10C, 10D, 10E Antenna device 20, 20A, 20B Antenna elements 22 Upper Element 221, 221A, 221B, 221C Upper conductor 223,223A,223B 1st leg 225,225A,225B 2nd leg 227, 227A, 227B Power supply unit 231,231A,231C central part 233, 233A, 233C Circular section 235,235A,235C connection part 24 Lower Element 241, 241A, 241B First lower conductor 243, 243A, 243B Second lower conductor 245 Ground Layer 261 1st Slot 263 2nd Slot 265 3rd Slot 30,30A Dielectric substrate 32 Power Pad 34 Dielectric 40, 40A, 40B Ground conductor

Claims

1. An antenna element that constitutes an antenna device by being provided on a ground conductor via a dielectric, the antenna element includes an upper conductor, at least one first lower conductor, at least one second lower conductor, at least one first leg, at least one second leg, and at least one feed; the upper conductor has a central portion, an annular portion, and a connecting portion; the annular portion is spaced apart from the central portion and seamlessly surrounds the central portion; the connecting portion connects the central portion and the annular portion, the at least one first leg extends from the central portion; the at least one second leg extends from the annular portion; the at least one first lower conductor is spaced apart from the upper conductor in the vertical direction and is connected to the at least one first leg; the at least one second lower conductor is separate from and spaced apart from the at least one first lower conductor; the at least one second lower conductor is spaced apart from the upper conductor in the vertical direction and is connected to the at least one second leg portion; The at least one feed portion extends from the upper conductor. Antenna element.

2. 2. The antenna element according to claim 1, The at least one power supply unit includes two power supplies, Two imaginary lines connecting the center of the central portion and the two power supply portions form an angle of 90 degrees in a plan view. Antenna element.

3. 2. The antenna element according to claim 1, the at least one first lower conductor and the at least one first leg are equal in number and connected to each other in a one-to-one relationship; The at least one second lower conductor and the at least one second leg are equal in number and connected one-to-one. Antenna element.

4. 4. The antenna element according to claim 3, the at least one first lower conductor comprises four first lower conductors; The at least one second lower conductor comprises four second lower conductors. Antenna element.

5. 2. The antenna element according to claim 1, the upper conductor extends in a plane intersecting the up-down direction, The upper conductor, the at least one first leg, the at least one second leg, and the at least one power supply portion are formed of a single metal plate. Antenna element.

6. 2. The antenna element according to claim 1, the upper conductor extends in a plane intersecting the up-down direction, The upper conductor, the at least one first lower conductor, the at least one second lower conductor, the at least one first leg, the at least one second leg, and the at least one power supply portion are formed of a single metal plate. Antenna element.

7. An antenna element according to any one of claims 1 to 6; A ground conductor; a dielectric interposed between the antenna element and the ground conductor; An antenna device comprising:

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