Antenna elements and antenna devices

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

[0006] , , , ,

[0005] , , ,

[0007] , , ,

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

Background Art

[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 able to be miniaturized as compared with a planar antenna device including a ceramic substrate.

[0003] Referring to FIG. 25, an antenna device 90 disclosed in Patent Document 1 includes a dielectric substrate 92, an antenna element 95 made of a metal plate disposed 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

Summary of the Invention

Problems 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] Therefore, an object of the present invention is to provide an antenna device that is small and capable of communicating in dual bands, and an antenna element used therefor.

Means for Solving the Problems

[0007] The present invention relates to an antenna element that constitutes an antenna device by being provided on a ground conductor via a dielectric as a first antenna element, The antenna element comprises 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 point. The upper conductor has a central portion, an annular portion, and a connecting portion. The annular portion is located away from the central portion and surrounds the central portion without any breaks. The aforementioned 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 separated from the upper conductor in the vertical direction and is connected to the at least one first leg portion. The at least one second lower conductor is separate from the at least one first lower conductor and is located away from the at least one first lower conductor. The at least one second lower conductor is separated from the upper conductor in the vertical direction and is connected to the at least one second leg portion. The at least one power supply unit extends from the upper conductor. Provides antenna elements.

[0008] Furthermore, the present invention provides a second antenna element, which is the first antenna element, The aforementioned at least one power supply unit comprises two power supply units, The two imaginary lines connecting the center of the central section and the two power supply sections form a 90-degree angle in a plan view. Provides antenna elements.

[0009] Furthermore, the present invention provides a third antenna element, which is the first antenna element, The at least one first lower conductor and the at least one first leg are numbered equally and connected 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 in a one-to-one relationship. Provides antenna elements.

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

[0011] Furthermore, the present invention provides a fifth antenna element, which is the first antenna element, The upper conductor extends in a plane that intersects the vertical direction, The upper conductor, the at least one first leg, the at least one second leg, and the at least one power supply section are made of a single metal plate. Provides antenna elements.

[0012] Furthermore, the present invention provides a sixth antenna element, which is the first antenna element, The upper conductor extends in a plane that intersects the vertical direction, The upper conductor, the at least one first lower conductor, the at least one second lower conductor, the at least one first leg portion, the at least one second leg portion, and the at least one power supply portion are made of a single metal plate. Provides antenna elements.

[0013] Furthermore, the present invention provides a first antenna device comprising one of the first to sixth antenna elements, Ground conductor and, A dielectric interposed between the antenna element and the ground conductor To provide an antenna device including the same.

Advantages of the Invention

[0014] In the antenna element according to the present invention, each of the first lower conductor and the second lower conductor forms a capacitor with the upper conductor. Thereby, miniaturization of the antenna element can be achieved. An antenna device including such an antenna element can also be miniaturized.

[0015] Particularly, the shape and size of the second lower conductor affect the setting of two frequencies of the first resonance and the second resonance, and the shape and size of the first lower conductor affect only the frequency of the first resonance. Therefore, by determining the shapes and sizes of the first lower conductor and the second lower conductor, the first resonance and the second resonance can be set to desired frequencies. That is, an antenna element for an antenna device capable of communicating in a dual band can be obtained.

Brief Description of the Drawings

[0016] [Figure 1] It is a perspective view showing an antenna device according to a first embodiment of the present invention. [Figure 2] It is a top view showing the antenna device of FIG. 1. [Figure 3] It is a side view showing the antenna device of FIG. 1. A part of the second leg portion and its periphery are shown enlarged. [Figure 4] It is a perspective view showing an upper element included in the antenna element used in the antenna device of FIG. 1. [Figure 5] It is a top view showing the upper element of FIG. 4. [Figure 6] It is a rear view showing the upper element of FIG. 4. [Figure 7] It is a perspective view showing a dielectric substrate used in the antenna device of FIG. 1. On the upper surface of the dielectric substrate, a lower element included in the antenna element used in the antenna device is provided. [Figure 8] Figure 7 is a top view showing the dielectric substrate. [Figure 9] Figure 7 is a rear view showing the dielectric substrate. [Figure 10] This is a perspective view showing an antenna device according to a second embodiment of the present invention. [Figure 11] Figure 10 is a top view showing the antenna device. [Figure 12] Figure 10 is a side view showing the antenna device. [Figure 13] This is a schematic diagram showing a first modified example of the antenna device according to the present invention. [Figure 14] This is a schematic diagram showing a second modified example of the antenna device according to the present invention. [Figure 15] This is a schematic diagram showing a third modified example of the antenna device according to the present invention. [Figure 16] This is a schematic diagram showing a fourth modified example of the antenna device according to the present invention. [Figure 17] This is a schematic diagram showing a first modified example of a slot formed in an antenna element according to the present invention. [Figure 18] This is a schematic diagram showing a second modified example of a slot formed in an antenna element according to the present invention. [Figure 19] This is a schematic diagram showing a third modified example of a slot formed in an antenna element according to the present invention. [Figure 20] This is a schematic diagram showing a fourth modified example of a slot formed in an antenna element according to the present invention. [Figure 21] This is a schematic diagram showing a fifth modified example of a slot formed in an antenna element according to the present invention. [Figure 22] This is a schematic diagram showing a sixth modified example of a slot formed in an antenna element according to the present invention. [Figure 23] This is a schematic diagram showing a seventh modified example of a slot formed in an antenna element according to the present invention. [Figure 24] This is a schematic diagram showing an eighth modified example of a slot formed in an antenna element according to the present invention. [Figure 25]This is a perspective view showing the antenna device described in Patent Document 1. [Modes for carrying out the invention]

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

[0018] As can be seen from Figures 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 Figures 4 to 6, the upper element 22 comprises an upper conductor 221, at least one first leg portion 223, at least one second leg portion 225, and at least one power supply portion 227.

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

[0021] As can be seen from Figures 4 to 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 portion 223, at least one second leg portion 225, and at least one power supply portion 227 are all made of a single metal plate. More specifically, the upper element 22 is integrally formed by punching and bending a single metal plate. However, the present invention is not limited thereto. The upper element 22 may be made using multiple metal plates. Alternatively, the upper element 22 may be formed by laser direct structuring (LDS).

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

[0023] As can be seen from Figure 8, in this embodiment, the lower element 24 comprises 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 of a predetermined shape to the upper surface of the dielectric substrate 30. However, the present invention is not limited thereto. 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. Also, 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 in different positions in the vertical direction. In that 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 isolated.

[0024] As can be seen from Figures 2, 5, and 8, each first lower conductor 241 corresponds to each first leg portion 223. In other words, there are an equal number of at least one first lower conductor 241 and at least one first leg portion 223. In this embodiment, there are four first lower conductors 241. In other words, at least one first lower conductor 241 comprises four first lower conductors 241. Also, each second lower conductor 243 corresponds to each second leg portion 225. In other words, there are an equal number of at least one second lower conductor 243 and at least one second leg portion 225. In this embodiment, there are four second lower conductors 243. In other words, at least one second lower conductor 243 comprises four second lower conductors 243. However, the present invention is not limited thereto. The number of first lower conductors 241 can be arbitrarily set as long as it is the same as the number of first legs 223. Similarly, the number of second lower conductors 243 can be arbitrarily set as long as it is the same as the number of second legs 225.

[0025] As shown in Figures 7 and 8, at least one power supply pad 32 is provided on the upper surface of the dielectric substrate 30. Each power supply pad 32 corresponds to a power supply unit 227. In this embodiment, there are two power supply pads 32. The power supply pads 32 are connected to a power supply line (not shown) provided on the lower surface of the dielectric substrate 30 via vias that penetrate the dielectric substrate 30 in the vertical direction.

[0026] As shown in Figure 3, the ground conductor 40 is positioned directly beneath the dielectric substrate 30. In other words, the antenna device 10 is mounted on the ground conductor 40. As the ground conductor 40, a circuit board can be used in which conductive layers are formed on the entire upper and lower surfaces of an insulating substrate. In this case, it is preferable that the conductive layer on the upper surface and the conductive layer on the lower surface are connected to each other using vias or the like.

[0027] As can be seen from Figures 3 and 9, in this embodiment, a ground layer 245 is formed on the lower surface of the dielectric substrate 30, covering almost its entire surface. The ground conductor 40, which is located beneath the dielectric substrate 30, is electrically connected to the ground layer 245. However, the present invention is not limited thereto. The dielectric substrate 30 does not have to have a ground layer 245.

[0028] Referring to Figure 5, in this embodiment, the outer shape of the upper conductor 221 is approximately 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 approximately square in plan view. However, in order to enable communication by circular polarization in the antenna device 10, it is preferable that the outer shape of the upper conductor 221 is approximately n times symmetric in plan view. Here, n is a multiple of 4 (the same applies hereafter).

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

[0030] As shown in Figure 5, in this embodiment, the outer shape of the central portion 231 is a square that is substantially similar to the outer shape of the upper conductor 221 in a plan view. In this embodiment, the annular portion 233 is a substantially square frame shape that follows the outer shape of the upper conductor 221. In a plan view, the annular portion 233 is located outside the central portion 231 and surrounds the central portion 231 without any breaks. In this embodiment, there are four connecting portions 235. Each connecting portion 235 corresponds to one of the four corners of the central portion 231 and each corresponding to one of the four corners of the annular portion 233. Each connecting portion 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 Figures 5 and 6, in this embodiment, the central portion 231, the annular portion 233, and the connecting portion 235 are located on a plane that intersects the vertical direction. In other words, the upper conductor 221 extends within a plane that intersects the vertical direction. In this embodiment, the upper conductor 221 extends within a plane perpendicular to the vertical direction. However, the present invention is not limited thereto. The annular portion 233 does not have to be located in part on the plane where the central portion 231 and the connecting portion 235 are located.

[0032] As shown in Figures 4 to 6, the first legs 223 extend from the central portion 231. In this embodiment, the first legs 223 extend outward in a plan view. More specifically, each of the first legs 223 extends outward horizontally from one of the four sides of the central portion 231, then diagonally downward, and further outward horizontally. In this embodiment, each of the first legs 223 extends in either the front-to-back direction or the side-to-side direction. In this embodiment, the front-to-back direction is the X direction, and the side-to-side direction is the Y direction. Also, the +X direction is forward, and the -X direction is backward.

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

[0034] As shown in Figures 4 to 6, the power supply section 227 extends from the upper conductor 221. In this embodiment, the power supply section 227 extends from two adjacent connecting sections 235 in the front-rear direction. However, the present invention is not limited thereto. The power supply section 227 may also extend from the central section 231.

[0035] As can be seen from Figure 5, the two virtual lines connecting the center of the central section 231 and the two power supply sections 227 form a 90-degree angle in plan view. This makes it possible to realize communication using circular polarization with a two-point power supply method using the antenna device 10.

[0036] As shown in Figures 7 and 8, the first lower conductors 241 are spaced apart from each other in the central part of the dielectric substrate 30. 231 The first lower conductor 241 is arranged in a plan view, with respect to the center of the dielectric substrate 30, with respect to four times symmetrical arrangement. In this embodiment, the shape of each of the first lower conductors 241 is a nonagon that is symmetrical with respect to a straight line. However, the present invention is not limited thereto. Each The shape can be set arbitrarily. However, it is preferable that the first lower conductor 241 is formed with approximately n rotational symmetry with respect to the center of the dielectric substrate 30 in a plan view.

[0037] As can be seen from Figures 1 to 3, each of the first lower conductors 241 is connected to the corresponding first leg 223. In other words, the first lower conductors 241 are connected one-to-one with the first leg 223. Due to the presence of the first leg 223, the first lower conductors 241 are separated from the upper conductor 221 in the vertical direction.

[0038] As shown in Figures 7 and 8, the second lower conductors 243 are arranged 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 square in plan view. However, the present invention is not limited thereto. The shape of each of the second lower conductors 243 can be arbitrarily set. However, it is preferable that the second lower conductors 243 are formed with approximately n rotational symmetry with respect to the center of the dielectric substrate 30 in plan view.

[0039] As can be seen from Figures 1 to 3, each of the second lower conductors 243 is connected to the corresponding second leg 225. In other words, the second lower conductors 243 are connected one-to-one with the second leg 225. Due to the presence of the second leg 225, the second lower conductors 243 are separated from the upper conductor 221 in the vertical direction.

[0040] As shown in Figures 7 and 8, each of the power supply pads 32 is positioned diagonally across 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 aligned in a straight line along the front-to-back direction, with one first lower conductor 241 in between.

[0041] In the antenna device 10 shown in Figures 1 to 3, the first lower conductor 241 and the second lower conductor 243 each constitute a capacitor with the upper conductor 221. That is, the presence of the first lower conductor 241 and the second lower conductor 243 affects the resonant frequency of the antenna device 10. More specifically, the presence of the first lower conductor 241 and the second lower conductor 243 lowers the resonant 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 resonant frequency, and thereby makes it possible to miniaturize the antenna device 10.

[0042] In the antenna device 10 shown in Figures 1 to 3, the first lower conductor 241 and the second lower conductor 243 each constitute a capacitor with the ground conductor 40. Instead of this capacitor, a capacitor element such as a chip capacitor may be connected between the first lower conductor 241 and the second lower conductor 243 and the ground conductor 40.

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

[0044] The antenna device 10 shown in Figures 1 to 3 employs a two-point feeding system. Specifically, by inputting a first input signal to one of the feeding pads 32 and a second input signal with a phase difference of 90 degrees from the first input signal to the other of the feeding pads 32, the antenna element 20 can be made to communicate using highly circularly polarized waves. In order to achieve highly circularly polarized communication, 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 be approximately n rotationally symmetric.

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

[0046] As can be seen from Figures 10 to 12, the antenna element 20A comprises an upper conductor 221A, at least one first leg portion 223A, at least one second leg portion 225A, at least one feed portion 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. The upper conductor 221A also has a central portion 231A, an annular portion 233A, and a connecting portion 235A, similar to the upper conductor 221 of the first embodiment.

[0047] As can be seen from Figures 10 to 12, in this embodiment, the number of first legs 223A, second legs 225A, first lower conductor 241A, and second lower conductor 243A are each four. Also, in this embodiment, the number of power supply units 227A is two.

[0048] As can be seen from Figures 10 to 12, the antenna element 20A is mounted on the upper surface of the 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 miniaturize the antenna element 20A and the antenna device 10A. Furthermore, according to this embodiment, it is possible to obtain an antenna element 20A and antenna device 10A capable of dual-band communication. Since the first lower conductor 241A and the second lower conductor 243A are integrated with 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] Although the present invention has been described above with reference to embodiments, the present invention is not limited to the embodiments described above, and various modifications and changes are possible without departing from the spirit of the present invention.

[0051] (First variation) Referring to Figure 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 feed point 227B.

[0052] As shown in Figure 13, the antenna element 20B is positioned above the ground conductor 40B, away from the ground conductor 40B, and constitutes the 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 as a dielectric between the antenna element 20B and the ground conductor 40B. Thus, in the antenna device of the present invention, the dielectric may be air.

[0053] (Second variation) Referring to Figure 14, the antenna device 10C is configured with the antenna element 20B positioned above the ground conductor 40B, 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. Various resins such as epoxy resin and Teflon (registered trademark) can be used as the dielectric 34. Thus, in the antenna device of the present invention, the dielectric does not need to be a rigid substrate.

[0054] (Third variation) Referring to Figure 15, the antenna device 10D is configured with the antenna element 20B positioned above the ground conductor 40B, away from the ground conductor 40B. In the vertical direction, Antenna element 20B A dielectric 34 is filled in the space between the upper conductor 221B and the ground conductor 40B. Various resins such as epoxy resin and Teflon (registered trademark) can be used as the dielectric 34. Thus, 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 variation) Referring to Figure 16, the antenna device 10E is configured with the antenna element 20B positioned above the ground conductor 40B, away from the ground conductor 40B. In the vertical direction, Antenna element 20B A dielectric 34 is filled in the space between the upper conductor 221B and the first lower conductor 241B or the second lower conductor 243B. 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. Thus, in the antenna device of the present invention, physical The dielectric material may be filled only inside the antenna element 20B.

[0056] (Slot machine variation) When the upper element 22 or antenna element 20A is manufactured using a single metal plate, the first leg portion 223 or 223A and the feed portion 227 or 227A are cut and bent. At this time, a slot (opening) is inevitably formed in the upper conductor 221 or 221A. The shape of the slot can be arbitrarily set, for example, as shown in Figures 17 to 24. However, the shape of the upper conductor, the shape and arrangement of the slot are preferably n times symmetric in order to realize circular polarization communication.

[0057] Referring to Figure 17, the upper conductor 221C has four first slots 261 and two second slots 263. The shape of each of the first slots 261 and second slots 263 is rectangular. The first slots 261 correspond to, for example, the first leg portion 223 of the first embodiment. The second slots 263 correspond to, for example, the power supply portion 227 of the first embodiment.

[0058] Referring to Figure 18, compared to the upper conductor 221C in Figure 17, two additional third slots 265 are formed. The third slots 265 are dummy slots that do not correspond to either the first leg portion 223 or the power supply portion 227 of the first embodiment. By forming the dummy slots, the shape of the upper conductor 221C in Figure 18 is symmetrical four times. This makes it possible to obtain circularly polarized waves with high circularity.

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

[0060] In each of the upper conductors 221C shown in Figures 17 to 20, each of the first slots 261 is positioned between the center and an edge of the upper conductor 221C, and each of the second slots 263 is positioned between the center and an edge of the upper conductor 221C. However, as shown in Figures 21 to 24, each of the first slots 261 may be positioned between the center and an edge of the upper conductor 221C, and each of the second slots 263 may be positioned between the center and an edge of the upper conductor 221C. Also, as shown in Figure 23 or Figure 24, the shape of the first slot 261 may be octagonal.

[0061] In all of the upper conductors 221C shown in Figures 17 to 24, the first slot 261, the second slot 263, and the third slot 265 do not extend to the center of the upper conductor 221C, nor do they extend to the outer edge. Therefore, each of the upper conductors 221C shown in Figures 17 to 24 has a central portion 231C, an annular portion 233C that surrounds it without interruption, and a connecting portion 235C that connects the central portion 231C and the annular portion 233C. [Explanation of Symbols]

[0062] 10, 10A, 10B, 10C, 10D, 10E Antenna equipment 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 section 231,231A,231C central part 233, 233A, 233C Annular 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 Slot 1 263 Second slot 265 Third Slot 30,30A dielectric substrate 32 Power supply pads 34 Dielectrics 40, 40A, 40B Ground conductor

Claims

1. An antenna element that constitutes an antenna device by being placed on a ground conductor via a dielectric, The antenna element comprises 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 point. The upper conductor has a central portion, an annular portion, and a connecting portion. The annular portion is located away from the central portion and surrounds the central portion without any breaks. The aforementioned 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 separated from the upper conductor in the vertical direction and is connected to the at least one first leg portion. The at least one second lower conductor is separate from the at least one first lower conductor and is located away from the at least one first lower conductor. The at least one second lower conductor is separated from the upper conductor in the vertical direction and is connected to the at least one second leg portion. The at least one power supply unit extends from the upper conductor, The at least one power supply unit is not directly connected to either the at least one first lower conductor or the at least one second lower conductor. The at least one first lower conductor and the at least one first leg are numbered equally and connected 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 in a one-to-one relationship. Antenna element.

2. The antenna element according to claim 1, The aforementioned at least one power supply unit comprises two power supply units, The two imaginary lines connecting the center of the central section and the two power supply sections form a 90-degree angle in a plan view. Antenna element.

3. The antenna element according to claim 1, The aforementioned at least one first lower conductor comprises four first lower conductors, The aforementioned at least one second lower conductor comprises four second lower conductors. Antenna element.

4. The antenna element according to claim 1, The upper conductor extends in a plane that intersects the vertical direction, The upper conductor, the at least one first leg, the at least one second leg, and the at least one power supply section are made of a single metal plate. Antenna element.

5. The antenna element according to claim 1, The upper conductor extends in a plane that intersects the vertical direction, The upper conductor, the at least one first lower conductor, the at least one second lower conductor, the at least one first leg portion, the at least one second leg portion, and the at least one power supply portion are made of a single metal plate. Antenna element.

6. An antenna element according to any one of claims 1 to 5, Ground conductor and, A dielectric interposed between the antenna element and the ground conductor An antenna device equipped with the following features.

Images