Antenna device

Abstract

[Problem] To achieve cost reduction and gain enhancement for antennas. [Solution] An antenna device of the present disclosure comprises: a substrate; a plurality of antenna elements that are disposed on a first surface of the substrate; a power-feeding circuit that is disposed on a second surface of the substrate that is the reverse side of the first surface; and a first conductor that is disposed to a position facing the power-feeding circuit. A void is formed between the power-feeding circuit and the first conductor.

Description

Antenna device and radio device

[0001] The present disclosure relates to an antenna device and a wireless device.

[0002] In 5G base station equipment, an increase in equivalent isotropically radiated power (EIRP) and a decrease in power consumption are required. To increase the EIRP, it is necessary to increase the transmission power of the radio equipment or improve the antenna gain. However, increasing the transmission power of the radio equipment leads to an increase in the power consumption of the base station equipment. Therefore, to increase the EIRP, it is desirable to improve the antenna gain.

[0003] International Publication No. 2022 / 176285

[0004] Here, in an array antenna device in which a large number of antenna elements are arranged, minimizing power loss in the feed circuit is important to improve antenna gain with the same antenna area. A feed circuit is a circuit in an array antenna device that distributes power supplied from a radio circuit unit to each element. Patent Document 1 discloses an antenna structure including a microstrip line. Generally, a microstrip line has a feed circuit formed on the front surface of a printed circuit board and a ground layer formed on the back surface of the printed circuit board. In this case, electromagnetic waves propagate within the printed circuit board, causing dielectric loss and reducing antenna gain. Therefore, in order to improve antenna gain in an antenna structure including a microstrip line, it is considered to use a printed circuit board with a low dielectric constant and low dielectric loss tangent, for example.

[0005] However, printed circuit boards with low dielectric constants and low dielectric loss tangents are generally expensive, so there is a demand for a structure that can improve antenna gain at lower cost.

[0006] In view of the above-mentioned problems, an object of the present disclosure is to provide an antenna device and a wireless device that enable improvement of antenna gain at low cost.

[0007] An antenna device in one aspect of the present invention comprises a substrate, a plurality of antenna elements arranged on a first surface of the substrate, a power supply circuit arranged on a second surface that is the reverse side of the first surface of the substrate, and a first conductor arranged in a position opposite the power supply circuit, and an air gap is formed between the power supply circuit and the first conductor.

[0008] An antenna device in one aspect of the present invention includes a substrate, a plurality of antenna elements arranged on a first surface of the substrate, a power supply circuit arranged on a second surface, which is the reverse side of the first surface of the substrate, for distributing power to the plurality of antenna elements, and a conductor arranged opposite the power supply circuit and functioning as a ground for the power supply circuit, wherein an air gap is formed between the power supply circuit and the conductor.

[0009] In one aspect of the present invention, a wireless device includes an antenna device and a transceiver, the antenna device including a substrate, a plurality of antenna elements arranged on a first surface of the substrate, a power supply circuit arranged on a second surface that is the reverse side of the first surface of the substrate, and a first conductor arranged in a position opposite the power supply circuit, with a gap formed between the power supply circuit and the first conductor.

[0010] According to the present disclosure, it is possible to provide an antenna device and a wireless device that can improve antenna gain at low cost.

[0011] FIG. 1 is a diagram illustrating a configuration of an antenna device according to a first embodiment. FIG. 2 is a diagram illustrating a configuration of an antenna device according to a second embodiment. FIG. 3 is a cross-sectional view of the antenna device according to the second embodiment. FIG. 4 is a diagram illustrating an example of dimensions of the antenna device according to the second embodiment. FIG. 5 is a diagram illustrating an example of a wireless device including the antenna device according to the second embodiment. FIG. 6 is a diagram illustrating a configuration of an antenna device according to a first modified example of the second embodiment. FIG. 7 is a diagram illustrating a configuration of an antenna device according to a second modified example of the second embodiment. FIG. 8 is a diagram illustrating a configuration of an antenna device according to a third embodiment. FIG. 9 is a cross-sectional view of the antenna device according to the third embodiment. FIG. 10 is a diagram illustrating an example arrangement of a support member according to the third embodiment. FIG. 11 is a diagram illustrating an example arrangement of a support member according to the third embodiment. FIG. 12 is a diagram illustrating an example of a wireless device including the antenna device according to the third embodiment.

[0012] Next, embodiments of the present invention will be described in detail with reference to the drawings. In each drawing and each embodiment described in the specification, components having similar functions are given similar reference numerals.

[0013] First Embodiment FIG. 1 is a diagram showing a configuration of an antenna device 1 according to a first embodiment of the present disclosure.

[0014] Referring to FIG. 1, an antenna device 1 according to this embodiment includes a substrate 10, an antenna element 20, a feed circuit 30, and a conductor 40.

[0015] The antenna device 1 is a device that performs transmission processing of radio frequency signals.

[0016] An electrical wiring pattern is provided on the substrate 10 of the antenna device 1, and a plurality of antenna elements 20 are arranged on a first surface, which is one side of the substrate 10. The plurality of antenna elements 20 are arranged along the X direction in Fig. 1 (the direction from the back to the front of the page or the opposite direction). The substrate 10 may also be called a printed circuit board.

[0017] The antenna element 20 of the antenna device 1 is disposed on a first surface, which is one surface of the substrate 10. The antenna element 20 functions as a primary resonator for the transceiver of the antenna device 1 to transmit and receive signals.

[0018] The power supply circuit 30 of the antenna device 1 is disposed on the second surface, which is the surface opposite to the first surface of the substrate 10. The power supply circuit 30 is a circuit that supplies power to the plurality of antenna elements 20.

[0019] The conductor 40 of the antenna device 1 serves as a first conductor and is disposed in a position facing the feed circuit 30. The conductor 40 functions as a ground for the feed circuit 30.

[0020] Furthermore, a gap 50 is formed between the power supply circuit 30 and the conductor 40. The gap 50 is, for example, an air layer.

[0021] 1 , in the antenna device 1 of this embodiment, electromagnetic waves propagate through the gap 50 formed between the substrate 10 and the conductor 40. On the other hand, as described above, in a typical microstrip line, electromagnetic waves propagate through a printed circuit board. Here, the air present in the gap has a lower relative dielectric constant than the printed circuit board. Therefore, the antenna device 1 of this embodiment can reduce dielectric loss during power feeding compared to an antenna device having a typical microstrip line.

[0022] Furthermore, in the antenna device 1 of this embodiment, the following effect can be obtained by propagating electromagnetic waves through the air gap 50. That is, in the antenna device 1 of this embodiment, it is not necessary to use a printed circuit board with a low dielectric constant and a low dielectric loss tangent, which is generally considered to be expensive, and a versatile, low-cost board can be used.

[0023] As described above, the antenna device 1 of this embodiment can improve the antenna gain at low cost.

[0024] Second Embodiment An antenna device 2 according to a second embodiment of the present disclosure will be described.

[0025] FIG. 2 is a diagram showing the configuration of the antenna device 2 according to this embodiment.

[0026] Referring to Figure 2, the antenna device 2 in this embodiment is an array antenna device including a substrate 10, a plurality of antenna elements 21, a feed circuit 30, a conductor 41, an antenna element feed section 60, a radome 70, a radome connection section 80, an antenna element 22, and a bandpass filter 90.

[0027] The antenna device 2 is a device that performs transmission processing of radio frequency signals.

[0028] An electric wiring pattern is provided on the substrate 10 of the antenna device 2, and a plurality of antenna elements 21 are arranged on a first surface, which is one surface of the substrate 10. The plurality of antenna elements 21 are arranged along the X direction in Fig. 2. The substrate 10 may also be referred to as a printed circuit board. The substrate 10 may be, for example, a general-purpose glass epoxy board, but is not limited to this.

[0029] The antenna element 21 of the antenna device 2 is disposed on a first surface, which is one side of the substrate 10. The first surface is the direction of radio wave emission from the antenna element 21 and may be referred to as the front surface or the top surface. A second surface of the substrate 10 opposite to the first surface may be referred to as the back surface or the bottom surface. The antenna element 21 functions as a primary resonator for transmitting and receiving signals by a transceiver 100, which will be described later. The multiple antenna elements 21 are disposed on the first surface of the substrate 10 at a predetermined distance from each other. The antenna elements 21 may be, for example, a patch antenna or a dipole antenna, but are not limited to these.

[0030] The antenna device 2 emits radio waves from the antenna element 22 in the Z direction in Figure 2 (the direction in which the first surface of the substrate 10 is oriented) through dual resonance between the antenna element 21 and the antenna element 22 described later, making it possible to send and receive signals with a communication device in that direction.

[0031] The feed circuit 30 of the antenna device 2 is disposed on the second surface, which is the opposite side of the first surface of the substrate 10. The feed circuit 30 is a circuit that feeds power to the multiple antenna elements 21. The feed circuit 30 is disposed along the multiple antenna elements 21. The feed circuit 30 distributes power to the multiple antenna elements 21. The feed circuit 30 is electrically connected to an antenna element feed unit 60, which will be described later. The feed circuit 30 is also connected to a connector 130, which will be described later. In FIG. 2 , the feed circuit 30 connects to the connector 130 on the second surface side of the substrate 10, passes through the first surface side of the substrate 10, and is again formed on the second surface side of the substrate 10. However, the feed circuit 30 may also be connected to the connector 130 on the second surface side of the substrate 10, and be formed only on the second surface side without passing through the first surface side of the substrate 10. Specifically, the connector 130 may be, but is not limited to, a coaxial connector.

[0032] As shown in FIG. 3 , which will be described later, the conductor 41 of the antenna device 2 serves as a first conductor and is disposed in a position facing the power feed circuit 30. The conductor 41 functions as a ground for the power feed circuit 30. A portion of the conductor 41 is adjacent to the substrate 10. The material of the conductor 41 may be, for example, metal, but is not limited to this. Furthermore, the conductor 41 may be formed in combination with an insulator as long as at least the surface thereof is conductive. For example, the conductor 41 may be formed by covering the surface of an insulating material such as plastic or resin with a conductor such as metal plating.

[0033] Furthermore, a gap 51 is formed between the power supply circuit 30 and the conductor 41. The gap 51 is, for example, an air layer. The positional relationship between the power supply circuit 30, the conductor 41, and the gap 51 will be described in detail with reference to FIG. 3 .

[0034] 3 is a cross-sectional view of the antenna device 2 of this embodiment. Specifically, FIG. 3 is a cross-sectional view of the antenna device 2 of this embodiment taken along the dotted line in FIG. 2(a).

[0035] The void 51 is formed along the power feed circuit 30. Electromagnetic waves generated from the power feed circuit 30 propagate within the void 51. The void 51 may be formed in a rectangular parallelepiped shape as shown in FIG. 3 , but is not limited to this. The void 51 is further formed so as to be surrounded by the substrate 10 and the conductor 41. The void 51 may be formed by cutting a part of the rectangular parallelepiped conductor 41 and placing it adjacent to the substrate 10. Alternatively, the void 51 may be formed by placing the conductor 41 cast in a U-shape adjacent to the substrate 10. However, the shape of the conductor 41 that forms the void 51 and the method for creating that shape are not limited to those described above.

[0036] The size of the gap 51 may be determined by, but is not limited to, the characteristic impedance. The size of the gap 51 may be determined by, for example, the characteristic impedance of the connector 130. The characteristic impedance of the connector 130 may be 50 Ω. Components that affect the characteristic impedance include the width of the power supply circuit 30 and the distance from the second surface of the substrate 10 to the surface of the conductor 41 facing the second surface of the substrate 10. In other words, components that affect the characteristic impedance include the Y-direction dimension of the power supply circuit 30 in FIG. 3 and the Z-direction dimension of the gap 51 in FIG. 3. Furthermore, the distance between the side surfaces of the conductor 41 adjacent to the gap 51 (the Y-direction dimension of the gap 51), indicated by the bidirectional arrow in FIG. 3, is preferably as long as possible. This is because the characteristic impedance is affected if the distance between the side surfaces of the conductor 41 adjacent to the gap 51 is shorter than a predetermined value.

[0037] FIG. 4 is a diagram showing an example of dimensions in a cross section of the antenna device 2 of this embodiment shown in FIG. 3 . The example dimensions of the antenna device 2 shown in FIG. 4 are an example of design and are not limited to these. As shown in FIG. 4 , the distance from the second surface of the substrate 10 to the surface of the conductor 41 facing the second surface of the substrate 10 (the Z-direction dimension of the gap 51) may be, for example, 0.5 mm. The width of the feed circuit 30 (the Y-direction dimension of the feed circuit 30 in FIG. 4) may be, for example, 2.0 mm. The distance between the side surfaces of the conductor 41 adjacent to the gap 51 (the Y-direction dimension of the gap 51 in FIG. 4) may be, for example, 8.0 mm or greater. The thickness of the substrate 10 (the Z-direction dimension of the substrate 10 in FIG. 4) may be 1.0 mm. The thickness of the conductor 41 may be 1.5 mm. The distance between one end of the feed circuit 30 and the side surface of the conductor 41 adjacent to the gap 51 (the dimension in the Y direction between one end of the feed circuit 30 and one end of the gap 51 in FIG. 4) may be 3.0 mm.

[0038] Now, let us return to the description of FIG.

[0039] The antenna element feed section 60 of the antenna device 2 connects the antenna element 21 to the feed circuit 30 arranged on the second surface of the substrate 10. The antenna element feed section 60 may be, but is not limited to, a through hole formed in the substrate 10.

[0040] The radome 70 of the antenna device 2 is disposed opposite to the first surface of the substrate 10 and covers the first surface. The radome 70 is connected to the substrate 10 via a radome connection part 80 (described later). The radome 70 protects the first surface of the substrate 10 and the antenna element 21. The radome 70 also has a function of dissipating heat generated within the antenna device 2 or within a radio connected to the antenna device 2 to the outside. Note that the main heat source generated within the antenna device 2 or within a radio connected to the antenna device 2 is, for example, a transceiver 100 (described later). For example, as shown in FIG. 5 (described later), the transceiver 100 is thermally connected to a conductor 41 via a bandpass filter 90 (described later). Heat from the transceiver 100 is then transmitted through the conductor 41 to the radome 70. The heat source and the conductor 41 may be adjacent to each other and directly connected. Alternatively, the heat source and the conductor 41 may be connected via another component, and heat from the heat source may be transmitted to the conductor 41 via the other component. The other component may be, but is not limited to, a metal component. The material of the radome 70 may be, for example, a resin, or a metal having high thermal conductivity such as aluminum, silver, or copper. The radome 70 may be made of the same material as the conductor 41, for example. The radome 70 may be thermally connected to the conductor 41. However, the material of the radome 70 is not limited to the above.

[0041] The radome connecting portion 80 of the antenna device 2 connects the substrate 10 and the radome 70. Therefore, the radome 70 and the radome connecting portion 80 serve as the second conductor. The radome connecting portion 80 is fixed to the conductor 41 and the substrate 10 by a fastening portion 140. The fastening portion 140 may be, for example, a screw, but is not limited to this.

[0042] The antenna element 22 of the antenna device is disposed on the radome 70. The plurality of antenna elements 22 are arranged along the X direction in FIG. 2 . The plurality of antenna elements 22 are disposed on the radome 70 at a predetermined distance from each other. The antenna element 22 is disposed in a position facing the antenna element 21. The antenna element 22 may be, for example, a slot antenna, but is not limited to this. The antenna element 22 couples and resonates with the antenna element 21.

[0043] The bandpass filter 90 of the antenna device 2 is connected to the power supply circuit 30 via a connector 130. The bandpass filter 90 is also connected to the conductor 41.

[0044] 2 and 3, the antenna device 2 of this embodiment has the same effects as the first embodiment. Furthermore, the antenna device 2 of this embodiment can adjust and maintain the size of the air gap by adjusting the shape of the conductor 41. Therefore, compared to the antenna device 3 of the third embodiment described later, it is possible to maintain higher dimensional accuracy of the air gap. This makes it possible to maintain a reduction in dielectric loss during power feeding.

[0045] The antenna device 2 of this embodiment may also be mounted on a wireless device. FIG. 5 shows an example of a wireless device 5 including the antenna device 2 of this embodiment. The wireless device 5 shown in FIG. 5 is a device that performs wireless communication and includes the antenna device 2 of this embodiment and a transceiver 100. The transceiver 100 is a mechanism that enables the antenna device 2 to transmit and receive signals. The transceiver 100 may be disposed adjacent to a bandpass filter 90. The transceiver 100 may also be referred to as a transceiver, an RF (Radio Frequency) circuit, or an amplifier. The radome 70 and antenna element 22 of the antenna device 2 are located on the surface of the wireless device 5. As shown in FIG. 5, the radome 70 of the antenna device 2 may be extended to cover the surface of the wireless device 5.

[0046] The wireless device 5 shown in Fig. 5 is, for example, a base station device. The base station device may be, for example, a Node B, an e-Node B, a g-Node B, a Home Node B, or a Home e-Node B. A base station device equipped with the antenna device 2 of this embodiment can increase the equivalent isotropic radiated power compared to a base station device equipped with a conventional antenna device. The wireless device 5 equipped with the antenna device 2 of this embodiment is not limited to a base station device, and may be other wireless devices that perform wireless communication.

[0047] Furthermore, in an antenna device using a general microstrip line, the heat transfer path from the heat source to the radome includes the substrate, which reduces heat transfer efficiency. On the other hand, in this embodiment, when the heat source is directly connected to the conductor 41, the heat transfer path from the heat source to the radome 70 is the heat source, conductor 41, fastening part 140, radome connecting part 80, and radome 70. Therefore, by forming the conductor 41, fastening part 140, and radome connecting part 80 from materials with high thermal conductivity, the heat dissipation effect can be improved. In addition, in this embodiment, compared to an antenna device using a general microstrip line, it is not necessary to add any additional metal parts to improve heat transfer efficiency to the radome. Therefore, it is possible to achieve low cost and low mass.

[0048] (Variation 1) In this embodiment, the conductor 41 of the antenna device 2 and the radome connecting portion 80 are thermally connected by using the fastening portion 140. Alternatively, a hole may be formed in the substrate 10, and the conductor 41 and the radome connecting portion 80 may be directly connected to each other.

[0049] FIG. 6 is an enlarged view showing the configuration of the antenna device 2 in Modification 1 of this embodiment. Referring to FIG. 6 , a conductor connection portion 110 is arranged on a part of the substrate 10. The conductor connection portion 110 is arranged on a portion of the substrate 10 that contacts the conductor 41 and the radome connection portion 80. The conductor connection portion 110 may also be a protrusion formed on the radome connection portion 80 or the conductor 41. For example, it may be a protrusion provided on the surface of the radome connection portion 80 adjacent to the substrate 10. The protrusion may protrude from the radome connection portion 80 in the direction opposite to the Z-direction arrow in FIG. 6 . Alternatively, the conductor connection portion 110 may be a protrusion provided on the surface of the conductor 41 that contacts the substrate 10. The protrusion may protrude from the conductor connection portion 110 in the same direction as the Z-direction arrow in FIG. 6 . The conductor 41 and the radome connection portion 80 may be directly connected by drilling a hole in the portion of the substrate 10 that contacts the conductor 41 and the radome connection portion 80 and fitting a protrusion into the hole. In other words, a hole may be formed in the substrate 10, the conductor 41 or the radome connecting part 80 may be inserted into the hole, and the conductor 41 may be directly connected to the radome connecting part 80. The radome 70, the radome connecting part 80, and the conductor connecting part 110 are preferably made of a material with high thermal conductivity. Specifically, the radome 70, the radome connecting part 80, and the conductor connecting part 110 may be made of a conductor such as a metal.

[0050] In this modification, when the heat source is directly connected to the conductor 41, heat is conducted from the heat source to the radome 70 via a transmission path that passes through the conductor 41, the conductor connecting portion 110, and the radome connecting portion 80. This provides the same heat dissipation effect as in the second embodiment.

[0051] (Variation 2) In this embodiment, the conductor 41 of the antenna device 2 and the radome connecting portion 80 are thermally connected by using the fastening portion 140. Alternatively, the conductor 41 and the radome connecting portion 80 may be thermally connected by providing a through hole 150 in a part of the substrate 10.

[0052] Fig. 7 is an enlarged view showing the configuration of the antenna device 2 in Modification 2 of this embodiment. Referring to Fig. 7, a plurality of through holes 150 are formed in the substrate 10. The through holes 150 are formed in a portion of the substrate 10 that contacts the conductor 41 and the radome connecting portion 80. That is, the conductor 41 and the radome connecting portion 80 are connected via the through holes 150 formed in the substrate 10. The conductor 41 and the radome connecting portion 80 are connected via the through holes 150 in the Z direction in Fig. 7. The radome 70 and the radome connecting portion 80 are preferably made of a material with high thermal conductivity. Specifically, the radome 70 and the radome connecting portion 80 may be made of a conductor such as a metal.

[0053] In this modification, when the heat source is directly connected to the conductor 41, heat is conducted from the heat source to the radome 70 via a transmission path including the conductor 41, the through hole 150, and the radome connection portion 80. This provides the same heat dissipation effect as in the second embodiment.

[0054] Third Embodiment An antenna device 3 according to a third embodiment of the present disclosure will be described. Note that, in the following, the same components as those in the second embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0055] FIG. 8 is a diagram showing the configuration of the antenna device 3 in this embodiment.

[0056] Referring to Figure 8, the antenna device 3 in this embodiment includes a substrate 10, an antenna element 21, a power supply circuit 30, a conductor 42, a support member 120, an antenna element power supply section 60, a radome 70, a radome connection section 80, an antenna element 22, and a bandpass filter 90.

[0057] The conductor 42 of the antenna device 3 is disposed on the second surface of the substrate 10 in a position facing the feeder circuit 30. The conductor 42 functions as a ground for the feeder circuit 30. The material of the conductor 42 may be, for example, metal, but is not limited to this. The conductor 42 is adjacent to a support member 120, which will be described later.

[0058] The support member 120 of the antenna device 3 is disposed between the conductor 42 and the substrate 10. The support member 120 has a function of maintaining a predetermined dimension of the gap 52 between the conductor 42 and the substrate 10. The material of the support member 120 may be, for example, metal, but is not limited to this. The support member 120 may also be referred to as a spacer. The shape of the support member 120 may be, for example, a rectangular parallelepiped, but is not limited to this.

[0059] A gap 52 is formed between the power supply circuit 30, the conductor 42, and the support member 120. The gap 52 is, for example, an air layer. The positional relationship between the power supply circuit 30, the conductor 42, the support member 120, and the gap 52 will be described in detail with reference to FIG. 9 .

[0060] Fig. 9 is a cross-sectional view of the antenna device 3 of this embodiment. Fig. 9 is a cross-sectional view of the antenna device 3 of this embodiment shown in Fig. 8 taken along the dotted line in (b).

[0061] The air gap 52 is formed along the power feed circuit 30. Electromagnetic waves generated from the power feed circuit 30 propagate through the air gap 52. The air gap 52 may be formed in a rectangular parallelepiped shape as shown in FIG. 9 , but is not limited to this. The air gap 52 is further formed so as to be surrounded by the substrate 10, the conductor 42, and the support member 120.

[0062] The size of the gap 52 may be determined by, but is not limited to, the characteristic impedance. The size of the gap 52 may be determined by, for example, the characteristic impedance of the connector 130. The characteristic impedance of the connector 130 may be 50 Ω. Components that affect the characteristic impedance include the width of the power supply circuit 30 and the distance from the second surface of the substrate 10 to the surface of the conductor 42 facing the second surface of the substrate 10. In other words, components that affect the characteristic impedance include the Y-direction dimension of the power supply circuit 30 in FIG. 9 and the Z-direction dimension of the gap 52 in FIG. 3. The distance from the second surface of the substrate 10 to the surface of the conductor 42 facing the second surface of the substrate 10 (the Z-direction dimension of the gap 52) may be, for example, 0.5 mm. Furthermore, it is preferable to make as long as possible the distance between the side surfaces of the support member 120 adjacent to the gap 52 (the Y-direction dimension of the gap 52), as indicated by the double-headed arrow in FIG. 9 . This is because if the distance between the side surfaces of the support member 120 adjacent to the void 52 is shorter than a predetermined value, it will affect the characteristic impedance. The distance between the side surfaces of the support member 120 adjacent to the void 52 may be, for example, 8.0 mm or may be 8.0 mm or more.

[0063] The position where the support member 120 is arranged will be described with reference to FIGS. 10 and 11, which are examples of top views of the antenna device 3 of FIG.

[0064] FIG. 10 shows an example of the arrangement of the support members 120 in this embodiment. As shown in FIG. 10 , multiple support members 120 may be arranged along the outer periphery of the substrate 10. The support members 120 may also be arranged at regular intervals. When the support members 120 are sparsely arranged as in FIG. 10 , fewer support members 120 are used, thereby reducing costs. The support members 120 may also be densely arranged along the outer periphery of the substrate 10. Similarly, FIG. 11 shows an example of the arrangement of the support members 120 in this embodiment. As shown in FIG. 11 , multiple support members 120 may be arranged along the power supply circuit 30. When the support members 120 are densely arranged as in FIG. 11 , the dimensions of the gaps 52 are likely to be kept constant. When the dimensions of the gaps 52 are kept constant, heat dissipation efficiency is higher than when the support members 120 are sparsely arranged. The support members 120 may also be sparsely arranged along the power supply circuit 30.

[0065] The antenna device 3 of this embodiment has the structure shown in FIGS. 8 to 11 and thus provides the same effects as the second embodiment. Furthermore, the antenna device 3 of this embodiment is easier to design to have a smaller conductor mass than the antenna device 2 of the second embodiment, thereby achieving lower costs and mass. Furthermore, the antenna device 3 of this embodiment may be mounted on a wireless device, similar to the antenna device 2 of the second embodiment. An example of a wireless device 6 including the antenna device 3 of this embodiment is shown in FIG. 12 . The wireless device 6 shown in FIG. 12 is a device that performs wireless communication and includes the antenna device 3 of this embodiment and a transceiver 100. The transceiver 100 may be the same as the transceiver included in the wireless device 6 shown in FIG. 5 . The radome 70 and antenna element 22 of the antenna device 3 are located on the surface of the wireless device 6. As shown in FIG. 12 , the radome 70 of the antenna device 3 may be extended to cover the surface of the wireless device 6.

[0066] The wireless device 6 shown in FIG. 12 is, for example, a base station device. The base station device may be, for example, a Node B, an e-Node B, a g-Node B, a Home Node B, or a Home e-Node B. A base station device equipped with the antenna device 3 of this embodiment can increase the equivalent isotropic radiated power compared to a base station device equipped with a conventional antenna device. Furthermore, compared to a base station device equipped with the antenna device 2 of the second embodiment, lower costs and lower mass can be achieved. Note that the wireless device 6 equipped with the antenna device 3 of this embodiment is not limited to a base station device, and may be other wireless devices that perform wireless communication.

[0067] The present disclosure is not limited to the above-described embodiments, and may be modified as appropriate without departing from the spirit of the present disclosure. Furthermore, the present disclosure may be implemented by appropriately combining the respective embodiments.

[0068] Furthermore, some or all of the above embodiments can be described as, but are not limited to, the following supplementary notes. (Supplementary Note 1) An antenna device comprising: a substrate; a plurality of antenna elements arranged on a first surface of the substrate; a feed circuit arranged on a second surface, which is the opposite surface of the first surface of the substrate; and a first conductor arranged in a position facing the feed circuit, wherein a gap is formed between the feed circuit and the first conductor. (Supplementary Note 2) The antenna device according to Supplementary Note 1, wherein the gap is formed along the feed circuit. (Supplementary Note 3) The antenna device according to Supplementary Note 2, wherein a portion of the first conductor is adjacent to the substrate, and wherein the gap is formed so as to be surrounded by the substrate and the first conductor. (Supplementary Note 4) The antenna device according to Supplementary Note 1, further comprising a support member arranged between the first conductor and the substrate, wherein the gap is formed by the substrate, the first conductor, and the support member. (Supplementary Note 5) The antenna device according to Supplementary Note 4, wherein a plurality of the members are arranged along the outer periphery of the substrate. (Supplementary Note 6) The antenna device according to Supplementary Note 4, wherein a plurality of the members are arranged along the feed circuit. (Supplementary Note 7) The antenna device according to any one of Supplements 1 to 6, comprising an antenna element feed section connecting the plurality of antenna elements to the feed circuit. (Supplementary Note 8) The antenna device according to Supplementary Note 7, further comprising: a radome covering the first surface side of the substrate; and a connection section connecting the substrate and the radome. (Supplementary Note 9) The antenna device according to Supplementary Note 8, wherein a hole is formed in the substrate, the first conductor or the connection section is inserted into the hole, the first conductor and the connection section are directly connected, and the radome and the connection section are second conductors. (Supplementary Note 10) The antenna device according to Supplementary Note 8, wherein the first conductor and the connection section are connected via a through hole formed in the substrate, and the radome and the connection section are second conductors. (Supplementary Note 11) The antenna device according to Supplementary Note 7, wherein the antenna element feeding portion is a through hole formed in the substrate. (Supplementary Note 12) The antenna device according to Supplementary Note 3 or 4, wherein the plurality of antenna elements include patch antennas.(Supplementary Note 13) The antenna device according to Supplementary Note 3 or 4, wherein the plurality of antenna elements include a dipole antenna. (Supplementary Note 14) The antenna device according to Supplementary Note 3 or 4, wherein the antenna device is an array antenna device. (Supplementary Note 15) The antenna device according to Supplementary Note 3 or 4, wherein the substrate includes a glass epoxy substrate. (Supplementary Note 16) The antenna device according to Supplementary Note 3 or 4, wherein the first conductor is metal. (Supplementary Note 17) The antenna device according to Supplementary Note 9 or 10, wherein the second conductor is metal. (Supplementary Note 18) An antenna device comprising: a substrate; a plurality of antenna elements arranged on a first surface of the substrate; a power feed circuit arranged on a second surface that is the reverse side of the first surface of the substrate, the power feed circuit distributing power to the plurality of antenna elements; and a conductor arranged at a position facing the power feed circuit and functioning as a ground of the power feed circuit, wherein an air gap is formed between the power feed circuit and the conductor. (Supplementary Note 19) A wireless device comprising: an antenna device including: a substrate; a plurality of antenna elements arranged on a first surface of the substrate; a power supply circuit arranged on a second surface that is the reverse side of the first surface of the substrate; and a first conductor arranged at a position facing the power supply circuit, wherein an air gap is formed between the power supply circuit and the first conductor; and a transceiver.

[0069] REFERENCE SIGNS LIST 1, 2, 3 Antenna device 5, 6 Radio device 10 Substrate 20, 21, 22 Antenna element 30 Power supply circuit 40, 41, 42 Conductor 50, 51, 52 Air gap 60 Antenna element power supply section 70 Radome 80 Radome connection section 90 Bandpass filter 100 Transceiver 110 Conductor connection section 120 Support member 130 Connector 140 Fastening section 150 Through hole

Claims

1. A substrate; a plurality of antenna elements disposed on a first surface of the substrate; a power supply circuit disposed on a second surface of the substrate, the second surface being the reverse side of the first surface; a first conductor disposed at a position facing the power supply circuit, an air gap is formed between the power supply circuit and the first conductor; Antenna device.

2. the air gap is formed along the power supply circuit. The antenna device according to claim 1 .

3. a portion of the first conductor adjacent to the substrate; the gap is formed so as to be surrounded by the substrate and the first conductor; The antenna device according to claim 2 .

4. a support member disposed between the first conductor and the substrate; the gap is formed by the substrate, the first conductor, and the support member. The antenna device according to claim 1 .

5. a plurality of the support members are arranged along the outer periphery of the substrate; 5. The antenna device according to claim 4.

6. a plurality of the support members are arranged along the power supply circuit; 5. The antenna device according to claim 4.

7. an antenna element feeding section that connects the plurality of antenna elements to the feeding circuit; 7. An antenna device according to claim 1.

8. a radome covering the first surface side of the substrate; a connection portion that connects the substrate and the radome, 8. The antenna device according to claim 7.

9. A hole is formed in the substrate, the first conductor or the connection portion is inserted into the hole, and the first conductor and the connection portion are directly connected to each other; the radome and the connection portion are second conductors; 9. The antenna device according to claim 8.

10. the first conductor and the connection portion are connected via a through hole formed in the substrate, the radome and the connection portion are second conductors; 9. The antenna device according to claim 8.