Multi-band antenna and multi-band antenna design method

Abstract

The present invention provides a multi-band antenna and a design method thereof, which can transmit and receive electromagnetic waves in at least a first band of a first central wavelength λ1 and a second band of a second central wavelength λ2 shorter than the first central wavelength λ1, wherein at least one antenna unit includes a first radiating conductor (11) and a first grounding conductor (31) spaced apart from the first radiating conductor (11) via a dielectric having a relative dielectric constant of εr, wherein the first radiating conductor (11) and the first grounding conductor (31) have a planar shape including a pair of opposing first sides (11c, 11d, 31c, 31d), and a distance Lrf1 between the pair of opposing first sides of the first radiating conductor and a distance Lg1 between the pair of opposing sides of the first grounding conductor satisfy 0.2λ1 / εr. 1 / 2 ≤Lrf1≤0.5λ1 / εr 1 / 2 , 0.7λ2 / εr 1 / 2 ≤Lg1≤1.25λ2 / εr 1 / 2 According to the present invention, the frequency band to be used can be easily adjusted.

Description

Technical Field

[0001] The invention relates to a multi-band antenna and a design method of the multi-band antenna. Background Art

[0002] With the growth of network communications, the development of high-definition imaging technology, and the advancement of IoT technology, the communication speeds required for wireless communications are also increasing, creating a need for high-frequency wireless communication technologies capable of transmitting and receiving more information. Furthermore, the frequency bands used for wireless communications often differ across countries and regions. To achieve lower costs for wireless communication equipment, wireless communication devices supporting multiple frequency bands are needed. Alternatively, wireless communication devices capable of transmitting more information by simultaneously utilizing radio waves in different frequency bands are needed.

[0003] In such wireless communication devices, multi-band antennas capable of transmitting and receiving radio waves in a plurality of different frequency bands are used. For example, Patent Document 1 discloses a multi-band antenna capable of ensuring antenna performance while achieving miniaturization.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-062276. Summary of the Invention

[0007] Technical problem to be solved by the invention

[0008] The present invention provides a multi-band antenna and a design method for the multi-band antenna, which can easily adjust the frequency band used.

[0009] Technical means to solve the problem

[0010] A multi-band antenna according to the present invention is capable of transmitting and receiving electromagnetic waves in at least a first wavelength band having a first central wavelength λ1 and a second wavelength band having a second central wavelength λ2 that is shorter than the first central wavelength λ1. The multi-band antenna includes at least one antenna element, the at least one antenna element comprising: a first radiating conductor; and a first ground conductor spaced apart from the first radiating conductor via a dielectric having a relative permittivity εr. The first radiating conductor and the first ground conductor each have a planar shape including a pair of opposing first sides. A distance Lrf1 between the pair of opposing first sides of the first radiating conductor and a distance Lg1 between the pair of opposing sides of the first ground conductor satisfy the following relationship:

[0011] 0.2λ1 / εr 1 / 2 ≤Lrf1≤0.7λ1 / εr 1 / 2 ,

[0012] 0.7λ2 / εr 1 / 2 ≤Lg1≤1.75λ2 / εr 1 / 2 .

[0013] In one embodiment, the at least one antenna unit further includes a second radiating conductor arranged between the first radiating conductor and the first ground conductor.

[0014] In one embodiment, the second radiation conductor has a planar shape including a pair of opposing first sides, and a distance Lrs1 between the pair of opposing sides of the second radiation conductor satisfies the following relationship:

[0015] 0.2λ1 / εr 1 / 2 ≤Lrs1≤0.5λ1 / εr 1 / 2 .

[0016] In one embodiment, the multi-band antenna further includes a first strip conductor disposed between the first ground conductor and the first radiating conductor or the second radiating conductor for feeding power to the first radiating conductor and the second radiating conductor.

[0017] In one embodiment, the multi-band antenna further includes a second strip conductor disposed between the first ground conductor and the first radiating conductor or the second radiating conductor for feeding power to the first radiating conductor and the second radiating conductor, wherein the first strip conductor and the second strip conductor extend in directions orthogonal to each other.

[0018] In one embodiment, the at least one antenna unit further includes a second ground conductor, the second ground conductor being arranged on the opposite side of the first radiation conductor with respect to the first ground conductor and having an outer edge surrounding the first ground conductor in a plan view.

[0019] In one embodiment, the first ground conductor is electrically connected to the second ground conductor.

[0020] In one embodiment, the at least one antenna unit includes: a hole provided in the second ground conductor; a feed conductor arranged to penetrate the hole in the second ground conductor and having one end connected to the first strip conductor; and a plurality of first through-hole conductors arranged to sandwich or surround the feed conductor when viewed from above and connecting the first ground conductor and the second ground conductor.

[0021] In one embodiment, the at least one antenna unit includes a plurality of second through-hole conductors connecting the first ground conductor and the second ground conductor, and the plurality of second through-hole conductors are arranged along at least a portion of the outer circumference of the first ground conductor and overlap with the first ground conductor when viewed from above.

[0022] In one embodiment, the first radiation conductor has a rectangular shape including the pair of first sides and a pair of opposing second sides, and a distance Lrf2 between the pair of opposing second sides of the first radiation conductor satisfies the following relationship:

[0023] 0.2λ1 / εr 1 / 2 ≤Lrf2≤0.7λ1 / εr 1 / 2 .

[0024] In one embodiment, the second radiation conductor has a rectangular shape including the pair of first sides and a pair of opposing second sides, and a distance Lrs2 between the pair of opposing second sides of the second radiation conductor satisfies the following relationship:

[0025] 0.2λ1 / εr 1 / 2 ≤Lrs2≤0.7λ1 / εr 1 / 2 .

[0026] In one embodiment, the planar shape of the first ground conductor further includes a pair of opposing second sides, and a distance Lg2 between the pair of opposing second sides of the first ground conductor satisfies the following relationship:

[0027] 0.7λ2 / εr 1 / 2 ≤Lg2≤1.75λ2 / εr 1 / 2 .

[0028] In one embodiment, the multi-band antenna includes a plurality of antenna units, and the plurality of antenna units are arranged along a first direction.

[0029] In one embodiment, the second ground conductor of each of the plurality of antenna units is connected to the second ground conductor of an adjacent antenna unit.

[0030] In one embodiment, in each of the plurality of antenna units, the pair of first sides of the first radiation conductor and the pair of first sides of the first ground conductor are arranged to form an angle of 45° or −45° with respect to the first direction in a plan view.

[0031] In one embodiment, the first ground conductor of each of the plurality of antenna units is connected to the first ground conductor of an adjacent antenna unit.

[0032] In one embodiment, the first ground conductor of each of the plurality of antenna units is separated from the first ground conductor of an adjacent antenna unit.

[0033] In a design method for a multi-band antenna according to the present invention, the multi-band antenna is capable of transmitting and receiving electromagnetic waves in a first wavelength band having a first center wavelength λ1 and a second wavelength band having a second center wavelength λ2 that is shorter than the first center wavelength λ1. The multi-band antenna includes at least one antenna element, the at least one antenna element comprising: a radiating conductor; and a first ground conductor spaced apart from the first radiating conductor via a dielectric. In the design method for the multi-band antenna, the dimensions of the first radiating conductor are determined based on the first center wavelength λ1, and the dimensions of the first ground conductor are determined based on the second center wavelength λ2.

[0034] In one embodiment, the first radiating conductor and the first ground conductor each have a planar shape including a pair of opposing first sides, and a distance Lrf1 between the pair of opposing first sides of the first radiating conductor and a distance Lg1 between the pair of opposing sides of the first ground conductor are determined based on the first center wavelength λ1 and the second center wavelength λ2.

[0035] In one embodiment, the at least one antenna unit further includes a second radiating conductor arranged between the first radiating conductor and the first ground conductor, the second radiating conductor having a planar shape including a pair of opposing first sides, and a distance Lrs1 between the pair of opposing sides of the second radiating conductor is determined based on the second center wavelength λ2.

[0036] Effects of the Invention

[0037] According to the present invention, it is possible to provide a multi-band antenna and a method for designing the multi-band antenna in which adjustment of a frequency band to be used is easily performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a perspective view showing an example of the first embodiment of the multi-band antenna.

[0039] Figure 2 yes Figure 1 An exploded perspective view of the main parts of the multi-band antenna is shown.

[0040] Figure 3 yes Figure 1 A top view of the multi-band antenna is shown.

[0041] Figure 4 yes Figure 3 Cross-sectional view of the IV-IV line multi-band antenna.

[0042] Figure 5A It is a diagram showing simulation results of the multi-band antenna according to the first embodiment.

[0043] Figure 5BIt is a diagram showing simulation results of the multi-band antenna according to the first embodiment.

[0044] Figure 6A It is a diagram showing simulation results of the multi-band antenna according to the first embodiment.

[0045] Figure 6B It is a diagram showing simulation results of the multi-band antenna according to the first embodiment.

[0046] Figure 7 It is a perspective view showing an example of a second embodiment of the multi-band antenna.

[0047] Figure 8 Yes Figure 7 An exploded perspective view of the main parts of the multi-band antenna shown.

[0048] Figure 9 yes Figure 7 A top view of the multi-band antenna is shown.

[0049] Figure 10 yes Figure 9 Cross-sectional view of the X-X line multi-band antenna.

[0050] Figure 11A It is a perspective view showing an example of a third embodiment of the multi-band antenna.

[0051] Figure 11B It is a perspective view showing another example of the third embodiment of the multi-band antenna.

[0052] Figure 12 It is a perspective view showing an example of a fourth embodiment of the multi-band antenna.

[0053] Figure 13 Yes Figure 12 A top view of one antenna element of the multi-band antenna is shown.

[0054] Figure 14 This is an enlarged perspective view showing another example of the fourth embodiment of the multi-band antenna.

[0055] Figure 15 It is a perspective view showing an example of a fifth embodiment of the multi-band antenna.

[0056] Figure 16 It means from Figure 15 Schematic diagram of the intensity distribution of electromagnetic waves radiated by the multi-band antenna shown.

[0057] Figure 17 It means from Figure 15 Schematic diagram of the intensity distribution of electromagnetic waves radiated by the multi-band antenna shown.

[0058] Figure 18 It is a schematic cross-sectional view showing an embodiment of a wireless communication module.

[0059] Figure 19 It is a schematic cross-sectional view showing another embodiment of a wireless communication module.

[0060] Figure 20A It is a schematic plan view showing one embodiment of a wireless communication device.

[0061] Figure 20B It is a schematic side view showing one embodiment of a wireless communication device.

[0062] Figure 21A It is a schematic plan view showing another embodiment of a wireless communication device.

[0063] Figure 21B This is a schematic side view showing another embodiment of a wireless communication device.

[0064] Figure 21C This is a schematic side view showing another embodiment of a wireless communication device.

[0065] Description of Reference Signs

[0066] 11: 1st radiating conductor

[0067] 11c, 11d, 12c, 12d, 31c, 31d: Side 1

[0068] 11e, 11f, 12e, 12f, 31e, 31f: Side 2

[0069] 12: Second radiation conductor

[0070] 21: The first strip conductor

[0071] 22: The second strip conductor

[0072] 23: Feed conductor

[0073] 25, 26: Linear radiating conductor

[0074] 27, 28: Feed conductor

[0075] 31: First ground conductor

[0076] 32: Second grounding conductor

[0077] 31w, 32w: Open

[0078] 40: Dielectric

[0079] 41: 1st through-hole conductor

[0080] 42: Second through-hole conductor

[0081] 55: Linear antenna

[0082] 61: Conductor

[0083] 62: Through-hole conductor

[0084] 63: Electrode

[0085] 64, 65: Active components

[0086] 66: Passive components

[0087] 67: Connectors

[0088] 68: hood

[0089] 69: Flexible wiring

[0090] 70: Motherboard

[0091] 70a: Main surface

[0092] 70b: Main surface

[0093] 70c~70f:side

[0094] 101, 102, 102', 102", 103A, 103B: Multi-band antennas

[0095] 104, 105, 106: Multi-band antennas

[0096] 107, 107A~107D, 108: Wireless communication module

[0097] 109, 110: Wireless communication device

[0098] 110: Wireless communication device DETAILED DESCRIPTION

[0099] The multi-band antenna and multi-band antenna design method of the present invention can be used, for example, for wireless communications in the quasi-microwave, centimeter-wave, quasi-millimeter-wave, and millimeter-wave bands. Wireless communications in the quasi-microwave band use radio waves with a wavelength of 10 cm to 30 cm and a frequency of 1 GHz to 3 GHz as carrier waves. Wireless communications in the centimeter-wave band use radio waves with a wavelength of 1 cm to 10 cm and a frequency of 3 GHz to 30 GHz as carrier waves. Wireless communications in the millimeter-wave band use radio waves with a wavelength of 1 mm to 10 mm and a frequency of 30 GHz to 300 GHz as carrier waves. Wireless communications in the quasi-millimeter-wave band use radio waves with a wavelength of 10 mm to 30 mm and a frequency of 10 GHz to 30 GHz as carrier waves. In wireless communications in these bands, the size of planar antennas ranges from a few centimeters to sub-millimeter levels. For example, when a quasi-microwave, centimeter-wave, quasi-millimeter-wave, or millimeter-wave wireless communication circuit is constructed using a multilayer ceramic sintered substrate, the multi-band antenna of the present invention can be mounted on the multilayer ceramic sintered substrate.

[0100] In this embodiment, unless otherwise specified, a multi-band antenna capable of transmitting and receiving electromagnetic waves in a first wavelength band of a first central wavelength λ1 and a second wavelength band of a second central wavelength λ2, which is shorter than the first central wavelength λ1, is described below as an example of a quasi-microwave, centimeter-wave, quasi-millimeter-wave, and millimeter-wave carrier. Specifically, the first wavelength band is 9.1 mm to 11.5 mm, corresponding to frequencies of 26 GHz to 33 GHz. The second wavelength band is 7.3 mm to 8.3 mm, corresponding to frequencies of 36 GHz to 41 GHz. Hereinafter, the first and second wavelength bands may be referred to as the 28 GHz and 38 GHz bands.

[0101] In this invention, a right-handed coordinate system is used to illustrate the arrangement and orientation of components. Specifically, a first right-handed coordinate system has mutually orthogonal x, y, and z axes, and a second right-handed coordinate system has mutually orthogonal u, v, and w axes. To distinguish the first from the second right-handed coordinate system and to determine the order of the axes in the right-handed coordinate system, the axes are labeled x, y, z and u, v, and w, and may also be referred to as the first, second, and third axes.

[0102] In the present invention, the two directions being consistent means that the angle formed by the two directions is roughly in the range of 0° to about 20°. Preferably, the angle formed by the two directions is in the range of about 0° to 10°. Parallel means that the angle formed by two planes, two straight lines, or a plane and a straight line is in the range of 0° to about 10°, more preferably in the range of 0° to about 5°. In addition, when describing a direction with reference to an axis, if it is important whether it is in the + direction or the - direction of the axis relative to the reference, the description is made distinguishing between the + and - directions of the axis. On the other hand, if it is important whether the direction is along any axis, regardless of whether it is in the + direction or the - direction of the axis, it is simply described as the "axis direction".

[0103] (First embodiment)

[0104] A first embodiment of the multi-band antenna of the present invention will be described. Figure 1 1 is a schematic perspective view of the multi-band antenna 101 of the present invention. Figure 2 This is an exploded perspective view of the main components of the multi-band antenna 101. Figure 3 is a top view of the multi-band antenna 101, Figure 4 yes Figure 3 Cross-sectional view along line IV-IV.

[0105] The multiband antenna 101 includes a first radiating conductor 11 and a first ground conductor 31. In this embodiment, the multiband antenna 101 further includes a first strip conductor 21 and a second strip conductor 22 for supplying power to the first radiating conductor 11. Furthermore, as will be described later, the multiband antenna 101 includes a dielectric 40.

[0106] The first radiation conductor 11 is a planar conductor arranged approximately parallel to the xy plane. The first radiation conductor 11 is a radiating element that radiates radio waves and has a shape designed to achieve the desired radiation characteristics and impedance matching. The first radiation conductor 11 has a planar shape including at least a pair of opposing first sides 11c and 11d. In this embodiment, the first radiation conductor 11 has a rectangular shape comprising two sets of sides that are approximately parallel in the x-axis and y-axis directions. Specifically, the first radiation conductor 11 has a pair of opposing first sides 11c and 11d and a pair of opposing second sides 11e and 11f. The first sides 11c and 11d are preferably parallel to each other, and the second sides 11e and 11f are preferably parallel to each other. Furthermore, the first sides 11c and 11d are preferably orthogonal to the second sides 11e and 11f.

[0107] Assuming that the relative permittivity of the dielectric 40 is εr and power is fed simultaneously from the first and second strip conductors 21 and 22 , the distance Lrf1 between the pair of opposing first sides 11 c and 11 d satisfies the following equation (1D).

[0108] 0.2λ1 / εr 1 / 2 ≤Lrf1≤0.5λ1 / εr 1 / 2 (1D)

[0109] Furthermore, it is preferable that a distance Lrf2 between a pair of opposing second sides 11e and 11f satisfies the condition of the following formula (2D).

[0110] 0.2λ1 / εr 1 / 2 ≤Lrf2≤0.5λ1 / εr 1 / 2 (2D)

[0111] Lrf2 may be equal to or different from Lrf1. More preferably, Lrf1 and Lrf2 satisfy the conditions of the following formulas (1D') and (2D').

[0112] 0.25λ1 / εr 1 / 2 ≤Lrf1≤0.4λ1 / εr 1 / 2 (1D')

[0113] 0.25λ1 / εr 1 / 2 ≤Lrf2≤0.4λ1 / εr 1 / 2 (2D')

[0114] When the relative permittivity of the dielectric 40 is εr and power is fed from the first strip conductor 21 or the second strip conductor 22 , the distance Lrf1 between the pair of opposing first sides 11 c and 11 d satisfies the following equation (1b).

[0115] 0.3λ1 / εr 1 / 2 ≤Lrf1≤0.7λ1 / εr 1 / 2 (1S)

[0116] Furthermore, it is preferable that a distance Lrf2 between a pair of opposing second sides 11e and 11f satisfies the condition of the following formula (2S).

[0117] 0.3λ1 / εr 1 / 2 ≤Lrf2≤0.7λ1 / εr 1 / 2 (2S)

[0118] Lrf2 may be equal to or different from Lrf1. More preferably, Lrf1 and Lrf2 satisfy the conditions of the following formulas (1'b) and (2'b).

[0119] 0.35λ1 / εr 1 / 2 ≤Lrf1≤0.6λ1 / εr 1 / 2 (1S')

[0120] 0.35λ1 / εr 1 / 2 ≤Lrf2≤0.6λ1 / εr 1 / 2 (2S')

[0121] Lrf1 and Lrf2 are determined so that the electromagnetic wave with the first central wavelength λ1 radiated by the first radiation conductor 11 resonates at (λ1) / 2. Therefore, the resonant frequency shifts according to the lengths of Lrf1 and Lrf2. In other words, the electromagnetic wave in the first wavelength band can be adjusted by the lengths of Lrf1 and Lrf2.

[0122] At this time, the distribution direction of the excited electromagnetic waves differs depending on whether signal power is supplied to both the first and second strip conductors 21, 22 simultaneously or to only one of them. When signal power is supplied to only one of the first and second strip conductors 21, 22, the electromagnetic waves are distributed in a direction perpendicular to the first sides 11c, 11d or the second sides 11e, 11f. Therefore, the resonant frequency of the electromagnetic waves is determined so that the first sides 11c, 11d or the second sides 11e, 11f are located at the nodal points of the electromagnetic waves. When signal power is supplied to both the first and second strip conductors 21, 22 simultaneously, the electromagnetic waves are distributed in a direction diagonal to the first radiating conductor 11. Therefore, the resonant frequency of the electromagnetic waves is determined so that the pair of vertices located diagonally to the first radiating conductor are located at the nodal points of the electromagnetic waves.

[0123] On the other hand, for electromagnetic waves with the second central wavelength λ2, Lrf1 and Lrf2 do not satisfy the resonance condition. Therefore, even if the lengths of Lrf1 and Lrf2 change, the characteristics of the electromagnetic waves in the second wavelength band do not change much.

[0124] As described above, the first sides 11c, 11d and the second sides 11e, 11f are located at nodal points of the electromagnetic wave and therefore preferably have a length corresponding to the width of the electromagnetic wave. When the first radiating conductor 11 has a rectangular shape, the length of the first sides 11c, 11d is equal to Lrf2, which is the distance between the second sides 11e, 11f, and the length of the second sides 11e, 11f is equal to Lrf1, which is the distance between the first sides 11c, 11d.

[0125] The first ground conductor 31 is a planar conductor generally parallel to the xy plane and spaced apart from the first radiation conductor 11 in the z-axis direction via the dielectric 40. The first ground conductor 31 regulates the distribution of electromagnetic waves radiated from the first radiation conductor 11. In a plan view (viewed from the z-axis), the first ground conductor 31 is larger than the first radiation conductor 11, and its outer edge surrounds the outside of the first radiation conductor 11.

[0126] The first ground conductor 31 has a planar shape including at least a pair of opposing first sides 31c and 31d. In this embodiment, the first ground conductor 31 has a rectangular shape with two sets of sides that are substantially parallel in the x-axis and y-axis directions. Specifically, the first radiation conductor 31 has a pair of opposing first sides 31c and 31d and a pair of opposing second sides 31e and 31f. The first sides 31c and 31d are preferably parallel to each other, and the second sides 31e and 31f are preferably parallel to each other. Furthermore, the first sides 31c and 31d are preferably orthogonal to the second sides 31e and 31f.

[0127] When power is fed simultaneously from the first strip conductor 21 and the second strip conductor 22 , the distance Lg1 between the pair of opposing first sides 31 c and 31 d satisfies the condition of the following formula (3D).

[0128] 0.7λ2 / εr 1 / 2 ≤Lg1≤1.25λ2 / εr 1 / 2 (3D)

[0129] Furthermore, it is preferable that the distance Lg2 between the pair of opposing second sides 31e and 31f satisfies the condition of the following formula (4D).

[0130] 0.7λ2 / εr 1 / 2 ≤Lg2≤1.25λ2 / εr 1 / 2 (4D)

[0131] Lg2 may be equal to or different from Lg1. More preferably, Lg1 and Lg2 satisfy the conditions of the following formulas (3') and (4').

[0132] 0.8λ2 / εr 1 / 2 ≤Lg1≤1.1λ2 / εr 1 / 2 (3D')

[0133] 0.8λ2 / εr 1 / 2 ≤Lg2≤1.1λ2 / εr 1 / 2 (4D')

[0134] When power is fed from the first strip conductor 21 or the second strip conductor 22 , the distance Lg1 between the pair of opposing first sides 31 c and 31 d satisfies the following equation (3S).

[0135] 1λ2 / εr 1 / 2 ≤Lg1≤1.75λ2 / εr 1 / 2 (3S)

[0136] Furthermore, it is preferable that the distance Lg2 between the pair of opposing second sides 31c and 31d satisfies the condition of the following formula (4S).

[0137] 1λ2 / εr 1 / 2 ≤Lg2≤1.75λ2 / εr 1 / 2 (4S)

[0138] Lg2 may be equal to or different from Lg1. More preferably, Lg1 and Lg2 satisfy the conditions of the following formulas (3'b) and (4'b).

[0139] 1.1λ2 / εr 1 / 2 ≤Lg1≤1.55λ2 / εr 1 / 2 (3S')

[0140] 1.1λ2 / εr 1 / 2 ≤Lg2≤1.55λ2 / εr 1 / 2 (4S')

[0141] The first sides 31c, 31d and the second sides 31e, 31f are located approximately at the nodal points of the electromagnetic waves in the second wavelength band radiated from the first ground conductor 31. Therefore, the resonant frequency of the electromagnetic waves in the second wavelength band shifts in accordance with the lengths of Lg1 and Lg2. In other words, the electromagnetic waves in the second wavelength band can be adjusted according to the lengths of Lg1 and Lg2.

[0142] On the other hand, the first sides 31c, 31d and the second sides 32e, 32f are not located at the node points of the electromagnetic waves in the first wavelength band radiated from the first ground conductor 31. Therefore, even if the lengths Lg1 and Lg2 change, the characteristics of the electromagnetic waves in the first wavelength band do not change much.

[0143] As described above, the first sides 31c, 31d and the second sides 31e, 31f are located at the nodal points of the electromagnetic wave and therefore preferably have a length corresponding to the width of the electromagnetic wave. However, since the first ground conductor 31 is significantly larger than the first radiation conductor 11, even if the first ground conductor 31 has a shape other than a rectangle, sufficient lengths can be ensured for the first sides 31c, 31d and the second sides 31e, 31f. For example, the first ground conductor 31 may have an octagonal shape. In this case, it is preferable that the first sides 31c, 31d and the second sides 31e, 31f are arranged orthogonally.

[0144] When the first radiation conductor 11 has a rectangular shape, the lengths of the first sides 11c and 11d are equal to Lrf2, which is the distance between the second sides 11e and 11f, and the lengths of the second sides 11e and 11f are equal to Lrf1, which is the distance between the first sides 11c and 11d.

[0145] As described above, when feeding power to one or both of the first strip conductor 21 and the second strip conductor 22 to form a multi-band antenna that radiates electromagnetic waves, the following conditions (1) to (4) are preferably satisfied.

[0146] 0.2λ1 / εr 1 / 2 ≤Lrf1≤0.7λ1 / εr 1 / 2 (1)

[0147] 0.2λ1 / εr 1 / 2 ≤Lrf2≤0.7λ1 / εr 1 / 2 (2)

[0148] 0.7λ2 / εr 1 / 2 ≤Lg1≤1.75λ2 / εr 1 / 2(3)

[0149] 0.7λ2 / εr 1 / 2 ≤Lg2≤1.75λ2 / εr 1 / 2 (4)

[0150] Furthermore, when feeding power to one or both of the first strip conductor 21 and the second strip conductor 22 to form a multi-band antenna that radiates electromagnetic waves, it is preferable that the following conditions (1M) to (4M) are satisfied.

[0151] 0.3λ1 / εr 1 / 2 ≤Lrf1≤0.5λ1 / εr 1 / 2 (1M)

[0152] 0.3λ1 / εr 1 / 2 ≤Lrf2≤0.5λ1 / εr 1 / 2 (2M)

[0153] 1λ2 / εr 1 / 2 ≤Lg1≤1.25λ2 / εr 1 / 2 (3M)

[0154] 1λ2 / εr 1 / 2 ≤Lg2≤1.25λ2 / εr 1 / 2 (4M)

[0155] The first and second strip conductors 21, 22 are arranged between the first radiating conductor 11 and the first ground conductor 31 in the z-axis direction. The first and second strip conductors 21, 22 are electromagnetically coupled to the first radiating conductor 11 to supply signal power. In this embodiment, the first strip conductor 21 extends in the x-axis direction, and the second strip conductor 22 extends in the y-axis direction, which is perpendicular to the direction in which the first strip conductor extends. The distance d1 between the first radiating conductor 11 and the first and second strip conductors 21, 22 in the z-axis direction is, for example, 5 μm to 500 μm.

[0156] The first and second strip conductors 21 and 22 extend in parallel with the first sides 11c and 11d or the second sides 11e and 11f of the first radiation conductor 11 and in parallel with the first sides 31c and 31d or the second sides 31e and 31f of the first ground conductor 31 .

[0157] One end 23a of the power feeding conductor 23 is connected to one end of each of the first strip conductor 21 and the second strip conductor 22. The power feeding conductor 23 extends in the z-axis direction and is inserted into the opening 31w provided in the first ground conductor 31.

[0158] Although not shown, the other end 23b of the power-feeding conductor 23 is connected to the active and passive components of the transmission and reception circuits, as well as the wiring connecting them, in a region of the dielectric 40 located on the back surface 31b side of the first ground conductor 31. Signal power output from the transmission circuit is supplied to the first and second strip conductors 21 and 22 via the power-feeding conductor 23, and further supplied to the first radiating conductor through capacitive coupling.

[0159] In this embodiment, the multi-band antenna 101 supplies signal power to the first radiating conductor 11 from the first strip conductor 21 and the second strip conductor 22 through electromagnetic coupling via capacitive coupling. However, the supply of signal power to the first radiating conductor 11 is not limited to this method. Instead of using the first strip conductor 21 and the second strip conductor 22, other methods may be used to supply signal power to the first radiating conductor 11. For example, direct coupling may be used by directly connecting a conductor supplying signal power to the first radiating conductor 11, or slot feeding may be used by electromagnetic coupling via a conductor having slots.

[0160] The dielectric 40 may also be made of resin, glass, ceramic, or the like having a relative dielectric constant εr of approximately 1.5 to 100. Preferably, the dielectric 40 is a multilayer dielectric formed by laminating multiple layers of resin, glass, ceramic, or the like. For example, the dielectric 40 is a multilayer ceramic body having multiple ceramic layers. The first radiation conductor 11, the first strip conductor 21, the second strip conductor 22, and the first ground conductor 31 are disposed between the multiple ceramic layers, and the power feed conductor 23 is disposed within one or more ceramic layers. The first radiation conductor 11 may be disposed on the main surface 40a of the dielectric 40, and the first ground conductor 31 may be disposed on the back surface 40b of the dielectric 40. The spacing between the components in the z-axis direction within the dielectric 40 can be adjusted by varying the thickness and number of ceramic layers disposed between the components.

[0161] Components other than the dielectric 40 of the multi-band antenna 101 are formed of a conductive material, for example, a material containing a metal such as Au, Ag, Cu, Ni, Al, Mo, or W.

[0162] Multi-band antenna 101 can be manufactured using the aforementioned dielectric and conductive materials using known techniques. In particular, it can be suitably manufactured using multilayer (laminated) substrate technologies using resin, glass, or ceramic. For example, when dielectric 40 uses a multilayer ceramic body, co-firing ceramic substrate technology can be suitably employed. In other words, multi-band antenna 101 can be manufactured as a co-firing ceramic substrate.

[0163] The co-fired ceramic substrate that constitutes multi-band antenna 101 can be either a low-temperature co-fired ceramic (LTCC) substrate or a high-temperature co-fired ceramic (HTCC) substrate. From the perspective of high-frequency characteristics, the use of a low-temperature co-fired ceramic substrate is sometimes preferred. For dielectric 40, first radiation conductor 11, first strip conductor 21, second strip conductor 22, and first ground conductor 31, ceramic materials and conductive materials are used that are appropriate for the firing temperature, application, and frequency of wireless communications. The conductive paste used to form these components is co-fired with the green sheets of the multilayer ceramic body that form dielectric 40. If the co-fired ceramic substrate is a low-temperature co-fired ceramic substrate, ceramic materials and conductive materials that can be sintered in a temperature range of approximately 800°C to 1000°C are used. For example, a ceramic material containing Al, Si, and Sr as main components and Ti, Bi, Cu, Mn, Na, and K as secondary components, a ceramic material containing Al, Si, and Sr as main components and Ca, Pb, Na, and K as secondary components, a ceramic material containing Al, Mg, Si, and Gd, or a ceramic material containing Al, Si, Zr, and Mg can be used. Furthermore, conductive materials containing Ag or Cu can also be used. The dielectric constant of the ceramic material is approximately 3 to 15. When the ceramic substrate is fired at a high temperature, a ceramic material containing Al as the main component and a conductive material containing W (tungsten) or Mo (molybdenum) can be used.

[0164] More specifically, as LTCC materials, various materials can be used, such as Al-Mg-Si-Gd-O type dielectric materials with low dielectric constant (relative dielectric constant 5 to 10), dielectric materials including a crystalline phase composed of Mg2SiO4 and glass composed of Si-Ba-La-B-O type, Al-Si-Sr-O type dielectric materials, Al-Si-Ba-O type dielectric materials, and Bi-Ca-Nb-O type dielectric materials with high dielectric constant (relative dielectric constant of 50 or more).

[0165] For example, in the case of an Al-Si-Sr-O type dielectric material containing oxides of Al, Si, Sr, and Ti as main components, when the main components Al, Si, Sr, and Ti are converted into Al2O3, SiO2, SrO, and TiO2, respectively, it is preferred that the material contains Al2O3: 10 to 60 mass%, SiO2: 25 to 60 mass%, SrO: 7.5 to 50 mass%, and TiO2: 20 mass% or less (including 0). Furthermore, it is preferred that, as a minor component, at least one of the group consisting of Bi, Na, K, and Co is contained in an amount of 0.1 to 10 parts by mass as calculated as Bi2O3, 0.1 to 5 parts by mass as calculated as Na2O, 0.1 to 5 parts by mass as calculated as K2O, and 0.1 to 5 parts by mass as calculated as CoO, relative to 100 parts by mass of the main component. Furthermore, it is preferred that at least one of the group consisting of Cu, Mn, and Ag is contained in an amount of 0.01 to 5 parts by mass as calculated as CuO, 0.01 to 5 parts by mass as calculated as Mn3O4, and 0.01 to 5 parts by mass as Ag. Other unavoidable impurities may also be contained.

[0166] Next, the operation of the multi-band antenna will be described. In multi-band antenna 101, when signal power is supplied to the first strip conductor 21, the antenna 101 emits electromagnetic waves traveling in the positive z-axis direction with an intensity distribution extending along a plane parallel to the direction in which the first strip conductor 21 extends. Furthermore, when signal power is supplied to the second strip conductor 22, the antenna 101 emits electromagnetic waves traveling in the positive z-axis direction with an intensity distribution extending along a plane parallel to the direction in which the second strip conductor 22 extends. By selecting the strip conductor to be fed, the antenna 101 can selectively radiate electromagnetic waves with different polarization directions.

[0167] Furthermore, when signal power is supplied simultaneously to the first and second strip conductors 21, 22, the first radiating conductor 11 emits an electromagnetic wave that is a composite of the two electromagnetic waves. Because the two electromagnetic waves are orthogonal, the signal generated by receiving the composite electromagnetic wave can be separated into two signals. Therefore, the multi-band antenna 101 can radiate different signal powers from the first radiating conductor 11 using the first and second strip conductors 21, 22, enabling the transmission and reception of more information.

[0168] Next, an example of obtaining the relationship between the dimensions of the first radiation conductor 11 and the first ground conductor 31 of the multi-band antenna 101 and the characteristics of radiated electromagnetic waves through simulation will be described. Figure 5A and Figure 5B The following shows the characteristics of electromagnetic waves radiated when the dimensions of the first ground conductor 31 are fixed and the dimensions of the first radiation conductor 11 are varied. Figure 5A Indicates the frequency characteristics of return loss, Figure 5BThe relationship between the length of one piece of the first radiation conductor 11 and the minimum value of the return loss is shown. Table 1 below shows the numerical values ​​of the parameters used in the simulation.

[0169] Calculations are performed assuming that the first radiation conductor 11 and the first ground conductor 31 each have a square shape. Specifically, Lrf1 = Lrf2, and the length of the first sides 11c, 11d and the second sides 11e, 11f is Lrf1. Similarly, Lg1 = Lg2, and the length of the first sides 31c, 31d and the second sides 31e, 31f is Lg1.

[0170] [Table 1]

[0171] Lrf1 and Lrf2 of the first radiation conductor 11 1, 1.1, 1.2, 1.3, 1.4 mm Lg1 and Lg2 of the first ground conductor 31 4.5mm Relative dielectric constant εr of dielectric 40 8

[0172] like Figure 5A As shown in FIG. 1 , when the dimensions of the first ground conductor 31 are fixed and the length of one side of the first radiation conductor 11 is varied, the position of the minimum return loss value Min2 observed around 38 GHz remains almost unchanged. In contrast, the position of the minimum return loss value Min1 observed around 28 GHz shifts significantly when the length of one side of the first radiation conductor 11 (Lrf1, Lrf2) is varied. Figure 5B As shown in FIG. 1 , as Lrf1 increases, the minimum value Min1 of the return loss moves toward the low frequency side. Furthermore, within the range of Lrf1 of 1 to 1.4 mm, the value of Lrf1 is proportional to the frequency of the minimum value Min1 of the return loss.

[0173] Figure 6A and Figure 6B The following shows the characteristics of electromagnetic waves radiated when the dimensions of the first radiation conductor 11 are fixed and the dimensions of the first ground conductor 31 are varied. Figure 6A Indicates the frequency characteristics of return loss, Figure 6B The relationship between the length of one piece of the first ground conductor 31 and the minimum value of the return loss is shown in Table 2 below. The numerical values ​​of the parameters used in the simulation are shown.

[0174] [Table 2]

[0175]

[0176] like Figure 6A As shown in FIG. 1 , when the dimensions of the first radiation conductor 11 are fixed and the length of one side of the first ground conductor 31 is varied, the position of the minimum return loss value Min1 seen around 28 GHz remains almost unchanged. In contrast, the position of the minimum return loss value Min2 seen around 38 GHz shifts significantly when the length of one side of the first ground conductor 31 (Lg1, Lg2) is varied. Figure 6BAs shown in FIG. 1 , as Lg1 increases, the minimum value Min2 of the return loss shifts toward the low-frequency side. Furthermore, within the range of Lg1 of 4 to 5 mm, the value of Lg1 and the frequency of the minimum value Min2 of the return loss are proportional.

[0177] These results demonstrate that multi-band antenna 101 is capable of transmitting and receiving electromagnetic waves in two frequency bands, and that the positions of the two frequency bands can be independently moved by changing the dimensions of first radiating conductor 11 and first ground conductor, specifically, the distances Lrf1, Lrf2, Lg1, and Lg2 between a pair of sides. This indicates that electromagnetic waves radiated from multi-band antenna 101 are transmitted and received in different modes for the first and second frequency bands, more specifically, the 28 GHz and 38 GHz bands.

[0178] As can be seen from the above features, the present invention provides a novel antenna design method for a multi-band antenna. Specifically, when designing a multi-band antenna capable of transmitting and receiving electromagnetic waves in a first wavelength band having a first central wavelength λ1 and a second wavelength band having a second central wavelength λ2 that is shorter than the first central wavelength λ1, the dimensions of the first radiating conductor are determined based on the first central wavelength λ1, and the dimensions of the first ground conductor are determined based on the second central wavelength λ2.

[0179] For example, first, the first center wavelength λ1 and the second center wavelength λ2 are determined according to the specifications of the multi-band antenna to be manufactured. Then, based on the first center wavelength λ1, the dimensions of the first radiating conductor 11 are determined. Specifically, the distance Lrf1 between a pair of opposing first sides and the distance Lrf2 between the second sides of the first radiating conductor are determined. More specifically, the distances Lrf1 and Lrf2 are determined so as to satisfy equations (1) and (2). In this case, the distances Lrf1 and Lrf2 can be varied within the range that satisfies equations (1) and (2) to determine the distances Lrf1 and Lrf2 that further reduce the minimum value Min1 of the return loss.

[0180] Next, the dimensions of the first ground conductor 31 are determined based on the second center wavelength λ2. Specifically, the distance Lg1 between a pair of opposing first sides and the distance Lg2 between a pair of opposing second sides of the first ground conductor 31 are determined. More specifically, the distances Lg1 and Lg2 are determined so as to satisfy equations (3) and (4). In this case, the distances Lg1 and Lg2 may be varied using the determined Lg1 and Lg2 within a range that satisfies equations (3) and (4) to determine distances Lg1 and Lg2 that further reduce the minimum value Min2 of the return loss.

[0181] In the above example, the dimensions of the first radiating conductor 11 are determined first, followed by the dimensions of the first ground conductor 31. Alternatively, the dimensions of the first ground conductor 31 may be determined first, followed by the dimensions of the first radiating conductor 11. Furthermore, as long as Lrf1, Lrf2, Lg1, and Lg2 vary within the ranges that satisfy equations (1), (2), (3), and (4), the dimensions of the first radiating conductor 11 have no significant effect on the radiation characteristics of electromagnetic waves in the second frequency band, and the dimensions of the first ground conductor 31 have no significant effect on the radiation characteristics of electromagnetic waves in the first frequency band, as described above. Therefore, a simulation may be performed while simultaneously varying Lrf1, Lrf2, Lg1, and Lg2 to search for the frequencies of the minimum return loss values ​​Min1 and Min2.

[0182] Thus, according to the multi-band antenna of this embodiment, at least the first radiating conductor 11 and the first ground conductor 31 have dimensions that satisfy the relationship between equations (1) and (3). This allows electromagnetic waves in the first frequency band and electromagnetic waves in the second frequency band to be transmitted and received in different modes. Therefore, the positions of electromagnetic waves in the first frequency band and the second frequency band can be adjusted independently, achieving a multi-band antenna and a multi-band antenna design method that easily adjusts the frequency bands used.

[0183] (Second embodiment)

[0184] A second embodiment of the multi-band antenna of the present invention will be described. Figure 7 is a schematic perspective view of the multi-band antenna 102 of the present invention. Figure 8 This is an exploded perspective view of the main components of the multi-band antenna 102. Figure 9 is a top view of the multi-band antenna 102, Figure 10 yes Figure 9 The multiband antenna 102 further includes a second radiation conductor 12 , a second ground conductor 32 , and a plurality of first via-hole conductors 41 , which is different from the multiband antenna 101 of the first embodiment.

[0185] The second radiation conductor 12 is a planar conductor arranged substantially parallel to the xy plane. The second radiation conductor 12 is located between the first radiation conductor 11 and the first ground conductor 31 in the z-axis direction. When the multi-band antenna 102 includes the first strip conductor 21 and the second strip conductor 22, the second radiation conductor is located between the first radiation conductor 11 and the first and second strip conductors 21 and 22.

[0186] The second radiation conductor 12 broadens the bandwidth of electromagnetic waves radiated from the first radiation conductor 11, particularly those in the first wavelength band. The second radiation conductor 12 has a planar shape including at least a pair of opposing first sides 12c and 12d. In this embodiment, the second radiation conductor 12 has a rectangular shape with two sets of sides substantially parallel to the x-axis and y-axis directions. Specifically, the second radiation conductor 12 has a pair of opposing first sides 12c and 12d and a pair of opposing second sides 12e and 12f.

[0187] A distance Lrs1 between a pair of opposing first sides 12c and 12d satisfies the following equation (5).

[0188] 0.2λ1 / εr 1 / 2 ≤Lrs1≤0.5λ1 / εr 1 / 2 (5)

[0189] Furthermore, it is preferable that the distance Lrs2 between the pair of opposing second sides 12e and 12f satisfies the condition of the following formula (6).

[0190] 0.2λ1 / εr 1 / 2 ≤Lrs2≤0.5λ1 / εr 1 / 2 (6)

[0191] Lrs2 may be equal to or different from Lrs1. More preferably, Lrs1 and Lrs2 satisfy the conditions of the following formulas (5') and (6').

[0192] 0.25λ1 / εr 1 / 2 ≤Lrs1≤0.4λ1 / εr 1 / 2 (5')

[0193] 0.25λ1 / εr 1 / 2 ≤Lrs2≤0.4λ1 / εr 1 / 2 (6')

[0194] In a plan view, the second radiation conductor 12 is preferably smaller than the first radiation conductor 11. In other words, the outer edge of the second radiation conductor 12 is preferably located inside the outer edge of the first radiation conductor 11. Therefore, Lrf1>Lrs1 and Lrf2>Lrs2 are preferably satisfied.

[0195] The z-axis distance d2 between the second radiation conductor 12 and the first and second strip conductors 21, 22 is, for example, 5 μm to 500 μm. The z-axis distance d1 between the first radiation conductor 11 and the first and second strip conductors 21, 22 may be the same as d1 of the multi-band antenna 101 of the first embodiment.

[0196] The second ground conductor 32 is a planar conductor substantially parallel to the xy plane and is arranged on the z-axis side of the first ground conductor 31 opposite to the first radiation conductor 11. In a plan view, the second ground conductor 32 is larger than the first ground conductor 31 and has an outer edge surrounding the first ground conductor 31.

[0197] The second ground conductor 32 has an opening 32 w . The power feeding conductor 23 is inserted into the opening 32 w of the second ground conductor 32 , and the other end 23 b of the power feeding conductor 23 is located on the back surface 32 b side of the second ground conductor 32 .

[0198] The second ground conductor 32 functions as a ground electrode for the entire multi-band antenna 102, or as a ground electrode for an information transmitting circuit, an information receiving circuit, etc., which are composed of active components such as filters, amplifiers, chip components, digital ICs, and passive components that can be arranged below the second ground conductor 32.

[0199] The plurality of first through-hole conductors 41 are arranged so as to sandwich or surround each power feed conductor 23 in a plan view. Furthermore, the plurality of first through-hole conductors 41 connect the first ground conductor 31 and the second ground conductor 32. For example, in this embodiment, eight first through-hole conductors 41 are arranged so as to surround the power feed conductor 23. The first through-hole conductors 41 shield the power feed conductor 23, thereby suppressing electromagnetic coupling between the power feed conductor 23 and the first ground conductor 31.

[0200] The multi-band antenna 102 of this embodiment includes the second radiating conductor 12, thereby transmitting the 28 GHz band, which is the first band and has a low return loss. This achieves broadband coverage of the 28 GHz band. Furthermore, the second ground conductor 32 and the first via-hole conductor 41 can be used to control the impedance of the power feed conductor 23 to an appropriate value (e.g., 50 ohms) and suppress unwanted resonance and reflection of electromagnetic waves.

[0201] (Third embodiment)

[0202] A third embodiment of the multi-band antenna according to the present invention will be described. Figure 11A and Figure 11B Schematic perspective views of multi-band antennas 103A and 103B of the present invention. The multi-band antennas 103A and 103B of this embodiment include multiple multi-band antennas 101 of the first embodiment or multiple multi-band antennas 102 of the second embodiment as antenna units, forming an antenna array.

[0203] Figure 11A The multi-band antenna 103A shown includes a plurality of multi-band antennas 102 arranged in one dimension. Figure 11AThe multi-band antennas 102 are arranged along the x-direction, but may also be arranged along the y-direction. In the multi-band antenna 103A, the second ground conductor 32 of each multi-band antenna 102 is connected to the second ground conductor 32 of the adjacent multi-band antenna 102. Therefore, in the multi-band antenna 103A, the second ground conductor 32 forms a single, continuous planar conductor. The first ground conductors 31 are separated from each other.

[0204] Figure 11B The multi-band antenna 103B shown includes a plurality of multi-band antennas 102 arranged in two dimensions. Figure 11B The multiband antennas 102 are arranged two-dimensionally along the x-axis and y-axis directions. In the multiband antenna 103B, the second ground conductor 32 of each multiband antenna 102 is connected to the second ground conductor 32 of the adjacent multiband antenna 102. Therefore, in the multiband antenna 103B, the second ground conductor 32 forms a single continuous planar conductor.

[0205] The number of multi-band antennas 103A and 103B as antenna units and the number of multi-band antennas 102 included is arbitrary. Figure 11A and Figure 11B The arrangement pitch of the multiband antennas 102 in the x-axis direction or the y-axis direction of the multiband antennas 103A and 103B (the distance between the centers of the multiband antennas 102 ) is, for example, 3 mm to 6 mm.

[0206] Multi-band antennas 103A and 103B are planar array antennas. When signal power is supplied to each multi-band antenna 102 at the same phase, the electromagnetic waves radiated from each multi-band antenna 102 are combined, enabling the emission of electromagnetic waves with higher directivity. Furthermore, by applying phase and amplitude differences to the signal power input to each multi-band antenna 102, the distribution and direction of the radiated electromagnetic waves can be controlled, achieving beamforming. Multi-band antennas 103A and 103B enable beamforming of electromagnetic waves in the first and second frequency bands.

[0207] (Fourth embodiment)

[0208] A fourth embodiment of the multi-band antenna according to the present invention will be described. Figure 12 1 is a schematic perspective view showing a multi-band antenna 104 of the present invention. The multi-band antenna 104 includes, as antenna elements, a plurality of multi-band antennas 102' arranged one-dimensionally along the x-direction. Figure 13 is a schematic top view of the multi-band antenna 102 ′.

[0209] The multi-band antenna 102' has an octagonal first ground conductor 31', which differs from the multi-band antenna 102 of the second embodiment. The multi-band antenna 102' includes a first radiating conductor 11, a second radiating conductor 12, a first strip conductor 21, a second strip conductor 22, a first ground conductor 31', and a second ground conductor 32. The arrangement of the first radiating conductor 11, the second radiating conductor 12, the first strip conductor 21, the second strip conductor 22, the first ground conductor 31', and the second ground conductor 32 in the z-axis direction is the same as that of the multi-band antenna 102.

[0210] In the multi-band antenna 102', the first radiating conductor 11, the second radiating conductor 12, the first strip conductor 21, and the second strip conductor 22 are arranged in an orientation rotated -45±3° about the z-axis relative to the multi-band antenna 102. Consequently, the first strip conductor 21 and the second strip conductor 22 are symmetrically positioned with respect to the yz plane.

[0211] In the first radiating conductor 11 and the second radiating conductor 12, the first sides 11c, 11d, 12c, and 12d form an angle of 45±3° with respect to the x-axis, and the second sides 11e, 11f, 12e, and 12f form an angle of -45±3° with respect to the x-axis. The first sides 11c, 11d, 12c, and 12d satisfy the relationships of equations (1) and (5), respectively, and the second sides 11e, 11f, 12e, and 12f satisfy the relationships of equations (2) and (6), respectively.

[0212] The first ground conductor 31' includes a pair of opposing first sides 31c and 31d, second sides 31e and 31f, third sides 31g and 31h, and fourth sides 31i and 31j. The first sides 31c and 31d form an angle of 45±3° with respect to the x-axis and intersect the first strip conductor 21. The second sides 31e and 31f form an angle of -45±3° with respect to the x-axis and intersect the second strip conductor 22. The first sides 31c and 31d and the second sides 31e and 31f satisfy the relationships of equations (3) and (4), respectively. The third sides 31g and 31h and the fourth sides 31i and 31j are parallel to the x-axis and y-axis, respectively.

[0213] However, if Figure 12 As shown, the first ground conductor 31' is connected to the first ground conductor 31' of the adjacent multi-band antenna 102' in the x-axis direction. Specifically, except for the multi-band antennas 102' at both ends in the x-axis direction, the fourth side 31j of the first ground conductor 31' is connected to the fourth side 31i of the first ground conductor 31' of the adjacent multi-band antenna 102'. In the multi-band antennas 102' at both ends in the x-axis direction, the fourth side 31i or 31j of the first ground conductor 31' is connected to the fourth side 31j or 31i of the first ground conductor 31' of the adjacent multi-band antenna 102', respectively.

[0214] In this embodiment, the first ground conductor 31' of the multi-band antenna 102' is connected to the first ground conductor 31' of the adjacent multi-band antenna 102'. However, the first ground conductor 31' of the multi-band antenna 102' may be separated from the first ground conductor 31' of the adjacent multi-band antenna 102'. Furthermore, the first ground conductor 31' has an octagonal shape with third sides 31g and 31h and fourth sides 31i and 31j. However, any other shape is acceptable. For example, depending on the distance Lg1 between the first sides 11c and 11d, the distance Lg2 between the second sides 12c and 12d, and the arrangement pitch of the multi-band antenna 102' in the x-axis direction, the first ground conductor 31' may have no third sides 31g and 31h, and may have the first side 31c connected to the second side 31e, and the first side 31d connected to the second side 31f. Furthermore, the first ground conductor 31' may not have fourth sides 31i and 31j, but may have first side 31d connected to second side 31e, and first side 31c connected to second side 31f. In this case, the first ground conductor 31' of each multi-band antenna 102' has a square shape, with each side forming an angle of 45° or -45° with respect to the x-axis, and being separated from adjacent first ground conductors 31' or connected at their vertices.

[0215] As in the first and second embodiments, according to the multi-band antenna 104, at least the first radiating conductor 11 and the first ground conductor 31' are dimensioned to satisfy the relationship between equations (1) and (3). This allows electromagnetic waves in the first frequency band and electromagnetic waves in the second frequency band to be transmitted and received in different modes. Therefore, the positions of the center frequencies (resonance frequencies) of the electromagnetic waves in the first frequency band and the second frequency band can be adjusted independently, providing a planar array antenna and a design method thereof that facilitates adjustment of the frequency bands used.

[0216] Furthermore, when signal power is simultaneously fed to the first and second strip conductors 21 and 22 of each multi-band antenna 104, electromagnetic waves are generated that have a distribution extending along planes tilted at +45° and -45° from the xz plane and centered on the z-axis. The resulting composite wave has a maximum intensity in the positive direction of the z-axis and an intensity distribution extending across both the xz and yz planes.

[0217] In this way, the electromagnetic waves caused by the signal power fed to the first strip conductor 21 and the electromagnetic waves caused by the signal power fed to the second strip conductor 22 are symmetrically distributed with respect to the xz plane including the x-axis as the arrangement direction, thereby suppressing the spread of the electromagnetic waves caused by the asymmetry of the electromagnetic waves and reducing the influence of unwanted interference from adjacent antennas.

[0218] Furthermore, since the first sides 11c, 11d, and second sides 11e, 11f of the first radiating conductor 11, and the first sides 31c, 31d, and second sides 3e, 3f of the first ground conductor 31, located at the nodal points of the electromagnetic waves, form the aforementioned angles relative to the x-axis, adverse effects such as undesirable interference with electromagnetic waves radiated from the adjacent multi-band antenna 102' can be suppressed. Consequently, the multi-band antenna 104 can perform beamforming with higher directivity.

[0219] Various modifications can be made to the multi-band antenna 104 . Figure 14 It is a stereoscopic diagram showing an enlarged representation of one of the multi-band antennas 102″ which is one of the antenna units of the multi-band antenna 105. The multi-band antenna 105 includes a plurality of multi-band antennas 102″, and the multi-band antenna 102″ also includes at least one second through-hole conductor 42 connecting the first ground conductor 31 and the second ground conductor 32, which is different from the multi-band antenna 102′. In the present embodiment, the multi-band antenna 102″ includes a plurality of second through-hole conductors 42. The plurality of second through-hole conductors 42 are arranged parallel to the outer edge of the first ground conductor 31 (either in line with the outer edge or located on the inner side thereof), with one end connected to the first ground conductor 31 and the other end connected to the second ground conductor 32. Alternatively, one end of the plurality of second through-hole conductors 42 may be connected to the first ground conductor 31, and the other end may not be connected to the second ground conductor 32. The diameter and spacing of the second through-hole conductors 42 may also be the same size as those of the first through-hole conductor 41. In addition, in Figure 14 Alternatively, gaps may be provided between the plurality of second through-hole conductors 42 so that the side surfaces of the second through-hole conductors 42 are in contact with each other.

[0220] The second via-hole conductor 42 can form a wall perpendicular to the resonance direction (a 45-degree direction when the first and second strip conductors are fed simultaneously), thereby enhancing the resonance effect within the space formed by the second via-hole conductor 42. By controlling the distance between the resonance direction (a 45-degree direction when the first and second strip conductors are fed simultaneously) in the space enclosed by the second via-hole conductor 42, the impedance and resonant frequency can be controlled.

[0221] The plurality of second via-hole conductors 42 function as a shielding member to suppress leakage of electromagnetic waves radiated from the first radiation conductor 11 to adjacent multi-band antennas 102". Therefore, adverse effects between the multi-band antennas 102" can be suppressed, and a multi-band antenna capable of beamforming with higher directivity can be realized.

[0222] (Fifth embodiment)

[0223] A fifth embodiment of the multi-band antenna will be described. Figure 151 is a schematic perspective view of a multiband antenna 106 of the present invention. The multiband antenna 106 is a multi-axis antenna including a multiband antenna 104 and a plurality of linear antennas 55. The multiband antenna 104 has the same structure as the multiband antenna 104 described in the fourth embodiment.

[0224] The plurality of linear antennas 55 correspond to one of the plurality of multi-band antennas 102' of the multi-band antenna 104 and are arranged at intervals in the y-axis direction. Each linear antenna 55 includes one or two linear radiation conductors extending parallel to the x-axis direction. Figure 15 In the illustrated embodiment, linear antenna 55 includes linear radiating conductors 25 and 26. Linear radiating conductors 25 and 26 each have a strip shape extending in the x-axis direction and are arranged closely together in the x-axis direction. Multi-band antenna 102' and linear antenna 55, arranged in the y-axis direction, constitute a single antenna unit.

[0225] The linear antenna 55 further includes feed conductors 27 and 28 to supply signal power to the linear radiation conductors 25 and 26. The feed conductors 27 and 28 have strip shapes extending in the y-axis direction. One end of each feed conductor 27 and 28 is connected to one end of each of the adjacent linear radiation conductors 25 and 26.

[0226] The linear radiation conductors 25 and 26 of the linear antenna 55 may or may not overlap with the second ground conductor 32 when viewed in the z-axis direction. When the linear radiation conductors 25 and 26 of the linear antenna 55 do not overlap with the second ground conductor 32 when viewed in the z-axis direction, the linear radiation conductors 25 and 26 of the linear antenna 55 are preferably spaced at least λ / 8 from the edge of the second ground conductor 32 in the y-axis direction. When the linear radiation conductors 25 and 26 overlap with the second ground conductor 32 when viewed in the z-axis direction, the second ground conductor 32 is preferably spaced at least λ / 8 from the linear radiation conductors 25 and 26 in the z-axis direction.

[0227] A portion of the other end of the linear antenna 55, including the feed conductors 27 and 28, may overlap with the second ground conductor 32 when viewed in the z-axis direction. One of the other ends of the feed conductors 27 and 28 is connected to a reference potential, while the other end of the feed conductors 27 and 28 supplies signal power. The length of the linear radiation conductors 25 and 26 in the x-axis direction is, for example, approximately 1.2 mm. Furthermore, the length (width) in the y-axis direction is, for example, approximately 0.2 mm.

[0228] Reference Figure 16 and Figure 17, the operation of the multi-band antenna 106 is described. In the multi-band antenna 106, when the first strip conductor 21 and the second strip conductor 22 simultaneously or selectively feed the multi-band antenna 102' of each antenna unit with signal power, as shown in FIG. Figure 16 As shown in FIG. 1 , the first radiation conductor 11 emits electromagnetic waves having an intensity distribution F+z having a maximum intensity in a direction perpendicular to the first radiation conductor 11, that is, in the positive direction of the z-axis. Figure 17 As shown, when signal power is supplied to the linear antenna 55 of each antenna unit, the linear radiation conductors 25 and 26 as a whole emit electromagnetic waves having a maximum intensity in the positive direction of the y-axis and an intensity distribution F+y extending in the yz plane.

[0229] In the multi-band antenna 106, the multi-band antenna 102' and the linear antenna 55 can be used simultaneously or selectively. In cases where simultaneous antenna feeding is not preferred and where gain reduction occurs due to interference, for example, in cases where the multi-band antenna 102' and the linear antenna 55 are supplied with signal power of the same phase, an RF switch or the like can be used to selectively input the signal to be transmitted or received to the multi-band antenna 102' or the linear antenna 55.

[0230] When using the multi-band antenna 102' and the linear antenna 55 simultaneously, it is preferable to apply a phase difference to the signals input to the multi-band antenna 102' and the linear antenna 55. This can suppress interference and improve gain. For example, a phase shifter composed of a diode switch, a MEMS switch, or the like can be used to selectively input the signals to be transmitted and received to the multi-band antenna 102' or the linear antenna 55.

[0231] The multi-band antenna 106 includes a plurality of antenna elements, and thus, it is possible to perform beamforming of electromagnetic waves radiated from the multi-band antenna 102 ′ and the linear antenna 55 .

[0232] (Sixth embodiment)

[0233] An embodiment of a wireless communication module according to the present invention will be described. Figure 18 This is a schematic cross-sectional view of the wireless communication module 107 taken along the xz plane. The wireless communication module 107 includes, for example, the multi-band antenna 106 of the third embodiment, active components 64 and 65, a passive component 66, and a connector 67. The wireless communication module 107 may also include a cover 68 that covers the active components 64 and 65 and the passive component 66. The cover 68 is made of metal or the like and functions as an electromagnetic shield, a heat sink, or both. If heat dissipation is not required, the active components 64 and 65 and the passive component 66 may be molded using resin in place of the cover 68.

[0234] On the main surface 40b side of the dielectric 40 of the multi-band antenna 106, there are provided a conductor 61 and a through-hole conductor 62 forming a wiring circuit pattern for connecting the multi-band antenna 102' and the linear antenna 55 (these are collectively indicated by the reference numeral 60). An electrode 63 is provided on the main surface 40b. Figure 18 The xz cross section shown does not show the components of the linear antenna 55 .

[0235] Active components 64 and 65 are DC / DC converters, low noise amplifiers (LNAs), power amplifiers (PAs), high-frequency ICs, etc. Passive components 66 are capacitors, coils, RF switches, etc. Connector 67 is used to connect wireless communication module 107 to the outside.

[0236] Active elements 64, 65, passive element 66, and connector 67 are connected to electrode 63 on main surface 40b of dielectric 40 of multi-band antenna 106 by soldering or the like, thereby being mounted on main surface 40b of multi-band antenna 106. The wiring circuit formed by conductor 61 and through-hole conductor 62, active elements 64, 65, passive element 66, and connector 67 constitute a signal processing circuit and the like.

[0237] In wireless communication module 107, the main surface 40a, where the multi-band antenna 102' and the linear antenna 55 are located, is located on the opposite side of the main surface 40b to which active elements 64, 65, and the like are connected. Therefore, electromagnetic waves can be radiated from the multi-band antenna 102' and the linear antenna 55 without being affected by active elements 64, 65, and the like. Furthermore, the multi-band antenna 102' and the linear antenna 55 can receive radio waves in the quasi-millimeter wave and millimeter wave bands arriving from the outside. Consequently, by including antennas capable of selectively transmitting and receiving electromagnetic waves in two orthogonal directions, a compact wireless communication module can be realized.

[0238] exist Figure 19 In the illustrated wireless communication module 108, electrode 63 of multi-band antenna 106 is electrically connected to flexible wiring 69. Flexible wiring 69 may be, for example, a flexible printed circuit board with a wiring circuit formed thereon, a coaxial cable, or a liquid crystal polymer substrate. Liquid crystal polymers are particularly well-suited for the wiring circuit connected to multi-band antenna 106 due to their excellent high-frequency characteristics.

[0239] (Seventh embodiment)

[0240] An embodiment of a wireless communication device according to the present invention will be described. Figure 20A and Figure 20B 1 is a schematic top view and side view of the wireless communication device 109. The wireless communication device 109 includes a main board (circuit board) 70 and one or more wireless communication modules 107. Figure 13The wireless communication device 109 includes four wireless communication modules 107A to 107D.

[0241] The main board 70 includes electronic circuits and wireless communication circuits required to realize the functions of the wireless communication device 109. In order to detect the orientation and position of the main board 70, a geomagnetic sensor, a GPS unit, etc. may also be included.

[0242] The main plate 70 has main surfaces 70a, 70b and four side portions 70c, 70d, 70e, and 70f. The main surfaces 70a, 70b are perpendicular to the w-axis of the second right-handed coordinate system, the side portions 70c, 70e are perpendicular to the v-axis, and the side portions 70d, 70f are perpendicular to the u-axis. Figure 20A , the main plate 70 is schematically shown as a cuboid having a rectangular main surface, but the side portions 70c, 70d, 70e, and 70f may each be composed of a plurality of surfaces.

[0243] The wireless communication device 109 includes one or more wireless communication modules. The number of wireless communication modules can be adjusted based on the specifications of the wireless communication device, the required performance, and other factors, such as the orientation of electromagnetic wave transmission and reception and the sensitivity of transmission and reception. The placement of the wireless communication modules on the mainboard 70 can be determined at any position, taking into account electromagnetic interference with other wireless communication modules and other functional modules of the wireless communication device, interference caused by configuration, and the sensitivity of electromagnetic wave transmission and reception when the wireless communication device is externally mounted. When placing the wireless communication modules on the main surfaces 70a or 70b of the mainboard 70, there are cases where placement near one of the side portions 70c, 70d, 70e, or 70f minimizes interference with other circuits installed on the mainboard 70. However, placement of the wireless communication modules on the main surfaces 70a or 70b is not limited to placement near the side portions 70c, 70d, 70e, or 70f; placement in the center of the main surfaces 70a or 70b is also possible.

[0244] In this embodiment, in wireless communication device 109, wireless communication modules 107A-107D are arranged on main surface 70a or main surface 70b of multi-band antenna 106, such that side surface 40c of dielectric 40 is adjacent to one of side portions 70c, 70d, 70e, or 70f, and main surface 40a of dielectric 40 is located on the opposite side of main board 70. Side surface 40c of dielectric 40 is adjacent to linear radiating conductors 25 and 26 of linear antenna 55, and electromagnetic waves are radiated from side surface 40c. Furthermore, main surface 40a of dielectric 40 is adjacent to first radiating conductor 11 of multi-band antenna 102, and electromagnetic waves are radiated from main surface 40a. Therefore, wireless communication modules 107A-107D are arranged on main board 70 in positions and directions where electromagnetic waves radiated from wireless communication modules 107A-107D are less likely to interfere with main board 70. Wireless communication modules 107A-107D can be positioned close to or separated from each other in the u / v directions.

[0245] For example, in Figure 20A and Figure 20B In the example shown, wireless communication modules 107A and 107C are arranged on main surface 70a, with side 40c of wireless communication modules 107A and 107C adjacent to either side 70c or 70d. Furthermore, wireless communication modules 107B and 107D are arranged on main surface 70b, with side 40c of wireless communication modules 107B and 107D adjacent to either side 70e or 70f. In this embodiment, side 40c of wireless communication module 107A is adjacent to side 70c, and side 40c of wireless communication module 107B is adjacent to side 70e. Furthermore, side 40c of wireless communication module 107C is adjacent to side 70d, and side 40c of wireless communication module 107D is adjacent to side 70f. Wireless communication modules 107A to 107D are arranged symmetrically with respect to the center point of main board 70.

[0246] Table 3 shows the directions of maximum intensity in the distribution of electromagnetic waves radiated from the multi-band antenna 102 and the linear antenna 55 of the wireless communication modules 107A to 107D configured in this manner.

[0247] [Table 3]

[0248] Wireless communication module Radiation direction of the multi-band antenna 102' Radiation direction of the linear antenna 55 107A +w +v 107B －w －v 107C +w －u 107D －w +u

[0249] In this way, electromagnetic waves can be radiated in all directions (±u, ±v, ±w directions) relative to the main board 70. For example, by detecting the position using the GPS unit of the wireless communication device 109, the nearest base station among multiple base stations whose position information is known around the wireless communication device 109 and the orientation of the base station relative to the wireless communication device 109 can be determined. In addition, by using the geomagnetic sensor of the wireless communication device 109, the orientation of the wireless communication device 109 can be determined, and the wireless communication modules 107A to 107D and the multi-band antenna 102' / linear antenna 55 that can radiate electromagnetic waves with the strongest intensity toward the determined base station to communicate with in the current orientation of the wireless communication device 109 can be determined. As a result, high-quality communication can be achieved by transmitting and receiving electromagnetic waves using the determined wireless communication module and antenna.

[0250] The wireless communication modules 107A to 107D may also be arranged on the side of the main board 70 . Figures 21A to 21CSchematic top and side views of wireless communication device 110. In wireless communication device 110, wireless communication modules 107A to 107D are arranged on any of side portions 70c to 70f such that side surface 40c of dielectric 40 of multi-band antenna 106 is adjacent to main surface 70a or main surface 70b, and main surface 40a of dielectric 40 is located on the opposite side of main board 70.

[0251] exist Figures 21A to 21C In the example shown, wireless communication modules 107A and 107B are arranged on side portions 70c and 70e, with side portions 40c of wireless communication modules 107A and 107B positioned adjacent to either of the main surfaces 70a and 70b. Furthermore, wireless communication modules 107C and 107D are arranged on side portions 70d and 70f, with side portions 40c of wireless communication modules 107C and 107D positioned adjacent to either of the main surfaces 70a and 70b. In this embodiment, side portion 40c of wireless communication module 107A is positioned adjacent to main surface 70a, while side portion 40c of wireless communication module 107B is positioned adjacent to main surface 70b. Furthermore, side portion 40c of wireless communication module 107C is positioned adjacent to main surface 70a, while side portion 40c of wireless communication module 107D is positioned adjacent to main surface 70b. Wireless communication modules 107A to 107D are arranged symmetrically about the center point of main board 70. The positions of the wireless communication modules 107A to 107D in the w-axis direction may be offset from the w-axis center of the main board 70. The wireless communication modules 107A to 107D may be in contact with the side portions 70c to 70f of the main board 70 or may be arranged with gaps therebetween.

[0252] Table 4 shows the directions of maximum intensity in the distribution of electromagnetic waves radiated from the multi-band antenna 102 ′ and the linear antenna 55 of the wireless communication modules 107A to 107D configured in this manner.

[0253] [Table 4]

[0254] Wireless communication module Radiation direction of the multi-band antenna 102' Radiation direction of the linear antenna 55 107A +v +w 107B －v －w 107C －u －w 107D +u +w

[0255] In this way, Figures 21A to 21C In the illustrated configuration, the wireless communication device 110 can also radiate electromagnetic waves in all directions (±u, ±v, ±w directions) relative to the main board 70 .

[0256] The arrangement of the wireless communication modules 107 in the wireless communication device is not limited to the above-described embodiment and can be modified in various ways. For example, some of the multiple wireless modules can be arranged on at least one of the main surfaces 70a and 70b of the main board 70, while the remaining wireless modules can be arranged on at least one of the side portions 70c, 70d, 70e, and 70f.

[0257] (Other methods)

[0258] The features of the multiband antenna and the like described in the first to seventh embodiments can be combined as appropriate. Furthermore, the number of planar antennas in the multiband antenna is not limited to the values ​​described in the embodiments.

[0259] Industrial applicability

[0260] The multi-band antenna of the present invention can be suitably used in various high-frequency wireless communication antennas and wireless communication circuits including the antenna, and is particularly preferably used in wireless communication devices in the quasi-microwave, centimeter-wave, quasi-millimeter-wave, and millimeter-wave frequency bands.

Claims

1. A multi-band antenna, characterized in that: capable of transmitting and receiving electromagnetic waves at least in a first wavelength band of a first central wavelength λ1 and a second wavelength band of a second central wavelength λ2 shorter than the first central wavelength λ1, The multi-band antenna includes at least one antenna unit, and the at least one antenna unit includes: first radiating conductor; a first ground conductor disposed spaced apart from the first radiation conductor via a dielectric having a relative dielectric constant εr; a second radiation conductor disposed between the first radiation conductor and the first ground conductor; and a first strip conductor disposed between the first ground conductor and the first radiation conductor or the second radiation conductor, for feeding power to the first radiation conductor and the second radiation conductor; The first radiation conductor and the first ground conductor each have a planar shape including a pair of opposing first sides. The distance Lrf1 between the pair of opposing first sides of the first radiation conductor and the distance Lg1 between the pair of opposing sides of the first ground conductor satisfy the following relationship: 0.2λ1 / εr 1 / 2 ≤Lrf1≤0.7λ1 / εr 1 / 2 , 0.7λ2 / εr 1 / 2 ≤Lg1≤1.75λ2 / εr 1 / 2 , The at least one antenna unit further comprises: Second grounding conductor; a hole provided in the second ground conductor; a power feeding conductor, which is arranged so as to pass through the hole of the second ground conductor and has one end connected to the first strip conductor; and The plurality of first via-hole conductors are arranged so as to sandwich or surround the power feeding conductor in a plan view, and connect the first ground conductor and the second ground conductor.

2. The multi-band antenna according to claim 1, wherein: The second radiation conductor has a planar shape including a pair of opposing first sides. The distance Lrs1 between the pair of opposing sides of the second radiation conductor satisfies the following relationship: 0.2λ1 / εr 1 / 2 ≤Lrs1≤0.5λ1 / εr 1 / 2 .

3. The multi-band antenna according to claim 1, wherein: further comprising a second strip conductor disposed between the first ground conductor and the first radiation conductor or the second radiation conductor for feeding power to the first radiation conductor and the second radiation conductor, The first strip-shaped conductor and the second strip-shaped conductor extend in directions perpendicular to each other.

4. The multi-band antenna according to claim 1, wherein: The second ground conductor is arranged on the opposite side of the first radiation conductor with respect to the first ground conductor, and has an outer edge surrounding the first ground conductor in a plan view.

5. The multi-band antenna according to claim 1, wherein: The at least one antenna unit includes a plurality of second via-hole conductors connecting the first ground conductor and the second ground conductor. The plurality of second via-hole conductors are arranged along at least a portion of the outer circumference of the first ground conductor and overlap with the first ground conductor in a plan view.

6. The multi-band antenna according to any one of claims 1 to 5, wherein: The first radiation conductor has a rectangular shape including a pair of first sides and a pair of opposing second sides. The distance Lrf2 between the pair of opposing second sides of the first radiation conductor satisfies the following relationship: 0.2λ1 / εr 1 / 2 ≤Lrf2≤0.7λ1 / εr 1 / 2 .

7. The multi-band antenna according to claim 2, wherein: The second radiation conductor has a rectangular shape including a pair of first sides and a pair of opposing second sides. The distance Lrs2 between the pair of opposing second sides of the second radiation conductor satisfies the following relationship: 0.2λ1 / εr 1 / 2 ≤Lrs2≤0.7λ1 / εr 1 / 2 .

8. The multi-band antenna according to any one of claims 1 to 5, wherein: The planar shape of the first ground conductor further includes a pair of opposite second sides. The distance Lg2 between the pair of opposing second sides of the first ground conductor satisfies the following relationship: 0.7λ2 / εr 1 / 2 ≤Lg2≤1.75λ2 / εr 1 / 2 .

9. The multi-band antenna according to any one of claims 1 to 5, wherein: comprising a plurality of antenna units, The plurality of antenna units are arranged along a first direction.

10. The multi-band antenna according to claim 4, wherein: comprising a plurality of antenna units, The plurality of antenna units are arranged along a first direction, The second ground conductor of each of the plurality of antenna units is connected to the second ground conductor of an adjacent antenna unit.

11. The multi-band antenna according to claim 10, wherein: In each of the plurality of antenna units, the pair of first sides of the first radiation conductor and the pair of first sides of the first ground conductor are arranged to form an angle of 45° or −45° with respect to the first direction in a plan view.

12. The multi-band antenna according to claim 11, wherein: The first ground conductor of each of the plurality of antenna units is connected to the first ground conductor of an adjacent antenna unit.

13. The multi-band antenna according to claim 11, wherein: The first ground conductor of each of the plurality of antenna units is separated from the first ground conductor of an adjacent antenna unit.

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