Antenna

Abstract

An antenna 1A comprises: a planar radiation conductor 10 that extends in a surface direction; a planar ground conductor 20 that is opposite of the radiation conductor 10 and extends in the surface direction; and a structure 30 that is interposed between the radiation conductor 10 and the ground conductor 20. The structure 30 includes a plurality of dielectrics 31. The plurality of dielectrics 31 are provided so as to be spaced apart from each other in the surface direction in a state of being separated from at least one of the radiation conductor 10 or the ground conductor 20.

Description

Antenna

[0001] The present invention relates to an antenna.

[0002] Patent Document 1 discloses a multi-frequency shared antenna having a plurality of different resonance frequencies, in which a feeding end of one feeding line is directly connected to a plurality of antenna parts having different resonance frequencies by respective microstrip lines, and the microstrip line matches the impedance seen from the feeding end to the antenna part side at the resonance frequency of the antenna part connected to the microstrip line with the impedance of the antenna part, and increases the impedance seen from the feeding end to the antenna part side at the resonance frequencies of other antenna parts. A multi-frequency shared antenna is disclosed.

[0003] Patent Document 2 discloses a dielectric substrate having a first surface and a second surface opposite to the first surface, a first radiation conductor, a second radiation conductor, and a ground conductor located on the dielectric substrate and arranged in order from the first surface to the second surface, a feeding via connected to the second radiation conductor, and a connection via connected to the second radiation conductor and the first radiation conductor. The radiation surface of the second radiation conductor has a first side and a second side facing the first side. The feeding via is located closer to the first side than the second side when viewed from a direction perpendicular to the radiation surface. The connection via is located in a region where the distance from the first side is within 3 / 4 of the distance between the first side and the second side when viewed from a direction perpendicular to the radiation surface. An antenna element is disclosed.

[0004] Japanese Patent Application Laid-Open No. 2004-112397, Japanese Patent Application Laid-Open No. 2022-22542

[0005] In antennas such as the multi-frequency shared antenna described in Patent Document 1 and the antenna element described in Patent Document 2, which are also called planar antennas, the size of the radiation conductor (antenna part) is determined by the frequency band in which the antenna operates. Therefore, in order to operate the antenna (planar antenna) in a plurality of frequency bands, radiation conductors of a plurality of sizes are required.

[0006] In the multi-frequency shared antenna described in Patent Document 1 (for example, Figure 1), it is conceivable that multiple antenna sections of different sizes are arranged in a planar direction to accommodate operation in multiple frequency bands. However, in the multi-frequency shared antenna described in Patent Document 1, the arrangement of multiple antenna sections of different sizes in a planar direction tends to increase the overall area of ​​the antenna, making it difficult to achieve space-saving in the antenna.

[0007] Furthermore, the antenna element described in Patent Document 2 (for example, Figure 1(C)) is designed to operate in multiple frequency bands by arranging multiple radiating conductors of different sizes perpendicular to the plane direction. However, in the antenna element described in Patent Document 2, because the multiple radiating conductors are arranged perpendicular to the plane direction with respect to the ground conductor, the distance between each radiating conductor and the ground conductor tends to become small. As a result, the frequency band in which each radiating conductor operates tends to become narrow, and consequently, it is difficult to achieve a broadband antenna.

[0008] Based on the above, conventional antennas (planar antennas) have room for improvement in terms of achieving both space-saving and wide bandwidth when operating across multiple frequency bands.

[0009] This invention was made to solve the above problems and aims to provide an antenna that can operate in multiple frequency bands while achieving both space saving and wide bandwidth.

[0010] The antenna of the present invention comprises a planar radiating conductor extending in the planar direction, a planar ground conductor facing the radiating conductor and extending in the planar direction, and a structure sandwiched between the radiating conductor and the ground conductor, wherein the structure includes a plurality of dielectrics, and the plurality of dielectrics are spaced apart from each other in the planar direction, away from at least one of the radiating conductor and the ground conductor.

[0011] According to the present invention, it is possible to provide an antenna that can operate in multiple frequency bands while achieving both space saving and wide bandwidth.

[0012] Figure 1 is a schematic perspective view showing a first example of the antenna of the present invention. Figure 2 is a schematic plan view showing the antenna in Figure 1 viewed from the radiating conductor side. Figure 3 is a schematic cross-sectional view showing the antenna in Figure 1 viewed in cross-section from the surface direction. Figure 4 is a schematic diagram to explain one example of the effects of the antenna in Figure 1. Figure 5 is a schematic diagram to explain another example of the effects of the antenna in Figure 1. Figure 6 is a schematic plan view showing a second example of the antenna of the present invention viewed from the radiating conductor side. Figure 7 is a schematic plan view showing a third example of the antenna of the present invention viewed from the radiating conductor side. Figure 8 is a schematic plan view showing a fourth example of the antenna of the present invention viewed from the radiating conductor side. Figure 9 is a schematic cross-sectional view showing a fifth example of the antenna of the present invention viewed in cross-section from the surface direction. Figure 10 is a schematic cross-sectional view showing a sixth example of the antenna of the present invention viewed in cross-section from the surface direction. Figure 11 is a schematic cross-sectional view of the seventh example of the antenna of the present invention, viewed from the planar direction. Figure 12 is a schematic cross-sectional view of the eighth example of the antenna of the present invention, viewed from the planar direction. Figure 13 is a schematic cross-sectional view of the ninth example of the antenna of the present invention, viewed from the planar direction. Figure 14 is a schematic cross-sectional view of the tenth example of the antenna of the present invention, viewed from the planar direction. Figure 15 is a schematic cross-sectional view of the eleventh example of the antenna of the present invention, viewed from the planar direction. Figure 16 is a schematic cross-sectional view of the twelfth example of the antenna of the present invention, viewed from the planar direction. Figure 17 is a schematic cross-sectional view of the thirteenth example of the antenna of the present invention, viewed from the planar direction. Figure 18 is a schematic cross-sectional view of the fourteenth example of the antenna of the present invention, viewed from the planar direction. Figure 19 is a schematic cross-sectional view of the simulation model of the antenna of Example 1, viewed from the planar direction. Figure 20 is a graph showing the frequency characteristics of the refractive index of the structure in the antenna of Example 1.

[0013] The antenna of the present invention will be described below. However, the present invention is not limited to the configuration described below, and may be modified as appropriate without departing from the spirit of the invention. Furthermore, a combination of several of the preferred configurations described below also constitutes the present invention.

[0014] In this specification, unless otherwise specified, terms describing relationships between elements (e.g., "same," "parallel," "perpendicular," etc.) and terms describing the shapes of elements mean not only the literal, exact form, but also a range of substantially equivalent forms, for example, a range including differences of a few percent (e.g., 5% or less).

[0015] [Antenna] The antenna of the present invention comprises a planar radiating conductor extending in the planar direction, a planar ground conductor facing the radiating conductor and extending in the planar direction, and a structure sandwiched between the radiating conductor and the ground conductor, wherein the structure includes a plurality of dielectrics, and the plurality of dielectrics are provided spaced apart from each other in the planar direction, away from at least one of the radiating conductor and the ground conductor.

[0016] Conventional antennas, when operating in multiple frequency bands, can be designed by arranging radiating conductors of various sizes in a planar direction (for example, Patent Document 1). However, arranging radiating conductors of various sizes in a planar direction tends to increase the overall area of ​​the antenna, making it difficult to achieve space-saving in antennas.

[0017] Furthermore, in conventional antennas, when operating in multiple frequency bands, it is conceivable to arrange multiple radiating conductors of different sizes perpendicular to the plane (for example, Patent Document 2). However, when multiple radiating conductors of different sizes are arranged perpendicular to the plane, the distance between each radiating conductor and the ground conductor tends to become small, which tends to narrow the frequency band in which each radiating conductor operates, and as a result, it is difficult to achieve a wideband antenna.

[0018] In contrast, in the antenna of the present invention, the structure sandwiched between the radiating conductor and the ground conductor includes multiple dielectrics. Furthermore, in the antenna of the present invention, the multiple dielectrics are provided spaced apart from each other in the planar direction, away from at least one of the radiating conductor and the ground conductor.

[0019] In the antenna of the present invention, when electromagnetic waves (e.g., radio waves) are incident on the structure during the transmission or reception of electromagnetic waves, multiple dielectrics within the structure resonate. In this case, because the multiple dielectrics within the structure of the antenna of the present invention are spaced apart from each other in the planar direction, divergence and relaxation of the dielectric constant (relative permittivity) of the structure occur near the resonant frequency of the multiple dielectrics, causing the dielectric constant (relative permittivity) of the structure to change around the resonant frequency. Furthermore, in the antenna of the present invention, the resonant frequency of the multiple dielectrics can be changed by changing the configuration of the structure, for example, the shape of the multiple dielectrics, the size of the multiple dielectrics, and the spacing between the multiple dielectrics in the planar direction. As a result, in the antenna of the present invention, the dielectric constant (relative permittivity) of the structure can be changed around any frequency (resonant frequency).

[0020] It is generally known that the dielectric constant (relative dielectric constant) has a predetermined relationship with the refractive index; specifically, the refractive index is proportional to the square root of the dielectric constant (relative dielectric constant). Therefore, in the antenna of the present invention, as described above, by changing the dielectric constant (relative dielectric constant) of the structure around an arbitrary frequency (resonant frequency), the refractive index of the structure can also be changed around an arbitrary frequency (resonant frequency).

[0021] Furthermore, it is generally known that when an electromagnetic wave with wavelength λ is incident on a medium with refractive index n, the wavelength of the electromagnetic wave in the medium changes to λ / n. Therefore, in the antenna of the present invention, when electromagnetic waves of multiple frequency bands are incident on the structure, if the resonant frequencies of multiple dielectric materials are controlled to be within the bands between the multiple frequency bands of the electromagnetic waves incident on the structure, then by changing the refractive index of the structure around the resonant frequency, specifically by changing the refractive index of the structure for each of the multiple frequency bands of the electromagnetic waves incident on the structure, the wavelength of the electromagnetic waves incident on the structure can be changed for each of the multiple frequency bands.

[0022] In the antenna of the present invention, the refractive index of the structure at any frequency can be changed by varying the configuration of the structure, for example, the shape of multiple dielectrics, the size of multiple dielectrics, and the spacing between multiple dielectrics in the planar direction. For example, in the antenna of the present invention, by combining M types of dielectrics (where M is an integer of 1 or more) in the structure, the refractive index of the structure can be changed for each of M+1 frequency bands of electromagnetic waves incident on the structure. When electromagnetic waves of M+1 frequency bands are incident on the structure, the refractive index of the structure at the highest frequency in the region where no dielectric is provided can be set as the reference refractive index (e.g., 1). Furthermore, if the structure is configured so that each dielectric size exhibits a refractive index greater than the reference refractive index (e.g., 1), then by providing M types of dielectrics, the refractive index of the structure at M types of frequencies can be made significantly different from the reference refractive index (e.g., 1). Therefore, when electromagnetic waves of M+1 frequency bands are incident on a structure, the refractive index of the structure at the highest frequency is set as the reference refractive index (e.g., 1), and the refractive index of the structure at the remaining M frequencies is set to be significantly different from the reference refractive index (e.g., 1). In this way, the refractive index of the structure can be changed for each of the M+1 frequency bands of electromagnetic waves incident on the structure.

[0023] From the above, in the antenna of the present invention, by considering the relationship (e.g., multiple relationship) of the wavelengths of electromagnetic waves in multiple frequency bands incident on the structure, and controlling the relationship (e.g., multiple relationship) of the refractive index of the structure in multiple frequency bands, the wavelengths of electromagnetic waves in multiple frequency bands incident on the structure can be changed to be approximately the same.

[0024] For example, with the antenna of the present invention, when transmitting or receiving a first electromagnetic wave with a frequency of 28 GHz / wavelength of 10.7 mm and a second electromagnetic wave with a frequency of 39 GHz / wavelength of 7.7 mm, which are in the millimeter-wave band and are being considered for use in the so-called 5G communication standard, it is possible to do the following.

[0025] First, in the antenna of the present invention, the resonant frequencies of the multiple dielectrics are controlled to a bandwidth between 28 GHz for the first electromagnetic wave and 39 GHz for the second electromagnetic wave. In this way, by controlling the resonant frequencies of the multiple dielectrics in the antenna of the present invention to a bandwidth between 28 GHz and 39 GHz, when the first electromagnetic wave and the second electromagnetic wave are incident on the structure during the transmission or reception of the first and second electromagnetic waves, the refractive index of the structure can be changed around the resonant frequency. Specifically, the refractive index of the structure at 28 GHz and the refractive index of the structure at 39 GHz can be made different. Furthermore, in the antenna of the present invention, considering that the wavelength of the first electromagnetic wave (10.7 mm) is approximately 1.39 times the wavelength of the second electromagnetic wave (7.7 mm), if the refractive index of the structure at 28 GHz, assuming the incidence of the first electromagnetic wave, is controlled to be approximately 1.39 times the refractive index of the structure at 39 GHz, assuming the incidence of the second electromagnetic wave, the wavelengths of the first and second electromagnetic waves incident on the structure can be changed to be approximately the same. For example, in the antenna of the present invention, if the refractive index of the structure at 28 GHz, assuming the incidence of the first electromagnetic wave, is controlled to 1.39, and the refractive index of the structure at 39 GHz, assuming the incidence of the second electromagnetic wave, is controlled to 1 (the reference refractive index), then when the first electromagnetic wave is incident on the structure, the wavelength changes to 10.7 mm / 1.39 ≈ 7.7 mm, and when the second electromagnetic wave is incident on the structure, the wavelength remains at 7.7 mm / 1 = 7.7 mm. Thus, the wavelengths of the first and second electromagnetic waves incident on the structure can be changed to be approximately the same.

[0026] In the above example, the present invention was shown in a case where the antenna transmits or receives electromagnetic waves in two different frequency bands. However, by, for example, combining two different sizes of dielectric materials in the structure, it is also possible to similarly transmit or receive electromagnetic waves in three different frequency bands.

[0027] For example, with the antenna of the present invention, when transmitting or receiving a first electromagnetic wave with a frequency of 28 GHz / wavelength of 10.7 mm, a second electromagnetic wave with a frequency of 39 GHz / wavelength of 7.7 mm, and a third electromagnetic wave with a frequency of 48 GHz / wavelength of 6.2 mm, which are among the millimeter-wave electromagnetic waves being considered for use in the so-called 5G communication standard, it is possible to do the following.

[0028] First, in the antenna of the present invention, the resonant frequencies of the multiple dielectrics are controlled to be in a band between 28 GHz of the first electromagnetic wave and 39 GHz of the second electromagnetic wave, and in a band between 39 GHz of the second electromagnetic wave and 48 GHz of the third electromagnetic wave. In this way, in the antenna of the present invention, by controlling the resonant frequencies of the multiple dielectrics to be in a band between 28 GHz and 39 GHz, and in a band between 39 GHz and 48 GHz, when the first electromagnetic wave, second electromagnetic wave, and third electromagnetic wave are incident on the structure during the transmission or reception operation of the first electromagnetic wave, second electromagnetic wave, and third electromagnetic wave, the refractive index of the structure can be changed around the resonant frequency. Specifically, the refractive index of the structure at 28 GHz, the refractive index of the structure at 39 GHz, and the refractive index of the structure at 48 GHz can be made different. Furthermore, in the antenna of the present invention, considering that the wavelength of the first electromagnetic wave (10.7 mm) is approximately 1.73 times the wavelength of the third electromagnetic wave (6.2 mm), and that the wavelength of the second electromagnetic wave (7.7 mm) is approximately 1.24 times the wavelength of the third electromagnetic wave (6.2 mm), the refractive index of the structure at 28 GHz, assuming the incidence of the first electromagnetic wave, is controlled to approximately 1.73 times the refractive index of the structure at 48 GHz, assuming the incidence of the third electromagnetic wave. Furthermore, the refractive index of the structure at 39 GHz, assuming the incidence of the second electromagnetic wave, is controlled to approximately 1.24 times the refractive index of the structure at 48 GHz, assuming the incidence of the third electromagnetic wave. By doing so, the wavelengths of the first, second, and third electromagnetic waves incident on the structure can be changed to be approximately the same. For example, in the antenna of the present invention, if the refractive index of the structure at 28 GHz, assuming the incidence of the first electromagnetic wave, is controlled to 1.73, the refractive index of the structure at 39 GHz, assuming the incidence of the second electromagnetic wave, is controlled to 1.24, and the refractive index of the structure at 48 GHz, assuming the incidence of the third electromagnetic wave, is controlled to 1 (the reference refractive index), then when the first electromagnetic wave is incident on the structure, the wavelength changes to 10.7 mm / 1.73 ≈ 6.2 mm, when the second electromagnetic wave is incident on the structure, the wavelength changes to 7.7 mm / 1.24 ≈ 6.2 mm, and when the third electromagnetic wave is incident on the structure, the wavelength remains at 6.2 mm / 1 = 6.2 mm. Thus, the wavelengths of the first, second, and third electromagnetic waves incident on the structure can be changed to be approximately the same.

[0029] In the above example, the present invention was shown in a case where the antenna transmits or receives electromagnetic waves in three different frequency bands. However, by, for example, combining three or more dielectric materials of different sizes in the structure, the same method can be used to show how the antenna transmits or receives electromagnetic waves in four or more frequency bands.

[0030] In the above example, the antenna of the present invention was shown transmitting or receiving electromagnetic waves in the millimeter-wave band, which are being considered for use in a communication standard known as 5G. However, the same applies, for example, when the antenna of the present invention transmits or receives electromagnetic waves in the terahertz-wave band, which are being considered for use in a communication standard known as 6G.

[0031] Furthermore, in the antenna of the present invention, since multiple dielectrics in the structure are separated from at least one of the radiating conductor and the ground conductor, electromagnetic waves to be transmitted or received can pass through the structure more easily, and as a result, the antenna function described above is more easily ensured.

[0032] Therefore, in the antenna of the present invention, since multiple dielectrics in the structure are provided spaced apart from each other in the planar direction, away from at least one of the radiating conductor and the ground conductor, the wavelengths of electromagnetic waves of multiple frequency bands incident on the structure can be changed to be approximately the same. Thus, electromagnetic waves of multiple frequency bands can be transmitted or received with a single radiating conductor without the need to provide multiple radiating conductors of different sizes for each frequency band. In the antenna of the present invention, since a single radiating conductor can handle operation across multiple frequency bands without requiring multiple radiating conductors of different sizes, the overall area of ​​the antenna can be reduced, resulting in space savings for the antenna. Furthermore, in the antenna of the present invention, since a single radiating conductor can handle operation across multiple frequency bands, it is easier to secure a large gap between the radiating conductor and the ground conductor, thus widening the frequency band in which the radiating conductor operates, resulting in a broadband antenna.

[0033] Based on the above, the antenna of the present invention makes it possible to realize an antenna that can operate in multiple frequency bands while achieving both space saving and wide bandwidth.

[0034] The following describes a specific example of the antenna of the present invention.

[0035] The drawings shown below are schematic representations, and their dimensions, aspect ratios, and scales may differ from those of the actual product.

[0036] Figure 1 is a schematic perspective view showing a first example of the antenna of the present invention. Figure 2 is a schematic plan view showing the antenna in Figure 1 viewed from the radiating conductor side. Figure 3 is a schematic cross-sectional view showing the antenna in Figure 1 viewed in cross-section from the surface direction. Note that Figure 3 corresponds to the cross section along the line III-III in Figure 1.

[0037] The antenna 1A shown in Figures 1, 2, and 3 comprises a radiating conductor 10, a ground conductor 20, and a structure 30.

[0038] Antenna 1A is a type of planar antenna, also known as a microstrip antenna or patch antenna.

[0039] In Figure 1, etc., the first direction D1, the second direction D2, and the third direction D3 are perpendicular to each other. The first direction D1 is perpendicular to the plane direction and corresponds to the thickness direction of antenna 1A. The second direction D2 and the third direction D3 are included in the plane direction. Thus, the plane direction is defined as including multiple directions.

[0040] <Radiating Conductor> The radiating conductor 10 is planar and extends in the planar direction. In the example shown in Figure 1, the radiating conductor 10 extends planarly in the second direction D2 and the third direction D3.

[0041] When viewed from the radiating conductor 10 side or the ground conductor 20 side (in Figure 2, when viewed from the first direction D1), the radiating conductor 10 only needs to overlap at least a part of the ground conductor 20. Specifically, it may overlap a part of the ground conductor 20 or it may overlap the entire ground conductor 20.

[0042] When viewed in a plan view from the side of the radiation conductor 10 (in FIG. 2, when viewed in a plan view from the first direction D1), the planar shape of the radiation conductor 10 is not particularly limited, and for example, it may be rectangular (square or rectangular), or may have a shape other than rectangular.

[0043] When viewed in a plan view from the side of the radiation conductor 10 (in FIG. 2, when viewed in a plan view from the first direction D1), the dimensions in the plane direction of the radiation conductor 10 are not particularly limited. For example, the dimension of the radiation conductor 10 in the second direction D2 and the dimension of the radiation conductor 10 in the third direction D3 are not particularly limited.

[0044] The radiation conductor 10 preferably contains a metal material as the conductor material. In this case, the metal material contained in the radiation conductor 10 is not particularly limited, and examples include copper, silver, gold, platinum, tungsten, molybdenum, manganese, palladium, nickel, cobalt, and alloys containing at least one of these metals.

[0045] The radiation conductor 10 may further contain a material other than the metal material in addition to the metal material as the conductor material.

[0046] The radiation conductor 10 may contain a material other than the metal material without containing the metal material as the conductor material.

[0047] The radiation conductor 10 may contain one type of conductor material or may contain a plurality of types of conductor materials.

[0048] The method for forming the radiation conductor 10 is not particularly limited. The radiation conductor 10 may be formed, for example, by firing a coating of a conductive paste containing a conductor material.

[0049] <Grand Conductor> The ground conductor 20 is planar and extends in a plane relative to the radiation conductor 10. In the example shown in FIG. 1 and the like, the ground conductor 20 is opposite to the radiation conductor 10 in the first direction D1 and extends planar in the second direction D2 and the third direction D3.

[0050] When viewed from the radiating conductor 10 side or the ground conductor 20 side (in Figure 2, when viewed from the first direction D1), the ground conductor 20 only needs to overlap at least a part of the radiating conductor 10. Specifically, it may overlap a part of the radiating conductor 10 or it may overlap the entire radiating conductor 10.

[0051] When viewed from a plan view from the side of the radiating conductor 10 or the side of the ground conductor 20 (in Figure 2, when viewed from a plan view from the first direction D1), the geometric center of the ground conductor 20 may or may not coincide with the geometric center of the radiating conductor 10.

[0052] The planar shape of the ground conductor 20 when viewed from the ground conductor 20 side (or, in Figure 2, when viewed from the first direction D1) is not particularly limited and may be rectangular (square or rectangular) or other shapes.

[0053] The planar shape of the ground conductor 20 may be the same as the planar shape of the radiating conductor 10, or it may be different from the planar shape of the radiating conductor 10.

[0054] If the planar shape of the ground conductor 20 is the same as the planar shape of the radiating conductor 10, the area of ​​the ground conductor 20 may be the same as the area of ​​the radiating conductor 10, or it may be different from the area of ​​the radiating conductor 10.

[0055] The dimensions of the ground conductor 20 in the planar direction when viewed from the ground conductor 20 side (in Figure 2, when viewed from the first direction D1) are not particularly limited. For example, the dimensions of the ground conductor 20 in the second direction D2 and the dimensions of the ground conductor 20 in the third direction D3 are not particularly limited.

[0056] The ground conductor 20 preferably contains a metallic material as its conductive material. In this case, the metallic material contained in the ground conductor 20 is not particularly limited and includes, for example, copper, silver, gold, platinum, tungsten, molybdenum, manganese, palladium, nickel, cobalt, and alloys containing at least one of these metals.

[0057] The ground conductor 20 may further contain materials other than metals in addition to metals as a conductor material.

[0058] The ground conductor 20 may contain materials other than metals as its conductor material, without including any metal materials.

[0059] The ground conductor 20 may contain one type of conductor material or may contain multiple types of conductor materials.

[0060] The conductor material included in the ground conductor 20 may be the same as the conductor material included in the radiating conductor 10, or it may be different from the conductor material included in the radiating conductor 10. For example, the metal material included in the ground conductor 20 may be the same as the metal material included in the radiating conductor 10, or it may be different from the metal material included in the radiating conductor 10.

[0061] The method for forming the ground conductor 20 is not particularly limited. The ground conductor 20 may be formed, for example, by firing a coating of conductive paste containing a conductive material.

[0062] <Structure> The structure 30 is sandwiched between the radiating conductor 10 and the ground conductor 20. In the example shown in Figure 1, etc., the structure 30 is sandwiched between the radiating conductor 10 and the ground conductor 20 in the first direction D1.

[0063] The structure 30 only needs to be sandwiched between the radiating conductor 10 and the ground conductor 20 in at least a portion of it. Specifically, a portion of the structure 30 may be sandwiched between the radiating conductor 10 and the ground conductor 20, or the entire structure 30 may be sandwiched between the radiating conductor 10 and the ground conductor 20. In other words, the structure 30 may be provided in areas other than the area between the radiating conductor 10 and the ground conductor 20, or it may not be provided in areas other than the area between the radiating conductor 10 and the ground conductor 20.

[0064] The structure 30 includes a plurality of dielectrics 31.

[0065] If multiple dielectrics 31 are provided in the region between the radiating conductor 10 and the ground conductor 20, they may also be provided outside the region between the radiating conductor 10 and the ground conductor 20, or they may not be provided outside the region between the radiating conductor 10 and the ground conductor 20.

[0066] The number of dielectrics 31 provided in the region between the radiating conductor 10 and the ground conductor 20 within the structure 30 is not particularly limited, as long as there are multiple dielectrics.

[0067] The number of dielectrics 31 in the entire structure 30 is not particularly limited, as long as there are multiple dielectrics.

[0068] Multiple dielectrics 31 are provided spaced apart from each other in the planar direction, away from at least one of the radiating conductor 10 and the ground conductor 20.

[0069] In the example shown in Figure 3, multiple dielectrics 31 are in contact with the ground conductor 20 while moving away from the radiating conductor 10 in the first direction D1.

[0070] In the example shown in Figure 2, multiple dielectrics 31 are provided spaced apart from each other in the second direction D2 and the third direction D3.

[0071] The multiple dielectrics 31 only need to be spaced apart from each other in the planar direction when viewed from a direction perpendicular to the planar direction (in this case, the first direction D1). Therefore, the multiple dielectrics 31 do not need to face each other (overlap) in the planar direction, and do not need to face each other (do not need to overlap) in the planar direction.

[0072] The arrangement of the multiple dielectrics 31 is not particularly limited, as long as they are spaced apart from each other in the planar direction. For example, they may be arranged in a grid pattern, a staggered pattern, or in any other manner.

[0073] The relative permittivity of the dielectric 31 is not particularly limited, but is preferably 10 or more, more preferably 50 or more, and even more preferably 100 or more at 25°C and 1 GHz. The relative permittivity of the dielectric 31 may be 10,000 or less, or 300 or less, at 25°C and 1 GHz. For example, the relative permittivity of the dielectric 31 is preferably 10 or more and 300 or less at 25°C and 1 GHz.

[0074] The relative permittivity of the dielectric 31 is measured by the resonator method.

[0075] The relative permittivity of the multiple dielectrics 31 may be the same as each other, may be different from each other, or may be different in some respects.

[0076] The dielectric material included in the dielectric 31 is not particularly limited, and examples include titanium oxide and strontium titanate. When the dielectric 31 contains at least one of titanium oxide and strontium titanate, the relative permittivity of the dielectric 31 tends to be 50 or more at 25°C and 1 GHz.

[0077] The dielectric 31 may contain one type of dielectric material or may contain multiple types of dielectric materials.

[0078] The dielectric materials contained in the multiple dielectrics 31 may be the same as each other, may be different from each other, or may be partially different.

[0079] The method for forming the multiple dielectrics 31 in the structure 30 is not particularly limited. The multiple dielectrics 31 may be formed, for example, by fabricating a dielectric film using known ceramic technology, then cutting the fabricated dielectric film into individual pieces, and spacing out the individual pieces of dielectric film.

[0080] The following describes the main effects and benefits of antenna 1A.

[0081] Conventional antennas, when operating in multiple frequency bands, can be designed by arranging radiating conductors of various sizes in a planar direction (for example, Patent Document 1). However, arranging radiating conductors of various sizes in a planar direction tends to increase the overall area of ​​the antenna, making it difficult to achieve space-saving in antennas.

[0082] Furthermore, in conventional antennas, when operating in multiple frequency bands, it is conceivable to arrange multiple radiating conductors of different sizes perpendicular to the plane (for example, Patent Document 2). However, when multiple radiating conductors of different sizes are arranged perpendicular to the plane, the distance between each radiating conductor and the ground conductor tends to become small, which tends to narrow the frequency band in which each radiating conductor operates, and as a result, it is difficult to achieve a wideband antenna.

[0083] In contrast, in antenna 1A, the structure 30 sandwiched between the radiating conductor 10 and the ground conductor 20 includes a plurality of dielectrics 31. Furthermore, in antenna 1A, the plurality of dielectrics 31 are provided spaced apart from each other in the planar direction, away from at least one of the radiating conductor 10 and the ground conductor 20.

[0084] In antenna 1A, when electromagnetic waves (e.g., radio waves) are transmitted or received, multiple dielectrics 31 within the structure 30 resonate when electromagnetic waves are incident on the structure 30. In antenna 1A, because the multiple dielectrics 31 within the structure 30 are spaced apart from each other in the planar direction, divergence and relaxation of the dielectric constant (relative permittivity) of the structure 30 occur near the resonant frequency of the multiple dielectrics 31, causing the dielectric constant (relative permittivity) of the structure 30 to change around the resonant frequency. Furthermore, in antenna 1A, the resonant frequency of the multiple dielectrics 31 can be changed by changing the configuration of the structure 30, for example, the shape of the multiple dielectrics 31, the size of the multiple dielectrics 31, and the spacing of the multiple dielectrics 31 in the planar direction. As a result, antenna 1A can change the dielectric constant (relative permittivity) of the structure 30 around any desired frequency (resonant frequency).

[0085] Here, it is generally known that the dielectric constant (relative dielectric constant) has a predetermined relationship with the refractive index, specifically that the refractive index is proportional to the square root of the dielectric constant (relative dielectric constant). From this, as described above, in antenna 1A, by changing the dielectric constant (relative dielectric constant) of the structure 30 around an arbitrary frequency (resonant frequency), the refractive index of the structure 30 can also be changed around an arbitrary frequency (resonant frequency).

[0086] Furthermore, it is generally known that when an electromagnetic wave with wavelength λ is incident on a medium with refractive index n, the wavelength of the electromagnetic wave in the medium changes to λ / n. Therefore, in antenna 1A, when electromagnetic waves of multiple frequency bands are incident on the structure 30, if the resonant frequencies of the multiple dielectrics 31 are controlled to be in a band between the multiple frequency bands of the electromagnetic waves incident on the structure 30, then by changing the refractive index of the structure 30 around the resonant frequency, specifically by changing the refractive index of the structure 30 for each of the multiple frequency bands of the electromagnetic waves incident on the structure 30, the wavelength of the electromagnetic waves incident on the structure 30 can be changed for each of the multiple frequency bands.

[0087] In antenna 1A, the refractive index of the structure 30 at any frequency can be changed by varying the configuration of the structure 30, for example, the shape of the multiple dielectrics 31, the size of the multiple dielectrics 31, and the spacing between the multiple dielectrics 31 in the planar direction. For example, in antenna 1A, by combining M types (M is an integer of 1 or more) of dielectrics 31 of size in the structure 30, the refractive index of the structure 30 can be changed for each of the M+1 frequency bands of electromagnetic waves incident on the structure 30. When electromagnetic waves of M+1 frequency bands are incident on the structure 30, the refractive index of the structure 30 at the highest frequency in the region where no dielectrics 31 are provided can be set as the reference refractive index (e.g., 1). Furthermore, if the structure 30 is configured so that each size of dielectric 31 exhibits a refractive index greater than the reference refractive index (e.g., 1), then by providing M types of dielectrics 31 of size, the refractive index of the structure 30 at M types of frequencies can be made significantly different from the reference refractive index (e.g., 1). Therefore, when electromagnetic waves of M+1 frequency bands are incident on the structure 30, the refractive index of the structure 30 can be changed for each of the M+1 frequency bands of electromagnetic waves incident on the structure 30. For example, the refractive index of the structure 30 at the highest frequency band can be set as the reference refractive index (e.g., 1), and the refractive index of the structure 30 at the remaining M frequencies can be set to be significantly different from the reference refractive index (e.g., 1).

[0088] From the above, in antenna 1A, by considering the relationship (e.g., multiple relationship) of the wavelengths of electromagnetic waves in multiple frequency bands incident on structure 30, and controlling the relationship (e.g., multiple relationship) of the refractive index of structure 30 in multiple frequency bands, it is possible to change the wavelengths of electromagnetic waves in multiple frequency bands incident on structure 30 to be approximately the same.

[0089] Figure 4 is a schematic diagram illustrating an example of the effects of the antenna shown in Figure 1.

[0090] As shown in Figure 4, for example, when antenna 1A transmits or receives a first electromagnetic wave W1 with a frequency of 28 GHz / wavelength of 10.7 mm and a second electromagnetic wave W2 with a frequency of 39 GHz / wavelength of 7.7 mm, which are millimeter-wave electromagnetic waves being considered for use in the so-called 5G communication standard, it is possible to do so as follows.

[0091] First, in antenna 1A, the resonant frequencies of the multiple dielectrics 31 are controlled to be within the bandwidth between 28 GHz for the first electromagnetic wave W1 and 39 GHz for the second electromagnetic wave W2. By controlling the resonant frequencies of the multiple dielectrics 31 in antenna 1A to be within the bandwidth between 28 GHz and 39 GHz, when the first electromagnetic wave W1 and the second electromagnetic wave W2 are incident on the structure 30 during the transmission or reception of the first electromagnetic wave W1 and the second electromagnetic wave W2, the refractive index of the structure 30 can be changed around the resonant frequency. Specifically, the refractive index of the structure 30 at 28 GHz and the refractive index of the structure 30 at 39 GHz can be made different. Furthermore, in antenna 1A, considering that the wavelength of the first electromagnetic wave W1 (10.7 mm) is approximately 1.39 times that of the second electromagnetic wave W2 (7.7 mm), if the refractive index of the structure 30 at 28 GHz, which is assumed to be when the first electromagnetic wave W1 is incident, is controlled to be approximately 1.39 times that of the refractive index of the structure 30 at 39 GHz, which is assumed to be when the second electromagnetic wave W2 is incident, then the wavelengths of the first electromagnetic wave W1 and the second electromagnetic wave W2 incident on the structure 30 can be changed to be almost the same. For example, as shown in Figure 4, in antenna 1A, if the refractive index of the structure 30 at 28 GHz, assuming the incidence of the first electromagnetic wave W1, is controlled to 1.39, and the refractive index of the structure 30 at 39 GHz, assuming the incidence of the second electromagnetic wave W2, is controlled to 1 (the reference refractive index), then when the first electromagnetic wave W1 is incident on the structure 30, the wavelength changes to 10.7 mm / 1.39 ≈ 7.7 mm, and when the second electromagnetic wave W2 is incident on the structure 30, the wavelength remains at 7.7 mm / 1 = 7.7 mm. Thus, the wavelengths of the first electromagnetic wave W1 and the second electromagnetic wave W2 incident on the structure 30 can be changed to be approximately the same.

[0092] In the example above, we showed the case where antenna 1A transmits or receives electromagnetic waves in two different frequency bands. However, by combining two dielectric materials 31 of different sizes in the structure 30, it is possible to similarly handle the case where antenna 1A transmits or receives electromagnetic waves in three different frequency bands.

[0093] Figure 5 is a schematic diagram illustrating another example of the effects of the antenna shown in Figure 1.

[0094] As shown in Figure 5, for example, when antenna 1A transmits or receives a first electromagnetic wave W1 with a frequency of 28 GHz / wavelength of 10.7 mm, a second electromagnetic wave W2 with a frequency of 39 GHz / wavelength of 7.7 mm, and a third electromagnetic wave W3 with a frequency of 48 GHz / wavelength of 6.2 mm, which are among the millimeter-wave electromagnetic waves being considered for use in the so-called 5G communication standard, it is possible to do the following.

[0095] First, in antenna 1A, the resonant frequencies of the multiple dielectrics 31 are controlled to be in the bandwidth between 28 GHz of the first electromagnetic wave W1 and 39 GHz of the second electromagnetic wave W2, and in the bandwidth between 39 GHz of the second electromagnetic wave W2 and 48 GHz of the third electromagnetic wave W3. By controlling the resonant frequencies of the multiple dielectrics 31 in antenna 1A to be in the bandwidth between 28 GHz and 39 GHz, and in the bandwidth between 39 GHz and 48 GHz, when the first electromagnetic wave W1, second electromagnetic wave W2, and third electromagnetic wave W3 are incident on the structure 30 during transmission or reception, the refractive index of the structure 30 can be changed around the resonant frequency. Specifically, the refractive index of the structure 30 at 28 GHz, the refractive index of the structure 30 at 39 GHz, and the refractive index of the structure 30 at 48 GHz can be made different. Furthermore, in antenna 1A, considering that the wavelength of the first electromagnetic wave W1 (10.7 mm) is approximately 1.73 times that of the third electromagnetic wave W3 (6.2 mm), and that the wavelength of the second electromagnetic wave W2 (7.7 mm) is approximately 1.24 times that of the third electromagnetic wave W3 (6.2 mm), the refractive index of the structure 30 at 28 GHz, assuming the incidence of the first electromagnetic wave W1, is controlled to be approximately 1.73 times that of the structure 30 at 48 GHz, assuming the incidence of the third electromagnetic wave W3. Furthermore, the refractive index of the structure 30 at 39 GHz, assuming the incidence of the second electromagnetic wave W2, is controlled to be approximately 1.24 times that of the structure 30 at 48 GHz, assuming the incidence of the third electromagnetic wave W3. By doing so, the wavelengths of the first electromagnetic wave W1, the second electromagnetic wave W2, and the third electromagnetic wave W3 incident on the structure 30 can be changed to be approximately the same.For example, as shown in Figure 5, in antenna 1A, if the refractive index of the structure 30 at 28 GHz, assuming the incidence of the first electromagnetic wave W1, is controlled to 1.73, the refractive index of the structure 30 at 39 GHz, assuming the incidence of the second electromagnetic wave W2, is controlled to 1.24, and the refractive index of the structure 30 at 48 GHz, assuming the incidence of the third electromagnetic wave W3, is controlled to 1 (the reference refractive index), then when the first electromagnetic wave W1 is incident on the structure 30, the wavelength changes to 10.7 mm / 1.73 ≈ 6.2 mm, when the second electromagnetic wave W2 is incident on the structure 30, the wavelength changes to 7.7 mm / 1.24 ≈ 6.2 mm, and when the third electromagnetic wave W3 is incident on the structure 30, the wavelength remains at 6.2 mm / 1 = 6.2 mm. Thus, the wavelengths of the first electromagnetic wave W1, the second electromagnetic wave W2, and the third electromagnetic wave W3 incident on the structure 30 can be changed to be approximately the same.

[0096] In the example above, we showed a case where antenna 1A transmits or receives electromagnetic waves in three different frequency bands. However, by, for example, combining three or more dielectric materials 31 of different sizes in the structure 30, it is possible to similarly handle cases where antenna 1A transmits or receives electromagnetic waves in four or more frequency bands.

[0097] The above example shows the case where antenna 1A transmits or receives electromagnetic waves in the millimeter-wave band, which are being considered for use in the so-called 5G communication standard. However, the same applies, for example, when antenna 1A transmits or receives electromagnetic waves in the terahertz-wave band, which are being considered for use in the so-called 6G communication standard.

[0098] Furthermore, in antenna 1A, since the multiple dielectrics 31 in the structure 30 are separated from at least one of the radiating conductor 10 and the ground conductor 20, electromagnetic waves to be transmitted or received can easily pass through the structure 30, and as a result, the function of antenna 1A as described above can be more easily ensured.

[0099] Therefore, in antenna 1A, the multiple dielectrics 31 in the structure 30 are spaced apart from each other in the planar direction, away from at least one of the radiating conductor 10 and the ground conductor 20. This allows the wavelengths of electromagnetic waves of multiple frequency bands incident on the structure 30 to be approximately the same. As a result, electromagnetic waves of multiple frequency bands can be transmitted or received with a single radiating conductor 10 without the need for multiple radiating conductors 10 of different sizes for each frequency band. In antenna 1A, since a single radiating conductor 10 can handle operation across multiple frequency bands without requiring multiple radiating conductors 10 of different sizes, the overall area of ​​antenna 1A can be reduced, resulting in space savings for antenna 1A. Furthermore, since a single radiating conductor 10 can handle operation across multiple frequency bands in antenna 1A, it is easier to secure a large gap between the radiating conductor 10 and the ground conductor 20. This allows the frequency band in which the radiating conductor 10 operates to be widened, resulting in a broadband antenna 1A.

[0100] Based on the above, antenna 1A makes it possible to realize an antenna that can operate in multiple frequency bands while achieving both space saving and wide bandwidth.

[0101] The following describes a preferred embodiment of antenna 1A in which it exhibits the above-mentioned effects.

[0102] Preferably, the spacing between the multiple dielectrics 31 in the planar direction when viewed from the radiating conductor 10 side is the same. In this case, the antenna 1A can accurately change the refractive index of the structure 30 around any frequency (resonant frequency), so that the wavelengths of electromagnetic waves of multiple frequency bands incident on the structure 30 can be accurately changed to the same wavelength, and as a result, electromagnetic waves of multiple frequency bands can be reliably transmitted or received with a single radiating conductor 10.

[0103] The spacing between the multiple dielectrics 31 in the planar direction when viewed from the radiating conductor 10 side is defined as the spacing in the same direction among the multiple directions included in the planar direction.

[0104] The distance between adjacent dielectrics 31 in the planar direction when viewed from the side of the radiating conductor 10 is determined as the distance between the geometric centers of the planar shapes of adjacent dielectrics 31 in the planar direction.

[0105] In the example shown in Figure 2, when viewed from the radiating conductor 10 side in the first direction D1, the spacing between the multiple dielectrics 31 in the second direction D2 is the same. Also in the example shown in Figure 2, when viewed from the radiating conductor 10 side in the first direction D1, the spacing between the multiple dielectrics 31 in the third direction D3 is the same. Furthermore, in the example shown in Figure 2, when viewed from the radiating conductor 10 side in the first direction D1, the spacing between the multiple dielectrics 31 in the second direction D2 and the spacing between the multiple dielectrics 31 in the third direction D3 are the same.

[0106] Furthermore, the spacing between the multiple dielectrics 31 in the planar direction when viewed from the radiating conductor 10 side may be different from each other, or may be different in some parts.

[0107] When viewed from the radiating conductor 10 side in a plan view, the spacing between the multiple dielectrics 31 in the planar direction is preferably 1 / 4 to 3 times the maximum dimension of each dielectric in the direction in which the multiple dielectrics 31 are aligned in the planar direction when viewed from the radiating conductor 10 side. In the example shown in Figure 2, it is preferable that the spacing between the multiple dielectrics 31 in the second direction D2 is 1 / 4 to 3 times the dimension of one side of each dielectric 31 in the second direction D2. Also, in the example shown in Figure 3, it is preferable that the spacing between the multiple dielectrics 31 in the third direction D3 is 1 / 4 to 3 times the dimension of one side of each dielectric 31 in the third direction D3.

[0108] The spacing between the multiple dielectrics 31 in the planar direction when viewed from the radiating conductor 10 side may be, for example, 0.05 mm or more and 5 mm or less. In this case, when transmitting or receiving a first electromagnetic wave with a frequency of 28 GHz / wavelength of 10.7 mm and a second electromagnetic wave with a frequency of 39 GHz / wavelength of 7.7 mm, which are millimeter-wave electromagnetic waves being considered for use in the so-called 5G communication standard, it becomes easy to control the resonant frequencies of the multiple dielectrics 31 to the band between 28 GHz and 39 GHz, and it also becomes easy to change the refractive index of the structure 30 around the resonant frequency in the band between 28 GHz and 39 GHz. As a result, it becomes easy to change the wavelengths of the first and second electromagnetic waves incident on the structure 30 to be the same, and consequently, it becomes easy to transmit or receive the first and second electromagnetic waves with a single radiating conductor 10.

[0109] Preferably, the planar shapes of the multiple dielectrics 31, when viewed from the radiating conductor 10 side, are the same. In this case, the antenna 1A can accurately change the refractive index of the structure 30 around any frequency (resonant frequency), so that the wavelengths of electromagnetic waves of multiple frequency bands incident on the structure 30 can be accurately changed to the same wavelength, and as a result, electromagnetic waves of multiple frequency bands can be reliably transmitted or received by a single radiating conductor 10.

[0110] The planar shape of the multiple dielectrics 31 when viewed from the radiating conductor 10 is not particularly limited, but from the viewpoint of the function of changing the wavelengths of electromagnetic waves of multiple frequency bands incident on the structure 30 to the same value, the following shape is preferable.

[0111] Figure 6 is a schematic plan view showing a second example of the antenna of the present invention as viewed from the radiating conductor side. Figure 7 is a schematic plan view showing a third example of the antenna of the present invention as viewed from the radiating conductor side.

[0112] The planar shapes of the multiple dielectrics 31 are preferably regular polygonal shapes. For example, the following shapes are possible: In antenna 1A shown in Figure 2, the planar shapes of the multiple dielectrics 31 are square (regular quadrilateral). In antenna 1B shown in Figure 6, the planar shapes of the multiple dielectrics 31 are equilateral triangles. In antenna 1C shown in Figure 7, the planar shapes of the multiple dielectrics 31 are regular pentagons. In addition, in the examples shown in Figures 2, 6, and 7, the planar shapes of the multiple dielectrics 31 are congruent. Note that the planar shapes of the multiple dielectrics 31 may be regular polygonal shapes other than those shown in Figures 2, 6, and 7.

[0113] Figure 8 is a schematic plan view showing a fourth example of the antenna of the present invention, viewed from the radiating conductor side.

[0114] The planar shapes of the multiple dielectrics 31 are preferably circular. In the antenna 1D shown in Figure 8, the planar shapes of the multiple dielectrics 31 are circular. Also, in the example shown in Figure 8, the planar shapes of the multiple dielectrics 31 are congruent.

[0115] When the planar shapes of the multiple dielectrics 31 are regular polygonal or circular, the function of changing the wavelengths of electromagnetic waves of multiple frequency bands incident on the structure 30 to the same value becomes less dependent on the direction of incidence of the electromagnetic waves on the structure 30. In other words, when the planar shapes of the multiple dielectrics 31 are regular polygonal or circular, the function of changing the wavelengths of electromagnetic waves of multiple frequency bands incident on the structure 30 to the same value tends to exhibit isotropy.

[0116] When the planar shapes of the multiple dielectrics 31 are the same when viewed from the radiating conductor 10, it is preferable that the planar shapes of the multiple dielectrics 31 are congruent. In this case, in the antenna 1A, since the shape and size of the multiple dielectrics 31 are the same, the refractive index of the structure 30 can be changed more accurately around an arbitrary frequency (resonance frequency). As a result, the wavelengths of electromagnetic waves of multiple frequency bands incident on the structure 30 can be changed more accurately to the same wavelength, and consequently, electromagnetic waves of multiple frequency bands can be transmitted or received more reliably with a single radiating conductor 10.

[0117] When the planar shapes of the multiple dielectrics 31 are viewed from the radiating conductor 10 side, it means that they are congruent, and that when the planar shapes of the multiple dielectrics 31 are translated without rotation, they substantially overlap. In this case, the planar shapes of the multiple dielectrics 31 may strictly overlap, or they may be shifted within a range that includes a difference of a few percent (for example, 5% or less) in terms of area.

[0118] Furthermore, the planar shapes of the multiple dielectrics 31, when viewed from the radiating conductor 10 side, may be similar.

[0119] When the planar shapes of the multiple dielectrics 31 are the same when viewed from the radiating conductor 10, it is preferable that the maximum dimensions of each of the multiple dielectrics 31 in the direction in which the multiple dielectrics 31 are aligned are the same when viewed from the radiating conductor 10. In this case, the refractive index of the structure 30 can be changed more accurately around an arbitrary frequency (resonance frequency) in the antenna 1A, so that the wavelengths of electromagnetic waves of multiple frequency bands incident on the structure 30 can be changed more accurately to the same wavelength, and as a result, electromagnetic waves of multiple frequency bands can be transmitted or received more reliably with a single radiating conductor 10.

[0120] In the example shown in Figure 2, multiple dielectrics 31 are arranged in a second direction D2 of the plane, and the maximum dimensions of each dielectric 31 in the second direction D2 are the same. Also in the example shown in Figure 2, multiple dielectrics 31 are arranged in a third direction D3 of the plane, and the maximum dimensions of each dielectric 31 in the third direction D3 are the same. Furthermore, in the example shown in Figure 2, the maximum dimensions of each dielectric 31 in the second direction D2 and the maximum dimensions of each dielectric 31 in the third direction D3 are the same.

[0121] In the above case, the maximum dimensions of each of the multiple dielectrics 31 in the direction in which the multiple dielectrics 31 are aligned in the planar direction only need to be substantially the same. In this case, the maximum dimensions of each of the multiple dielectrics 31 in the direction in which the multiple dielectrics 31 are aligned in the planar direction may be exactly the same, or they may contain a difference of a few percent (for example, 5% or less).

[0122] Furthermore, when viewed from the radiating conductor 10 in a plan view, the maximum dimensions of each of the multiple dielectrics 31 in the direction in which the multiple dielectrics 31 are aligned in the plane direction may be different from each other, or may be different in some parts.

[0123] When viewed from the radiating conductor 10 in a plan view, the maximum dimension of each of the multiple dielectrics 31 in the direction in which the multiple dielectrics 31 are aligned in the plane direction is preferably 0.1 mm or more and 1.7 mm or less. In the example shown in Figure 2, the dimension of one side of each dielectric 31 in the second direction D2 or the third direction D3 is preferably 0.1 mm or more and 1.7 mm or less.

[0124] When viewed in cross-section from the planar direction, the thickness (height) of each of the multiple dielectrics 31 is preferably 0.2 mm or more and 1.0 mm or less. In the example shown in Figure 3, the dimension of each dielectric 31 in the first direction D1 is preferably 0.2 mm or more and 1.0 mm or less.

[0125] Furthermore, the planar shapes of the multiple dielectrics 31 when viewed from the radiating conductor 10 side may be different from each other, or may be different in some parts.

[0126] The three-dimensional shapes of the multiple dielectrics 31 are not particularly limited and may be, for example, polygonal prisms (including cubic and rectangular parallelepipeds), cylindrical, polygonal pyramidal, conical, spherical, etc.

[0127] The three-dimensional shapes of the multiple dielectrics 31 may be the same as each other, different from each other, or partially different.

[0128] If the three-dimensional shape of the dielectric 31 is a regular polygonal prism or a regular polygonal pyramidal shape, the planar shape of the dielectric 31 when viewed from the side of the radiating conductor 10 may be a regular polygon. Also, if the three-dimensional shape of the dielectric 31 is cylindrical, conical, or spherical, the planar shape of the dielectric 31 when viewed from the side of the radiating conductor 10 may be circular.

[0129] As described above, in the example shown in Figure 3, the multiple dielectrics 31 are in contact with the ground conductor 20 while moving away from the radiating conductor 10 in the first direction D1. The positional relationship between the radiating conductor 10, the ground conductor 20, and the dielectrics 31 may be in a configuration other than that shown in Figure 3. Below, specific examples of configurations other than those shown in Figure 3 regarding the positional relationship between the radiating conductor 10, the ground conductor 20, and the dielectrics 31 are shown. All of the specific examples shown below correspond to a configuration in which the multiple dielectrics 31 are separated from at least one of the radiating conductor 10 and the ground conductor 20.

[0130] Figure 9 is a schematic cross-sectional view showing a fifth example of the antenna of the present invention, viewed from the planar direction.

[0131] In the antenna 1E shown in Figure 9, multiple dielectrics 31 are in contact with the radiating conductor 10 in the first direction D1, while being separated from the ground conductor 20.

[0132] Figure 10 is a schematic cross-sectional view showing a sixth example of the antenna of the present invention viewed in cross-section from the planar direction.

[0133] In the antenna 1F shown in Figure 10, multiple dielectrics 31 are separated from the radiating conductor 10 and also from the ground conductor 20 in the first direction D1.

[0134] Figure 11 is a schematic cross-sectional view showing a seventh example of the antenna of the present invention, viewed from the planar direction.

[0135] In the antenna 1G shown in Figure 11, the multiple dielectrics 31 include a first dielectric 31A and a second dielectric 31B.

[0136] The first dielectric 31A is in contact with the ground conductor 20 while moving away from the radiating conductor 10 in the first direction D1. The first dielectrics 31A are spaced apart from each other in the planar direction (in this case, the third direction D3).

[0137] The second dielectric 31B is in contact with the radiating conductor 10 in the first direction D1, but is separated from the ground conductor 20. The second dielectrics 31B are spaced apart from each other in the planar direction (in this case, the third direction D3).

[0138] The first dielectric 31A and the second dielectric 31B are facing each other (overlapping) in the first direction D1. When viewed from a plane in the first direction D1, the first dielectric 31A only needs to overlap at least a part of the second dielectric 31B, specifically it may overlap a part of the second dielectric 31B or it may overlap the entire second dielectric 31B. Also, when viewed from a plane in the first direction D1, the second dielectric 31B only needs to overlap at least a part of the first dielectric 31A, specifically it may overlap a part of the first dielectric 31A or it may overlap the entire first dielectric 31A.

[0139] Figure 12 is a schematic cross-sectional view showing an eighth example of the antenna of the present invention viewed in cross-section from a planar direction.

[0140] In the antenna 1H shown in Figure 12, the multiple dielectrics 31 include a first dielectric 31A and a second dielectric 31B.

[0141] The first dielectric 31A is in contact with the ground conductor 20 while moving away from the radiating conductor 10 in the first direction D1. The first dielectrics 31A are spaced apart from each other in the planar direction (in this case, the third direction D3).

[0142] The second dielectric 31B is in contact with the radiating conductor 10 in the first direction D1, but is separated from the ground conductor 20. The second dielectrics 31B are spaced apart from each other in the planar direction (in this case, the third direction D3).

[0143] The first dielectric 31A and the second dielectric 31B are not facing each other (they do not overlap) in the first direction D1.

[0144] The first dielectric 31A and the second dielectric 31B face each other (overlap) in the planar direction (in this case, the third direction D3). When viewed from a planar perspective from the planar direction (in this case, the third direction D3), it is sufficient that the first dielectric 31A and the second dielectric 31B partially overlap each other.

[0145] When multiple dielectrics 31, including the first dielectric 31A and the second dielectric 31B, are viewed together (overall), the first dielectric 31A and the second dielectric 31B are arranged alternately with spacing between them in the planar direction (in this case, the third direction D3).

[0146] Figure 13 is a schematic cross-sectional view showing a ninth example of the antenna of the present invention, viewed from the planar direction.

[0147] In the antenna 1J shown in Figure 13, the multiple dielectrics 31 include a first dielectric 31A and a second dielectric 31B.

[0148] The first dielectric 31A is in contact with the ground conductor 20 while moving away from the radiating conductor 10 in the first direction D1. The first dielectrics 31A are spaced apart from each other in the planar direction (in this case, the third direction D3).

[0149] The second dielectric 31B is in contact with the radiating conductor 10 in the first direction D1, but is separated from the ground conductor 20. The second dielectrics 31B are spaced apart from each other in the planar direction (in this case, the third direction D3).

[0150] The first dielectric 31A and the second dielectric 31B are not facing each other (they do not overlap) in the first direction D1.

[0151] The first dielectric 31A and the second dielectric 31B are not facing each other (they do not overlap) in the planar direction (in this case, the third direction D3).

[0152] When multiple dielectrics 31, including the first dielectric 31A and the second dielectric 31B, are viewed together (overall), the first dielectric 31A and the second dielectric 31B are arranged alternately with spacing between them in the planar direction (in this case, the third direction D3).

[0153] In the examples shown in Figures 3, 9, 10, 11, 12, and 13, the dimensions of the multiple dielectrics 31 in the first direction D1 are the same. However, the dimensions of the multiple dielectrics 31 in the first direction D1 may be different from each other, or may be different in some respects, as described below.

[0154] Figure 14 is a schematic cross-sectional view showing a tenth example of the antenna of the present invention viewed in cross-section from a planar direction.

[0155] In the antenna 1K shown in Figure 14, the multiple dielectrics 31 include a first dielectric 31A and a second dielectric 31B.

[0156] The first dielectric 31A is in contact with the ground conductor 20 while moving away from the radiating conductor 10 in the first direction D1.

[0157] The second dielectric 31B is in contact with the ground conductor 20 while moving away from the radiating conductor 10 in the first direction D1.

[0158] When multiple dielectrics 31, including the first dielectric 31A and the second dielectric 31B, are viewed together (overall), the first dielectric 31A and the second dielectric 31B are arranged alternately with spacing between them in the planar direction (in this case, the third direction D3).

[0159] The dimensions of the first dielectric 31A and the second dielectric 31B in the first direction D1 are different from each other. Specifically, the dimension of the first dielectric 31A in the first direction D1 is greater than the dimension of the second dielectric 31B in the first direction D1.

[0160] Furthermore, the dimension of the first dielectric 31A in the first direction D1 may be smaller than the dimension of the second dielectric 31B in the first direction D1.

[0161] In the example shown in Figure 14, there are two types of dielectrics 31 that have different dimensions in the first direction D1, but there may be three or more types of dielectrics 31 that have different dimensions in the first direction D1.

[0162] In the examples shown in Figures 11, 12, 13, and 14, the number of first dielectrics 31A and second dielectrics 31B are the same, but the number of first dielectrics 31A and second dielectrics 31B may be different.

[0163] In the examples shown in Figures 12, 13, and 14, the first dielectric 31A and the second dielectric 31B are arranged alternately in the planar direction (here, the third direction D3). However, the first dielectric 31A and the second dielectric 31B do not have to be arranged alternately in the planar direction (here, the third direction D3). For example, in the planar direction (here, the third direction D3), only the first dielectric 31A may be provided continuously, only the second dielectric 31B may be provided continuously, or each of the first dielectric 31A and the second dielectric 31B may be provided continuously.

[0164] In the examples shown in Figures 3, 9, 10, 11, 12, 13, and 14, the multiple dielectrics 31 are provided at equal intervals in the planar direction (here, the third direction D3). However, the multiple dielectrics 31 do not necessarily have to be provided at equal intervals in the planar direction (here, the third direction D3), as described below.

[0165] Figure 15 is a schematic cross-sectional view showing an eleventh example of the antenna of the present invention, viewed from the planar direction.

[0166] In antenna 1L shown in Figure 15, some of the dielectrics 31 (in this case, the second dielectric from the right) are missing compared to antenna 1A shown in Figure 3. Therefore, in antenna 1L, the dielectrics 31 are not provided at equal intervals in the planar direction (in this case, the third direction D3).

[0167] Multiple examples from those shown in Figures 3, 9, 10, 11, 12, 13, 14, and 15 may be combined. For example, by combining the example shown in Figure 14, in the examples shown in Figures 9, 10, 11, 12, 13, or 15, multiple dielectric materials 31 of different types with different dimensions in the first direction D1 may be provided. Also, by combining the example shown in Figure 15, in the examples shown in Figures 9, 10, 11, 12, 13, or 14, the multiple dielectric materials 31 do not have to be provided at equal intervals in the planar direction (here, the third direction D3).

[0168] Regarding the positional relationship between the radiating conductor 10, the ground conductor 20, and the dielectric 31, any configuration other than the example described above is acceptable, as long as the multiple dielectrics 31 are separated from at least one of the radiating conductor 10 and the ground conductor 20.

[0169] As described above, the structure 30 may include a plurality of dielectrics 31. In addition to the plurality of dielectrics 31, the structure 30 may include members other than the dielectrics 31, or it may not include members other than the dielectrics 31. Below, specific examples of an embodiment in which the structure 30 includes members other than the dielectrics 31 are shown.

[0170] <Dielectric Support> Figure 16 is a schematic cross-sectional view showing a twelfth example of the antenna of the present invention viewed in cross-section from the planar direction.

[0171] As shown in Figure 16, the structure 30 may further include at least one dielectric support 32. Preferably, the dielectric support 32 is provided in contact with both the radiating conductor 10 and the ground conductor 20, and spaced apart from the dielectric 31 in the planar direction (here, the third direction D3). In this case, since the dielectric support 32 functions as a support for the radiating conductor 10 and the ground conductor 20, it becomes easy to configure the structure 30 to be sandwiched between the radiating conductor 10 and the ground conductor 20.

[0172] The number of dielectric supports 32 in the structure 30 is not particularly limited, as long as there is at least one; it may be one or more.

[0173] The position of the dielectric support 32 in the structure 30 when viewed from the radiating conductor 10 side or the ground conductor 20 side (or, in Figure 16, when viewed from the first direction D1) is not particularly limited. For example, when viewed from the radiating conductor 10 side or the ground conductor 20 side (or, in Figure 16, when viewed from the first direction D1), the dielectric support 32 may be provided on the periphery of the region sandwiched between the radiating conductor 10 and the ground conductor 20 (the region where the radiating conductor 10 and the ground conductor 20 overlap), or it may be provided on a part other than the periphery.

[0174] In the example shown in Figure 16, a dielectric support 32 is provided in addition to the example shown in Figure 3. However, the dielectric support 32 may also be provided in other examples besides the one shown in Figure 3, such as in Figures 9, 10, 11, 12, 13, 14, or 15.

[0175] <Resin part> Figure 17 is a schematic cross-sectional view showing a 13th example of the antenna of the present invention viewed in cross-section from the planar direction.

[0176] As shown in Figure 17, the structure 30 may further include a resin portion 33 sandwiched between the dielectric 31 and the radiating conductor 10, and between the dielectric 31 and the ground conductor 20. In this case, the resin portion 33 functions as a support for the radiating conductor 10 and the dielectric 31, or as a support for the ground conductor 20 and the dielectric 31, or as a support for the radiating conductor 10, the ground conductor 20, and the dielectric 31, making it easy to configure the structure 30 to be sandwiched between the radiating conductor 10 and the ground conductor 20.

[0177] The composition of the resin portion 33 is not particularly limited. The resin portion 33 may be composed of, for example, a filler made of resin material, or it may be composed of a resin film (resin sheet). If the resin portion 33 is composed of a resin film (resin sheet), the resin portion 33 may be a laminate of a plurality of resin films (resin sheets).

[0178] The method for providing the resin portion 33 so as to be sandwiched between the dielectric 31 and the radiating conductor 10, and between the dielectric 31 and the ground conductor 20, is not particularly limited. For example, the resin portion 33 may be formed by injecting a resin material into at least one of the spaces between the dielectric 31 and the radiating conductor 10, and between the dielectric 31 and the ground conductor 20, or by inserting a resin film (resin sheet). Alternatively, the resin portion 33 may be formed using a resin material or a resin film (resin sheet), and then the dielectric 31 may be provided on one side of the resin portion 33, and the radiating conductor 10 or ground conductor 20 may be provided on the other side of the resin portion 33. When using a resin film (resin sheet) to form the resin portion 33, the number of sheets is not particularly limited.

[0179] In the example shown in Figure 17, the resin portion 33 is sandwiched between the dielectric 31 and the radiating conductor 10 in the first direction D1.

[0180] When the resin portion 33 is sandwiched between the dielectric 31 and the radiating conductor 10 in the first direction D1, the resin portion 33 may or may not protrude outward from the region between the dielectric 31 and the radiating conductor 10 in the planar direction (here, the third direction D3).

[0181] If the resin portion 33 protrudes outward from the region between the dielectric 31 and the radiating conductor 10 in the planar direction (here, the third direction D3), adjacent resin portions 33 in the planar direction (here, the third direction D3) may be connected or separated in the planar direction (here, the third direction D3).

[0182] In the example shown in Figure 17, a resin portion 33 is provided compared to the example shown in Figure 3. However, in examples other than the example shown in Figure 3, for example, in Figures 9, 10, 11, 12, 13, 14, 15, or 16, the resin portion 33 may be sandwiched between the dielectric 31 and the radiating conductor 10, and between the dielectric 31 and the ground conductor 20, at least one of the two.

[0183] When the resin portion 33 is sandwiched between the dielectric 31 and the ground conductor 20, the resin portion 33 may or may not protrude outward from the region between the dielectric 31 and the ground conductor 20 in the planar direction (here, the third direction D3).

[0184] If the resin portion 33 protrudes outward from the region between the dielectric 31 and the ground conductor 20 in the planar direction (here, the third direction D3), adjacent resin portions 33 in the planar direction (here, the third direction D3) may be connected or separated in the planar direction (here, the third direction D3).

[0185] If the resin part 33 is provided in a portion of the space between the radiating conductor 10 and the ground conductor 20, specifically in a portion of the space between the radiating conductor 10 and the ground conductor 20 where the dielectric 31 is not provided (for example, the example shown in Figure 17), then nothing may be provided in the remaining space (it may remain empty), or other members may be provided in the space as long as they do not hinder the function of the antenna.

[0186] Figure 18 is a schematic cross-sectional view showing a 14th example of the antenna of the present invention, viewed from the planar direction.

[0187] As shown in the antenna 1P in Figure 18, the resin portion 33 may fill the entire space between the radiating conductor 10 and the ground conductor 20. Specifically, the resin portion 33 may fill the entire space between the radiating conductor 10 and the ground conductor 20 where the dielectric 31 is not provided. In this case, since the resin portion 33 functions as a support for the radiating conductor 10, the ground conductor 20, and the dielectric 31, it becomes easier to configure the structure 30 to be sandwiched between the radiating conductor 10 and the ground conductor 20.

[0188] The method for providing the resin portion 33 so as to fill the entire space between the radiating conductor 10 and the ground conductor 20 is not particularly limited. For example, the resin portion 33 may be formed by injecting a resin material into the entire space between the radiating conductor 10 and the ground conductor 20. Alternatively, the resin portion 33 may be formed by sealing a plurality of dielectrics 31 with a resin material or a resin film (resin sheet), and then the radiating conductor 10 may be provided on one side of the resin portion 33 and the ground conductor 20 on the other side of the resin portion 33.

[0189] In the example shown in Figure 18, a resin portion 33 is provided compared to the example shown in Figure 3. However, in examples other than the example shown in Figure 3, for example, in Figures 9, 10, 11, 12, 13, 14, 15, or 16, the resin portion 33 may be filled into the entire space between the radiating conductor 10 and the ground conductor 20.

[0190] Furthermore, the resin portion 33 does not necessarily have to be provided in the space between the radiating conductor 10 and the ground conductor 20. In this case, the space between the radiating conductor 10 and the ground conductor 20 where the dielectric 31 is not provided may be left empty (it may remain empty), or other members besides the resin portion 33 may be provided to the extent that they do not hinder the function of the antenna.

[0191] The antenna of the present invention is not limited to the above-described form, and various applications and modifications can be made within the scope of the present invention regarding the antenna's configuration, manufacturing conditions, etc.

[0192] For example, the feeding structure and feeding method for the radiating conductor in the antenna of the present invention are not particularly limited, and known feeding structures and feeding methods may be used.

[0193] The following are examples that more specifically disclose the antenna of the present invention. However, the present invention is not limited to the following examples.

[0194] [Example 1] Figure 19 is a schematic cross-sectional view showing the simulation model of the antenna of Example 1 viewed in cross-section from the planar direction.

[0195] As shown in Figure 19, the same configuration as antenna 1F shown in Figure 10 was adopted as the simulation model for the antenna of Example 1. The specifications of the simulation model for the antenna of Example 1 are as follows: Three-dimensional shape of dielectric 31: cubic Relative permittivity of dielectric 31: 95 (25℃, 1GHz) Dimension of dielectric 31 in the first direction D1: 0.75 mm Dimension of dielectric 31 in the second direction D2: 0.75 mm Dimension of dielectric 31 in the third direction D3: 0.75 mm Distance between dielectric 31s in the third direction D3: 0.85 mm Distance between dielectric 31 and radiating conductor 10: 0.10 mm Distance between dielectric 31 and ground conductor 20: 0.15 mm Distance between radiating conductor 10 and ground conductor 20: 1.00 mm

[0196] [Evaluation] A simulation evaluation of the frequency characteristics of the refractive index of the structure was performed using the simulation model of the antenna from Example 1. For the simulation evaluation, Ansys HFSS, a 3D electromagnetic field simulator manufactured by Ansys, Inc., was used.

[0197] Figure 20 is a graph showing the frequency characteristics of the refractive index of the structure in the antenna of Example 1.

[0198] In the antenna of Embodiment 1, which has a structure characterized by having multiple dielectrics spaced apart from each other in the planar direction, away from at least one of the radiating conductor and the ground conductor, it was confirmed that the refractive index of the structure changes significantly before and after the boundary, approximately between 34 GHz and 36 GHz, as shown in Figure 20. From this, it was considered that in the antenna of Embodiment 1, the resonant frequencies of the multiple dielectrics are located within the range of approximately 34 GHz and 36 GHz.

[0199] In the antenna of Example 1, as shown in Figure 20, the refractive index of the structure was approximately 1.6 at 28 GHz and approximately 1.1 at 39 GHz. From this, it was considered that in the antenna of Example 1, when transmitting or receiving a first electromagnetic wave with a frequency of 28 GHz / wavelength of 10.7 mm and a second electromagnetic wave with a frequency of 39 GHz / wavelength of 7.7 mm, which are millimeter-wave electromagnetic waves being considered for use in the so-called 5G communication standard, the wavelength of the first electromagnetic wave changes to 10.7 mm / 1.6 ≈ 6.7 mm when incident on the structure, and the wavelength changes to 7.7 mm / 1.1 = 7.0 mm when incident on the structure. Thus, it was considered that the wavelengths of the first and second electromagnetic waves incident on the structure can be made to be approximately the same.

[0200] Therefore, in the antenna of Example 1, since the wavelengths of the first and second electromagnetic waves incident on the structure can be changed to be almost the same, it was considered that the first and second electromagnetic waves can be transmitted or received with a single radiating conductor, without the need to provide two radiating conductors of different sizes for each frequency band, such as 28 GHz for the first electromagnetic wave and 39 GHz for the second electromagnetic wave. In the antenna of Example 1, since a single radiating conductor can handle two frequency bands such as 28 GHz and 39 GHz without the need for two radiating conductors of different sizes, the overall area of ​​the antenna can be reduced, and as a result, space saving of the antenna can be achieved. Furthermore, in the antenna of Example 1, since a single radiating conductor can handle two frequency bands such as 28 GHz and 39 GHz, it is easier to secure a large gap between the radiating conductor and the ground conductor, so the frequency band in which the radiating conductor operates can be widened, and as a result, a wideband antenna can be achieved.

[0201] Based on the above, it was concluded that the antenna of Example 1 can achieve both space saving and wide bandwidth while realizing an antenna capable of operating in two frequency bands, 28 GHz and 39 GHz.

[0202] 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1J, 1K, 1L, 1M, 1N, 1P Antenna 10 Radiating conductor 20 Ground conductor 30 Structure 31 Dielectric 31A First dielectric 31B Second dielectric 32 Dielectric support 33 Resin part D1 First direction D2 Second direction D3 Third direction W1 First electromagnetic wave W2 Second electromagnetic wave W3 Third electromagnetic wave

Claims

1. An antenna comprising: a planar radiating conductor extending in the planar direction; a planar ground conductor extending in the planar direction opposite to the radiating conductor; and a structure sandwiched between the radiating conductor and the ground conductor, wherein the structure includes a plurality of dielectrics, and the plurality of dielectrics are spaced apart from each other in the planar direction, away from at least one of the radiating conductor and the ground conductor.

2. The antenna according to claim 1, wherein the spacing between the plurality of dielectrics in the planar direction when viewed from the radiating conductor side is the same.

3. The antenna according to claim 1 or 2, wherein the planar shapes of the plurality of dielectrics, when viewed from the radiating conductor side, are the same as those of the others.

4. The antenna according to claim 3, wherein the planar shapes of the plurality of dielectrics are regular polygonal shapes.

5. The antenna according to claim 3, wherein the planar shapes of the plurality of dielectrics are circular.

6. The antenna according to any one of claims 1 to 5, wherein the structure further includes at least one dielectric support, the dielectric support being provided at a distance from the dielectric in the planar direction while in contact with both the radiating conductor and the ground conductor.

7. The antenna according to any one of claims 1 to 6, wherein the structure further includes a resin portion sandwiched between the dielectric and the radiating conductor, and between the dielectric and the ground conductor, at least one of the two.

8. The antenna according to claim 7, wherein the resin portion fills the entire space between the radiating conductor and the ground conductor.

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