Radio wave control element and antenna

Abstract

In this invention, a dielectric includes a region in which relative permittivity continuously changes.

Description

Radio wave control element and antenna

[0001] The present disclosure relates to a radio wave control element and an antenna.

[0002] In recent years, the speed of communication devices has increased, and the frequencies used in communication have tended to become very high. To improve the signal-to-noise ratio of signals in high-frequency bands, there is a growing demand for radio wave control elements that can focus radio waves and transmit them without loss. Furthermore, as sensing technologies, such as high-precision measurement and imaging, have become more sophisticated, there is a trend toward using high-frequency radio waves that have high directionality and a wide bandwidth, and there is a growing demand for radar with high gain and long detection distances. Another application of high-frequency radar is also being considered: non-contact biosensing, using antennas with improved gain in a specific direction.

[0003] For example, Patent Document 1 describes a radio wave dielectric component that is a lens using a molded body including a spherical shape as a device for focusing radio waves. Patent Document 2 describes a high-dielectric-constant thermosetting resin composition containing (A) a thermosetting resin and (B) at least one inorganic filler selected from the group consisting of titanium-based inorganic fillers and zircon-based inorganic fillers, and an antenna module. Patent Document 3 describes an antenna including a lens and a waveguide provided behind the lens. Patent Document 4 describes a radar antenna device with reduced bulkiness intended for non-contact biosensing.

[0004] Patent Document 1: International Publication No. 2023 / 248882 Patent Document 2: International Publication No. 2023 / 145327 Patent Document 3: Japanese Patent Application Laid-Open No. 2005-253103 Patent Document 4: Japanese Patent Application Laid-Open No. 2021-57868

[0005] As communication frequencies become higher, radio wave propagation loss increases, weakening the radio waves that can be received. This has led to a demand for radio wave control elements that can focus weak radio waves to increase signal strength and transmit radio waves without loss.

[0006] An object of one embodiment of the present disclosure is to provide a radio wave control element and an antenna that control radio waves to a desired state.

[0007] Specific means for solving the problems include the following aspects. [1] A radio wave control element including a dielectric including a region where the dielectric constant changes continuously. [2] The radio wave control element according to [1], wherein the amount of change in the dielectric constant in the region where the dielectric constant changes continuously is 0.1 to 1000. [3] The radio wave control element according to [1] or [2], wherein the dielectric has a thickness that changes by 10% or less in the region where the dielectric constant changes continuously. [4] The radio wave control element according to any one of [1] to [3], wherein the dielectric includes at least two materials having different dielectric constants, and the mixing ratio of the at least two materials changes gradually in the region where the dielectric constant changes continuously. [5] The radio wave control element according to any one of [1] to [4], wherein the dielectric includes at least one material, and the density of the material changes gradually in the region where the dielectric constant changes continuously. [6] The radio wave control element according to any one of [1] to [5], wherein the dielectric contains at least one material and air, and the air content gradually changes within a region where the dielectric constant changes continuously. [7] The radio wave control element according to any one of [1] to [6], wherein the dielectric constant changes monotonically from one of two opposing sides to the other within the region where the dielectric constant changes continuously. [8] The radio wave control element according to any one of [1] to [6], wherein the dielectric constant changes monotonically from the two opposing sides within the region where the dielectric constant changes continuously within the in-plane direction. [9] The radio wave control element according to any one of [1] to [6], wherein the dielectric constant changes monotonically from the center to the periphery within the in-plane direction within the region where the dielectric constant changes continuously.

[10] The radio wave control element according to any one of [1] to [6], wherein the dielectric has a dielectric constant that changes monotonically from the inside to the outer periphery in the thickness direction in the region where the dielectric constant changes continuously.

[11] The radio wave control element according to any one of [1] to [9], wherein the dielectric has a thickness that changes continuously in the region where the dielectric constant changes continuously, and the direction of increase in the dielectric constant coincides with the direction of increase in the thickness.

[12] The radio wave control element according to

[11] , wherein the dielectric has a thickness change rate of more than 10% in the region where the dielectric constant changes continuously.

[13] The radio wave control element according to [9], wherein the dielectric constant of the interior is higher than that of the outer periphery.

[14] The radio wave control element according to [9], wherein the dielectric constant of the interior is lower than that of the outer periphery.

[15] The radio wave control element according to

[10] , wherein the dielectric constant of the interior is higher than that of the surface.

[16] An antenna comprising the radio wave control element according to any one of [1] to

[15] and a radio wave emitting element or a radio wave receiving element.

[0008] According to one embodiment of the present disclosure, there is provided a radio wave control element for controlling radio waves to a desired state, and an antenna.

[0009] FIG. 1 is a diagram illustrating the dielectric in the radio wave control element of the first embodiment. FIG. 2 is a diagram illustrating the dielectric in the radio wave control element of the second embodiment. FIG. 3 is a diagram illustrating another aspect of the dielectric in the radio wave control element of the second embodiment. FIG. 4 is a diagram illustrating the dielectric in the radio wave control element of the third embodiment. FIG. 5 is a diagram illustrating another aspect of the dielectric in the radio wave control element of the third embodiment. FIG. 6 is a diagram illustrating the dielectric in the radio wave control element of the fifth embodiment. FIG. 7 is a diagram illustrating a modified example of the dielectric in the radio wave control element of the second embodiment.

[0010] The contents of the present disclosure are described in detail below. The following description of the constituent elements may be based on a representative embodiment of the present disclosure, but the present disclosure is not limited to such an embodiment. In this specification, the term "to" indicating a numerical range is used to mean that the numerical values ​​before and after it are included as the upper and lower limits. In the numerical ranges described in stages in this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit of that numerical range may be replaced with a value shown in the examples. Furthermore, in the description of groups (atomic groups) in this specification, a notation that does not specify whether they are substituted or unsubstituted encompasses both unsubstituted and substituted groups. For example, the term "alkyl group" encompasses not only alkyl groups without substituents (unsubstituted alkyl groups) but also alkyl groups with substituents (substituted alkyl groups). In this specification, "(meth)acrylic" is a term used as a concept that encompasses both acrylic and methacrylic, and "(meth)acryloyl" is a term used as a concept that encompasses both acryloyl and methacryloyl. Furthermore, the term "process" in this specification does not only refer to an independent process, but also includes a process that cannot be clearly distinguished from other processes as long as the intended purpose of the process is achieved. Furthermore, in this disclosure, a combination of two or more preferred embodiments is a more preferred embodiment. The elements in each drawing shown in this disclosure are not necessarily drawn to scale, and emphasis is placed on clearly illustrating the principles of the present disclosure, with some parts being emphasized.

[0011] <Dielectric> The radio wave control element of the present disclosure is a radio wave control element that includes a dielectric that includes a region in which the relative dielectric constant changes continuously.

[0012] According to the radio wave control element of the present disclosure, the antenna has good transmission and reception efficiency, and radio waves can be controlled to a desired state, such as by converging or bending the radio waves.

[0013] The mode in which the dielectric constant changes continuously refers to the mode in which the dielectric constant gradually increases or decreases like a gradation, and is distinguished from the mode in which the dielectric constant changes stepwise. Hereinafter, the region in which the dielectric constant changes continuously is also referred to as the "dielectric constant changing region."

[0014] The dielectric constant of a dielectric can be evaluated by a known method. For example, a desired location on the dielectric can be measured by a resonance perturbation method at a frequency of 10 GHz. Specifically, a 10 GHz cavity resonator (Kanto Electronics Application Development Co., Ltd., CP531) is connected to a network analyzer (Agilent Technology, Inc., E8363B), a measurement sample of the dielectric is inserted into the cavity resonator, and the change in resonance frequency before and after insertion is measured under an environment of 25°C and 60% RH for 96 hours. At this time, the dielectric loss tangent can also be evaluated. The dielectric may be a laminate.

[0015] The fact that the dielectric constant is continuously changing can be determined by the following method. The dielectric constants of an arbitrary location (location A) and another location (location B) of the dielectric are evaluated, respectively. Furthermore, the dielectric constant at the midpoint between locations A and B is evaluated in detail. It is confirmed whether the dielectric constant at the midpoint is an intermediate value between the dielectric constants at locations A and B. If the dielectric constant at the midpoint is an intermediate value between the dielectric constants at locations A and B, and these three points form a line in which the dielectric constant increases or decreases sequentially, it is determined that the dielectric constant is continuously changing. Then, the measurement region from location A to location B is determined to be a region where the dielectric constant changes.

[0016] Another method involves evaluating indicators such as the material composition ratio, orientation state, specific gravity, and porosity at positions A and B, and determining whether the distribution of these indicators at the midpoint gradually changes. If the distribution of these indicators at the midpoint gradually changes, it is determined that the dielectric constant is continuously changing. The measurement region from position A to position B is then determined to be a dielectric constant change region. For example, if the material composition ratio gradually changes, forming a gradation region in which the dielectric constant changes continuously, it is determined that the dielectric constant is continuously changing. Specifically, even if the material composition ratio has a step-like distribution profile under microscopic observation, it is determined that the dielectric constant is continuously changing if the size of the step is 1 / 500 or less of the wavelength of the controlled radio wave. On the other hand, if it is greater than 1 / 500 of the wavelength of the controlled radio wave, it is determined that the dielectric constant is changing stepwise. Furthermore, the direction in which the dielectric constant continuously changes is not particularly limited, and can be adjusted appropriately in either the in-plane direction or the thickness direction depending on the application of the dielectric.

[0017] The dielectric may have one or more dielectric constant change regions. The dielectric may include regions other than the dielectric constant change region (i.e., regions where the dielectric constant does not change continuously). Alternatively, the dielectric may include only the dielectric constant change region.

[0018] The average value of the dielectric constant of the dielectric is not particularly limited, since it is adjusted as appropriate depending on the application of the dielectric. Furthermore, the amount of change in the dielectric constant in the dielectric constant change region is not particularly limited, but is preferably 0.1 to 1000, more preferably 0.5 to 100, even more preferably 1 to 50, and particularly preferably 1 to 30.

[0019] The amount of change in the relative dielectric constant is a value calculated as the absolute value of the difference between the maximum and minimum values ​​of the relative dielectric constant in the relative dielectric constant change region.

[0020] For example, in the case of an application such as a lens that focuses radio waves from the front, from the viewpoint of suppressing loss due to interfacial reflection while simultaneously improving the focusing efficiency of the radio waves and miniaturizing the element, the relative dielectric constant is preferably 1 to 50, and in this case the change amount is 49. At a more preferable relative dielectric constant of 1.5 to 30, the change amount is 28.5. Furthermore, in the case of an application as a radio wave waveguide, from the viewpoint of simultaneously suppressing transmission loss and achieving wave-guiding performance, the relative dielectric constant is preferably 1 to 6, and in this case the change amount is 5. At a more preferable relative dielectric constant of 1.1 to 4, the change amount is 2.9, and at an even more preferable relative dielectric constant of 1.1 to 3.5, the change amount is 2.4. When the radio wave control material of the present disclosure is a lens, the lens focuses radio waves from the front, and the focal position is located outside the lens, not on the surface of the lens.

[0021] The thickness of the dielectric is not particularly limited, as it is adjusted appropriately depending on the application of the dielectric. From the viewpoints of formability of elements, devices, parts, and circuits using the dielectric, processability such as lamination and pressure bonding, thinning, and appearance, it is preferable that the thickness is nearly uniform.

[0022] In the radio wave control material of the present disclosure, since the dielectric includes a region where the relative dielectric constant changes, radio waves can be controlled to a desired state even if the thickness of the region where the relative dielectric constant changes is uniform. Specifically, since the dielectric includes a region where the relative dielectric constant changes, radio waves can be bent in a specific direction. Furthermore, radio waves can easily pass through regions with high relative dielectric constants, allowing radio waves to be focused.

[0023] The thickness change rate in the dielectric constant change region is preferably 10% or less, more preferably 5% or less, and even more preferably 3% or less. The lower limit of the thickness change rate is not particularly limited, but from the viewpoint of suitability for mass production, it is usually 0.01% or more. The thickness change rate is calculated using the following formula: Thickness change rate (%) = {(maximum thickness - minimum thickness) / average thickness} × 100. The thickness is measured using a known contact film thickness meter, but if there are restrictions such as a small measurement range, an optical film thickness meter or the like can also be used as appropriate. The average thickness is the average value of the values ​​obtained by measuring the thickness at five locations in the dielectric constant change region.

[0024] The change rate of the thickness of the dielectric is also preferably 10% or less, more preferably 5% or less, and even more preferably 3% or less. The lower limit of the change rate of the thickness is not particularly limited, but from the viewpoint of suitability for mass production, it is usually 0.01% or more.

[0025] Furthermore, in order to improve the ability to focus and refract radio waves, for example, to thin the radio wave control element, it is preferable to continuously change the thickness in the dielectric constant changing region. Specifically, it is preferable that the thickness of the dielectric continuously changes in the dielectric constant changing region, and that the direction of increase in the dielectric constant coincides with the direction of increase in the thickness. In this case, the rate of change in thickness in the dielectric constant changing region can be set appropriately and may be greater than 10%.

[0026] When the thickness changes continuously in the dielectric constant change region, the rate of change of thickness in the dielectric constant change region is preferably greater than 10%, more preferably 15% or more. The upper limit of the rate of change of thickness is not particularly limited, but is 1000% or less from the viewpoint of handleability such as brittleness. The rate of change of thickness of the dielectric is also preferably greater than 10%, more preferably 15% or more. The upper limit of the rate of change of thickness is not particularly limited, but is 1000% or less from the viewpoint of handleability such as brittleness.

[0027] The relative dielectric constant of the dielectric can be controlled by combining a matrix material with a material having a lower or higher relative dielectric constant than the matrix material as a relative dielectric constant adjuster, and gradually changing the mixing ratio of the materials.

[0028] In one embodiment, the dielectric preferably includes at least two materials having different dielectric constants, and the mixing ratio of the at least two materials varies gradually within the dielectric constant variation region. The term "gradually varying" the mixing ratio includes not only a case where the mixing ratio varies gradually at regular intervals in one direction (the direction in which the specific component increases or decreases), but also a case where the mixing ratio varies gradually in one direction even if the intervals are not fixed.

[0029] The relative permittivity of the dielectric can also be controlled by gradually changing the density of a single material using a phenomenon such as phase transition.

[0030] In another embodiment, it is preferable that the dielectric contains at least one type of material, and the density of the material gradually changes within the relative dielectric constant change region. The density "gradually changes" includes not only cases where the density changes little by little at regular intervals in one direction (increasing or decreasing direction), but also cases where the density changes little by little in one direction even if the intervals are not fixed. The unit of density is "g / cm ３ " and is calculated as the ratio of the weight of the material in question to the volume of the dielectric.

[0031] The relative permittivity of a dielectric can also be controlled by introducing air into the material and gradually changing the air content. "Gradually changing" the air content includes not only cases where the content changes little by little at regular intervals in one direction, but also cases where the content changes little by little in one direction even if the intervals are not fixed.

[0032] In another embodiment, the dielectric material contains at least one material and air, and the air content preferably varies gradually within the dielectric constant change region. This embodiment is suitable for waveguiding applications. The air content can be determined by observing a cross section of the sample with a scanning electron microscope.

[0033] The air content can be adjusted as appropriate to obtain a desired relative dielectric constant. Increasing the air content can reduce the relative dielectric constant of the dielectric. The air content can be evaluated by known methods, and can be evaluated from the specific gravity of the sample. As another method, the sample can be cut using a method such as a focused ion beam, which is less likely to apply mechanical stress, and the cut surface can be observed with a scanning electron microscope (SEM) to evaluate the morphology. The air content is not particularly limited, but is preferably 1% to 95%, more preferably 5% to 90%, and even more preferably 10% to 80%. When the air content is 1% to 95%, it is possible to achieve both the effect of reducing the relative dielectric constant and mechanical strength.

[0034] The relative dielectric constant of the dielectric can also be controlled by appropriately combining these methods.

[0035] The density of the dielectric is not particularly limited, but in order to reduce the weight of the dielectric and the radio wave control element, it is set to 3.9 g / cm ３ Preferably, it is 3.5 g / cm or less. ３ The density can be measured by a known method, for example, the Archimedes method.

[0036] In the case of applications for refracting, converging, and guiding radio waves, as a first embodiment, it is preferable that the dielectric constant of the dielectric changes monotonically from one side to the other side of two opposing sides in the dielectric constant changing region.

[0037] In the present disclosure, the term "dielectric constant varies monotonically" refers to, for example, when the dielectric constant is distributed in only one direction and not in other directions, continuously evaluating the dielectric constant in the direction in which the dielectric constant varies shows a constant sign of the rate of change, or continuously evaluating the material mixture ratio shows a constant sign of the rate of change. The rate of change of the dielectric constant can be set appropriately depending on the application of the radio wave control element, and may be a linear or nonlinear change. A linear change is preferable for applications that refract radio waves, while a nonlinear change is particularly preferable for applications that focus and guide radio waves. Here, "linear" refers to a constant rate of change, and anything else is referred to as nonlinear. Note that "constant" here means constant, including tolerances such as manufacturing errors.

[0038] Specifically, in the case of applications requiring waveguiding, it is preferable that the distribution of the relative dielectric constant follows the following formula (1): ε(x)=ε1×(1−(ε1−ε2) / ε1×(x / d) ２ ) ...Equation (1) Here, ε(x) represents the relative dielectric constant at the distance x from the center of the dielectric, ε1 represents the maximum relative dielectric constant at the center, ε2 represents the relative dielectric constant at both ends of the dielectric, and d represents the distance over which the relative dielectric constant changes.

[0039] FIG. 1 is a plan view (upper view on the paper) and a perspective view (lower view on the paper) for explaining the dielectric in the radio wave control element of the first embodiment. In FIG. 1, the darker the color, the higher the relative dielectric constant. The same applies to FIGS. 2 to 7 described below. In FIGS. 1 to 7, the color shading is an image that indicates the level of the relative dielectric constant, and the color density is not accurate. Even in areas where the color density changes abruptly, the relative dielectric constant actually changes monotonically. In the dielectric shown in FIG. 1, the relative dielectric constant increases monotonically and continuously from the left side to the right side in the plan view of FIG. 1.

[0040] In the case of applications as a lens and waveguiding, as a second embodiment, it is also preferable that the dielectric constant of the dielectric changes monotonically from two opposing sides toward the in-plane direction in the dielectric constant changing region. When the dielectric has a distribution of the dielectric constant only in one direction and no distribution in other directions, the two opposing sides refer to sides perpendicular to the direction in which the dielectric constant changes. Note that the angle between the two opposing sides and the direction in which the dielectric constant changes does not need to be strictly 90 degrees, and may be 80 degrees to 100 degrees. Furthermore, one of the two opposing sides includes the position where the dielectric constant starts to change, and the other includes the position where the change in the dielectric constant ends.

[0041] The inside refers to the position sandwiched between two opposing sides. The rate of change in the relative dielectric constant can be set appropriately depending on the application of the radio wave control element, and may be a linear change or a nonlinear change. In the case of an application in which radio waves are refracted, a linear change is preferable, and in the case of an application in which radio waves are focused or guided, a nonlinear change is preferable.

[0042] 2 and 3 are a plan view (the upper view on the paper) and a perspective view (the lower-upper view on the paper), respectively, for explaining a dielectric in a radio wave control element of a second embodiment. In the dielectric shown in FIG. 2, the dielectric constant increases monotonically and continuously from the left and right sides toward the inside in the plan view of FIG. 2. Note that in FIG. 2, the maximum value of the dielectric constant is shown at the center of the left and right sides, but the maximum value of the dielectric constant may be closer to either the left or right side. In the dielectric shown in FIG. 3, the dielectric constant decreases monotonically and continuously from the left and right sides toward the inside in the plan view of FIG. 3. Note that in FIG. 3, the minimum value of the dielectric constant is shown at the center of the left and right sides, but the minimum value of the dielectric constant may be closer to either the left or right side.

[0043] As shown in Fig. 2, the dielectric constant of the interior may be relatively high compared to the dielectric constants of the two opposing sides, or as shown in Fig. 3, the dielectric constant of the interior may be relatively low compared to the dielectric constants of the two opposing sides. In the former case, the dielectric constant is suitable for use as a lens. In the latter case, the dielectric constant is suitable for use in waveguiding.

[0044] In the case of use as a lens, as a third embodiment, it is preferable that the dielectric constant of the dielectric changes monotonically from the center to the outer periphery in the in-plane direction in the dielectric constant changing region, where the in-plane direction is a direction perpendicular to the thickness direction.

[0045] 4 and 5 are a plan view (upper view on the paper) and a perspective view (lower view on the paper), respectively, for explaining the dielectric in the radio wave control element of the third embodiment. In the dielectric shown in Fig. 4, the relative dielectric constant increases monotonically and continuously from the outer periphery toward the inside. In the dielectric shown in Fig. 5, the relative dielectric constant decreases monotonically and continuously from the outer periphery toward the inside.

[0046] As shown in Fig. 4, the dielectric constant of the interior may be higher than that of the outer periphery, or as shown in Fig. 5, the dielectric constant of the interior may be lower than that of the outer periphery. In the former case, it is suitable for use as a convex lens. In the latter case, it is suitable for use as a concave lens. Note that, although Figs. 4 and 5 show the maximum or minimum values ​​of the dielectric constant equidistant from two "opposing sides" of the quadrangle, the maximum or minimum value of the dielectric constant may be closer to either one of the "opposing sides" of the quadrangle.

[0047] In the case of applications involving wave guiding, as a fourth embodiment, it is preferable that the dielectric constant of the dielectric changes monotonically from the interior toward the surface in the thickness direction in the dielectric constant changing region.

[0048] The dielectric constant of the interior may be higher than that of the surface, or may be lower than that of the surface, in which case it is suitable for waveguiding applications.

[0049] As described above, in order to improve the ability to focus and refract radio waves and, for example, to thin the radio wave control element, it is preferable to continuously change the thickness in the relative dielectric constant changing region. Specifically, in the fifth embodiment, it is preferable that the thickness of the dielectric continuously changes in the relative dielectric constant changing region, and that the direction of increase in the relative dielectric constant coincides with the direction of increase in the thickness.

[0050] Fig. 6 is a perspective view illustrating the dielectric in the radio wave control element of the fifth embodiment. In the dielectric shown in Fig. 6, the relative dielectric constant increases monotonically and continuously from the two opposing sides toward the in-plane direction, and the thickness also increases monotonically from the two opposing sides toward the in-plane direction.

[0051] The dielectric may have two or more dielectric constant change regions. Fig. 7 is a plan view (upper view on the paper) and a perspective view (lower-upper view on the paper) for explaining a modified example of the dielectric in the radio wave control element of the second embodiment. In the dielectric shown in Fig. 7, there are portions where the dielectric constant monotonically and continuously increases and portions where the dielectric constant monotonically and continuously decreases from the left and right sides in the plan view of Fig. 7 toward the inside. That is, the dielectric shown in Fig. 7 has two dielectric constant change regions.

[0052] (Matrix Material) The dielectric preferably contains a matrix material. The matrix material may be any of an organic material, an inorganic material, and a combination thereof. From the viewpoint of moldability, the matrix material preferably contains an organic material. In the case of an organic material, a resin can be preferably used from the viewpoints of moldability, impact resistance, etc. Examples of the resin include a thermoplastic resin, a thermoplastic elastomer; a semi-cured or cured product of a thermosetting resin or a photocurable resin, a thermosetting elastomer; a semi-cured or cured product of a photocurable elastomer, etc. The matrix material preferably contains at least one resin selected from these resins. The matrix material may contain a curing agent (initiator) and a curing accelerator as necessary. Furthermore, a resin exhibiting crystallinity or liquid crystallinity can also be used as the resin.

[0053] Examples of thermoplastic resins include polyester resins, polyesteramide resins, polyester ether resins, polyester carbonate resins (including liquid crystal polymers), cyanate resins, coumarone resins, polyurethane resins, (meth)acrylic resins, polystyrene resins, fluororesins, polyimide resins, fluorinated polyimide resins, polyamide resins, polyamideimide resins, polyetherimide resins, cellulose acylate resins, polyurethane resins, polyether ether ketone resins, polycarbonate resins, polyolefin resins (e.g., polyethylene resins, polypropylene resins, resins made of cyclic olefin copolymers, alicyclic polyolefin resins), polyarylate resins, polyethersulfone resins, polysulfone resins, fluorene ring-modified polycarbonate resins, alicyclic modified polycarbonate resins, fluorene ring-modified polyester resins, urea-formalin resins, cured epoxy resins, crosslinked benzoguanamine resins, and crosslinked acrylic resins.

[0054] Examples of thermoplastic elastomers include elastomers containing structural units derived from styrene (polystyrene-based elastomers), polyester-based elastomers, polyolefin-based elastomers, polyurethane-based elastomers, polyamide-based elastomers, polyacrylic-based elastomers, silicone-based elastomers, polyimide-based elastomers, etc. The thermoplastic elastomer may be a hydrogenated product.

[0055] Examples of polystyrene elastomers include styrene-butadiene-styrene block copolymers (SBS), styrene-isoprene-styrene block copolymers (SIS), polystyrene-poly(ethylene-propylene) diblock copolymers (SEP), polystyrene-poly(ethylene-propylene)-polystyrene triblock copolymers (SEPS), styrene-ethylene-butylene-styrene block copolymers (SEBS), polystyrene-poly(ethylene / ethylene-propylene)-polystyrene triblock copolymers (SEEPS), styrene-isobutylene-styrene block copolymers (SIBS), and hydrogenated products thereof.

[0056] Examples of thermosetting resins include epoxy resins, which are monomers, oligomers, or polymers having two or more epoxy groups in one molecule, phenolic resins, melamine resins, urea resins, unsaturated polyester resins, alkyd resins, urethane resins, polyimide resins such as bismaleimide resins, polyamide resins, polyamideimide resins, silicone resins, and acrylic resins, and the molecular weight and molecular structure thereof are not particularly limited. From the viewpoint of moldability and electrical properties, the thermosetting resin is preferably at least one selected from the group consisting of epoxy resins and polyimide resins, more preferably at least one selected from the group consisting of epoxy resins and bismaleimide resins, and even more preferably an epoxy resin.

[0057] Specific examples of epoxy resins include biphenyl-type epoxy resins; bisphenol-type epoxy resins such as bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, and tetramethylbisphenol F-type epoxy resins; stilbene-type epoxy resins; novolac-type epoxy resins such as phenol novolac-type epoxy resins and cresol novolac-type epoxy resins; polyfunctional epoxy resins such as triphenolmethane-type epoxy resins and alkyl-modified triphenolmethane-type epoxy resins; aralkyl-type epoxy resins such as phenol aralkyl-type epoxy resins having a phenylene skeleton and phenol aralkyl-type epoxy resins having a biphenylene skeleton; naphthol-type epoxy resins such as dihydroxynaphthalene-type epoxy resins and epoxy resins obtained by glycidyl etherifying a dihydroxynaphthalene dimer; triazine-nucleus-containing epoxy resins such as triglycidyl isocyanurate and monoallyl diglycidyl isocyanurate; and bridged cyclic hydrocarbon compound-modified phenol-type epoxy resins such as dicyclopentadiene-modified phenol-type epoxy resins. These may be used alone or in combination of two or more.

[0058] Among these, from the viewpoint of improving the balance between moisture resistance reliability and moldability, the epoxy resin preferably contains at least one selected from the group consisting of bisphenol-type epoxy resins, novolac-type epoxy resins, biphenyl-type epoxy resins, phenol aralkyl-type epoxy resins, and triphenolmethane-type epoxy resins, and more preferably contains at least one selected from the group consisting of biphenyl-type epoxy resins and phenol aralkyl-type epoxy resins.

[0059] Furthermore, when the matrix material contains an epoxy resin, the matrix material may also contain a curing agent that reacts with the epoxy resin to harden it. Examples of the curing agent include linear aliphatic diamines having 2 to 20 carbon atoms, such as ethylenediamine, trimethylenediamine, tetramethylenediamine, and hexamethylenediamine; metaphenylenediamine, paraphenylenediamine, paraxylenediamine; active ester compounds; amines such as 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylether, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodicyclohexane, bis(4-aminophenyl)phenylmethane, 1,5-diaminonaphthalene, metaxylenediamine, paraxylenediamine, 1,1-bis(4-aminophenyl)cyclohexane, and dicyanodiamide; resol-type phenolic resins, such as aniline-modified resol resins and dimethyl ether resol resins; phenol novolac resins, cresol novolac resins, tert-butylphenol novolac resins, and nonylphenol novolac resins. Examples of suitable phenolic resins include novolac phenolic resins such as lac resins; polyfunctional phenolic resins such as trisphenolmethane phenolic resins; phenol aralkyl resins such as phenylene skeleton-containing phenol aralkyl resins and biphenylene skeleton-containing phenol aralkyl resins; phenolic resins having a condensed polycyclic structure such as a naphthalene skeleton or an anthracene skeleton; polyoxystyrenes such as polyparaoxystyrene; alicyclic acid anhydrides such as hexahydrophthalic anhydride (HHPA) and methyltetrahydrophthalic anhydride (MTHPA), and acid anhydrides including aromatic acid anhydrides such as trimellitic anhydride (TMA), pyromellitic anhydride (PMDA), and benzophenonetetracarboxylic acid (BTDA); polymercaptan compounds such as polysulfides, thioesters, and thioethers; isocyanate compounds such as isocyanate prepolymers and blocked isocyanates; organic acids such as carboxylic acid-containing polyester resins; and polyaminoamides. These may be used alone or in combination of two or more.

[0060] The curing agent is not particularly limited, but can be selected as a compound that initiates the curing reaction depending on the type of curable resin, the desired properties of the dielectric, and the like. At least one known thermal initiator or photoinitiator may be used as the curing agent. When a photoinitiator is included, the curable resin or curable elastomer can be used as a photocurable resin or photocurable elastomer. Furthermore, the curing agent preferably includes at least one active ester compound. Two or more active ester compounds may be used in combination. Here, an active ester compound refers to a compound that has one or more ester groups per molecule that react with epoxy groups and has the ability to cure epoxy resins. When the curing agent includes an active ester compound, the curing agent may or may not contain a curing agent other than the active ester compound.

[0061] The use of an active ester compound as a curing agent can reduce the dielectric loss tangent of a dielectric compared to the use of other curing agents. In the reaction between an epoxy resin and a phenolic or amine curing agent, secondary hydroxyl groups are generated. In contrast, in the reaction between an epoxy resin and an active ester compound, ester groups are generated instead of secondary hydroxyl groups. Because ester groups have lower polarity than secondary hydroxyl groups, the use of an active ester compound as a curing agent can reduce the dielectric loss tangent of a dielectric compared to the use of only a curing agent that generates secondary hydroxyl groups. Furthermore, while polar groups in a dielectric increase the water absorption of the dielectric, the use of an active ester compound as a curing agent can reduce the concentration of polar groups in the dielectric, thereby reducing the water absorption of the dielectric. Furthermore, by reducing the water absorption of the dielectric, i.e., by reducing the content of water molecules, which are polar molecules, the dielectric loss tangent of the dielectric can be further reduced.

[0062] The type of active ester compound is not particularly limited as long as it is a compound having one or more ester groups in the molecule that react with an epoxy group, and examples thereof include phenol ester compounds, thiophenol ester compounds, N-hydroxyamine ester compounds, and esterified products of heterocyclic hydroxy compounds.

[0063] The equivalent ratio (ester group / epoxy group) between the epoxy resin and the active ester compound is preferably 0.9 or more, more preferably 0.95 or more, and even more preferably 0.97 or more, from the viewpoint of keeping the dielectric loss tangent of the cured product low. The equivalent ratio (ester group / epoxy group) between the epoxy resin and the active ester compound is preferably 1.1 or less, more preferably 1.05 or less, and even more preferably 1.03 or less, from the viewpoint of keeping the unreacted active ester compound low.

[0064] The amount of the curing agent added is not particularly limited, but for example, when the entire resin composition is taken as 100% by mass, it is preferably 0.1% by mass to 20% by mass, more preferably 0.5% by mass to 10% by mass or less, and even more preferably 1% by mass to 5% by mass.

[0065] The semi-cured product of the thermosetting resin and the cured product of the thermosetting resin are preferably those obtained by semi-curing and curing the above-mentioned thermosetting resin, respectively.

[0066] Examples of the thermosetting elastomer include curable elastomers such as silicone rubber, fluororubber, and urethane rubber.

[0067] Examples of silicone rubbers include vinyl group-containing organopolysiloxanes, etc. The semi-cured thermosetting elastomer and the cured thermosetting elastomer are preferably the semi-cured and cured products of the above-mentioned thermosetting resins, respectively.

[0068] The curing accelerator is not particularly limited, and can be selected as a compound that accelerates the curing reaction depending on the type of curable resin, the desired properties of the molding resin composition, etc. Two or more types of curing accelerators may be used in combination.

[0069] The dielectric may contain only one type of resin, or two or more types. From the viewpoint of achieving both dielectric properties and mechanical properties, the resin content is preferably 10 to 90% by volume, more preferably 20 to 70% by volume, and even more preferably 30 to 60% by volume.

[0070] (Dielectric Constant Adjuster) The dielectric constant adjuster (sometimes abbreviated as dielectric constant adjuster) is a material having a dielectric constant different from that of the matrix material, and may be organic, inorganic, or a combination thereof. To improve the mechanical properties of the dielectric, an organic material is preferred as the dielectric constant adjuster, while an inorganic material is preferred to improve the controllability of the dielectric constant. The dielectric constant adjuster may be added by blending with the matrix material, or by processing into a powder form and mixing as a filler. As the organic dielectric constant adjuster, any of the organic materials exemplified as the matrix material may be used, which has a dielectric constant different from that of the matrix material. As the inorganic material, any inorganic material having a dielectric constant different from that of the matrix material may be used. Specific examples of inorganic dielectric constant adjusters include barium titanate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, zirconium titanate, zinc titanate, titanium dioxide, magnesium oxide, alumina, tantalum pentoxide, niobium pentoxide, and silica. The dielectric constant adjuster preferably contains at least one selected from these inorganic materials. Furthermore, the inorganic dielectric constant adjuster may be one obtained by adding a dopant compound containing another element and then firing the mixture in order to adjust the relative dielectric constant. Among these, from the viewpoint of a high dielectric constant, barium titanate is preferred as the inorganic dielectric constant adjuster. From the viewpoint of a high dielectric constant and a low dielectric loss tangent, titanium oxide, strontium titanate, calcium titanate, or zirconium titanate is preferred as the inorganic dielectric constant adjuster. Two or more types of inorganic dielectric constant adjusters may be used in combination.

[0071] (Relative Dielectric Constant of Materials) The matrix material and the dielectric constant modifier preferably have a relative dielectric constant of 1 to 20,000 at 25°C and a measurement frequency of 10 GHz. When an organic matrix material is used, the relative dielectric constant is usually about 2 to 6. When forming a gradation that increases the relative dielectric constant relative to the matrix material, the relative dielectric constant of the dielectric constant modifier is preferably 6 to 20,000, more preferably 20 to 20,000. When forming a gradation that decreases the relative dielectric constant relative to the matrix material, the relative dielectric constant of the dielectric constant modifier is preferably 1 to 6, more preferably 1 to 4, and even more preferably 1 to 3. Furthermore, when the dielectric constant modifier is mixed as a filler, the average particle size of the dielectric constant modifier is preferably 0.01 μm to 50 μm, more preferably 0.05 μm to 30 μm, and even more preferably 0.1 μm to 20 μm, from the viewpoints of mixability and controllability of dielectric properties. The dielectric constant modifier may be a mixture of two or more fillers with different average particle sizes. The shape of the dielectric constant adjuster is not particularly limited, and may be amorphous, spherical, or elliptical. Among these, the shape of the dielectric constant adjuster is preferably spherical, from the viewpoint of facilitating an increase in the amount mixed into the matrix.

[0072] One or more types of dielectric constant modifiers can be used, and the content is preferably 1 to 95% by volume, and more preferably 10 to 60% by mass, relative to the total amount of the dielectric, from the viewpoint of achieving both dielectric properties and mechanical properties. When two or more types of dielectric constant modifiers with different average particle sizes are used, or when spherical fillers are used, the mixed amount of the dielectric constant modifiers is preferably 10 to 80% by volume. The dielectric constant modifier may also be surface-treated with an inorganic or organic substance. Surface treatment methods used for modification include coating, topochemical or mechanochemical reaction, encapsulation, and radiation exposure.

[0073] The dielectric may further contain additives in addition to the resin, the dielectric constant modifier, and the air. Examples of the additives include dispersants, surfactants, crosslinking agents, antioxidants, flame retardants, colorants, and stress relaxation agents. Two or more types of additives may be used in combination.

[0074] (Adjustment of Relative Dielectric Constant) In both organic and inorganic materials, the relative dielectric constant can be adjusted during the molding process of the dielectric. For example, the density can be changed by using a phase transition of the material, such as amorphous, liquid crystal, or crystalline, to adjust the relative dielectric constant. Furthermore, during the molding process of the dielectric, phase separation or foaming can be caused inside the dielectric to introduce air into the matrix material, thereby adjusting the relative dielectric constant. Alternatively, hollow particles with voids inside can be added to introduce air, thereby adjusting the relative dielectric constant.

[0075] <Method for Producing Dielectric> There are no particular limitations on the method for producing the dielectric, and known molding methods such as injection molding, press molding, melt film-forming, solution film-forming, and coating can be used.

[0076] When the mixing ratio of two or more materials is changed in order to continuously change the relative dielectric constant, examples of the method include a method of gradually increasing or decreasing the amount of dielectric constant adjuster used in molding; a method of preparing two types of liquids each having a different mixing ratio of materials, applying the two liquids in layers while changing the liquid feed ratio in the width direction using a slot die or the like, and allowing the two liquids to diffuse during drying; and a method of preparing two types of liquids each having a different mixing ratio of materials, forming one of the liquids into a film of a certain thickness using a slot die or the like, subsequently applying the film in layers using a spray coater or the like, and allowing the film to diffuse during drying.

[0077] In the case of controlling the relative dielectric constant by utilizing the phase transition of a material, examples of the method include a method in which two types of liquids containing different amounts of a phase transition additive that promotes or inhibits crystallinity or liquid crystallinity are prepared, a distribution is imparted to the concentration of the phase transition controller by the same application method as described above, and after molding, external energy such as uniform heat or electromagnetic waves is applied to the dielectric to change the degree of phase transition, and a method in which external energy such as heat or electromagnetic waves is applied to the dielectric after molding to impart a distribution to the dielectric.

[0078] In the case of controlling the relative dielectric constant by the internal porosity, methods such as the method of imparting a distribution of a material such as hollow silica, hollow glass, or a foaming agent by the same method as described above, or the method of imparting a distribution to the foaming rate by processing with a distribution of external energy such as heat, can be mentioned.

[0079] <Radio wave control element> The radio wave control material of the present disclosure is compatible with high frequency band signals, is suitable for focusing radio waves, and functions as a waveguide with low loss. The dielectric has a region of change in relative permittivity, so that it can be used as an element for controlling radio waves. Examples of radio wave control elements include a cylindrical convex lens, a cylindrical concave lens, a conventional convex lens, a conventional concave lens, and a waveguide.

[0080] As an element for converging radio waves, it enables thinning, which is a challenge with conventional lenses including spherical shapes, and suppresses noise that periodically gets mixed in, which is a challenge with thin lenses such as Fresnel lenses.

[0081] Furthermore, as an element that transmits received radio waves without loss, it enables greater freedom in shape, which was a challenge with conventional metal waveguides, and enables the suppression of losses due to interface reflection and deviations in signal propagation speed caused by changes in the angle of incidence, which were challenges with conventional dielectric waveguides.

[0082] (Radio wave lens) At least two dielectrics (for example, the first embodiment of the dielectric) whose relative dielectric constant changes monotonically from one of two opposing sides to the other are used, and by arranging the sides with the higher relative dielectric constants or the sides with the lower relative dielectric constants facing each other, the element can be used as a radio wave control element having the function of a cylindrical convex lens or a cylindrical concave lens.

[0083] Furthermore, in a dielectric whose relative permittivity changes monotonically from two opposing sides toward the in-plane direction (for example, the dielectric in the radio wave control element of the second embodiment), if the relative permittivity inside is higher than that of the two opposing sides, it can be used as a radio wave control element having the function of a cylindrical convex lens, and if the relative permittivity inside is lower than that of the two opposing sides, it can be used as a radio wave control element having the function of a cylindrical concave lens.

[0084] In the case of a dielectric whose relative permittivity changes monotonically from the inside to the outer periphery in the in-plane direction (for example, the dielectric in the radio wave control element of the third embodiment), by increasing the relative permittivity of the inside relative to the outer periphery, it can be used as a radio wave control element having the function of a convex lens, and by decreasing the relative permittivity of the inside relative to the outer periphery, it can be used as a radio wave control element having the function of a concave lens.

[0085] In these radio wave control elements having the function of a lens, the distance of the focused radio waves can be controlled to a desired value by varying the amount and rate of change in the relative dielectric constant and the thickness of the element. In the present disclosure, by using a dielectric having a relative dielectric constant change region, it is possible to manufacture a thin lens with a flat shape, and since it does not have a stepped structure like a Fresnel lens, it is thought that disturbance of light propagation, diffraction, interference, etc. due to defects during manufacturing are less likely to occur, making it possible to suppress noise.

[0086] When the dielectric is used as a lens, it is preferable that the sign of the rate of change of the dielectric constant and the sign of the rate of change of the thickness of the dielectric in the dielectric constant changing region are the same. The sign of the rate of change of the dielectric constant and the sign of the rate of change of the thickness are the same. This means that the thickness of the dielectric or laminate in the dielectric constant changing region increases as the dielectric constant increases.

[0087] By making the sign of the rate of change of the dielectric constant the same as the sign of the rate of change of the thickness, the ability to focus and refract radio waves is improved, and for example, the lens can be made thinner. Furthermore, when a dielectric is used as a lens, it is preferable that the rate of change of the thickness of the dielectric in the region where the dielectric constant changes is greater than 10%. By making the rate of change of the thickness greater than 10%, for example, the focal length can be shortened, and the device can be made smaller.

[0088] (Waveguide) A dielectric whose relative permittivity changes monotonically from the interior to the periphery in the in-plane direction or thickness direction, with the interior having a higher relative permittivity than the periphery (for example, the dielectric in the radio wave control element of the fourth embodiment), can be used as a radio wave control element that functions as a waveguide. In such a waveguide, the relative permittivity changes continuously, and therefore, unlike a waveguide whose relative permittivity changes stepwise, it can be used as a waveguide in which pulse signals are less spread and errors are less likely to occur.

[0089] By using a dielectric whose relative permittivity is high in the interior and continuously decreases toward the periphery, the speed of radio waves slows down in the interior where the distance is short and speeds up on the exterior where the distance is long. This makes it possible to equalize signal propagation time even when the angle of incidence changes, and, for example, suppresses the spread of pulse signals, which is thought to suppress degradation of signal quality.

[0090] (Antenna) By using a dielectric-based radio wave control element as a lens and further arranging an antenna element as a radio wave emitting element or radio wave receiving element behind the lens, a highly directional and high-gain antenna can be fabricated. The gain can be evaluated using known techniques such as the free space method. Because of advantages such as the ability to control the thickness by thermocompression bonding, excellent lamination with other components, and excellent maintainability, it is preferable for the radio wave control element to have a small thickness distribution; specifically, the thickness variation rate is 10% or less. However, for the purpose of improving the radio wave control ability of the radio wave control element and reducing the height of the device, the dielectric can also be processed into, for example, a lens shape, in which case the thickness variation rate can be greater than 10%. Known microstrip antennas, waveguides, horn antennas, etc. can be preferably used as the antenna element, and from the viewpoint of loss reduction, waveguides or horn antennas are more preferred.

[0091] The present disclosure will be explained in more detail below with reference to examples. The materials, amounts used, ratios, processing details, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present disclosure. Therefore, the scope of the present disclosure is not limited to the specific examples shown below.

[0092] <Matrix> B1: Aromatic polyesteramide prepared according to the following production method

[0093] -Synthesis of aromatic polyesteramide B1- A reactor equipped with a stirrer, torque meter, nitrogen gas inlet tube, thermometer, and reflux condenser was charged with 940.9 g (5.0 mol) of 6-hydroxy-2-naphthoic acid, 415.3 g (2.5 mol) of isophthalic acid, 377.9 g (2.5 mol) of acetaminophen, and 867.8 g (8.4 mol) of acetic anhydride. The gas inside the reactor was replaced with nitrogen gas, and the mixture was stirred under a nitrogen gas stream while being heated from room temperature (23°C, the same applies hereinafter) to 140°C over 60 minutes and refluxed at 140°C for 3 hours. Next, while distilling off by-product acetic acid and unreacted acetic anhydride, the mixture was heated from 150°C to 300°C over 5 hours and held at 300°C for 30 minutes. The contents were then removed from the reactor and cooled to room temperature. The resulting solid was pulverized in a pulverizer to obtain powdered aromatic polyesteramide P1a. The flow initiation temperature of the aromatic polyesteramide B1a is 193°C. The aromatic polyesteramide B1a is a wholly aromatic polyesteramide. The aromatic polyesteramide B1a is heated from room temperature to 160°C over 2 hours and 20 minutes under a nitrogen atmosphere, then heated from 160°C to 180°C over 3 hours and 20 minutes, and held at 180°C for 5 hours to undergo solid-state polymerization, followed by cooling. The mixture is then pulverized in a grinder to obtain powdered aromatic polyesteramide B1b. The flow initiation temperature of the aromatic polyesteramide B1b is 220°C. The aromatic polyesteramide B1b is heated from room temperature to 180°C over 1 hour and 25 minutes under a nitrogen atmosphere, then heated from 180°C to 255°C over 6 hours and 40 minutes, and held at 255°C for 5 hours to undergo solid-state polymerization, followed by cooling to obtain powdered aromatic polyesteramide B1.

[0094] <Dielectric constant adjuster> F1: Hollow silica particles (product name "Glass Bubbles iM16K", manufactured by 3M, average particle size 20 μm, relative dielectric constant 1.5, dielectric dissipation factor 0.005, density 0.6 g / cm ３ F2: Pulverized strontium titanate (average particle size 1 μm, relative dielectric constant 300, dielectric loss tangent 0.0005)

[0095] <Production and Evaluation of Dielectric> (Example 1) Matrix B1 and N-methylpyrrolidone were mixed to a solids concentration of 20% by mass, and the mixture was heated and stirred to obtain solution A1. Matrix B1 and dielectric constant modifier F1 were mixed in a mass ratio of 78:22, and N-methylpyrrolidone was further added to the mixture to a solids concentration of 23% by mass, and the mixture was heated and stirred to obtain solution B1.

[0096] A film is produced by simultaneously coating and drying the A1 and B1 liquids in multiple layers using a two-layer slot die coater. The liquids are supplied to the slot die coater by supplying the A1 liquid from the left side of the die pocket to the right side and the B1 liquid from the right side to the left side of the die pocket. In this case, the ratio of the A1 and B1 liquids discharged from the slot die in the width direction can be changed by adjusting the pressure loss inside the pocket or slit. The thickness of each coating film formed by the A1 and B1 liquids can be changed by adjusting the discharge rate. Here, the dielectric constant is adjusted so that it increases from one side parallel to the width direction to the other, and the thickness is constant in the width direction. Specifically, a 200 μm-thick film is produced so that the thickness of the coating film formed by the A1 liquid decreases from the left side of the die to the right side, and the thickness of the coating film formed by the B1 liquid decreases from the right side of the die to the left side, and the total thickness of the coating films formed by the A1 and B1 liquids is constant in the width direction.

[0097] Ten layers of the obtained films are stacked in the same direction, and a lamination process is carried out for 1 minute using a laminator (product name "Vacuum Laminator V-130", manufactured by Nikko Materials Co., Ltd.) at 140°C and a lamination pressure of 0.4 MPa to obtain a precursor of a dielectric laminate. Further, using a thermocompression bonding machine (product name "MP-SNL", manufactured by Toyo Seiki Seisakusho, Ltd.), the obtained precursor of the laminate is thermocompression bonded at 320°C to produce a dielectric laminate (structure shown in Figure 1) with a thickness of 2 mm.

[0098] The dielectric constant of the obtained laminate is measured. The obtained laminate has a continuous distribution of dielectric constant and density. At one point on one of two opposing sides parallel to the width direction of the laminate, the dielectric constant is 3.5 and the density is 1.4 g / cm. ３ A point 150 mm away from a point on one of the two opposing sides has a relative dielectric constant of 2.5 and a density of 1.1 g / cm ３ is.

[0099] Furthermore, the dielectric constant is evaluated at eight points, shifting the positions at equal intervals between one point where the dielectric constant is 3.5 and another point 150 mm away from that point where the dielectric constant is 2.5. By evaluating the dielectric constant at a total of 10 points, including the two ends and the eight points between them, it is evaluated whether the dielectric constant changes continuously. If the dielectric constant changes continuously, it is evaluated whether the change is monotonic, linear, or nonlinear. The obtained laminate has a region where the dielectric constant changes continuously, and the change in the dielectric constant is nonlinear.

[0100] The obtained laminate was also evaluated as a cylindrical convex lens. A pair of omnidirectional antennas was prepared, the distance between the transmitting antenna and the receiving antenna was 1 m, and two laminates of Example 1 were inserted 100 mm from the receiving antenna, aligned so that the sides with higher dielectric constants faced each other. At 30 GHz, the receiving antenna's reception strength improved by 2 dB compared to before the insertion of the laminate of Example 1, i.e., the gain improved. In Example 1, by combining two laminates, radio waves can be focused, allowing the radio waves to be controlled to a desired state.

[0101] Example 2 In the same manner as in Example 1, liquids A1 and B1 are obtained.

[0102] A film is produced by simultaneously coating and drying the A1 and B1 liquids in multiple layers using a two-layer slot die coater. The slot die coater is supplied with both the A1 and B1 liquids at the center of the die pocket. In this case, the ratio of the A1 and B1 liquids discharged from the slot die in the width direction can be changed by adjusting the pressure loss inside the pocket or slit. The thickness of each coating film formed by the A1 and B1 liquids can be varied by adjusting the discharge rate. Here, the dielectric constant is adjusted so that it increases from two opposing sides parallel to the width direction toward the in-plane direction and maintains a constant thickness in the width direction. Specifically, a 200 μm-thick film is produced so that the thickness of the coating film formed by the A1 liquid decreases from the center of the die toward both ends, while the thickness of the coating film formed by the B1 liquid increases from the center of the die toward both ends, and so that the total thickness of the coating films formed by the A1 and B1 liquids remains constant in the width direction.

[0103] Ten layers of the obtained films are stacked in the same direction, and a lamination process is carried out for 1 minute using a laminator (product name "Vacuum Laminator V-130", manufactured by Nikko Materials Co., Ltd.) at 140°C and a lamination pressure of 0.4 MPa to obtain a precursor of a dielectric laminate. Further, using a thermocompression bonding machine (product name "MP-SNL", manufactured by Toyo Seiki Seisakusho, Ltd.), the obtained precursor of the laminate is thermocompression bonded at 320°C to produce a dielectric laminate (structure shown in Figure 2) with a thickness of 2 mm.

[0104] The resulting laminate has a dielectric constant distribution, with a dielectric constant of 3.5 at one internal point and 2.5 at two points 150 mm apart toward two opposing sides. The dielectric constant is evaluated at eight points, with the two points 150 mm apart from a central point in the in-plane direction toward the opposing sides, where the dielectric constant is 2.5, and the other point being shifted at equal intervals. The dielectric constant is evaluated at a total of 10 points, including the two points where the dielectric constant is 2.5 and the eight points between them. The resulting laminate has a region where the dielectric constant changes continuously, and the change in the dielectric constant is nonlinear.

[0105] The obtained laminate was evaluated as a cylindrical convex lens. A pair of omnidirectional antennas was prepared, the distance between the transmitting antenna and the receiving antenna was 1 m, and the laminate of Example 2 was inserted at a position 100 mm from the receiving antenna. At 30 GHz, the gain was improved by 2 dB compared to before the laminate of Example 2 was inserted. In Example 2, radio waves can be focused, so that the radio waves can be controlled to a desired state.

[0106] Example 3 In the same manner as in Example 1, liquids A1 and B1 are obtained.

[0107] A film is produced by applying layered coating of B1 liquid using a slot die and A1 liquid using a spray, followed by drying. Here, the dielectric constant is adjusted to increase from the outer periphery toward the inside in the circumferential direction. Specifically, the coating film formed by B1 liquid is adjusted with the slot die to have a constant thickness, and the coating film formed by A1 liquid is adjusted to have a thickness that decreases from the inside toward the outer periphery of the coating film formed by B1 liquid.

[0108] The obtained films are stacked in the same direction and subjected to lamination treatment for 1 minute using a laminator (product name "Vacuum Laminator V-130", manufactured by Nikko Materials Co., Ltd.) at 140°C and a lamination pressure of 0.4 MPa to obtain a precursor of a dielectric laminate. Further, the obtained precursor of the laminate is thermocompression bonded at 320°C using a thermocompression bonding machine (product name "MP-SNL", manufactured by Toyo Seiki Seisakusho, Ltd.) to produce a dielectric laminate (structure shown in FIG. 4) having a thickness of 2 mm.

[0109] The obtained laminate has a dielectric constant distribution in the circumferential direction, with a dielectric constant of 3.5 at one internal point (point a) and 2.5 at two points (point b1, point b2) located 150 mm away from point a toward the outer periphery. Points b1 and b2 are both located 150 mm away from point a, with point a as the center. The dielectric constant is evaluated at eight points, with the positions shifted at equal intervals between points b1 and b2. The dielectric constant is evaluated at a total of 10 points, including points b1, b2, and the eight points between them.

[0110] The resulting laminate has a region where the relative dielectric constant changes continuously, and the change in the relative dielectric constant is nonlinear.

[0111] The laminate obtained is used as a convex lens and evaluated. A pair of omnidirectional antennas is prepared, the distance between the transmitting antenna and the receiving antenna is 1 m, and the laminate of Example 3 is inserted at a position 100 mm from the receiving antenna. At 30 GHz, the gain is improved by 4 dB compared to before the laminate of Example 3 is inserted. In Example 3, radio waves can be focused, so that the radio waves can be controlled to a desired state.

[0112] Example 4: Matrix B1, dielectric constant modifier F2 were mixed in a mass ratio of 30:70 with N-methylpyrrolidone to a solids concentration of 23 mass%, and the mixture was heated and stirred to obtain solution A2. Matrix B1 and N-methylpyrrolidone were also mixed in a solids concentration of 20 mass%, and the mixture was heated and stirred to obtain solution B2.

[0113] A film and a laminate (structure of FIG. 4) are produced in the same manner as in Example 2, except that the A1 liquid is replaced with the A2 liquid and the B1 liquid is replaced with the B2 liquid.

[0114] The dielectric constant is evaluated in the same manner as in Example 2. The obtained laminate has a distribution of dielectric constant, with the dielectric constant at one point inside being 10 and the dielectric constant at two points 150 mm apart along two opposing sides being 3.5.

[0115] The dielectric constant is evaluated in the same manner as in Example 2. The obtained laminate has a region where the dielectric constant changes continuously, and the change in the dielectric constant is not linear but nonlinear.

[0116] The laminate obtained is used as a cylindrical convex lens and evaluated. A pair of omnidirectional antennas is prepared, the distance between the transmitting antenna and the receiving antenna is 1 m, and the laminate of Example 4 is inserted at a position 100 mm from the receiving antenna. At 30 GHz, the gain is improved by 1 dB compared to before the insertion of the laminate of Example 4. In Example 4, radio waves can be focused, so that the radio waves can be controlled to a desired state.

[0117] Example 5 In the same manner as in Example 4, liquids A2 and B2 are obtained.

[0118] A film and a laminate (structure of FIG. 4) are produced in the same manner as in Example 3, except that the A1 liquid is replaced with the A2 liquid and the B1 liquid is replaced with the B2 liquid.

[0119] The relative dielectric constant is evaluated in the same manner as in Example 3.

[0120] The obtained laminate has a distribution of the dielectric constant in the circumferential direction, with the dielectric constant at one point inside being 10 and the dielectric constant at two points 150 mm away from the one point inside towards the outer periphery being 3.5. The obtained laminate has a region where the dielectric constant changes continuously, and the change in the dielectric constant is nonlinear.

[0121] The laminate obtained is used as a convex lens and evaluated. A pair of omnidirectional antennas is prepared, the distance between the transmitting antenna and the receiving antenna is 1 m, and the laminate of Example 5 is inserted at a position 100 mm from the receiving antenna. At 30 GHz, the gain is improved by 3 dB compared to before the laminate of Example 5 is inserted. In Example 5, radio waves can be focused, so that the radio waves can be controlled to a desired state.

[0122] Example 6 A dielectric and a laminate (structure of FIG. 1 ) were produced in the same manner as in Example 1, except that the A1 liquid and the B1 liquid were prepared in the same manner as in Example 1, and the mixing ratio of the A1 liquid and the B1 liquid was changed linearly by adjusting the pressure loss inside the pocket or the slit.

[0123] The relative dielectric constant is evaluated in the same manner as in Example 1.

[0124] The obtained laminate has a distribution of the dielectric constant, with the dielectric constant at one point at one end being 3.5 and the dielectric constant at another point 150 mm away being 2.5. The obtained laminate has a region where the dielectric constant changes continuously, and the change in the dielectric constant is monotonic and linear.

[0125] The resulting laminate is evaluated as a refracting plate. A horn antenna is installed as a directional transmitting antenna, and a movable omnidirectional antenna is installed as a receiving antenna, at a distance of 1 m, and the laminate of Example 6 is inserted at a position 100 mm from the transmitting antenna. 30 GHz radio waves are emitted from the transmitting antenna, and the gain is measured while changing the position of the receiving antenna, thereby confirming that the radio waves are refracted in the laminate. In Example 6, it can be said that the radio waves can be refracted and controlled to a desired state.

[0126] Example 7 Ten layers of the film of Example 2 were laminated in the same orientation, and a laminator (product name "Vacuum Laminator V-130", manufactured by Nikko Materials Co., Ltd.) was used to perform a lamination process for 1 minute under conditions of 140°C and a lamination pressure of 0.4 MPa, thereby obtaining a precursor of a dielectric laminate. Furthermore, a thermocompression bonding machine (product name "MP-SNL", manufactured by Toyo Seiki Seisakusho Co., Ltd.) was used to thermocompress the obtained precursor of the laminate at 320°C to produce a dielectric laminate. The obtained laminate was used as the dielectric of a waveguide, and the angle of incidence of radio waves was changed using a 60±6 GHz signal using a known method to evaluate the transmission characteristics. The signal was transmitted without deviation in propagation velocity, and the eye pattern was wider than that of a waveguide using air, demonstrating better characteristics. In Example 7, radio waves can be guided inside the laminate, allowing the radio waves to be controlled to the desired state.

[0127] Example 7-1 A film was produced in the same manner as in Example 2, except that both the A1 liquid and the B1 liquid in Example 2 were replaced with B1 liquid, producing a film with no distribution of dielectric constant. The resulting film was used as the two outermost layers (the first and tenth layers from one surface) of the 10-layer film laminated in Example 7, the four inner layers (the fourth to seventh layers from one surface) were the same as in Example 7, and the remaining four layers (the second, third, eighth, and ninth layers from one surface) were films with a 50:50 mixture ratio of A1 liquid to B1 liquid. Ten layers were laminated in the same direction as in Example 7 to produce a dielectric laminate. The resulting laminate was used as the dielectric of a waveguide, and the transmission characteristics were evaluated in the same manner as in Example 7. The eye pattern was wider than that of a waveguide using air, demonstrating good characteristics. In Example 7-1, radio waves can be guided within the laminate, allowing the radio waves to be controlled to the desired state.

[0128] Example 7-2 Two sets of the 10-layer film laminated in Example 7-1 were prepared and stacked in the same direction to form a 20-layer laminate of dielectrics in the same manner as in Example 7-1. The resulting laminate was used as the dielectric of a waveguide, and the transmission characteristics of both the top 10 layers and the bottom 10 layers were evaluated. The eye pattern was wider than that of a waveguide using air, demonstrating good characteristics. In Example 7-2, radio waves can be guided inside the laminate, allowing them to be controlled to a desired state.

[0129] Example 8: Matrix B1, dielectric constant modifier F2 were mixed in a mass ratio of 72:28 with N-methylpyrrolidone to a solids concentration of 23 mass%, and the mixture was heated and stirred to obtain solution A3. Matrix B1 and N-methylpyrrolidone were also mixed in a solids concentration of 20 mass%, and the mixture was heated and stirred to obtain solution B3.

[0130] A film and a laminate (structure of FIG. 2) are produced in the same manner as in Example 2, except that the A1 solution is replaced with the A3 solution and the B1 solution is replaced with the B3 solution.

[0131] The relative dielectric constant is evaluated in the same manner as in Example 2.

[0132] The obtained laminate has a dielectric constant distribution, with the dielectric constant at the center in the in-plane direction being 3.55 and the dielectric constants at two points 150 mm apart along two opposing sides being 3.5. The obtained laminate has a region where the dielectric constant changes continuously, and the change in the dielectric constant is nonlinear.

[0133] The resulting laminate was evaluated as a cylindrical convex lens. A pair of omnidirectional antennas was prepared, the distance between the transmitting antenna and the receiving antenna was 1 m, and the laminate of Example 8 was inserted at a position 100 mm from the receiving antenna. At 30 GHz, neither an improvement nor a decrease in gain was observed before and after inserting the laminate of Example 8. In Example 8, radio waves can be focused, allowing them to be controlled to a desired state.

[0134] Example 9: The laminate obtained in Example 4 was used as a cylindrical convex lens, and a lens antenna was fabricated by placing it above a known waveguide antenna with a gap. A separately prepared directional horn antenna was used as the transmitting antenna. When the distance between the transmitting antenna and the receiving antenna was 1 m, it was confirmed that the gain was improved by 4 dB compared to before placing the laminate of Example 9, even though the thickness of the laminate was the same as in Comparative Example 2. Furthermore, by rotating the antenna and examining the angular dependence of the antenna's radiation characteristics, a beam radiation pattern was obtained. The angular range in which the main lobe intensity decreased by 3 dB relative to the front direction was evaluated as the main lobe width, and it was confirmed that it was sharper than in Comparative Example 2. In Example 9, radio waves can be focused, allowing the radio waves to be controlled to a desired state.

[0135] Example 10 The same procedure as in Example 9 was carried out, except that the number of dielectric sheets to be laminated in Example 4 was adjusted to prepare a laminate with a thickness that was 67% of that of Example 4, and the laminate was disposed so that the gap between the waveguide antenna and the laminate was narrower than that of Example 9. Although the thickness of the laminate was thinner than that of Comparative Example 2, the gap was also narrower, and the antenna was made thinner, it was confirmed that the gain was improved by 1 dB and the main lobe was also sharper than before the laminate of Example 10 was disposed. In Example 10, radio waves can be focused, so that the radio waves can be controlled to a desired state.

[0136] (Example 11) The laminate obtained in Example 9 is further heat-pressed in a mold to form a cylindrical convex lens shape having an average thickness thinner than that of Example 9 and increasing in thickness from two opposing sides in the in-plane direction. The resulting laminate has the same dielectric constant and thickness change direction. When this laminate is evaluated in the same manner as in Example 10, it is confirmed that the gain is improved by 2 dB and the main lobe is sharper than before the laminate of Example 11 is placed, even though the average thickness of the laminate and the antenna thickness are the same as those of Example 10. In Example 11, radio waves can be focused, allowing the radio waves to be controlled to a desired state.

[0137] Example 12: A2 liquid and B2 liquid are obtained in the same manner as in Example 4. The procedure of Example 2 was repeated, except that the A1 liquid in Example 2 was replaced with the B2 liquid and the B1 liquid with the A2 liquid, to produce a film and a laminate. The resulting laminate had a dielectric constant distribution, with a dielectric constant of 3.5 at one point in the center and a dielectric constant of 10 at two points 150 mm apart toward the two opposing sides. The resulting laminate was further pressed using a mold to form a cylindrical convex lens shape with an average thickness thinner than that of Example 9 and a thickness that increased in the in-plane direction from the two opposing sides. The resulting laminate had a non-uniform direction of change in dielectric constant and thickness. When this laminate was evaluated in the same manner as in Example 9, it was confirmed that, despite the thickness of the laminate being thinner than that of Comparative Example 2, the gap was narrower, and the antenna was thinner, the gain was improved by 0.5 dB and the main lobe was sharper than before the laminate of Example 12 was placed. In the twelfth embodiment, the radio waves can be focused, so that the radio waves can be controlled to a desired state.

[0138] Example 13 The laminate obtained in Example 5 was further heat-pressed in a mold to form a convex lens shape having an average thickness thinner than that of Example 9 and a thickness that increases from the outer periphery toward the inside. This was then laminated above a known horn antenna so that the gap was narrower than that of Example 9, thereby producing a lens antenna for use as a receiving antenna. When a separately prepared directional horn antenna was used as a transmitting antenna and the distance between the transmitting antenna and the receiving antenna was set to 1 m, it was confirmed that, despite the thickness of the laminate being thinner than that of Example 9, the gain was improved by 9 dB and the main lobe was also sharper than before the laminate of Example 13 was placed. In Example 13, radio waves can be focused, allowing the radio waves to be controlled to a desired state.

[0139] Example 14: The laminate obtained in Example 5 was used as a planar convex lens, and a lens antenna was fabricated by placing a gap above a known 16 × 16 element phased array antenna. This lens antenna was used as a transmitting antenna. The diameter of the lens formed by the distribution of dielectric material was twice the length of one side of the phased array antenna. Furthermore, a directional horn antenna was used as the receiving antenna. The distance between the transmitting antenna and the receiving antenna was set to 5 m, and the directivity of the radio wave intensity was evaluated while rotating the transmitting antenna. It was confirmed that the main lobe was sharper than before the laminate of Example 14 was placed, and that the sharpness was equivalent to that of a separately prepared 32 × 32 element phased array antenna. In Example 14, radio waves can be focused, allowing the radio waves to be controlled to a desired state.

[0140] Example 15 The same procedure as in Example 14 was carried out except that the 16 × 16 element phased array antennas used in Example 14 were arranged in a tiled pattern of 2 × 2 pieces with a gap between them, and a laminate with a dielectric distribution applied to four locations to coincide with the position of the phased array was formed as an array of planar convex lenses and placed above the phased array to fabricate a lens antenna array and use it as a transmitting antenna. The diameter of the lens formed by the dielectric distribution was twice the length of one side of each phased array. Furthermore, a directional horn antenna was used as the receiving antenna, and the distance between the transmitting antenna and the receiving antenna was set to 5 m. When the directivity of the radio wave intensity was evaluated while rotating the transmitting antenna, it was confirmed that the main lobe of each radio wave transmitted from the four antennas was sharper than before the laminate of Example 15 was placed, and that the sharpness was similar to that when a separately prepared 32 × 32 element phased array antenna was used. In Example 15, radio waves can be focused, so the radio waves can be controlled to a desired state.

[0141] Comparative Example 1 Matrix B1 and dielectric constant modifier F2 were mixed in a mass ratio of 65:35, and N-methylpyrrolidone was added to give a solids concentration of 23 mass %, followed by heating and stirring to obtain liquid C1.

[0142] A film and a laminate were produced in the same manner as in Example 2, except that both the A1 liquid and the B1 liquid in Example 2 were replaced with the C1 liquid. The dielectric constant was evaluated at eight points, with the positions shifted evenly between any two points located 150 mm apart from one internal point toward two opposing sides. The dielectric constant was evaluated at a total of 10 points, including two points on the opposing sides and eight points between them, resulting in a laminate with no dielectric constant distribution. A pair of omnidirectional antennas was prepared, the distance between the transmitting antenna and the receiving antenna was set to 1 m, and the laminate of Comparative Example 1 was inserted 100 mm from the receiving antenna. A 3 dB decrease in gain was confirmed compared to before the laminate of Comparative Example 1 was inserted.

[0143] (Comparative Example 2) The laminate obtained in Comparative Example 1 was laminated on top of a known waveguide antenna to produce an antenna laminated with a dielectric, and this antenna was used as a receiving antenna. When a separately prepared omnidirectional antenna was used as a transmitting antenna and the distance between the transmitting antenna and the receiving antenna was set to 1 m, a 3 dB decrease in gain was confirmed compared to when the laminate was not laminated.

[0144] The evaluation results of Examples 1 to 13 and Comparative Examples 1 and 2 are shown in Tables 1 and 2. The evaluation methods will be described later. The thicknesses of the laminates in Table 2 are shown as relative values, with the average thickness of the laminate in Example 9 being set to 1. The gap between the laminate and the antenna in Table 2 ("Gap" in Table 2) is shown as a relative value, with the distance between the surface of the laminate on the waveguide antenna side and the surface of the waveguide antenna on the laminate side in Example 9 being set to 1.

[0145] <Evaluation Method> (Dielectric Constant) The dielectric constant is measured by a resonance perturbation method at a frequency of 28 GHz. A 28 GHz cavity resonator ("CP531" manufactured by Kanto Electronics Application Development Co., Ltd.) is connected to a network analyzer ("E8363B" manufactured by Agilent Technology), a dielectric is inserted into the cavity resonator, and the dielectric constant of the dielectric or laminate is measured from the change in resonance frequency before and after insertion for 96 hours in an environment of a temperature of 25°C and a humidity of 60% RH. The change in the dielectric constant is calculated as the difference between the maximum and minimum values ​​of the dielectric constants measured at a total of 10 points.

[0146] (Thickness) The thickness of the dielectric or laminate is measured using a stylus film thickness meter at the 10 positions where the relative dielectric constant was evaluated, and the average value is calculated.

[0147] (Direction of change in dielectric constant and thickness) Whether the direction of change in dielectric constant and thickness matches or does not match is determined by finding the sign of the rate of change from the data at adjacent positions for the above 10 data points.

[0148] (Gain) A pair of omnidirectional antennas is prepared, and the distance between the transmitting antenna and the receiving antenna is set to 1 m. Two laminates obtained in the examples are inserted at a position 100 mm from the receiving antenna, with the sides with higher dielectric constants facing each other. The improvement (unit: dB) in the receiving strength of the receiving antenna at 30 GHz is confirmed compared to before the laminates were inserted.

[0149]

[0150]

[0151] Tables 1 and 2 show that the gain of all antennas does not decrease. (Compare Examples 1 to 13 with Comparative Examples 1 and 2.) Furthermore, a comparison of Examples 10 to 12 reveals that by imparting a lens-shaped thickness distribution to the dielectric laminate and further aligning the direction of change in the dielectric constant and thickness, it is possible to achieve both a thin lens antenna and high gain. Furthermore, by using a dielectric whose direction of change in the dielectric constant and the direction of change in the thickness are aligned, it is possible to improve gain even when the laminate is thin and the gap between the laminate and the antenna is small. (Compare Examples 11 and 12.) Furthermore, by using a dielectric whose direction of change in the dielectric constant and the thickness are aligned and whose thickness change rate is greater than 10% in a region where the dielectric constant changes continuously, it is possible to improve gain even when the laminate is thin and the gap between the laminate and the antenna is small. (Compare Examples 10 and 11.)

[0152] The disclosures of Japanese Patent Application No. 2024-137826 filed on August 19, 2024, Japanese Patent Application No. 2024-146894 filed on August 28, 2024, and Japanese Patent Application No. 2025-135713 filed on August 18, 2025 are incorporated herein by reference in their entirety. In addition, all documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.

Claims

A radio wave control element including a dielectric material including a region in which the relative permittivity changes continuously.

2. The radio wave control element according to claim 1, wherein the dielectric has a range of change in the relative dielectric constant of 0.1 to 1000 in the region where the relative dielectric constant changes continuously.

2. The radio wave control element according to claim 1, wherein the dielectric has a thickness that varies by 10% or less in the region where the dielectric constant varies continuously.

2. The radio wave control element according to claim 1, wherein the dielectric material includes at least two kinds of materials having different relative dielectric constants, and the mixing ratio of the at least two kinds of materials gradually changes within a region in which the relative dielectric constant changes continuously.

2. The radio wave control element according to claim 1, wherein the dielectric material includes at least one type of material, and the density of the material gradually changes within the region where the relative dielectric constant changes continuously.

2. The radio wave control element according to claim 1, wherein the dielectric material contains at least one material and air, and the air content gradually changes within the region where the relative dielectric constant changes continuously.

2. The radio wave control element according to claim 1, wherein the dielectric constant of the dielectric material changes monotonically from one side to the other side of two opposing sides in the region where the dielectric constant changes continuously.

2. The radio wave control element according to claim 1, wherein the dielectric constant of said dielectric material changes monotonically from two opposing sides toward an in-plane direction in the region where the dielectric constant changes continuously.

2. The radio wave control element according to claim 1, wherein the dielectric constant of said dielectric material changes monotonically from the center toward the outer periphery in the in-plane direction in said region where the dielectric constant changes continuously.

2. The radio wave control element according to claim 1, wherein the dielectric constant of said dielectric material changes monotonically from the inside to the surface in the thickness direction in the region where the dielectric constant changes continuously.

2. The radio wave control element according to claim 1, wherein the thickness of the dielectric material changes continuously in the region where the dielectric constant changes continuously, and the direction of increase in the dielectric constant coincides with the direction of increase in the thickness.

12. The radio wave control element according to claim 11, wherein the rate of change in thickness of the dielectric material in the region where the relative dielectric constant changes continuously is greater than 10%.

10. The radio wave control element according to claim 9, wherein the relative dielectric constant of the inner portion is higher than the relative dielectric constant of the outer periphery.

10. The radio wave control element according to claim 9, wherein the relative dielectric constant of the inner portion is lower than the relative dielectric constant of the outer periphery.

11. The radio wave control element according to claim 10, wherein the relative dielectric constant of the interior is higher than the relative dielectric constant of the surface. 　 An antenna comprising the radio wave control element according to any one of claims 1 to 15 and a radio wave emitting element or a radio wave receiving element.

Images