WO2019044000A1 - Meta-material device and antenna device - Google Patents

Meta-material device and antenna device Download PDF

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Publication number
WO2019044000A1
WO2019044000A1 PCT/JP2018/008402 JP2018008402W WO2019044000A1 WO 2019044000 A1 WO2019044000 A1 WO 2019044000A1 JP 2018008402 W JP2018008402 W JP 2018008402W WO 2019044000 A1 WO2019044000 A1 WO 2019044000A1
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Prior art keywords
resonator
unit
unit resonator
resonant
metamaterial device
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PCT/JP2018/008402
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French (fr)
Japanese (ja)
Inventor
上田　哲也
伸之 久本
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国立大学法人京都工芸繊維大学
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Priority to JP2019538941A priority Critical patent/JPWO2019044000A1/en
Publication of WO2019044000A1 publication Critical patent/WO2019044000A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P1/00—Auxiliary devices
    • H01P1/165—Auxiliary devices for rotating the plane of polarisation
    • H01P1/17—Auxiliary devices for rotating the plane of polarisation for producing a continuously rotating polarisation, e.g. circular polarisation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P1/00—Auxiliary devices
    • H01P1/20—Frequency-selective devices, e.g. filters
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q11/00—Electrically-long antennas having dimensions more than twice the shortest operating wavelength and consisting of conductive active radiating elements
    • H01Q11/02—Non-resonant antennas, e.g. travelling-wave antenna
    • H01Q11/08—Helical antennas
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
    • H01Q15/14—Reflecting surfaces; Equivalent structures
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/30—Resonant antennas with feed to end of elongated active element, e.g. unipole

Definitions

  • the present invention relates to a metamaterial device and an antenna device comprising at least one unitary resonator configured as a metamaterial.
  • a metamaterial refers to an electromagnetic artificial medium or structure composed of unit components (unit resonators) sufficiently smaller than the wavelength of an electromagnetic wave.
  • unit components unit resonators
  • macroscopic parameters of the metamaterial such as the effective permittivity, the effective permeability, and the refractive index.
  • various applications of metamaterials have been proposed.
  • Patent Document 1 discloses a three-dimensional metamaterial including a plurality of unit cells periodically arranged in three dimensions.
  • each unit cell includes a dielectric resonator disposed at the center of the unit cell, a plurality of rod-shaped conductors disposed to surround the dielectric resonator, and dielectric resonance. And a host medium for supporting the rod-like conductor.
  • Patent Document 2 discloses that a meta-helical antenna having excellent power efficiency can be configured by using a configuration example of a meta-helical antenna having a "chiral (spiral) structure", that is, a meta-helical arm formed on a dielectric substrate.
  • An object of the present invention is to provide a metamaterial device and an antenna device provided with at least one unit resonator that interacts more strongly with electromagnetic waves than before.
  • a metamaterial device comprising at least one unitary resonator, wherein The unit resonator is A resonant element comprising at least one strip-shaped subelement, having a path without parallel circuit parts through which current flows simultaneously in the reverse direction, and having substantially zero effective permeability; A plurality of reflective elements respectively connected to respective end portions of the partial elements of the resonant element, wherein the impedance when viewed from the partial elements is substantially zero; Equipped with The unit resonator operates as a zero-order resonator.
  • the resonant element includes a plurality of series LC resonant circuits connected in series with one another, The resonant frequency of each series LC resonant circuit is set to match the operating frequency of the metamaterial device.
  • Each of the series LC resonant circuits includes a strip conductor and a capacitor provided between the strip conductors of series LC resonant circuits adjacent to each other.
  • Each series LC resonant circuit comprises a strip conductor, The end of the strip conductor of each series LC resonant circuit is formed to capacitively couple with the end of the strip conductor of the adjacent series LC resonant circuit.
  • the reflective element has a quarter length of the operating wavelength of the metamaterial device and has a meander shape or a spiral shape.
  • the unit resonator is formed to have chirality.
  • the resonant element has a strip shape having first and second ends, The unit resonator is spirally wound.
  • the unit resonators are formed on a flat substrate,
  • the resonant element is formed asymmetrically with respect to any straight line in the plane of the substrate.
  • the resonant element includes a plurality of subelements each having a bent or curved strip shape in the plane of the substrate, One end of each of the partial elements is connected to one of the plurality of reflective elements, and the other end of each of the partial elements is connected to the other partial element,
  • the resonant elements are formed substantially rotationally symmetric.
  • the unit resonators are formed on a flat substrate, According to the metamaterial device of the tenth aspect of the present invention, in the metamaterial device of the sixth to ninth aspects,
  • the unit resonator includes a plurality of partial resonators respectively formed on a plurality of different conductor layers of the substrate and including the resonant element and the plurality of reflective elements.
  • the respective resonant elements of the plurality of partial resonators have the same shape, and are formed offset by a predetermined angle around an axis passing through the centers of rotational symmetry of the respective resonant elements.
  • the metamaterial device in the metamaterial device of one of the first to tenth aspects, includes a plurality of unit resonators arranged in a two-dimensional array.
  • the metamaterial device rotates the polarization plane of the incident electromagnetic wave.
  • the metamaterial device transmits a portion of the energy of the incident electromagnetic wave and reflects a portion of the energy of the incident electromagnetic wave.
  • An antenna apparatus comprising one unit resonator, the antenna apparatus comprising:
  • the unit resonator is A resonant element having a strip shape having first and second ends, the path not including a parallel circuit portion in which current flows simultaneously in the opposite direction between the first and second ends, And a resonant element having an effective permeability of substantially zero.
  • a reflective element connected to the first end of the resonant element, the reflective element having a substantially zero impedance when viewed from the resonant element;
  • a feed point is provided at the second end of the resonant element,
  • the unit resonator operates as a zero-order resonator.
  • a metamaterial device and an antenna device provided with at least one unit resonator that interacts more strongly with electromagnetic waves than in the past.
  • FIG. 10A It is a perspective view showing the 1st unit cell 10A containing unit resonator 1 concerning a 1st embodiment. It is an expanded view of the unit resonator 1 of FIG. It is the schematic which shows the electromagnetic field intensity of the transmission line which carries out a half wavelength resonance. It is the schematic which shows the electromagnetic field intensity of the transmission line which carries out zero order resonance. It is a perspective view showing the 2nd unit cell 10B containing unit resonator 1 concerning a 1st embodiment. It is a figure which shows the strength (electric current distribution) in the unit resonator 201 which concerns on the 1st comparative example of 1st Embodiment.
  • FIG. 10 It is a figure which shows the intensity (current distribution) of the magnetic field in unit resonator 1 concerning a 1st embodiment. It is a perspective view showing unit cell 10A containing unit resonator 201A concerning the 2nd comparative example of a 1st embodiment. It is a perspective view showing unit cell 10A containing unit resonator 201B concerning the 3rd comparative example of a 1st embodiment. It is a graph which shows the change of the polarization
  • FIG. 1 It is a schematic diagram showing a measurement system of a metamaterial device provided with unit resonator 1 concerning a 1st embodiment. It is a figure showing a metamaterial device provided with unit resonator 1 concerning the 1st example of a 1st embodiment.
  • FIG. 1 It is a figure showing a metamaterial device provided with unit resonator 1 concerning the 2nd example of a 1st embodiment. It is a figure which shows the electromagnetic wave apparatus provided with the unit resonator 201 which concerns on the 4th comparative example of 1st Embodiment. It is a figure which shows the electromagnetic wave apparatus provided with the unit resonator 201 which concerns on the 5th comparative example of 1st Embodiment. Polarization of a metamaterial device including the unit resonator 1 according to the first example of the first embodiment and an electromagnetic wave device including the unit resonator 201 according to the fourth comparative example of the first embodiment It is a graph which shows the frequency characteristic of a rotation angle.
  • Polarization of a metamaterial device including the unit resonator 1 according to the second example of the first embodiment and an electromagnetic wave device including the unit resonator 201 according to the fifth comparative example of the first embodiment It is a graph which shows the frequency characteristic of a rotation angle. It is a perspective view showing unit resonator 1A concerning the 1st modification of a 1st embodiment. It is a perspective view showing unit resonator 1B concerning the 2nd modification of a 1st embodiment. It is the schematic which shows operation
  • FIG. 10C It is a perspective view showing the 3rd unit cell 10C containing unit resonator 201C concerning a comparative example of a 5th embodiment.
  • FIG. 1 is a perspective view showing a first unit cell 10A including the unit resonator 1 according to the first embodiment
  • FIG. 2 is a developed view of the unit resonator 1 of FIG.
  • the unit cell 10A has lengths d1, d2 and d3 along the X, Y and Z directions, respectively.
  • the unit cell 10A includes, in the X and Y directions, a plurality of unit cells 10A each including a resonant element 21 including a strip conductor 23 and a capacitor 24 and a reflective element 22 having a meander line structure.
  • a metamaterial device is configured by arranging along a two-dimensional array. In the present disclosure, it is assumed that a planar wave electromagnetic wave in the -Z direction is incident on each unit cell.
  • the unit resonator 1 includes a resonant element 21 and a pair of reflecting elements 22 of meander line structure connected to both ends thereof.
  • the resonant element 21 and the reflective element 22 are formed on, for example, a flexible substrate 20.
  • the resonant element 21 has a strip shape and has a path that does not include a parallel circuit portion in which current simultaneously flows in the opposite direction between both ends thereof.
  • the resonant element 21 includes a plurality of series LC resonant circuits connected in series with one another.
  • Each series LC resonant circuit includes a strip conductor 23 having a predetermined inductance having a length l and a width w, and a capacitor 24 provided between the strip conductors 23 of series LC resonant circuits adjacent to each other.
  • the capacitor 24 is, for example, a chip capacitor.
  • the resonant element 21 includes ten strip conductors 23 and eleven capacitors 24.
  • the resonant frequency of each series LC resonant circuit is set to match the operating frequency of the metamaterial device. Thereby, the resonant element 21 has an effective permeability of substantially zero, and thus an index of refraction of substantially zero.
  • Each reflective element 22 has a quarter length of the operating wavelength of the metamaterial device, so that the impedance when looking at each reflective element 22 from the resonant element 21 is substantially zero (that is, short circuited) To meet the requirements).
  • the reflective element 22 is, for example, a strip conductor having a meander shape included in a rectangular area so as to be sufficiently smaller than the length of the resonant element 21.
  • the unit resonator 1 has a substantially zero effective permeability, and the impedance at the time when each reflective element 22 is viewed from the resonant element 21 is substantially zero. Act as).
  • the unit resonator 1 is wound in a spiral shape having a radius r and a spiral angle ⁇ .
  • the unit resonator 1 has chirality.
  • FIG. 1 shows the case where the direction of the axis of the spiral (axis parallel to the Z axis) in the unit cell 10A coincides with the propagation direction of the electromagnetic wave (-Z direction).
  • a unit cell in which the axis of the spiral unit resonator coincides with the propagation direction of the electromagnetic wave is indicated by a symbol “10A”.
  • optically active a medium that rotates the polarization plane of propagating light or electromagnetic wave by electro-magnetic coupling.
  • chiral medium a medium that rotates the polarization plane of propagating light or electromagnetic wave by electro-magnetic coupling.
  • the structural relational expression for the electromagnetic wave propagating in the chiral medium is expressed as the following equation.
  • E electric field strength
  • D electric flux density
  • H magnetic field strength
  • B magnetic flux density
  • ⁇ , ⁇ , and ⁇ ⁇ are permittivity, permeability, and chirality, respectively.
  • j represents an imaginary unit.
  • the permittivity ⁇ , the permeability ⁇ , and the chirality ⁇ are tensor amounts.
  • a coupling term of electric field and magnetic field appears in a constitutive relational expression due to chirality, and it is also called a multi-anisotropic medium.
  • Chiral media are not limited to those with microscopic scales such as atoms and molecules. Even on a large scale, a structure such as a screw, a spiral, and a wedge shape, in which an electromagnetic coupling appears due to a space inversion symmetry breaking in which a real image and a virtual image do not coincide with each other is called a "chiral structure”.
  • a metamaterial having a chirality as the unit component as shown in FIG. 1 is called “chiral metamaterial”.
  • the chiral structure has, for example, the following application.
  • a spiral structure is mentioned as a typical chiral structure.
  • a helical antenna having circular polarization characteristics has been put to practical use, using a single spiral resonator as a radiator.
  • Not only a single helical antenna, but also an antenna device in which a plurality of helical antennas are periodically arranged has been proposed.
  • Applications to frequency selective reflectors and transmission plates have also been proposed as applications other than antennas.
  • Such frequency selective reflectors and transmission plates are, for an incident wave having a specific operating frequency or a specific polarization characteristic, a reflected wave or transmission having a desired polarization rotation characteristic in a desired direction. Create a wave.
  • the chiral structure is considered as an electromagnetic scatterer.
  • each helical structure consisting of a single metal wire
  • the lowest-order resonant mode is obtained when the total length of the metal wire corresponds to half the operating wavelength of the electromagnetic wave (half-wave resonance)
  • the second lowest resonance A mode is obtained when the total length of the metal thin wire matches the operating wavelength of the electromagnetic wave (one-wavelength resonance).
  • a large current flows on the surface of the metal, and the electromagnetic field stored inside and near the resonator is also maximized.
  • the interaction between the external electromagnetic wave and the chiral structure is maximized.
  • the interaction between the incident electromagnetic wave and the helical structure is maximized and the polarization rotation effect is also maximized in the vicinity of the unique resonance frequency determined by the length and the shape.
  • a standing wave occurs in the chiral structure at resonance, and antinodes and nodes always appear in the electromagnetic field distribution.
  • the chiral structure is made of a metal material, antinodes and nodes appear in the current distribution flowing on the surface of the metal material at resonance.
  • the electromagnetic field has a predetermined distribution according to the order of the resonance mode, so the current distribution in the resonator must be in accordance with the electromagnetic field distribution.
  • a resonator whose electromagnetic field distribution is uniform throughout the electromagnetic field distribution and the current distribution is a zeroth-order resonator, as compared with a conventional resonator (such as a half-wave resonator and a single-wavelength resonator) whose electromagnetic field distribution has antinodes and nodes It is.
  • the zeroth-order resonator can be composed of a transmission line of finite length, which is a right-hand / left-handed composite transmission line which is a kind of metamaterial, and a pair of reflecting elements connected to both ends thereof.
  • the right-hand / left-handed composite transmission line consists of unit cells of a sub-wavelength size composed of a series LC resonant circuit in series branches and a parallel LC resonant circuit in shunt branches, and one or more unit cells have a (quasi) period It has a complex structure arranged side by side.
  • the two types of resonant circuits in series and in parallel included in the unit cell selectively operate according to the conditions (short circuit or open) realized by the reflective elements at both ends. When the pair of reflective elements connected to both ends is impedance 0 (meaning a shorted end), the series LC resonant circuit included in the series branch of each unit cell selectively operates.
  • the impedance of the serial branch of each unit cell is almost all zero.
  • a large current having uniform magnitude and phase flows through the serial branch of each unit cell. That is, it is zero-order resonance in the case of short circuit at both ends.
  • the impedance at both ends is infinite (meaning an open end)
  • the parallel LC resonance circuit included in the shunt branch of each unit cell selectively operates.
  • the admittance of the shunt branch of each unit cell is almost all zero.
  • a voltage having uniform magnitude and phase is applied across the shunt branches of each unit cell. That is, it is a zero-order resonance in the case of both ends open.
  • an electromagnetic field distribution having uniform amplitude and phase is obtained along the transmission line, so the wavelength in the tube becomes infinite and the phase constant (the amount of change in phase per unit length) ⁇ is zero. It becomes.
  • FIG. 3 is a schematic view showing the electromagnetic field strength of the transmission line which resonates at a half wavelength.
  • FIG. 4 is a schematic view showing the electromagnetic field strength of the transmission line at which the zero order resonance occurs.
  • the horizontal direction indicates the position along the transmission line, and the vertical direction indicates the strength of the electromagnetic field.
  • a chiral structure is configured by winding the right / left handed composite transmission line in a spiral shape. Further, a chiral zero-order resonator is configured by connecting a pair of reflective elements to both ends thereof.
  • a transmission line when using a transmission line as a chiral structure, it differs from the conventional chiral structure which consists of metal thin wires as follows.
  • the transmission line is a two-terminal pair network in which a signal line and a ground conductor are combined, while the conventional chiral structure consists of one metal thin wire.
  • the chiral structure which consists of a transmission line is provided mutually in parallel with the circuit part corresponded to a signal line, and the circuit part corresponded to a grounding conductor.
  • the chiral structure including the transmission line when a current flows in the circuit portion corresponding to the signal line, in the circuit portion corresponding to the ground conductor, the current of the same size in the opposite direction to the circuit portion corresponding to the signal line Flows. Therefore, when currents of the same magnitude flow in opposite directions in the two circuit portions, the scattered waves of the electromagnetic waves respectively incident on these circuit portions completely cancel each other. If the two circuit portions have a geometrically asymmetric structure, the scattered waves of the electromagnetic waves respectively incident on these circuit portions do not completely cancel each other, but the destructive effects are inevitable.
  • the presence of a large conductor having a shielding effect means that the interaction between the electromagnetic wave and the chiral structure (electromagnetic scatterer) Equivalent to increasing the area not contributing to Therefore, in order to increase the effect of increasing the polarization rotation, the chiral structure from which the circuit portion corresponding to the ground conductor is removed is subjected to zero-order resonance.
  • the resonant element 21 has a strip shape and has a path that does not include a parallel circuit portion in which current simultaneously flows in the opposite direction between both ends thereof. . Therefore, the unit resonator 1 has a configuration in which the circuit portion corresponding to the ground conductor is removed from the transmission line. Since there is no shunt branch in the unit resonator 1 and there is only a series branch, series resonance operation is realized as a zero-order resonator whose both ends are shorted by the reflective element 22.
  • the metamaterial device provided with the unit resonator 1 of FIG. 1 is a conventional electromagnetic wave device provided with a half-wave resonator or a single-wavelength resonator as a unit resonator by the unit resonator 1 operating as a zero-order resonator. Can also interact strongly with electromagnetic waves.
  • the metamaterial device including the unit resonator 1 of FIG. 1 can operate as a chiral metamaterial by winding the unit resonator 1 in a spiral shape.
  • the polarization rotation angle is significantly increased as compared with the chiral periodic structure made of conventional metal thin wires. It was confirmed by numerical calculation and actual measurement.
  • the metamaterial device provided with the unit resonator 1 of FIG. 1 is confirmed by numerical calculation and actual measurement that the polarization rotation angle is increased even compared to the case of the chiral structure including the circuit portion corresponding to the ground conductor. did.
  • FIG. 5 is a perspective view showing a second unit cell 10B including the unit resonator 1 according to the first embodiment.
  • FIG. 5 shows the case where the direction of the axis of the spiral (axis parallel to the Y axis) in the unit cell 10B is orthogonal to the propagation direction of the electromagnetic wave (-Z direction).
  • a metamaterial device in which a plurality of unit cells 10B are arranged as a two-dimensional array can also interact more strongly with electromagnetic waves than in the prior art, similarly to the metamaterial device having the unit resonator 1 of FIG. It can also act as a chiral metamaterial.
  • Each unit cell 10B has lengths d1, d2 and d3 along the X, Y and Z directions, respectively.
  • a unit cell in which the axis of the spiral unit resonator is parallel to the propagation direction of the electromagnetic wave is indicated by the code “10A”
  • the axis of the spiral unit resonator is A unit cell orthogonal to the propagation direction of the electromagnetic wave is indicated by a code "10B”.
  • the entire parameters (effective permittivity, effective permeability, and the like) of the metamaterial device can be selected by appropriately selecting the orientation and arrangement of each unit resonator 1. And chirality etc. can be set to a desired value.
  • the anisotropy appears prominently.
  • the unit resonators 1 are randomly arranged with respect to at least one of the orientation and the arrangement, it is also possible to obtain isotropic chirality. Even when the unit resonators 1 are periodically arranged or when the unit resonators 1 are randomly arranged, the plurality of unit resonators 1 are one-dimensionally, two-dimensionally, or three-dimensionally depending on the application. Can be arranged in
  • the plane wave electromagnetic wave was set to be incident from the upper surface to the lower surface of the unit cell 10A. Therefore, in each unit cell 10A, the axis of the spiral coincides with the propagation direction of the electromagnetic wave.
  • a portion other than the unit resonator 1 is a free space.
  • the configuration parameters of the unit resonator 1 were as follows.
  • Capacitance of capacitor 24: C 0.8 pF Total length of reflective element 22: 59 mm Width of reflective element 22: 0.5 mm
  • Dimensions of reflective element 22: lm ⁇ wm 14.5 mm ⁇ 9.0 mm
  • Spiral radius: r 10 mm
  • Helix angle: theta 25 Donishi linear in wound Z-direction length of the resonance element 21: 0.26 ⁇ 0 ( ⁇ 0: operating wavelength)
  • a model of an electromagnetic wave device provided with a unit resonator 201 consisting only of a resonant element of a strip conductor as shown in FIG. 6 was set.
  • the unit resonator 201 is a conventional half-wave resonator.
  • the configuration parameters of the unit resonator 201 were as follows.
  • FIG. 6 is a diagram showing the strength (current distribution) of the magnetic field in the unit resonator 201 according to the first comparative example of the first embodiment.
  • FIG. 7 is a diagram showing the strength (current distribution) of the magnetic field in the unit resonator 1 according to the first embodiment.
  • these unit resonators 1 and 201 were set to approximately the same configuration parameters and approximately the same operating frequency.
  • the current intensity is maximum near the center of the element of the unit resonator 201.
  • the intensity of the current weakens as it approaches both ends of the element, and eventually becomes zero at the end.
  • FIG. 7 in the case of the unit resonator 1 which is a zero-order resonator, it is understood that the magnitude of the current is substantially constant throughout the resonant element 21 and is maintained at the maximum value.
  • the transmission characteristic T cir of the electromagnetic wave propagating in the circular polarization can be expressed as the following equation using the transmission characteristic of the electromagnetic wave propagating in the linear polarization.
  • T ++ permeability coefficient of the right circular polarization component at the time when the right circularly polarized wave is incident
  • T + - permeability coefficient of the left circularly polarized component in when the right circularly polarized wave is incident
  • T - permeability coefficient of the left circularly polarized component in when the left circularly polarized wave is incident
  • T xx definitive when linearly polarized wave is incident in the x direction of the x-direction
  • T yx Transmission coefficient of linear polarization component in y direction when linear polarization in x direction is incident
  • T xy linear polarization in x direction when linear polarization in y direction is incident
  • T yy Transmission coefficient of linear polarization component in y direction when linear polarization in y direction is incident
  • this equation was used to evaluate the polarization rotation angle of the transmitted wave of the metamaterial device.
  • the electromagnetic wave device including the unit resonator 201 according to the first comparative example of the first embodiment and the metamaterial device including the unit resonator 1 according to the first embodiment the following polarization rotation angles was gotten.
  • a polarization rotation angle of 2.72 degrees was obtained at a resonance frequency of 2.44 GHz.
  • a polarization rotation angle of 12.5 degrees was obtained at a resonance frequency of 2.42 GHz.
  • the polarization rotation angle of the metamaterial device including the unit resonator 1 that is the zeroth-order resonator is about 4.6 as compared to the polarization rotation angle of the electromagnetic wave device that includes the unit resonator 201 that is a half-wave resonator. It was found to be doubled.
  • FIG. 8 is a perspective view showing a unit cell 10A including a unit resonator 201A according to a second comparative example of the first embodiment.
  • the unit resonator 201A includes two circuit parts provided in parallel with each other, and one circuit part is configured in the same manner as the resonant element 21 (see FIG. 2) of the unit resonator 1 according to the first embodiment.
  • the other circuit part consists only of a strip conductor.
  • the unit resonator 201A has a configuration in which a transmission line including a signal conductor and a ground conductor is spirally wound, that is, a circuit portion corresponding to the signal conductor and a circuit portion corresponding to the ground conductor. At both ends of the unit resonator 201A, the two circuit parts are shorted to each other.
  • FIG. 9 is a perspective view showing a unit cell 10A including a unit resonator 201B according to a third comparative example of the first embodiment.
  • the unit resonator 201B includes two circuit portions provided in parallel to each other, and both of these circuit portions are similar to the resonant element 21 (see FIG. 2) of the unit resonator 1 according to the first embodiment. That is, it is configured as a line including a plurality of series LC resonant circuits connected in series with one another. At both ends of the unit resonator 201B, the two circuit parts are shorted to each other.
  • the same value as that of the corresponding part of the unit resonator 1 according to the first embodiment is set to each of the configuration parameters of the unit resonators 201A and 201B.
  • the polarization rotation angle of 12.5 degrees is obtained at the resonance frequency of 2.42 GHz.
  • the polarization rotation angle of 1.33 degrees was obtained at the resonance frequency of 3.14 GHz.
  • the polarization rotation angle of 1.86 degrees was obtained at the resonance frequency of 3.86 GHz.
  • the metamaterial device that is, the metamaterial device including the unit resonator 1 not including the parallel circuit portion in which the current flows in the reverse direction simultaneously, the current flows in the reverse direction simultaneously. It has been found that the polarization rotation angle several times larger can be obtained as compared with the electromagnetic wave apparatus including the unit resonators 201A and 201B including the circuit portion.
  • the resonance frequencies of the metamaterial device and the electromagnetic wave device provided with the three types of unit resonators 1, 201A and 201B are different from each other.
  • the resonance frequency of the metamaterial device provided with the unit resonator 1 is the smallest, and the resonance frequency of the electromagnetic wave device provided with the other unit resonators 201A and 201B is higher.
  • wavelength ratio it is considered that, since the sizes of the unit resonators 201A and 201B are relatively larger than that of the unit resonator 1, larger polarization rotation should occur.
  • the electromagnetic wave apparatus having the unit resonators 201A and 201B only the polarization rotation angle similar to that of the electromagnetic wave apparatus having the unit resonator 201 according to the first comparative example of the first embodiment. Not obtained. From the above, by adopting the structure of the metamaterial device including the unit resonator 1 according to the first embodiment, the effect of increasing the polarization rotation angle is clear.
  • the metamaterial device including the unit resonator 1 according to the first embodiment differs from the electromagnetic wave device including the unit resonator 201A of FIG. 8 and the unit resonator 201B of FIG. Since the part is removed, a larger polarization rotation angle is obtained.
  • FIG. 10 is a graph showing a change in polarization rotation angle with respect to the spiral radius of the electromagnetic wave device provided with the unit resonator 201 according to the first comparative example of the first embodiment.
  • FIG. 11 is a graph showing a change in polarization rotation angle with respect to the spiral radius of the metamaterial device provided with the unit resonator 1 according to the first embodiment.
  • FIG. 12 is a graph showing the change in polarization rotation angle with respect to the spiral angle of the electromagnetic wave device provided with the unit resonator 201 according to the first comparative example of the first embodiment.
  • FIG. 13 is a graph showing the change in the polarization rotation angle with respect to the spiral angle of the metamaterial device provided with the unit resonator 1 according to the first embodiment.
  • the polarization rotation angle is at most about 3 degrees even if the spiral radius and the spiral angle are changed.
  • the size of the polarization rotation angle can be increased up to a maximum of 20 degrees by optimally setting the spiral radius and the spiral angle. .
  • FIG. 14 shows a metamaterial device including the unit resonator 1 according to the first embodiment (example) and an electromagnetic wave device including the unit resonator 201 according to the first comparative example of the first embodiment, It is a graph which shows the frequency characteristic of a polarization rotation angle.
  • the unit cell 10A in which the axis of the spiral unit resonator coincides with the propagation direction of the electromagnetic wave was used.
  • the configuration parameters of the unit resonator 201 are as follows.
  • a polarization rotation angle of 7.31 degrees is obtained at a frequency of 2.8 GHz.
  • a polarization rotation angle of 33.6 degrees was obtained at a frequency of 2.44 GHz. Therefore, also in this case, the polarization rotation angle of the metamaterial device provided with the unit resonator 1 which is the zero-order resonator is compared with the polarization rotation angle of the electromagnetic wave device provided with the unit resonator 201 which is the half wavelength resonator. Increased about 4.6 times.
  • FIG. 15 shows a metamaterial device including the unit resonator 1 according to the first embodiment (example) and an electromagnetic wave device including the unit resonator 201 according to the first comparative example of the first embodiment, It is a graph which shows the frequency characteristic of a polarization rotation angle.
  • the unit cell 10B in which the axis of the spiral unit resonator is orthogonal to the propagation direction of the electromagnetic wave was used.
  • the configuration parameters of the unit resonator 201 are as follows.
  • a polarization rotation angle of 1.48 degrees was obtained at a frequency of 2.48 GHz.
  • a polarization rotation angle of 32.1 degrees was obtained at a frequency of 2.68 GHz. Accordingly, also in the case of FIG. 15, it is understood that the polarization rotation angle of the metamaterial device provided with the unit resonator 1 which is the zero-order resonator is increased to the same extent as in the case of FIG. 14.
  • the metamaterial device according to the first embodiment is actually created, and the results of actually measuring the characteristics thereof will be described.
  • FIG. 16 is a schematic view showing a measurement system of a metamaterial device provided with the unit resonator 1 according to the first embodiment.
  • the metamaterial device 100 of FIG. 16 includes a plurality of unit resonators 1 arranged as a two-dimensional array along the X direction and the Y direction.
  • the transmitting antenna 31 and the receiving antenna 32 are connected to a network analyzer, and the metamaterial device 100 is disposed as a measurement sample between the transmitting antenna 31 and the receiving antenna 32.
  • the transmitting antenna 31 and the receiving antenna 32 are, for example, horn antennas.
  • the transmission characteristics T xx , T yx , T xy , and T yy of the linearly polarized light of the metamaterial device 100 were measured by transmitting and receiving radio waves while changing the polarization directions of the transmitting antenna 31 and the receiving antenna 32. Thus, the polarization rotation angle of the metamaterial device 100 was actually measured.
  • FIG. 17 is a view showing a metamaterial device provided with the unit resonator 1 according to the first example of the first embodiment.
  • the metamaterial device of FIG. 17 includes a plurality of unit resonators 1, a plurality of cylindrical members 2, and a base member 3.
  • the plurality of unit resonators 1 are spirally wound around the plurality of cylindrical members 2 respectively.
  • the plurality of unit resonators 1 and the plurality of cylindrical members 2 are disposed on the plate-like base member 3 such that the axes of the spiral unit resonators coincide with the propagation direction (Z direction) of the electromagnetic wave. .
  • Z direction propagation direction
  • the same configuration parameters as those described with reference to FIG. 14 were set in each unit resonator 1 of FIG.
  • FIG. 18 is a view showing a metamaterial device provided with a unit resonator 1 according to a second example of the first embodiment.
  • the metamaterial device of FIG. 18 includes a plurality of unit resonators 1, a plurality of cylindrical members 2, and a base member 3.
  • the plurality of unit resonators 1 and the plurality of cylindrical members 2 are disposed on the plate-like base member 3 such that the axes of the spiral unit resonators are orthogonal to the propagation direction (Z direction) of the electromagnetic wave. .
  • the same configuration parameters as those described with reference to FIG. 15 were set in each unit resonator 1 of FIG. 18.
  • FIG. 19 is a view showing an electromagnetic wave apparatus provided with a unit resonator 201 according to a fourth comparative example of the first embodiment.
  • the electromagnetic wave device of FIG. 19 includes a plurality of unit resonators 201, a plurality of cylindrical members 202, and a base member 203.
  • the plurality of unit resonators 201 are spirally wound around the plurality of cylindrical members 202, respectively.
  • the plurality of unit resonators 201 and the plurality of cylindrical members 202 are disposed on the plate-like base member 203 such that the axes of the spiral unit resonators coincide with the propagation direction (Z direction) of the electromagnetic wave. .
  • Z direction propagation direction
  • the same configuration parameters as those described with reference to FIG. 14 were set in each unit resonator 201 of FIG.
  • FIG. 20 is a diagram showing an electromagnetic wave apparatus provided with a unit resonator 201 according to a fifth comparative example of the first embodiment.
  • the electromagnetic wave device in FIG. 20 includes a plurality of unit resonators 201, a plurality of cylindrical members 202, and a base member 203.
  • the plurality of unit resonators 201 and the plurality of cylindrical members 202 are disposed on the plate-like base member 203 such that the axes of the spiral unit resonators are orthogonal to the propagation direction (Z direction) of the electromagnetic wave. .
  • the same configuration parameters as those described with reference to FIG. 15 were set in each unit resonator 201 of FIG.
  • the unit resonators 1, 201 each include a copper thin film disposed on a double-sided tape as a strip conductor 23, and further include a chip capacitor connected by solder between adjacent copper thin films as a capacitor 24.
  • FIG. 21 shows a metamaterial device provided with the unit resonator 1 according to the first example of the first embodiment, and an electromagnetic wave device provided with the unit resonator 201 according to the fourth comparative example of the first embodiment Is a graph showing the frequency characteristics of the polarization rotation angle. That is, FIG. 21 is the case where the axis of the spiral unit resonator coincides with the propagation direction of the electromagnetic wave, and the metamaterial device (first embodiment) of FIG. 17 and the electromagnetic wave device (fourth example) of FIG. And the frequency characteristics of the polarization rotation angle. In the fourth comparative example, a polarization rotation angle of 9.1 degrees was obtained at a frequency of 2.68 GHz.
  • a resonant frequency of 7.31 degrees is obtained at a frequency of 2.8 GHz as described above with reference to FIG. It can be seen that the frequency characteristics of the wave rotation angle are relatively well matched between the numerical calculation and the actual measurement.
  • a polarization rotation angle of 32.5 degrees was obtained at a frequency of 2.37 GHz.
  • the polarization rotation angle of 33.6 degrees is obtained at 2.44 GHz as described above with reference to FIG. It can be seen that the frequency characteristics of the polarization rotation angle are comparable between numerical calculation and actual measurement.
  • the polarization rotation angle of the metamaterial device of the first example provided with the unit resonator 1 which is a zero-order resonator is the fourth comparative example provided with the unit resonator 201 which is a half-wave resonator.
  • the polarization rotation angle of the electromagnetic wave device significantly increases.
  • FIG. 22 shows a metamaterial device including the unit resonator 1 according to the second example of the first embodiment, and an electromagnetic wave device including the unit resonator 201 according to the fifth comparative example of the first embodiment Is a graph showing the frequency characteristics of the polarization rotation angle. That is, FIG. 22 is the case where the axis of the spiral unit resonator is orthogonal to the propagation direction of the electromagnetic wave, and the metamaterial device (second example) of FIG. 18 and the electromagnetic wave device (fifth example of FIG. And the frequency characteristics of the polarization rotation angle. In the fifth comparative example, a polarization rotation angle of 3.56 degrees was obtained at a frequency of 2.42 GHz.
  • a polarization rotation angle of 1.48 degrees is obtained at a frequency of 2.48 GHz as described above with reference to FIG. It can be seen that the frequency characteristics of the polarization rotation angle are comparable between numerical calculation and actual measurement.
  • a polarization rotation angle of 31.9 degrees was obtained at a frequency of 2.595 GHz.
  • a polarization rotation angle of 32.1 degrees is obtained at a frequency of 2.68 GHz as described above with reference to FIG.
  • the frequency characteristics of the polarization rotation angle are relatively well matched between the numerical calculation and the actual measurement.
  • the polarization rotation angle of the metamaterial device of the second embodiment including the unit resonator 1 which is a zero-order resonator is the fifth comparative example including the unit resonator 201 which is a half-wave resonator.
  • the polarization rotation angle of the electromagnetic wave device significantly increases.
  • FIG. 23 is a perspective view showing a unit resonator 1A according to a first modified example of the first embodiment.
  • a strip conductor having a meander shape is used, but the shape of the reflective element 22 is not limited to this.
  • the reflective element 22 may have any shape as long as it has a length of 1 ⁇ 4 of the operating wavelength and satisfies the short circuit condition at both ends of the resonant element 21.
  • a reflective element 22A having a spiral shape may be provided.
  • the reflective elements 22 and 22A do not have to be made of a metal material, and may be made of a dielectric.
  • FIG. 24 is a perspective view showing a unit resonator 1B according to a second modified example of the first embodiment.
  • the unit resonator 1B may include a capacitor 24B which is a distributed constant capacitor such as an interdigital capacitor, instead of the capacitor 24 of FIG. 2 which is a chip capacitor.
  • each series LC resonance circuit includes a strip conductor 23B, and an end of the strip conductor 23B of each series LC resonance circuit is an end of the strip conductor 23B of the adjacent series LC resonance circuit. It is formed to be capacitively coupled.
  • the unit resonator 1B of FIG. 24 there is no need to mount the chip capacitor on the unit resonator, and the unit resonator 1B can be manufactured only with the conductor pattern, so that the manufacture can be simplified.
  • each series LC resonant circuit of the resonant element 21 includes the strip conductor 23 having a predetermined inductance, but the element having the inductance is not limited to this.
  • a chip inductor may be used instead of the strip conductor 23.
  • the unit resonator according to the first embodiment may have a shape other than a spiral.
  • the unit resonator may have a planar shape, such as a spiral shape, as long as chirality can be generated.
  • the optical activity is increased by providing the unit resonator 1 which is a zero-order resonator wound in a spiral shape. It was confirmed that the degree of polarization rotation was greatly increased by the next resonance as compared with the electromagnetic wave device provided with the conventional half-wave resonator. This is expected to improve the characteristics of various devices using chiral structures.
  • FIG. 25 is a schematic view showing the operation of the polarization selection plate according to the second embodiment.
  • the metamaterial device 100 according to the first embodiment operates as a polarization selection plate that selectively transmits or reflects a part of the energy of the incident electromagnetic wave according to the polarization plane of the electromagnetic wave. May be
  • FIG. 26 is a graph showing transmission coefficients of electromagnetic waves having different polarization planes of a metamaterial device provided with unit resonators according to an example of the second embodiment.
  • a unit resonator 1 similar to that of FIG. 2 is formed along a substrate perpendicular to the propagation direction of the electromagnetic wave, and a plane wave (Tx) having a polarization plane orthogonal to the longitudinal direction of the resonant element 21;
  • Tx plane wave having a polarization plane orthogonal to the longitudinal direction of the resonant element 21
  • Ty plane wave having a polarization plane along the longitudinal direction of the resonant element 21 is emitted toward the unit resonator 1 is shown.
  • FIG. 27 is a graph showing transmission coefficients of electromagnetic waves having different polarization planes of a metamaterial device provided with unit resonators according to a comparative example of the second embodiment.
  • a half-wave resonator formed of a linear strip conductor is formed along a substrate perpendicular to the propagation direction of the electromagnetic wave, and a plane wave (Tx having a polarization plane orthogonal to the longitudinal direction of the half-wave resonator) And a plane wave (Ty) having a polarization plane along the longitudinal direction of the half-wave resonator toward the half-wave resonator.
  • a polarization selection plate that reflects the energy of the incident electromagnetic wave better than the metamaterial device provided with a half wavelength resonator, a single wavelength resonator, etc. Can be provided.
  • FIG. 28 is a schematic view showing the operation of the polarization rotating plate according to the third embodiment.
  • the metamaterial device 100 according to the first embodiment may operate as a polarization rotation plate that rotates the polarization plane of an incident electromagnetic wave across an angle ⁇ .
  • FIG. 29 is a schematic view showing the operation of the frequency selection plate according to the fourth embodiment.
  • the metamaterial device 100 according to the first embodiment operates as a frequency selection plate that transmits part of the energy of the incident electromagnetic wave and reflects the remaining part of the energy of the incident electromagnetic wave. You may When transmitting part of the energy of the incident electromagnetic wave, the metamaterial device 100 rotates its polarization plane through an angle ⁇ 1. Further, when the metamaterial device 100 reflects a part of the energy of the incident electromagnetic wave, the metamaterial device 100 rotates its polarization plane through an angle ⁇ 2.
  • a frequency selection plate that can better separate the frequency components of the incident electromagnetic wave than the metamaterial device provided with a half wavelength resonator, a single wavelength resonator, etc. Can be provided.
  • the unit resonator is spirally wound in order to obtain chirality.
  • planar structures such as V-shaped and spiral also have chiral structures.
  • a metamaterial device provided with a flat unit resonator having a chiral structure will be described.
  • FIG. 30 is a perspective view showing a third unit cell 10C including the unit resonator 1C according to the fifth embodiment.
  • the unit resonator 1C is formed on a flat substrate 20C.
  • FIG. 30 shows the case where the surface (surface parallel to the XY plane) of the substrate 20C in the unit cell 10C is orthogonal to the propagation direction (-Z direction) of the electromagnetic wave.
  • the substrate 20C is made of, for example, a dielectric.
  • unit cell 10C has lengths d1, d2 and d3 along the X direction, Y direction and Z direction, respectively.
  • a unit cell in which the surface of the substrate on which the unit resonator is formed is orthogonal to the propagation direction of the electromagnetic wave is indicated by a symbol “10C”.
  • FIG. 31 is a plan view showing a configuration of the unit resonator 1C of FIG.
  • the unit resonator 1 ⁇ / b> C includes one resonant element 21 ⁇ / b> C and a plurality of reflective elements 22.
  • the resonant element 21C includes at least one strip-shaped subelement and has a path that does not include a parallel circuit part through which current flows simultaneously in the opposite direction.
  • the resonant element 21C includes a plurality of subelements each having a bent or curved strip shape in the plane of the substrate 20C, four arms 26 in the example of FIG. In the example of FIG. 31, the resonant element 21C is formed in a wedge shape.
  • Each arm 26 includes a strip conductor 23 and a capacitor 24 as with the resonant element 21 of FIG.
  • One end of each arm 26 is connected to one of the plurality of reflective elements 22, and the other end of each arm 26 is connected to the other arm 26 via the central conductor 25.
  • the resonant element 21C is formed substantially rotationally symmetric around the center O. Thereby, the resonant element 21C is formed asymmetrically with respect to any straight line in the plane of the substrate 20C.
  • Each reflective element 22 of FIG. 31 is configured in the same manner as the reflective element 22 of FIG.
  • Each reflective element 22 is connected to each end of each arm 26 of the resonant element 21C, and is configured such that the impedance when viewing each reflective element 22C from each arm 26 is substantially zero.
  • the unit resonator 1C also operates as a zero-order resonator as in the unit resonator 1 of FIG. Therefore, the metamaterial device including the unit resonator 1C can also interact more strongly with the electromagnetic wave than the conventional electromagnetic wave device including the half wavelength resonator or the single wavelength resonator as the unit resonator. Further, by forming the resonant element 21C asymmetrically with respect to any straight line in the plane of the substrate 20C, the metamaterial device provided with the unit resonator 1C can also operate as a chiral metamaterial.
  • configuration parameters of the metamaterial device provided with the unit resonator 1C were as follows.
  • Unit cell 10C size: d1 x d2 45 mm x 45 mm (0.34 times the operating wavelength) Thickness of substrate 20C: 0.8 mm Thickness of conductor of unit resonator 1C: 0.5 mm
  • FIG. 32 is a perspective view showing a third unit cell 10C including a unit resonator 201C according to a comparative example of the fifth embodiment.
  • Unit resonator 201C includes only a wedge-shaped strip conductor.
  • configuration parameters of the unit resonator 201C were as follows.
  • Unit cell 10C size: d1 x d2 35 mm x 35 mm (0.24 times the operating wavelength) Thickness of substrate 20C: 0.8 mm Thickness of conductor of unit resonator 1C: 0.5 mm
  • FIG. 33 The frequency characteristic of a polarization rotation angle about the metamaterial apparatus provided with unit resonator 1C which concerns on 5th Embodiment, and the electromagnetic wave apparatus provided with unit resonator 201C which concerns on the comparative example of 5th Embodiment. Is a graph showing According to FIG. 33, in the electromagnetic wave apparatus provided with the unit resonator 201C according to the comparative example of the fifth embodiment, the polarization rotation angle of 0.44 degrees was obtained at a frequency of 2.08 GHz (dotted line in FIG. 33).
  • the metamaterial device including the unit resonator 1C according to the fifth embodiment (example), a polarization rotation angle of 3.49 degrees was obtained at a frequency of 2.28 GHz (solid line in FIG. 33). Therefore, in this case, the polarization rotation angle of the metamaterial device including the unit resonator 1C, which is a zero-order resonator, is increased by about 7.9 times in comparison with the polarization rotation angle of the electromagnetic wave device including the unit resonator 201. did.
  • the manufacture of the metamaterial device can be simplified as compared with the first embodiment.
  • the unit resonator 1C includes the resonance element 21C having four arms 26 and formed in a wedge shape (or also referred to as tetraskelion), but has another shape.
  • the formed resonant element may be used.
  • triskelions having three arms, pentaskelions having five arms, hexaskelions having six arms, and resonant elements having similar shapes can be used.
  • each arm 26 of the resonant element 21C is bent at 90 degrees
  • each arm may be bent at another angle, and is curved as in FIGS. 40 to 41. It is also good.
  • the sixth embodiment also describes a metamaterial device provided with a flat unit resonator having a chiral structure.
  • FIG. 34 is a plan view showing the configuration of a unit resonator 1D according to the sixth embodiment.
  • the substrate 20D is a multilayer substrate having at least one dielectric layer and a plurality of conductor layers.
  • the unit resonator 1D includes a plurality of partial resonators 1Da to 1Dc that are respectively formed on a plurality of different conductor layers of the substrate 20D and each include a resonant element 21D and a plurality of reflective elements 22.
  • Resonant elements 21D of the plurality of partial resonators 1Da to 1Dc have the same shape, and are formed so as to be offset from each other by a predetermined angle ⁇ around an axis passing through the center O of rotational symmetry of each resonant element 21D.
  • the partial resonators 1Da to 1Dc are configured the same as the unit resonator 1C of FIG. 31, and the resonant element 21D is configured the same as the resonant element 21C of FIG.
  • the chirality of the unit resonator 1D changes in accordance with the relative angle ⁇ of the partial resonators 1Da to 1Dc. Further, the state of the zero-order resonance of the unit resonator 1 D changes according to the total length of the reflecting element 22. Next, maximizing the polarization rotation angle of the metamaterial device provided with the unit resonator 1D by changing these parameters will be described.
  • the relative angle ⁇ of the partial resonators 1Da to 1Dc is changed to find the angle ⁇ that maximizes the polarization rotation angle.
  • This step corresponds to adjusting the spiral angle (or pitch) of the unit resonator in the case of the spirally wound unit resonator.
  • the angle ⁇ is fixed, and in the next step, the total length of the reflecting element 22 is changed to obtain the length that maximizes the polarization rotation angle.
  • the entire effective parameter of the unit resonator 1D has changed, so it becomes necessary to readjust the reflective element 22 so as to realize an optimum zero-order resonance. Because it is executed.
  • the total length of the reflective element 22 is determined to effectively have a length of one quarter of the operating wavelength of the metamaterial device, as described above.
  • the configuration parameters of the unit resonator 1D were as follows.
  • FIG. 35 is a graph showing a change in polarization rotation angle with respect to the relative angle ⁇ of the partial resonators 1Da to 1Dc of the metamaterial device including the unit resonator 1D according to the sixth embodiment.
  • FIG. 35 shows changes in the polarization rotation angle when the relative angle ⁇ of the partial resonators 1Da to 1Dc is changed from 8 degrees to 16 degrees. According to FIG. 35, it can be seen that the polarization rotation angle is maximized when the angle ⁇ is 11 degrees. The angle ⁇ was fixed, and then the total length of the reflective element 22 was adjusted.
  • FIG. 36 is a graph showing a change in polarization rotation angle with respect to the width wm of the reflective element 22 of the metamaterial device provided with the unit resonator 1D according to the sixth embodiment.
  • the optimum relative angle ⁇ of the partial resonators 1Da to 1Dc and the optimum total length of each reflecting element 22 can be determined so as to maximize the polarization rotation angle.
  • the unit resonator 1D also operates as a zero-order resonator as in the unit resonator 1 of FIG. Therefore, the metamaterial device provided with the unit resonator 1D can also interact more strongly with the electromagnetic wave than the conventional electromagnetic wave device provided with the half wavelength resonator or the single wavelength resonator as the unit resonator. Further, by forming the respective resonant elements 21D of the plurality of partial resonators 1Da to 1Dc mutually offset by a predetermined angle ⁇ , the metamaterial device provided with the unit resonator 1D can also operate as a chiral metamaterial .
  • FIG. 37 is a plan view showing a configuration of a unit resonator 1DA according to a first modified example of the sixth embodiment.
  • the unit resonator 1DA is formed on a plurality of different conductor layers of the substrate 20D, and includes partial resonators 1DAa to 1DAb each including a resonant element and a plurality of reflective elements.
  • the resonance elements of each of the partial resonators 1DAa-1DAb are formed linearly, that is, axisymmetrically. Therefore, each partial resonator 1DAa to 1DAb itself has no chirality.
  • the entire unit resonator 1DA is made chiral. Have.
  • FIG. 38 is a plan view showing a configuration of a unit resonator 1DB according to a second modified example of the sixth embodiment.
  • the unit resonators 1DB are respectively formed on a plurality of different conductor layers of the substrate 20D, and include partial resonators 1DBa to 1DBb each including a resonant element and a plurality of reflective elements.
  • the resonance elements of the partial resonators 1DBa to 1DBb are formed in a cross shape, that is, in line symmetry. Therefore, each of the partial resonators 1 DBa to 1 DBb itself has no chirality.
  • the whole unit resonator 1DB is made chiral.
  • FIG. 39 is a plan view showing a configuration of a unit resonator 1DC according to a third modified example of the sixth embodiment.
  • the unit resonator 1DC is respectively formed on a plurality of different conductor layers of the substrate 20D, and includes a plurality of partial resonators 1DCa to 1DCb each including a resonant element and a plurality of reflective elements.
  • Each partial resonator 1 DCa to 1 DCb is configured in the same manner as the unit resonator 1 C of FIG. Therefore, as in the unit resonator 1C of FIG. 31, the partial resonators 1DCa to 1DCb themselves have chirality.
  • the respective resonator elements of the partial resonators 1 DCa to 1 DCb are formed mutually offset by a predetermined angle around an axis passing through the rotational symmetry center O of each resonator element, whereby the entire unit resonator 1 DC is It has a chirality greater than that of the partial resonators 1 DCa to 1 DCb.
  • FIG. 40 is a plan view showing a configuration of a unit resonator 1DD according to a fourth modified embodiment of the sixth embodiment.
  • the unit resonator 1DD is respectively formed on a plurality of different conductor layers of the substrate 20D, and includes a plurality of partial resonators 1DDa to 1DDb each including a resonant element and a plurality of reflective elements.
  • Each of the partial resonators 1DDa to 1DDb includes four curved arms instead of the four arms bent as in the unit resonator 1D of FIG. Therefore, as in the unit resonator 1D of FIG. 31, the partial resonators 1DDa to 1DDb themselves have chirality.
  • the respective resonator elements of the partial resonators 1DDa to 1DDb are formed offset from each other by a predetermined angle around an axis passing through the rotational symmetry center O of each resonator element, so that the entire unit resonator 1DD is It has a chirality greater than that of the partial resonators 1DDa-1DDb.
  • FIG. 41 is a plan view showing the configuration of a unit resonator 1DE according to a fifth modification of the sixth embodiment.
  • the unit resonator 1DE is formed on a plurality of different conductor layers of the substrate 20D, and includes a plurality of partial resonators 1DEa to 1DEb each including a resonant element and a plurality of reflective elements.
  • Each of the partial resonators 1DEa to 1DEb has six curved arms instead of the four curved arms of the unit resonator 1DD shown in FIG. Therefore, like the unit resonator 1DD of FIG. 40, the partial resonators 1DEa to 1DEb themselves have chirality.
  • the respective resonator elements of the partial resonators 1DEa to 1DEb are formed so as to be offset from each other by a predetermined angle around an axis passing through the rotational symmetry center O of each resonator element, so that the whole unit resonator 1DE is It has larger chirality than that of the partial resonators 1DEa-1DEb.
  • the unit resonators 1DA to 1DE also operate as zeroth-order resonators, similarly to the unit resonator 1D of FIG. Therefore, the metamaterial device provided with any of the unit resonators 1DA to 1DE can also interact more strongly with the electromagnetic wave than the conventional electromagnetic wave device provided with the half wavelength resonator or the single wavelength resonator as the unit resonator. it can.
  • the metamaterial devices provided with any of the unit resonators 1DA to 1DE can also operate as chiral metamaterials by forming the respective resonant elements of the plurality of partial resonators to be offset from each other by a predetermined angle. .
  • the unit cell 10C has the same size as possible in the range of 45 to 55 mm and the operating frequency in the vicinity of about 2.2 to about 2.4 GHz. I chose to be.
  • the relative angle of the two partial resonators of each unit resonator 1DA to 1DE was 10 degrees.
  • the capacitance of the capacitor 24 was adjusted to match the frequency of the zeroth resonance, and the total length of the reflective element 22 was adjusted to achieve the optimum zeroth resonance state.
  • FIG. 42 is a graph showing frequency characteristics of polarization rotation angle for five metamaterial devices provided with the unit resonators 1DA to 1DE of FIGS. 37 to 41, respectively.
  • the polarization rotation angles of the metamaterial devices provided with the unit resonator 1DA of FIG. 37 and the unit resonator 1DB of FIG. 38 are compared.
  • the resonant elements of the partial resonators of the unit resonators 1DA and 1DB are formed in line symmetry, they themselves have no chirality.
  • the respective resonator elements of the partial resonators are formed offset from each other by a predetermined angle around an axis passing through the rotational symmetry center O of each resonator element, whereby the entire unit resonators 1DA and 1DB have chirality.
  • each of the partial resonators 1DAa to 1DAb of the unit resonator 1DA is provided with linear (that is, having two arms connected to the center O) resonant elements
  • Each partial resonator 1DBa to 1DBb of the unit resonator 1DB is provided with a cruciform (that is, having four arms) resonant elements.
  • the metamaterial device provided with unit resonator 1DA achieves a polarization rotation angle of 4.25 degrees at an operating frequency of 2.48 GHz.
  • the metamaterial device including the unit resonator 1DB achieves a polarization rotation angle of 10.3 degrees at an operating frequency of 2.2 GHz. From this result, it is understood that the polarization rotation angle is increased by increasing the number of arms of the resonant element.
  • the polarization rotation angles of the metamaterial devices provided with the unit resonator 1DB of FIG. 38 and the unit resonator 1DC of FIG. 39 are compared.
  • the resonant elements of the partial resonators of the unit resonator 1DB are formed in line symmetry, they themselves have no chirality.
  • the resonant elements of the partial resonators of the unit resonator 1DB are formed asymmetrically with respect to any straight line in the plane of the substrate 20D, they have chirality by themselves.
  • the metamaterial device provided with the unit resonator 1DB achieves a polarization rotation angle of 10.3 degrees at an operating frequency of 2.2 GHz.
  • the metamaterial device provided with unit resonator 1DC achieves a polarization rotation angle of 17.2 degrees at an operating frequency of 2.34 GHz.
  • the metamaterial device including the unit resonator 1DC in addition to the chirality due to the relative angle of the partial resonators 1DCa to 1DCb, the chirality of the resonant elements themselves of the partial resonators 1DCa to 1DCb is present, thereby the unit resonator 1DB
  • the polarization rotation angle is increased compared to the metamaterial device provided with
  • the polarization rotation angles of the metamaterial devices provided with the unit resonator 1DC of FIG. 39 and the unit resonator 1DD of FIG. 40 are compared.
  • the metamaterial device provided with unit resonator 1DC achieves a polarization rotation angle of 17.2 degrees at an operating frequency of 2.34 GHz.
  • the metamaterial device provided with the unit resonator 1DD achieves a polarization rotation angle of 20.7 degrees at an operating frequency of 2.24 GHz.
  • the resonant element of each of the partial resonators 1DDa to 1DDb includes the curved arm, so that the resonant element itself is more than the metamaterial device including the unit resonator 1DC. This is considered to be because the chirality is increased and the effect of polarization rotation is increased.
  • the polarization rotation angles of the metamaterial devices provided with the unit resonator 1DD of FIG. 40 and the unit resonator 1DE of FIG. 41 are compared.
  • the metamaterial device provided with the unit resonator 1DD achieves a polarization rotation angle of 20.7 degrees at an operating frequency of 2.24 GHz.
  • the metamaterial device comprising the unit resonator 1DE achieves a polarization rotation angle of 22.8 degrees at an operating frequency of 2.16 GHz.
  • the polarization rotation angle is increased by increasing the number of arms of the resonant element. Is seen to increase.
  • the effect of the increase in the polarization rotation angle with the increase in the number of arms is small because the electromagnetic field is not concentrated in all the arms, and the number of arms The effect of increasing the chirality is diminishing even if That is, the increase in the polarization rotation angle with the increase in the number of arms is limited. Thus, depending on the desired polarization rotation angle, the appropriate number of arms can be determined.
  • the structure of the zeroth-resonant unit resonator 1 described in the first embodiment is also applicable to a linear antenna. This allows the radiation gain and directivity of the linear antenna to be improved over the prior art.
  • FIG. 43 is a perspective view showing a configuration of an antenna apparatus 40 according to a first example of the seventh embodiment.
  • the antenna device 40 of FIG. 43 includes one unit resonator including the resonant element 21 and the reflective element 22 on the ground conductor 42.
  • the resonant element 21 has a strip shape, has a path that does not include a parallel circuit portion between which the current flows simultaneously in the opposite direction, and has a substantially zero effective permeability.
  • the resonant element 21 comprises a plurality of series LC resonant circuits connected in series with one another, each comprising a strip conductor 23 and a capacitor 24.
  • the resonant element 21 is formed linearly.
  • the reflective element 22 is connected to one end of the resonant element 21 and is configured such that the impedance when the reflective element 22 is viewed from the resonant element 21 is substantially zero.
  • a feeding point is provided at the other end of the resonant element 21, and the feeding point is connected to the radio signal source 41 via a coaxial cable.
  • the antenna device 40 operates as a zero-order resonator as in the unit resonator 1 according to the first embodiment, and can thereby transmit and receive electromagnetic waves with high efficiency.
  • the configuration parameters of the antenna device 40 were as follows.
  • FIG. 45 is a graph showing the H-plane gain of the antenna device 40 of FIG.
  • FIG. 46 is a graph showing the E-plane gain of the antenna device 40 of FIG.
  • the average radiation gain (FIG. 45) in the horizontal plane was 5.79 dBi and the half beam width (FIG. 46) was 68 degrees.
  • FIG. 44 is a perspective view showing a configuration of an antenna apparatus according to a first comparative example of the seventh embodiment.
  • the antenna device of FIG. 44 includes an antenna element 240 formed of a quarter-wave linear conductor provided on the ground conductor 42.
  • a feed point is provided at one end of the antenna element 240, and the feed point is connected to the radio signal source 41 via a coaxial cable.
  • FIG. 47 is a graph showing the H-plane gain of the antenna device of FIG.
  • FIG. 48 is a graph showing an E-plane gain of the antenna device of FIG.
  • the average radiation gain in the horizontal plane was 5.16 dBi, and the half beam width was 76 degrees.
  • the band below VSWR 2 was 0.11 GHz (ratio band 11.4%).
  • the antenna device 40 of FIG. 43 has a large effective size of the antenna device 40 due to the uniform current distribution of the antenna device 40 resonating at zero order, and as a result, the antenna of FIG. It can be seen that the radiation gain and directivity have improved compared to the device.
  • FIG. 49 is a perspective view showing a configuration of an antenna apparatus 40A according to a second example of the seventh embodiment.
  • the antenna device 40A of FIG. 49 includes one unit resonator including the resonant element 21 and the reflective element 22 on the ground conductor 42.
  • the resonant element 21 has a strip shape, has a path that does not include a parallel circuit portion between which the current flows simultaneously in the opposite direction, and has a substantially zero effective permeability.
  • the resonant element 21 comprises a plurality of series LC resonant circuits connected in series with one another, each comprising a strip conductor 23 and a capacitor 24.
  • the resonant element 21 is spirally wound.
  • the reflective element 22 is connected to one end of the resonant element 21 and is configured such that the impedance when the reflective element 22 is viewed from the resonant element 21 is substantially zero.
  • a feeding point is provided at the other end of the resonant element 21, and the feeding point is connected to the wireless signal source 41.
  • the antenna device 40A operates as a zero-order resonator as in the unit resonator 1 according to the first embodiment, and can thereby transmit and receive electromagnetic waves with high efficiency.
  • configuration parameters of the antenna device 40A were as follows.
  • FIG. 51 is a graph showing the H-plane gain of the antenna device 40A of FIG.
  • FIG. 52 is a graph showing the E-plane gain of the antenna device 40A of FIG.
  • the average radiation gain (FIG. 51) in the horizontal plane was 4.53 dBi, and the half beam width (FIG. 52) was 86 degrees.
  • FIG. 50 is a perspective view showing a configuration of an antenna apparatus according to a second comparative example of the seventh embodiment.
  • the antenna device of FIG. 50 includes an antenna element 240A made of a strip conductor spirally wound on the ground conductor 42.
  • a feed point is provided at one end of the antenna element 240A, and the feed point is connected to the radio signal source 41 via a coaxial cable.
  • antenna device 240A 2.56 GHz
  • Antenna element 240A width 0.2 mm
  • Thickness of antenna element 240A 1.8 ⁇ m
  • Height of the reflective elements: d31 0.323 ⁇ 0 ( ⁇ 0 : operating wavelength)
  • Screw diameter: d32 1.8 mm
  • Spiral pitch: d33 3 mm
  • Number of turns of screw: N 3
  • FIG. 53 is a graph showing the H-plane gain of the antenna device of FIG. 50.
  • FIG. 54 is a graph showing an E-plane gain of the antenna device of FIG.
  • the average radiation gain in the horizontal plane was 4.34 dBi, and the half beam width was 86 degrees.
  • the antenna device 40A of FIG. 49 also increases the effective size of the antenna device 40A due to the uniform current distribution of the antenna device 40A that resonates at zero order, and as a result, FIG. It can be seen that the radiation gain is improved compared to the antenna device.
  • the distribution of the amplitude and phase of the current flowing in the antenna element is uniform over the entire length of the antenna element.
  • Can be This can increase the radiation gain of the antenna.
  • Increasing the size of the antenna also increases the radiation gain.
  • the size of the antenna can be freely changed.
  • a metamaterial device is applicable to, for example, an antenna device for a satellite and a car.
  • 1, 1A to 1D, 1DA to 1DE unit resonators, 1Da to 1Dc, 1DAa to 1DEb ... partial resonator, 2 ... cylindrical member, 3 ...
  • Base member, 10A, 10B, 10C ... unit cell, 20 ... flexible substrate, 20C, 20D ... board, 21, 21 B, 21 C: resonant elements, 22, 22A ... reflective element, 23, 23 B: Strip conductor, 24, 24 B ... capacitor, 25 ... central conductor, 26 ... arm, 31 ... Transmitting antenna, 32 ... Receiving antenna, 40, 40A: antenna device, 41 ... wireless signal source, 42 ... grounding conductor, 100 ... metamaterial device.

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Abstract

This meta-material device is provided with at least one unit resonator (1). The unit resonator (1) is provided with a resonance element (21), and a pair of reflection elements (22). The resonance element (21) has a strip shape having first and second end parts, has a path that does not include a parallel circuit section in which current flows simultaneously in reverse directions between the first and second end parts, and has substantially zero effective magnetic permeability. Each of the pair of reflection elements (22) is connected respectively to the first and second end parts of the resonance element, and the impedance when each reflection element (22) is viewed from the resonance element (21) becomes substantially zero. The unit resonator (1) operates as a zero-order resonator.

Description

メタマテリアル装置及びアンテナ装置Metamaterial device and antenna device
　本発明は、メタマテリアルとして構成された少なくとも１つの単位共振器を備えるメタマテリアル装置及びアンテナ装置に関する。 The present invention relates to a metamaterial device and an antenna device comprising at least one unitary resonator configured as a metamaterial.
　メタマテリアルとは、電磁波の波長に比べて十分小さな単位構成要素（単位共振器）からなる電磁人工媒質もしくは構造体のことを表す。単位構成要素の形状及び配置を適切に決定することにより、実効誘電率、実効透磁率、及び屈折率など、メタマテリアルの巨視的なパラメータを操作することができる。従来、メタマテリアルの様々な応用例が提案されている。 A metamaterial refers to an electromagnetic artificial medium or structure composed of unit components (unit resonators) sufficiently smaller than the wavelength of an electromagnetic wave. By appropriately determining the shape and arrangement of unit components, it is possible to manipulate macroscopic parameters of the metamaterial, such as the effective permittivity, the effective permeability, and the refractive index. Heretofore, various applications of metamaterials have been proposed.
　例えば、特許文献１は、３次元的に周期的に配置された複数の単位セルを含む３次元メタマテリアルを開示している。特許文献１の３次元メタマテリアルにおいて、各単位セルは、単位セルの中央に配置された誘電体共振器と、誘電体共振器を包囲するように配置された複数の棒状導体と、誘電体共振器及び棒状導体を支持するホスト媒質とを備える。 For example, Patent Document 1 discloses a three-dimensional metamaterial including a plurality of unit cells periodically arranged in three dimensions. In the three-dimensional metamaterial of Patent Document 1, each unit cell includes a dielectric resonator disposed at the center of the unit cell, a plurality of rod-shaped conductors disposed to surround the dielectric resonator, and dielectric resonance. And a host medium for supporting the rod-like conductor.
　特許文献２では、「カイラル（スパイラル）構造」のメタヘリカルアンテナの構成例、つまり誘電体基板に形成されたメタヘリカルアームにより、電力効率に優れたメタヘリカルアンテナが構成できることが開示されている。 Patent Document 2 discloses that a meta-helical antenna having excellent power efficiency can be configured by using a configuration example of a meta-helical antenna having a "chiral (spiral) structure", that is, a meta-helical arm formed on a dielectric substrate.
国際公開第２０１３／１３３１７５号International Publication No. 2013/133175 特開２０１６－０５４４５４号公報JP, 2016-054454, A
　一般に、メタマテリアルの実効誘電率、実効透磁率、及び屈折率などのパラメータを効率的に操作するためには、動作周波数において単位共振器を共振させ、単位共振器を電磁波と強く相互作用させることが求められる。従来技術では、動作周波数において単位共振器を共振させるために、単位構成要素の寸法を動作波長又はその半分の長さに合わせる場合が多い。しかしながら、単位共振器を電磁波とより強く相互作用させるために、このような寸法上及び構造上の制約を受けることがない新規なメタマテリアル装置が求められる。 Generally, in order to operate parameters such as the effective permittivity, effective permeability, and refractive index of metamaterials efficiently, resonate the unit resonator at the operating frequency and make the unit resonator interact strongly with the electromagnetic wave. Is required. In the prior art, in order to resonate the unit resonator at the operating frequency, the dimensions of the unit component are often adjusted to the operating wavelength or half of the length. However, in order to make the unit resonator interact more strongly with the electromagnetic wave, a novel metamaterial device that does not suffer from such dimensional and structural constraints is required.
　本発明の目的は、従来よりも電磁波と強く相互作用する少なくとも１つの単位共振器を備えるメタマテリアル装置及びアンテナ装置を提供することにある。 An object of the present invention is to provide a metamaterial device and an antenna device provided with at least one unit resonator that interacts more strongly with electromagnetic waves than before.
　本発明の第１の態様に係るメタマテリアル装置によれば、
　少なくとも１つの単位共振器を備えるメタマテリアル装置であって、
　前記単位共振器は、
　少なくとも１つのストリップ形状の部分素子を含む共振素子であって、電流が同時に逆向きに流れる並列回路部分を含まない経路を有し、かつ、実質的にゼロの実効透磁率を有する共振素子と、
　前記共振素子の前記部分素子の各端部にそれぞれ接続された複数の反射素子であって、前記部分素子から前記各反射素子を見たときのインピーダンスが実質的にゼロになる複数の反射素子とを備え、
　前記単位共振器は０次共振器として動作する。 According to the metamaterial device of the first aspect of the present invention,
A metamaterial device comprising at least one unitary resonator, wherein
The unit resonator is
A resonant element comprising at least one strip-shaped subelement, having a path without parallel circuit parts through which current flows simultaneously in the reverse direction, and having substantially zero effective permeability;
A plurality of reflective elements respectively connected to respective end portions of the partial elements of the resonant element, wherein the impedance when viewed from the partial elements is substantially zero; Equipped with
The unit resonator operates as a zero-order resonator.
　本発明の第２の態様に係るメタマテリアル装置によれば、第１の態様に係るメタマテリアル装置において、
　前記共振素子は、互いに直列接続された複数の直列ＬＣ共振回路を含み、
　前記各直列ＬＣ共振回路の共振周波数は、前記メタマテリアル装置の動作周波数に一致するように設定される。 According to the metamaterial device of the second aspect of the present invention, in the metamaterial device of the first aspect,
The resonant element includes a plurality of series LC resonant circuits connected in series with one another,
The resonant frequency of each series LC resonant circuit is set to match the operating frequency of the metamaterial device.
　本発明の第３の態様に係るメタマテリアル装置によれば、第２の態様に係るメタマテリアル装置において、
　前記各直列ＬＣ共振回路は、ストリップ導体と、互いに隣接する直列ＬＣ共振回路のストリップ導体の間に設けられたキャパシタとを備える。 According to the metamaterial device of the third aspect of the present invention, in the metamaterial device of the second aspect,
Each of the series LC resonant circuits includes a strip conductor and a capacitor provided between the strip conductors of series LC resonant circuits adjacent to each other.
　本発明の第４の態様に係るメタマテリアル装置によれば、第２の態様に係るメタマテリアル装置において、
　前記各直列ＬＣ共振回路はストリップ導体を備え、
　前記各直列ＬＣ共振回路のストリップ導体の端部は、隣接する直列ＬＣ共振回路のストリップ導体の端部と容量結合するように形成される。 According to the metamaterial device of the fourth aspect of the present invention, in the metamaterial device of the second aspect,
Each series LC resonant circuit comprises a strip conductor,
The end of the strip conductor of each series LC resonant circuit is formed to capacitively couple with the end of the strip conductor of the adjacent series LC resonant circuit.
　本発明の第５の態様に係るメタマテリアル装置によれば、第１～第４のうちの１つの態様に係るメタマテリアル装置において、
　前記反射素子は、前記メタマテリアル装置の動作波長の４分の１の長さを有し、ミアンダ形状又は渦巻き形状を有する。 According to the metamaterial device of the fifth aspect of the present invention, in the metamaterial device of the first to fourth aspects,
The reflective element has a quarter length of the operating wavelength of the metamaterial device and has a meander shape or a spiral shape.
　本発明の第６の態様に係るメタマテリアル装置によれば、第１～第５のうちの１つの態様に係るメタマテリアル装置において、
　前記単位共振器は、カイラリティを有するように形成される。 According to the metamaterial device of the sixth aspect of the present invention, in the metamaterial device of the first to fifth aspects,
The unit resonator is formed to have chirality.
　本発明の第７の態様に係るメタマテリアル装置によれば、第６の態様に係るメタマテリアル装置において、
　前記共振素子は、第１及び第２の端部を有するストリップ形状を有し、
　前記単位共振器は螺線状に巻回される。 According to the metamaterial device of the seventh aspect of the present invention, in the metamaterial device of the sixth aspect,
The resonant element has a strip shape having first and second ends,
The unit resonator is spirally wound.
　本発明の第８の態様に係るメタマテリアル装置によれば、第６の態様に係るメタマテリアル装置において、
　前記単位共振器は、平坦な基板上に形成され、
　前記共振素子は、前記基板の面内の任意の直線に対して非対称に形成される。 According to the metamaterial device of the eighth aspect of the present invention, in the metamaterial device of the sixth aspect,
The unit resonators are formed on a flat substrate,
The resonant element is formed asymmetrically with respect to any straight line in the plane of the substrate.
　本発明の第９の態様に係るメタマテリアル装置によれば、第８の態様に係るメタマテリアル装置において、
　前記共振素子は、前記基板の面内において屈曲又は湾曲したストリップ形状をそれぞれ有する複数の部分素子を含み、
　前記各部分素子の一端は、前記複数の反射素子のうちの１つに接続され、前記各部分素子の他端は、他の前記部分素子に接続され、
　前記共振素子は実質的に回転対称に形成される。 According to the metamaterial device of the ninth aspect of the present invention, in the metamaterial device of the eighth aspect,
The resonant element includes a plurality of subelements each having a bent or curved strip shape in the plane of the substrate,
One end of each of the partial elements is connected to one of the plurality of reflective elements, and the other end of each of the partial elements is connected to the other partial element,
The resonant elements are formed substantially rotationally symmetric.
　前記単位共振器は、平坦な基板上に形成され、
　本発明の第１０の態様に係るメタマテリアル装置によれば、第６～第９のうちの１つの態様に係るメタマテリアル装置において、
　前記単位共振器は、前記基板の互いに異なる複数の導体層にそれぞれ形成され、前記共振素子及び前記複数の反射素子をそれぞれ備える複数の部分共振器を含み、
　前記複数の部分共振器の前記各共振素子は、互いに同じ形状を有し、前記各共振素子の回転対称の中心を通る軸の周りに互いに所定角度だけずれて形成される。 The unit resonators are formed on a flat substrate,
According to the metamaterial device of the tenth aspect of the present invention, in the metamaterial device of the sixth to ninth aspects,
The unit resonator includes a plurality of partial resonators respectively formed on a plurality of different conductor layers of the substrate and including the resonant element and the plurality of reflective elements.
The respective resonant elements of the plurality of partial resonators have the same shape, and are formed offset by a predetermined angle around an axis passing through the centers of rotational symmetry of the respective resonant elements.
　本発明の第１１の態様に係るメタマテリアル装置によれば、第１～第１０のうちの１つの態様に係るメタマテリアル装置において、
　前記メタマテリアル装置は、２次元アレイに配列された複数の単位共振器を含む。 According to the metamaterial device of the eleventh aspect of the present invention, in the metamaterial device of one of the first to tenth aspects,
The metamaterial device includes a plurality of unit resonators arranged in a two-dimensional array.
　本発明の第１２の態様に係るメタマテリアル装置によれば、第１１の態様に係るメタマテリアル装置において、
　前記メタマテリアル装置は、入射する電磁波の偏波面を回転させる。 According to the metamaterial device of the twelfth aspect of the present invention, in the metamaterial device of the eleventh aspect,
The metamaterial device rotates the polarization plane of the incident electromagnetic wave.
　本発明の第１３の態様に係るメタマテリアル装置によれば、第１１の態様に係るメタマテリアル装置において、
　前記メタマテリアル装置は、入射する電磁波のエネルギーの一部を透過させ、前記入射する電磁波のエネルギーの残りの一部を反射する。 According to the metamaterial device of the thirteenth aspect of the present invention, in the metamaterial device of the eleventh aspect,
The metamaterial device transmits a portion of the energy of the incident electromagnetic wave and reflects a portion of the energy of the incident electromagnetic wave.
　本発明の第１４の態様に係るアンテナ装置によれば、
　１つの単位共振器を備えるアンテナ装置であって、
　前記単位共振器は、
　第１及び第２の端部を有するストリップ形状を有する共振素子であって、前記第１及び第２の端部の間で電流が同時に逆向きに流れる並列回路部分を含まない経路を有し、かつ、実質的にゼロの実効透磁率を有する共振素子と、
　前記共振素子の第１の端部に接続された反射素子であって、前記共振素子から前記反射素子を見たときのインピーダンスが実質的にゼロになる反射素子とを備え、
　前記共振素子の第２の端部に給電点が設けられ、
　前記単位共振器は０次共振器として動作する。 According to the antenna device of the fourteenth aspect of the present invention,
An antenna apparatus comprising one unit resonator, the antenna apparatus comprising:
The unit resonator is
A resonant element having a strip shape having first and second ends, the path not including a parallel circuit portion in which current flows simultaneously in the opposite direction between the first and second ends, And a resonant element having an effective permeability of substantially zero.
A reflective element connected to the first end of the resonant element, the reflective element having a substantially zero impedance when viewed from the resonant element;
A feed point is provided at the second end of the resonant element,
The unit resonator operates as a zero-order resonator.
　本発明の一態様によれば、従来よりも電磁波と強く相互作用する少なくとも１つの単位共振器を備えるメタマテリアル装置及びアンテナ装置を提供することができる。 According to one aspect of the present invention, it is possible to provide a metamaterial device and an antenna device provided with at least one unit resonator that interacts more strongly with electromagnetic waves than in the past.
第１の実施形態に係る単位共振器１を含む第１の単位セル１０Ａを示す斜視図である。It is a perspective view showing the 1st unit cell 10A containing unit resonator 1 concerning a 1st embodiment. 図１の単位共振器１の展開図である。It is an expanded view of the unit resonator 1 of FIG. 半波長共振する伝送線路の電磁界強度を示す概略図である。It is the schematic which shows the electromagnetic field intensity of the transmission line which carries out a half wavelength resonance. ０次共振する伝送線路の電磁界強度を示す概略図である。It is the schematic which shows the electromagnetic field intensity of the transmission line which carries out zero order resonance. 第１の実施形態に係る単位共振器１を含む第２の単位セル１０Ｂを示す斜視図である。It is a perspective view showing the 2nd unit cell 10B containing unit resonator 1 concerning a 1st embodiment. 第１の実施形態の第１の比較例に係る単位共振器２０１における磁界の強さ（電流分布）を示す図である。It is a figure which shows the strength (electric current distribution) in the unit resonator 201 which concerns on the 1st comparative example of 1st Embodiment. 第１の実施形態に係る単位共振器１における磁界の強さ（電流分布）を示す図である。It is a figure which shows the intensity (current distribution) of the magnetic field in unit resonator 1 concerning a 1st embodiment. 第１の実施形態の第２の比較例に係る単位共振器２０１Ａを含む単位セル１０Ａを示す斜視図である。It is a perspective view showing unit cell 10A containing unit resonator 201A concerning the 2nd comparative example of a 1st embodiment. 第１の実施形態の第３の比較例に係る単位共振器２０１Ｂを含む単位セル１０Ａを示す斜視図である。It is a perspective view showing unit cell 10A containing unit resonator 201B concerning the 3rd comparative example of a 1st embodiment. 第１の実施形態の第１の比較例に係る単位共振器２０１を備える電磁波装置の螺線半径に対する偏波回転角の変化を示すグラフである。It is a graph which shows the change of the polarization | polarized-light rotation angle with respect to the spiral radius of the electromagnetic wave apparatus provided with the unit resonator 201 which concerns on the 1st comparative example of 1st Embodiment. 第１の実施形態に係る単位共振器１を備えるメタマテリアル装置の螺線半径に対する偏波回転角の変化を示すグラフである。It is a graph which shows the change of the polarization | polarized-light rotation angle with respect to the spiral radius of a metamaterial apparatus provided with the unit resonator 1 which concerns on 1st Embodiment. 第１の実施形態の第１の比較例に係る単位共振器２０１を備える電磁波装置の螺線角に対する偏波回転角の変化を示すグラフである。It is a graph which shows the change of the polarization | polarized-light rotation angle with respect to the spiral angle of an electromagnetic wave apparatus provided with the unit resonator 201 which concerns on the 1st comparative example of 1st Embodiment. 第１の実施形態に係る単位共振器１を備えるメタマテリアル装置の螺線角に対する偏波回転角の変化を示すグラフである。It is a graph which shows the change of the polarization | polarized-light rotation angle with respect to the spiral angle of the metamaterial apparatus provided with the unit resonator 1 which concerns on 1st Embodiment. 第１の実施形態に係る単位共振器１を備えるメタマテリアル装置と、第１の実施形態の第１の比較例に係る単位共振器２０１を備える電磁波装置とについて、偏波回転角の周波数特性を示すグラフである。The frequency characteristics of the polarization rotation angle of the metamaterial device including the unit resonator 1 according to the first embodiment and the electromagnetic wave device including the unit resonator 201 according to the first comparative example of the first embodiment FIG. 第１の実施形態に係る単位共振器１を備えるメタマテリアル装置と、第１の実施形態の第１の比較例に係る単位共振器２０１を備える電磁波装置とについて、偏波回転角の周波数特性を示すグラフである。The frequency characteristics of the polarization rotation angle of the metamaterial device including the unit resonator 1 according to the first embodiment and the electromagnetic wave device including the unit resonator 201 according to the first comparative example of the first embodiment FIG. 第１の実施形態に係る単位共振器１を備えるメタマテリアル装置の測定システムを示す概略図である。It is a schematic diagram showing a measurement system of a metamaterial device provided with unit resonator 1 concerning a 1st embodiment. 第１の実施形態の第１の実施例に係る単位共振器１を備えるメタマテリアル装置を示す図である。It is a figure showing a metamaterial device provided with unit resonator 1 concerning the 1st example of a 1st embodiment. 第１の実施形態の第２の実施例に係る単位共振器１を備えるメタマテリアル装置を示す図である。It is a figure showing a metamaterial device provided with unit resonator 1 concerning the 2nd example of a 1st embodiment. 第１の実施形態の第４の比較例に係る単位共振器２０１を備える電磁波装置を示す図である。It is a figure which shows the electromagnetic wave apparatus provided with the unit resonator 201 which concerns on the 4th comparative example of 1st Embodiment. 第１の実施形態の第５の比較例に係る単位共振器２０１を備える電磁波装置を示す図である。It is a figure which shows the electromagnetic wave apparatus provided with the unit resonator 201 which concerns on the 5th comparative example of 1st Embodiment. 第１の実施形態の第１の実施例に係る単位共振器１を備えるメタマテリアル装置と、第１の実施形態の第４の比較例に係る単位共振器２０１を備える電磁波装置とについて、偏波回転角の周波数特性を示すグラフである。Polarization of a metamaterial device including the unit resonator 1 according to the first example of the first embodiment and an electromagnetic wave device including the unit resonator 201 according to the fourth comparative example of the first embodiment It is a graph which shows the frequency characteristic of a rotation angle. 第１の実施形態の第２の実施例に係る単位共振器１を備えるメタマテリアル装置と、第１の実施形態の第５の比較例に係る単位共振器２０１を備える電磁波装置とについて、偏波回転角の周波数特性を示すグラフである。Polarization of a metamaterial device including the unit resonator 1 according to the second example of the first embodiment and an electromagnetic wave device including the unit resonator 201 according to the fifth comparative example of the first embodiment It is a graph which shows the frequency characteristic of a rotation angle. 第１の実施形態の第１の変形例に係る単位共振器１Ａを示す斜視図である。It is a perspective view showing unit resonator 1A concerning the 1st modification of a 1st embodiment. 第１の実施形態の第２の変形例に係る単位共振器１Ｂを示す斜視図である。It is a perspective view showing unit resonator 1B concerning the 2nd modification of a 1st embodiment. 第２の実施形態に係る偏波選択板の動作を示す概略図である。It is the schematic which shows operation | movement of the polarized-wave selection plate concerning 2nd Embodiment. 第２の実施形態の実施例に係る単位共振器を備えるメタマテリアル装置の、異なる偏波面を有する電磁波の透過係数を示すグラフである。It is a graph which shows the transmission coefficient of electromagnetic waves which have a different polarization plane of the metamaterial device provided with the unit resonator concerning the example of a 2nd embodiment. 第２の実施形態の比較例に係る単位共振器を備えるメタマテリアル装置の、異なる偏波面を有する電磁波の透過係数を示すグラフである。It is a graph which shows the transmission coefficient of electromagnetic waves which have a different polarization plane of the metamaterial device provided with the unit resonator concerning the comparative example of a 2nd embodiment. 第３の実施形態に係る偏波回転板の動作を示す概略図である。It is the schematic which shows operation | movement of the polarization | polarized-light rotating plate which concerns on 3rd Embodiment. 第４の実施形態に係る周波数選択板の動作を示す概略図である。It is the schematic which shows operation | movement of the frequency selection board which concerns on 4th Embodiment. 第５の実施形態に係る単位共振器１Ｃを含む第３の単位セル１０Ｃを示す斜視図である。It is a perspective view showing the 3rd unit cell 10C containing unit resonator 1C concerning a 5th embodiment. 図３０の単位共振器１Ｃの構成を示す平面図である。It is a top view which shows the structure of 1 C of unit resonators of FIG. 第５の実施形態の比較例に係る単位共振器２０１Ｃを含む第３の単位セル１０Ｃを示す斜視図である。It is a perspective view showing the 3rd unit cell 10C containing unit resonator 201C concerning a comparative example of a 5th embodiment. 第５の実施形態に係る単位共振器１Ｃを備えるメタマテリアル装置と、第５の実施形態の比較例に係る単位共振器２０１Ｃを備える電磁波装置とについて、偏波回転角の周波数特性を示すグラフである。The graph showing the frequency characteristics of the polarization rotation angle for the metamaterial device including the unit resonator 1C according to the fifth embodiment and the electromagnetic wave device including the unit resonator 201C according to the comparative example of the fifth embodiment is there. 第６の実施形態に係る単位共振器１Ｄの構成を示す平面図である。It is a top view which shows the structure of unit resonator 1D which concerns on 6th Embodiment. 第６の実施形態に係る単位共振器１Ｄを備えるメタマテリアル装置の部分共振器１Ｄａ～１Ｄｃの相対角度φに対する偏波回転角の変化を示すグラフである。It is a graph which shows change of a polarization rotation angle to relative angle phi of partial resonators 1Da-1Dc of a metamaterial device provided with unit resonator 1D concerning a 6th embodiment. 第６の実施形態に係る単位共振器１Ｄを備えるメタマテリアル装置の反射素子２２の幅に対する偏波回転角の変化を示すグラフである。It is a graph which shows the change of the polarization | polarized-light rotation angle with respect to the width | variety of the reflective element 22 of a metamaterial apparatus provided with unit resonator 1D which concerns on 6th Embodiment. 第６の実施形態の第１の変形例に係る単位共振器１ＤＡの構成を示す平面図である。It is a top view which shows the structure of unit resonator 1DA which concerns on the 1st modification of 6th Embodiment. 第６の実施形態の第２の変形例に係る単位共振器１ＤＢの構成を示す平面図である。It is a top view which shows the structure of unit resonator 1DB which concerns on the 2nd modification of 6th Embodiment. 第６の実施形態の第３の変形例に係る単位共振器１ＤＣの構成を示す平面図である。It is a top view which shows the structure of unit resonator 1DC which concerns on the 3rd modification of 6th Embodiment. 第６の実施形態の第４の変形例に係る単位共振器１ＤＤの構成を示す平面図である。It is a top view which shows the structure of unit resonator 1DD which concerns on the 4th modification of 6th Embodiment. 第６の実施形態の第５の変形例に係る単位共振器１ＤＥの構成を示す平面図である。It is a top view which shows the structure of unit resonator 1DE which concerns on the 5th modification of 6th Embodiment. 図３７～図４１の単位共振器１ＤＡ～１ＤＥをそれぞれ備える５つのメタマテリアル装置について、偏波回転角の周波数特性を示すグラフである。It is a graph which shows the frequency characteristic of a polarization | polarized-light rotation angle about five metamaterial apparatuses respectively equipped with unit resonator 1DA-1DE of FIGS. 37-41. 第７の実施形態の第１の実施例に係るアンテナ装置４０の構成を示す斜視図である。It is a perspective view which shows the structure of the antenna apparatus 40 which concerns on the 1st Example of 7th Embodiment. 第７の実施形態の第１の比較例に係るアンテナ装置の構成を示す斜視図である。It is a perspective view which shows the structure of the antenna apparatus which concerns on the 1st comparative example of 7th Embodiment. 図４３のアンテナ装置４０のＨ面利得を示すグラフである。It is a graph which shows H plane gain of the antenna apparatus 40 of FIG. 図４３のアンテナ装置４０のＥ面利得を示すグラフである。It is a graph which shows E surface gain of the antenna apparatus 40 of FIG. 図４４のアンテナ装置のＨ面利得を示すグラフである。It is a graph which shows H plane gain of the antenna apparatus of FIG. 図４４のアンテナ装置のＥ面利得を示すグラフである。It is a graph which shows E surface gain of the antenna apparatus of FIG. 第７の実施形態の第２の実施例に係るアンテナ装置４０Ａの構成を示す斜視図である。It is a perspective view showing the composition of antenna system 40A concerning the 2nd example of a 7th embodiment. 第７の実施形態の第２の比較例に係るアンテナ装置の構成を示す斜視図である。It is a perspective view which shows the structure of the antenna apparatus which concerns on the 2nd comparative example of 7th Embodiment. 図４９のアンテナ装置４０ＡのＨ面利得を示すグラフである。It is a graph which shows H plane gain of antenna apparatus 40A of FIG. 図４９のアンテナ装置４０ＡのＥ面利得を示すグラフである。It is a graph which shows E surface gain of antenna apparatus 40A of FIG. 図５０のアンテナ装置のＨ面利得を示すグラフである。It is a graph which shows H plane gain of the antenna apparatus of FIG. 図５０のアンテナ装置のＥ面利得を示すグラフである。It is a graph which shows E surface gain of the antenna apparatus of FIG.
第１の実施形態．
　図１は、第１の実施形態に係る単位共振器１を含む第１の単位セル１０Ａを示す斜視図であり、図２は、図１の単位共振器１の展開図である。単位セル１０Ａは、Ｘ方向、Ｙ方向、及びＺ方向に沿って、長さｄ１、ｄ２、及びｄ３をそれぞれ有する。単位セル１０Ａは、例えば、図２に示すように、ストリップ導体２３及びキャパシタ２４を含む共振素子２１と、ミアンダライン構造の反射素子２２とを備える複数の単位セル１０Ａを、Ｘ方向及びＹ方向に沿って２次元アレイとして配列することにより、メタマテリアル装置を構成する。本開示では、－Ｚ方向の平面波の電磁波が各単位セルに入射するものとする。 First Embodiment
FIG. 1 is a perspective view showing a first unit cell 10A including the unit resonator 1 according to the first embodiment, and FIG. 2 is a developed view of the unit resonator 1 of FIG. The unit cell 10A has lengths d1, d2 and d3 along the X, Y and Z directions, respectively. For example, as shown in FIG. 2, the unit cell 10A includes, in the X and Y directions, a plurality of unit cells 10A each including a resonant element 21 including a strip conductor 23 and a capacitor 24 and a reflective element 22 having a meander line structure. A metamaterial device is configured by arranging along a two-dimensional array. In the present disclosure, it is assumed that a planar wave electromagnetic wave in the -Z direction is incident on each unit cell.
　図２において、単位共振器１は、共振素子２１と、その両端にそれぞれ接続された一対のミアンダライン構造の反射素子２２とを備える。共振素子２１及び反射素子２２は、例えばフレキシブル基板２０に形成される。 In FIG. 2, the unit resonator 1 includes a resonant element 21 and a pair of reflecting elements 22 of meander line structure connected to both ends thereof. The resonant element 21 and the reflective element 22 are formed on, for example, a flexible substrate 20.
　共振素子２１は、ストリップ形状を有し、その両端の間で電流が同時に逆向きに流れる並列回路部分を含まない経路を有する。共振素子２１は、互いに直列接続された複数の直列ＬＣ共振回路を含む。各直列ＬＣ共振回路は、長さｌ及び幅ｗを有する所定のインダクタンスを有するストリップ導体２３と、互いに隣接する直列ＬＣ共振回路のストリップ導体２３の間に設けられたキャパシタ２４とを備える。キャパシタ２４は、例えばチップキャパシタである。図２の場合、共振素子２１は、１０個のストリップ導体２３と、１１個のキャパシタ２４とを含む。各直列ＬＣ共振回路の共振周波数は、メタマテリアル装置の動作周波数に一致するように設定される。これにより、共振素子２１は実質的にゼロの実効透磁率を有し、従って、実質的にゼロの屈折率を有する。 The resonant element 21 has a strip shape and has a path that does not include a parallel circuit portion in which current simultaneously flows in the opposite direction between both ends thereof. The resonant element 21 includes a plurality of series LC resonant circuits connected in series with one another. Each series LC resonant circuit includes a strip conductor 23 having a predetermined inductance having a length l and a width w, and a capacitor 24 provided between the strip conductors 23 of series LC resonant circuits adjacent to each other. The capacitor 24 is, for example, a chip capacitor. In the case of FIG. 2, the resonant element 21 includes ten strip conductors 23 and eleven capacitors 24. The resonant frequency of each series LC resonant circuit is set to match the operating frequency of the metamaterial device. Thereby, the resonant element 21 has an effective permeability of substantially zero, and thus an index of refraction of substantially zero.
　各反射素子２２は、メタマテリアル装置の動作波長の４分の１の長さを有することにより、共振素子２１から各反射素子２２を見たときのインピーダンスが実質的にゼロになる（つまり、短絡条件を満たす）ように構成される。反射素子２２は、例えば、共振素子２１の長さに比べて十分小さくなるように、矩形領域に含まれるミアンダ形状を有するストリップ導体である。 Each reflective element 22 has a quarter length of the operating wavelength of the metamaterial device, so that the impedance when looking at each reflective element 22 from the resonant element 21 is substantially zero (that is, short circuited) To meet the requirements). The reflective element 22 is, for example, a strip conductor having a meander shape included in a rectangular area so as to be sufficiently smaller than the length of the resonant element 21.
　単位共振器１は、実質的にゼロの実効透磁率を有することと、共振素子２１から各反射素子２２を見たときのインピーダンスが実質的にゼロになることとにより、０次共振器（後述）として動作する。 The unit resonator 1 has a substantially zero effective permeability, and the impedance at the time when each reflective element 22 is viewed from the resonant element 21 is substantially zero. Act as).
　再び図１を参照すると、単位共振器１は、半径ｒ及び螺線角θを有する螺線状に巻回される。これにより、単位共振器１はカイラリティを有する。図１は、単位セル１０Ａにおいて螺線の軸（Ｚ軸に平行な軸）の方向が電磁波の伝搬方向（－Ｚ方向）に一致する場合を示す。 Referring again to FIG. 1, the unit resonator 1 is wound in a spiral shape having a radius r and a spiral angle θ. Thus, the unit resonator 1 has chirality. FIG. 1 shows the case where the direction of the axis of the spiral (axis parallel to the Z axis) in the unit cell 10A coincides with the propagation direction of the electromagnetic wave (-Z direction).
　本明細書では、螺線状の単位共振器の軸が電磁波の伝搬方向に一致する単位セルを、符号「１０Ａ」により示す。 In the present specification, a unit cell in which the axis of the spiral unit resonator coincides with the propagation direction of the electromagnetic wave is indicated by a symbol “10A”.
　次に、本開示のメタマテリアル装置の動作原理について説明する。 Next, the operation principle of the metamaterial device of the present disclosure will be described.
　まず、カイラリティを有するカイラル媒質について説明する。 First, chiral media having chirality will be described.
　水に溶けた砂糖など、分子構造のもつ空間反転対称性の破れにより光学的な実像と虚像とが一致しない。つまり、電気磁気結合により、伝搬する光又は電磁波の偏波面を回転させる（光学活性という）媒質を「カイラル媒質」という。カイラル媒質を伝搬する電磁波に対する構成関係式は、次式のように表される。 The optical reversal between the real image and the virtual image does not match due to the breaking of the space inversion symmetry possessed by the molecular structure, such as sugar dissolved in water. That is, a medium (referred to as optically active) that rotates the polarization plane of propagating light or electromagnetic wave by electro-magnetic coupling is referred to as a "chiral medium". The structural relational expression for the electromagnetic wave propagating in the chiral medium is expressed as the following equation.
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000001
　ここで、Ｅは電界強度であり、Ｄは電束密度であり、Ｈは磁界強度であり、Ｂは磁束密度であり、ε、μ、及びχはそれぞれ、誘電率、透磁率、及びカイラリティを表し、ｊは虚数単位を表す。一般に異方性媒質の場合には、誘電率ε、透磁率μ、及びカイラリティχはテンソル量となる。このようにカイラリティを有する媒質では、カイラリティχにより構成関係式に電界と磁界との結合項が現れ、複異方性媒質とも呼ばれる。 Here, E is electric field strength, D is electric flux density, H is magnetic field strength, B is magnetic flux density, ε, μ, and 誘 電 are permittivity, permeability, and chirality, respectively. And j represents an imaginary unit. In general, in the case of an anisotropic medium, the permittivity ε, the permeability μ, and the chirality χ are tensor amounts. As described above, in a medium having chirality, a coupling term of electric field and magnetic field appears in a constitutive relational expression due to chirality, and it is also called a multi-anisotropic medium.
　次に、カイラル構造を有するカイラルメタマテリアルについて説明する。 Next, a chiral metamaterial having a chiral structure is described.
　カイラル媒質は、原子及び分子のような微視的なスケールを有するものに限らない。大きなスケールであっても、ネジ、渦巻き、及び卍字形など、実像と虚像とが一致しない空間反転対称性の破れにより電気磁気結合が現れる構造を「カイラル構造」と呼ぶ。図１のように単位構成要素がカイラリティを有するメタマテリルは「カイラルメタマテリアル」と呼ばれる。単位構成要素の形状及び配列を適切に決定することにより、メタマテリアルの巨視的なパラメータとして、実効誘電率及び実効透磁率を所望値に設定し、さらに、実効カイラリティを所望値に設定することもできる。 Chiral media are not limited to those with microscopic scales such as atoms and molecules. Even on a large scale, a structure such as a screw, a spiral, and a wedge shape, in which an electromagnetic coupling appears due to a space inversion symmetry breaking in which a real image and a virtual image do not coincide with each other is called a "chiral structure". A metamaterial having a chirality as the unit component as shown in FIG. 1 is called “chiral metamaterial”. By appropriately determining the shape and arrangement of unit components, it is possible to set the effective dielectric constant and the effective permeability to desired values as macroscopic parameters of the metamaterial, and further to set the effective chirality to a desired value. it can.
　カイラル構造は、例えば、以下のような応用を有する。 The chiral structure has, for example, the following application.
　典型的なカイラル構造として、螺線構造が挙げられる。単体の螺線状の共振器を放射器として使用し、円偏波特性を有するヘリカルアンテナが実用化されている。単体のヘリカルアンテナに限らず、複数のヘリカルアンテナを周期的に配列したアンテナ装置も提案されている。アンテナ以外の応用例として、周波数選択性の反射板及び透過板への応用も提案されている。このような周波数選択性の反射板及び透過板は、特定の動作周波数あるいは特定の偏波特性をもつ入射波に対して、所望の方向に、所望の偏波回転特性をもつ反射波あるいは透過波を作り出す。カイラル構造は電磁散乱体として考えられる。 A spiral structure is mentioned as a typical chiral structure. A helical antenna having circular polarization characteristics has been put to practical use, using a single spiral resonator as a radiator. Not only a single helical antenna, but also an antenna device in which a plurality of helical antennas are periodically arranged has been proposed. Applications to frequency selective reflectors and transmission plates have also been proposed as applications other than antennas. Such frequency selective reflectors and transmission plates are, for an incident wave having a specific operating frequency or a specific polarization characteristic, a reflected wave or transmission having a desired polarization rotation characteristic in a desired direction. Create a wave. The chiral structure is considered as an electromagnetic scatterer.
　単体のヘリカルアンテナの場合でも、複数のヘリカルアンテナを配列したアンテナ装置の場合であっても、各要素がもたらす偏波回転角を増大させることによるメリットは大きい。例えば、ヘリカルアンテナの素子の単位長さあたりの偏波回転角を増大することにより、従来のヘリカルアンテナを小型化及び薄型化することが可能となる。 Even in the case of a single helical antenna or in the case of an antenna apparatus in which a plurality of helical antennas are arranged, the merit of increasing the polarization rotation angle provided by each element is great. For example, by increasing the polarization rotation angle per unit length of the element of the helical antenna, it becomes possible to miniaturize and thin the conventional helical antenna.
　このように、外部電磁波とカイラル構造との相互作用を増大させて偏波回転角を大きくすることが期待されている。発明者は、実現する方法の一つとして、各ヘリカル構造のもつ共振状態に着目した。一本の金属細線からなる従来のヘリカル構造の場合、最低次の共振モードは、金属細線の全長が電磁波の動作波長の半分に一致する場合に得られ（半波長共振）、その次に低い共振モードは、金属細線の全長が電磁波の動作波長に一致する場合に得られる（一波長共振）。共振時には、金属の表面に大電流が流れ、共振器の内部及び近傍に蓄えられる電磁界も極大化する。その結果、外部電磁波とカイラル構造との相互作用が極大化する。このように、ヘリカル構造では、その長さ及び形状で決まる固有の共振周波数の付近において、入射電磁波とヘリカル構造との相互作用が極大化され、偏波回転効果も極大化される。 As described above, it is expected to increase the polarization rotation angle by increasing the interaction between the external electromagnetic wave and the chiral structure. The inventor paid attention to the resonance state of each helical structure as one of the methods to be realized. In the case of a conventional helical structure consisting of a single metal wire, the lowest-order resonant mode is obtained when the total length of the metal wire corresponds to half the operating wavelength of the electromagnetic wave (half-wave resonance), the second lowest resonance A mode is obtained when the total length of the metal thin wire matches the operating wavelength of the electromagnetic wave (one-wavelength resonance). At the time of resonance, a large current flows on the surface of the metal, and the electromagnetic field stored inside and near the resonator is also maximized. As a result, the interaction between the external electromagnetic wave and the chiral structure is maximized. As described above, in the helical structure, the interaction between the incident electromagnetic wave and the helical structure is maximized and the polarization rotation effect is also maximized in the vicinity of the unique resonance frequency determined by the length and the shape.
　しかしながら、従来のカイラル構造は以下のような問題点を有する。 However, conventional chiral structures have the following problems.
　従来のカイラル構造に見られる半波長共振及び一波長共振の場合、共振時にカイラル構造内で定在波が生じ、電磁界分布に腹及び節が必ず現れる。カイラル構造が金属材料から構成されている場合、共振時に金属材料の表面を流れる電流分布にも腹及び節が現れる。カイラル構造に流れる電流自体の大きさは共振周波数付近で極大化されるものの、電磁界は共振モードの次数により所定の分布となるので、必ず、電磁界分布に対応して共振器内の電流分布に強弱が生じる。入射する電磁波に対して可能な限り大きな偏波回転を与えようとする場合、上記のような不均一な電流分布は、外部電磁波とカイラル構造との相互作用を高めることの妨げとなり、大きな偏波回転を与えることは困難である。発明者は、入射電磁波とカイラル構造との相互作用をさらに増大するためには、カイラル構造に沿って流れる電流が最大振幅の状態で一様に分布することが望ましいことを見出した。 In the case of half-wavelength resonance and single-wavelength resonance found in conventional chiral structures, a standing wave occurs in the chiral structure at resonance, and antinodes and nodes always appear in the electromagnetic field distribution. When the chiral structure is made of a metal material, antinodes and nodes appear in the current distribution flowing on the surface of the metal material at resonance. Although the magnitude of the current itself flowing through the chiral structure is maximized near the resonant frequency, the electromagnetic field has a predetermined distribution according to the order of the resonance mode, so the current distribution in the resonator must be in accordance with the electromagnetic field distribution. Strength occurs in When trying to give as large polarization rotation as possible to the incident electromagnetic wave, the non-uniform current distribution as described above hinders the enhancement of the interaction between the external electromagnetic wave and the chiral structure, resulting in large polarization. It is difficult to give a turn. The inventor has found that it is desirable that the current flowing along the chiral structure be uniformly distributed at maximum amplitude in order to further increase the interaction between the incident electromagnetic wave and the chiral structure.
　次に、一様な電磁界分布及び電流分布をもたらす０次共振について説明する。 Next, zero-order resonance that results in uniform electromagnetic field distribution and current distribution will be described.
　電磁界分布が腹及び節を持つ従来の共振器（半波長共振器及び一波長共振器など）に対して、電磁界分布及び電流分布が至る所で一様となる共振器は０次共振器である。０次共振器は、メタマテリアルの一種である右手／左手系複合伝送線路である有限長の伝送線路と、その両端に接続された一対の反射素子で構成することができる。右手／左手系複合伝送線路は、直列枝の直列ＬＣ共振回路とシャント枝の並列ＬＣ共振回路とから構成されるサブ波長サイズの単位セルからなり、一個もしくは複数個の単位セルを（準）周期的に並べた複合構造を有する。単位セルに含まれる直列及び並列の２種類の共振回路は、両端の反射素子が実現する条件（短絡または開放）により選択的に動作する。両端に接続される一対の反射素子がインピーダンス０（短絡端を意味する）である場合、各単位セルの直列枝に含まれる直列ＬＣ共振回路が選択的に動作する。このとき、各単位セルの直列枝のインピーダンスはほぼ全て０となる。その結果、各単位セルの直列枝には、一様な大きさ及び位相を有する大電流が流れる。つまり、両端短絡の場合の０次共振である。一方、両端のインピーダンスが無限大（開放端を意味する）である場合、各単位セルのシャント枝に含まれる並列ＬＣ共振回路が選択的に動作する。このとき、各単位セルのシャント枝のアドミタンスはほぼ全て０となる。その結果、各単位セルのシャント枝の両端には一様な大きさ及び位相を有する電圧がかかる。つまり、両端開放の場合の０次共振である。０次共振の場合、伝送線路に沿って一様な振幅及び位相を有する電磁界分布が得られるので、管内波長が無限大となり、位相定数（単位長さあたりの位相の変化量）βがゼロとなる。 A resonator whose electromagnetic field distribution is uniform throughout the electromagnetic field distribution and the current distribution is a zeroth-order resonator, as compared with a conventional resonator (such as a half-wave resonator and a single-wavelength resonator) whose electromagnetic field distribution has antinodes and nodes It is. The zeroth-order resonator can be composed of a transmission line of finite length, which is a right-hand / left-handed composite transmission line which is a kind of metamaterial, and a pair of reflecting elements connected to both ends thereof. The right-hand / left-handed composite transmission line consists of unit cells of a sub-wavelength size composed of a series LC resonant circuit in series branches and a parallel LC resonant circuit in shunt branches, and one or more unit cells have a (quasi) period It has a complex structure arranged side by side. The two types of resonant circuits in series and in parallel included in the unit cell selectively operate according to the conditions (short circuit or open) realized by the reflective elements at both ends. When the pair of reflective elements connected to both ends is impedance 0 (meaning a shorted end), the series LC resonant circuit included in the series branch of each unit cell selectively operates. At this time, the impedance of the serial branch of each unit cell is almost all zero. As a result, a large current having uniform magnitude and phase flows through the serial branch of each unit cell. That is, it is zero-order resonance in the case of short circuit at both ends. On the other hand, when the impedance at both ends is infinite (meaning an open end), the parallel LC resonance circuit included in the shunt branch of each unit cell selectively operates. At this time, the admittance of the shunt branch of each unit cell is almost all zero. As a result, a voltage having uniform magnitude and phase is applied across the shunt branches of each unit cell. That is, it is a zero-order resonance in the case of both ends open. In the case of zero-order resonance, an electromagnetic field distribution having uniform amplitude and phase is obtained along the transmission line, so the wavelength in the tube becomes infinite and the phase constant (the amount of change in phase per unit length) β is zero. It becomes.
　図３は、半波長共振する伝送線路の電磁界強度を示す概略図である。図４は、０次共振する伝送線路の電磁界強度を示す概略図である。図３及び図４において、横方向は伝送線路に沿った位置を示し、縦方向は電磁界の強さを示す。 FIG. 3 is a schematic view showing the electromagnetic field strength of the transmission line which resonates at a half wavelength. FIG. 4 is a schematic view showing the electromagnetic field strength of the transmission line at which the zero order resonance occurs. In FIG. 3 and FIG. 4, the horizontal direction indicates the position along the transmission line, and the vertical direction indicates the strength of the electromagnetic field.
　このように、伝送線路に沿って一様な電流あるいは電圧分布を形成する０次共振の原理を、所定の電磁界分布及び電流分布を有するカイラル構造に応用することにより、カイラル構造の偏波回転を増大する効果を期待できる。 Thus, by applying the principle of zero-order resonance that forms a uniform current or voltage distribution along the transmission line to a chiral structure having a predetermined electromagnetic field distribution and current distribution, polarization rotation of the chiral structure is achieved. The effect of increasing the
　次に、右手／左手系複合伝送線路を用いたカイラル構造について説明する。 Next, a chiral structure using a right / left handed composite transmission line will be described.
　右手／左手系複合伝送線路を螺旋形状に巻回することにより、カイラル構造が構成される。さらにその両端に一対の反射素子を接続することにより、カイラル０次共振器が構成される。ただし、伝送線路をカイラル構造として用いる場合、従来の金属細線からなるカイラル構造とは以下のように異なる。例えば、従来のカイラル構造が１本の金属細線からなるのに対して、伝送線路は、信号線と接地導体とを組み合わせた２端子対網である。伝送線路からなるカイラル構造は、互いに並列に設けられた、信号線に相当する回路部分と、接地導体に相当する回路部分とを備える。その結果、伝送線路からなるカイラル構造では、信号線に相当する回路部分に電流が流れるとき、接地導体に相当する回路部分において、信号線に相当する回路部分とは逆向きに同じ大きさの電流が流れる。従って、２つの回路部分に逆向きに同じ大きさの電流が流れることにより、これらの回路部分にそれぞれ入射した電磁波の散乱波が完全に打ち消しあう。２つの回路部分が幾何学的に非対称な構造を有するのであれば、これらの回路部分にそれぞれ入射した電磁波の散乱波が完全に打ち消しあうことはないが、互いに弱め合う影響は避けられない。また、信号線に相当する回路部分と比べて接地導体に相当する回路部分のサイズが大きい場合、遮蔽効果のある大きな導体が存在することは、電磁波とカイラル構造（電磁散乱体）との相互作用に寄与しない領域を増やすことに相当する。従って、偏波回転を増大する効果を大きくするために、接地導体に相当する回路部分を除去したカイラル構造を０次共振させる。 A chiral structure is configured by winding the right / left handed composite transmission line in a spiral shape. Further, a chiral zero-order resonator is configured by connecting a pair of reflective elements to both ends thereof. However, when using a transmission line as a chiral structure, it differs from the conventional chiral structure which consists of metal thin wires as follows. For example, the transmission line is a two-terminal pair network in which a signal line and a ground conductor are combined, while the conventional chiral structure consists of one metal thin wire. The chiral structure which consists of a transmission line is provided mutually in parallel with the circuit part corresponded to a signal line, and the circuit part corresponded to a grounding conductor. As a result, in the chiral structure including the transmission line, when a current flows in the circuit portion corresponding to the signal line, in the circuit portion corresponding to the ground conductor, the current of the same size in the opposite direction to the circuit portion corresponding to the signal line Flows. Therefore, when currents of the same magnitude flow in opposite directions in the two circuit portions, the scattered waves of the electromagnetic waves respectively incident on these circuit portions completely cancel each other. If the two circuit portions have a geometrically asymmetric structure, the scattered waves of the electromagnetic waves respectively incident on these circuit portions do not completely cancel each other, but the destructive effects are inevitable. Moreover, when the size of the circuit portion corresponding to the ground conductor is larger than the circuit portion corresponding to the signal line, the presence of a large conductor having a shielding effect means that the interaction between the electromagnetic wave and the chiral structure (electromagnetic scatterer) Equivalent to increasing the area not contributing to Therefore, in order to increase the effect of increasing the polarization rotation, the chiral structure from which the circuit portion corresponding to the ground conductor is removed is subjected to zero-order resonance.
　第１の実施形態に係る単位共振器１では、前述のように、共振素子２１は、ストリップ形状を有し、その両端の間で電流が同時に逆向きに流れる並列回路部分を含まない経路を有する。従って、単位共振器１は、伝送線路から、接地導体に相当する回路部分を除去した構成を有する。単位共振器１には、シャント枝がなく、直列枝しか存在しないので、両端が反射素子２２により短絡された０次共振器として直列共振動作を実現する。 In the unit resonator 1 according to the first embodiment, as described above, the resonant element 21 has a strip shape and has a path that does not include a parallel circuit portion in which current simultaneously flows in the opposite direction between both ends thereof. . Therefore, the unit resonator 1 has a configuration in which the circuit portion corresponding to the ground conductor is removed from the transmission line. Since there is no shunt branch in the unit resonator 1 and there is only a series branch, series resonance operation is realized as a zero-order resonator whose both ends are shorted by the reflective element 22.
　図１の単位共振器１を備えるメタマテリアル装置は、単位共振器１が０次共振器として動作することにより、半波長共振器又は一波長共振器を単位共振器として備えた従来の電磁波装置よりも、電磁波と強く相互作用することができる。 The metamaterial device provided with the unit resonator 1 of FIG. 1 is a conventional electromagnetic wave device provided with a half-wave resonator or a single-wavelength resonator as a unit resonator by the unit resonator 1 operating as a zero-order resonator. Can also interact strongly with electromagnetic waves.
　また、図１の単位共振器１を備えるメタマテリアル装置は、単位共振器１を螺線状に巻回したことにより、カイラルメタマテリアルとして動作することができる。後述するように、図１の単位共振器１を備えるメタマテリアル装置を周波数選択性の透過板として用いた場合、従来の金属細線からなるカイラル周期構造と比べて偏波回転角が大幅に増大することを数値計算及び実際の測定により確認した。また、図１の単位共振器１を備えるメタマテリアル装置は、接地導体に相当する回路部分を含むカイラル構造の場合と比べても偏波回転角が増大することを数値計算及び実際の測定により確認した。 In addition, the metamaterial device including the unit resonator 1 of FIG. 1 can operate as a chiral metamaterial by winding the unit resonator 1 in a spiral shape. As will be described later, when the metamaterial device including the unit resonator 1 of FIG. 1 is used as a frequency selective transmission plate, the polarization rotation angle is significantly increased as compared with the chiral periodic structure made of conventional metal thin wires. It was confirmed by numerical calculation and actual measurement. In addition, the metamaterial device provided with the unit resonator 1 of FIG. 1 is confirmed by numerical calculation and actual measurement that the polarization rotation angle is increased even compared to the case of the chiral structure including the circuit portion corresponding to the ground conductor. did.
　図５は、第１の実施形態に係る単位共振器１を含む第２の単位セル１０Ｂを示す斜視図である。図５は、単位セル１０Ｂにおいて螺線の軸（Ｙ軸に平行な軸）の方向が電磁波の伝搬方向（－Ｚ方向）に直交する場合を示す。後述するように、複数の単位セル１０Ｂを２次元アレイとして配列したメタマテリアル装置もまた、図１の単位共振器１を備えるメタマテリアル装置と同様に、従来よりも電磁波と強く相互作用することができ、また、カイラルメタマテリアルとして動作することができる。また、単位セル１０Ｂは、Ｘ方向、Ｙ方向、及びＺ方向に沿って、長さｄ１、ｄ２、及びｄ３をそれぞれ有する。 FIG. 5 is a perspective view showing a second unit cell 10B including the unit resonator 1 according to the first embodiment. FIG. 5 shows the case where the direction of the axis of the spiral (axis parallel to the Y axis) in the unit cell 10B is orthogonal to the propagation direction of the electromagnetic wave (-Z direction). As will be described later, a metamaterial device in which a plurality of unit cells 10B are arranged as a two-dimensional array can also interact more strongly with electromagnetic waves than in the prior art, similarly to the metamaterial device having the unit resonator 1 of FIG. It can also act as a chiral metamaterial. Each unit cell 10B has lengths d1, d2 and d3 along the X, Y and Z directions, respectively.
　本明細書では、前述のように、螺線状の単位共振器の軸が電磁波の伝搬方向に平行である単位セルを、符号「１０Ａ」により示し、また、螺線状の単位共振器の軸が電磁波の伝搬方向に直交する単位セルを、符号「１０Ｂ」により示す。 In the present specification, as described above, a unit cell in which the axis of the spiral unit resonator is parallel to the propagation direction of the electromagnetic wave is indicated by the code “10A”, and the axis of the spiral unit resonator is A unit cell orthogonal to the propagation direction of the electromagnetic wave is indicated by a code "10B".
　複数の単位共振器１の単位セルを配列したメタマテリアル装置において、各単位共振器１の配向及び配列を適切に選択することにより、メタマテリアル装置の全体のパラメータ（実効誘電率、実効透磁率、及びカイラリティなど）を所望値に設定することができる。各単位共振器１を周期的に配列する場合、異方性が顕著に現れる。一方、各単位共振器１を配向及び配列のうちの少なくとも一方に関してランダムに配列する場合、等方性のカイラリティを得ることもできる。各単位共振器１を周期的に配列する場合も、各単位共振器１をランダムに配列する場合も、用途に応じて、複数の単位共振器１を１次元的、２次元的、あるいは３次元的に配列することができる。 In the metamaterial device in which unit cells of a plurality of unit resonators 1 are arrayed, the entire parameters (effective permittivity, effective permeability, and the like) of the metamaterial device can be selected by appropriately selecting the orientation and arrangement of each unit resonator 1. And chirality etc. can be set to a desired value. When the unit resonators 1 are periodically arranged, the anisotropy appears prominently. On the other hand, when the unit resonators 1 are randomly arranged with respect to at least one of the orientation and the arrangement, it is also possible to obtain isotropic chirality. Even when the unit resonators 1 are periodically arranged or when the unit resonators 1 are randomly arranged, the plurality of unit resonators 1 are one-dimensionally, two-dimensionally, or three-dimensionally depending on the application. Can be arranged in
　次に、図６～図１５を参照して、第１の実施形態に係るメタマテリアル装置について行った数値計算の結果について説明する。 Next, with reference to FIGS. 6 to 15, the result of numerical calculation performed for the metamaterial device according to the first embodiment will be described.
　まず、数値計算のためのモデルを設定する。単位セル１０Ａの４つの側面に周期境界条件を課すことで、Ｘ方向及びＹ方向に無限の大きさの格子構造を有する２次元アレイを設定した。この２次元アレイをメタマテリアル装置と呼ぶ。各単位セル１０Ａのサイズ（すなわち周期）を、ｄ１＝ｄ２＝５０ｍｍに設定した。平面波の電磁波が単位セル１０Ａの上面から下面に向かって入射するように設定した。従って、各単位セル１０Ａにおいて螺線の軸が電磁波の伝搬方向に一致する。各単位セル１０Ａにおいて、単位共振器１以外の部分は自由空間とした。単位共振器１の構成パラメータは、以下の通りであった。 First, set up a model for numerical calculation. By imposing periodic boundary conditions on the four sides of the unit cell 10A, a two-dimensional array having a lattice structure of infinite size in the X and Y directions was set. This two-dimensional array is called a metamaterial device. The size (that is, the period) of each unit cell 10A was set to d1 = d2 = 50 mm. The plane wave electromagnetic wave was set to be incident from the upper surface to the lower surface of the unit cell 10A. Therefore, in each unit cell 10A, the axis of the spiral coincides with the propagation direction of the electromagnetic wave. In each unit cell 10A, a portion other than the unit resonator 1 is a free space. The configuration parameters of the unit resonator 1 were as follows.
ストリップ導体２３の長さ：ｌ＝６ｍｍ
ストリップ導体２３の幅：ｗ＝２ｍｍ
ストリップ導体２３の厚さ：ｔ＝１８μｍ
キャパシタ２４の容量：Ｃ＝０．８ｐＦ
反射素子２２の全長：５９ｍｍ
反射素子２２の幅：０．５ｍｍ
反射素子２２の外形寸法：ｌｍ×ｗｍ＝１４．５ｍｍ×９．０ｍｍ
螺線半径：ｒ＝１０ｍｍ
螺旋角：θ＝２５度
螺線状に巻回された共振素子２１のＺ方向の長さ：０．２６λ０（λ０：動作波長） Length of strip conductor 23: l = 6 mm
Width of strip conductor 23: w = 2 mm
Thickness of strip conductor 23: t = 18 μm
Capacitance of capacitor 24: C = 0.8 pF
Total length of reflective element 22: 59 mm
Width of reflective element 22: 0.5 mm
Dimensions of reflective element 22: lm × wm = 14.5 mm × 9.0 mm
Spiral radius: r = 10 mm
Helix angle: theta = 25 Donishi linear in wound Z-direction length of the resonance element 21: 0.26λ 0 (λ 0: operating wavelength)
　また、第１の実施形態の第１の比較例として、図６に示すようなストリップ導体の共振素子のみからなる単位共振器２０１を備える電磁波装置のモデルを設定した。単位共振器２０１は従来の半波長共振器である。単位共振器２０１を含む各単位セルのサイズ（周期）もまた、単位セル１０Ａのサイズと同様に、ｄ１＝ｄ２＝５０ｍｍに設定した。単位共振器２０１の構成パラメータは、以下の通りであった。 In addition, as a first comparative example of the first embodiment, a model of an electromagnetic wave device provided with a unit resonator 201 consisting only of a resonant element of a strip conductor as shown in FIG. 6 was set. The unit resonator 201 is a conventional half-wave resonator. The size (period) of each unit cell including the unit resonator 201 was also set to d1 = d2 = 50 mm, similarly to the size of the unit cell 10A. The configuration parameters of the unit resonator 201 were as follows.
共振素子の全長：６５．５ｍｍ
共振素子の幅：２ｍｍ
螺線半径：ｒ＝１０ｍｍ
螺旋角：θ＝２３度
螺線状に巻回された共振素子２１のＺ方向の長さ：０．２３λ０（λ０：動作波長） Total length of resonant element: 65.5 mm
Width of resonant element: 2 mm
Spiral radius: r = 10 mm
Helical angle: θ = 23 degrees Length in the Z direction of the resonant element 21 wound in a spiral shape: 0.23λ 0 (λ 0 : operating wavelength)
　図６は、第１の実施形態の第１の比較例に係る単位共振器２０１における磁界の強さ（電流分布）を示す図である。図７は、第１の実施形態に係る単位共振器１における磁界の強さ（電流分布）を示す図である。比較のため、これらの単位共振器１及び２０１に、ほぼ同じ構成パラメータと、ほぼ同じ動作周波数とを設定した。図６からわかるように、半波長共振器である単位共振器２０１の場合、単位共振器２０１の素子中央付近で電流強度が最大となっている。また、素子の両端に近づくにつれて電流の強度は弱まり、最終的に端部ではゼロとなっている。一方、図７によれば、０次共振器である単位共振器１の場合、共振素子２１の至る所で電流の大きさはほぼ一定であり、最大値に維持されていることがわかる。 FIG. 6 is a diagram showing the strength (current distribution) of the magnetic field in the unit resonator 201 according to the first comparative example of the first embodiment. FIG. 7 is a diagram showing the strength (current distribution) of the magnetic field in the unit resonator 1 according to the first embodiment. For comparison, these unit resonators 1 and 201 were set to approximately the same configuration parameters and approximately the same operating frequency. As can be seen from FIG. 6, in the case of the unit resonator 201 which is a half wavelength resonator, the current intensity is maximum near the center of the element of the unit resonator 201. Also, the intensity of the current weakens as it approaches both ends of the element, and eventually becomes zero at the end. On the other hand, according to FIG. 7, in the case of the unit resonator 1 which is a zero-order resonator, it is understood that the magnitude of the current is substantially constant throughout the resonant element 21 and is maintained at the maximum value.
　次に、偏波回転角の算出方法について説明する。 Next, a method of calculating the polarization rotation angle will be described.
　カイラリティによる偏波回転は、カイラル媒質における左右の円偏波の透過特性の差から生じる。非特許文献１によれば、円偏波で伝搬する電磁波の透過特性Ｔｃｉｒは、直線偏波で伝搬する電磁波の透過特性を用いて次式のように表すことができる。 Polarization rotation due to chirality results from the difference in transmission characteristics of left and right circular polarization in the chiral medium. According to Non-Patent Document 1, the transmission characteristic T cir of the electromagnetic wave propagating in the circular polarization can be expressed as the following equation using the transmission characteristic of the electromagnetic wave propagating in the linear polarization.
Figure JPOXMLDOC01-appb-M000002
Figure JPOXMLDOC01-appb-M000002
　ここで、以下の表記を用いる。 Here, the following notation is used.
Ｔ＋＋：右円偏波が入射したときにおける右円偏波成分の透過係数
Ｔ＋－：右円偏波が入射したときにおける左円偏波成分の透過係数
Ｔ－＋：左円偏波が入射したときにおける右円偏波成分の透過係数
Ｔ－－：左円偏波が入射したときにおける左円偏波成分の透過係数
Ｔｘｘ：ｘ方向の直線偏波が入射したときにおけるｘ方向の直線偏波成分の透過係数
Ｔｙｘ：ｘ方向の直線偏波が入射したときにおけるｙ方向の直線偏波成分の透過係数
Ｔｘｙ：ｙ方向の直線偏波が入射したときにおけるｘ方向の直線偏波成分の透過係数
Ｔｙｙ：ｙ方向の直線偏波が入射したときにおけるｙ方向の直線偏波成分の透過係数 T ++: permeability coefficient of the right circular polarization component at the time when the right circularly polarized wave is incident T + -: permeability coefficient of the left circularly polarized component in when the right circularly polarized wave is incident T - +: left-handed circularly polarized wave permeability coefficient of the right circular polarization component at the time when the incident T -: permeability coefficient of the left circularly polarized component in when the left circularly polarized wave is incident T xx: definitive when linearly polarized wave is incident in the x direction of the x-direction Transmission coefficient of linear polarization component T yx : Transmission coefficient of linear polarization component in y direction when linear polarization in x direction is incident T xy : linear polarization in x direction when linear polarization in y direction is incident Transmission coefficient of wave component T yy : Transmission coefficient of linear polarization component in y direction when linear polarization in y direction is incident
　このとき、偏波回転角φは次式で与えられる。 At this time, the polarization rotation angle φ is given by the following equation.
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000003
　以下に説明するように、この式を用いてメタマテリアル装置の透過波の偏波回転角を評価した。 As described below, this equation was used to evaluate the polarization rotation angle of the transmitted wave of the metamaterial device.
　第１の実施形態の第１の比較例に係る単位共振器２０１を備える電磁波装置と、第１の実施形態に係る単位共振器１を備えるメタマテリアル装置とにおいて、以下のような偏波回転角が得られた。単位共振器２０１を備えた電磁波装置では、共振周波数２．４４ＧＨｚにおいて偏波回転角２．７２度が得られた。一方、単位共振器１を備えるメタマテリアル装置では、共振周波数２．４２ＧＨｚにおいて偏波回転角１２．５度が得られた。従って、０次共振器である単位共振器１を備えるメタマテリアル装置の偏波回転角は、半波長共振器である単位共振器２０１を備える電磁波装置の偏波回転角に比べて約４．６倍に増大することがわかった。 In the electromagnetic wave device including the unit resonator 201 according to the first comparative example of the first embodiment and the metamaterial device including the unit resonator 1 according to the first embodiment, the following polarization rotation angles was gotten. In the electromagnetic wave apparatus provided with the unit resonator 201, a polarization rotation angle of 2.72 degrees was obtained at a resonance frequency of 2.44 GHz. On the other hand, in the metamaterial device including the unit resonator 1, a polarization rotation angle of 12.5 degrees was obtained at a resonance frequency of 2.42 GHz. Therefore, the polarization rotation angle of the metamaterial device including the unit resonator 1 that is the zeroth-order resonator is about 4.6 as compared to the polarization rotation angle of the electromagnetic wave device that includes the unit resonator 201 that is a half-wave resonator. It was found to be doubled.
　次に、電流が同時に逆向きに流れる並列回路部分を含む場合及び含まない場合のメタマテリアル装置の偏波回転角について説明する。 Next, the polarization rotation angle of the metamaterial device with and without the parallel circuit portion in which the current flows simultaneously in the opposite direction will be described.
　図８は、第１の実施形態の第２の比較例に係る単位共振器２０１Ａを含む単位セル１０Ａを示す斜視図である。単位共振器２０１Ａは、互いに並列に設けられた２つの回路部分を備え、一方の回路部分は第１の実施形態に係る単位共振器１の共振素子２１（図２を参照）と同様に構成され、他方の回路部分はストリップ導体のみからなる。言い換えると、単位共振器２０１Ａは、信号線とともに接地導体からなる伝送線路を螺線状に巻回した構成、すなわち、信号線に相当する回路部分と、接地導体に相当する回路部分とを備える。単位共振器２０１Ａの両端において、２つの回路部分は互いに短絡されている。 FIG. 8 is a perspective view showing a unit cell 10A including a unit resonator 201A according to a second comparative example of the first embodiment. The unit resonator 201A includes two circuit parts provided in parallel with each other, and one circuit part is configured in the same manner as the resonant element 21 (see FIG. 2) of the unit resonator 1 according to the first embodiment. , The other circuit part consists only of a strip conductor. In other words, the unit resonator 201A has a configuration in which a transmission line including a signal conductor and a ground conductor is spirally wound, that is, a circuit portion corresponding to the signal conductor and a circuit portion corresponding to the ground conductor. At both ends of the unit resonator 201A, the two circuit parts are shorted to each other.
　図９は、第１の実施形態の第３の比較例に係る単位共振器２０１Ｂを含む単位セル１０Ａを示す斜視図である。単位共振器２０１Ｂは、互いに並列に設けられた２つの回路部分を備え、これらの回路部分の両方が、第１の実施形態に係る単位共振器１の共振素子２１（図２を参照）と同様に、すなわち、互いに直列接続された複数の直列ＬＣ共振回路を含む線路として構成される。単位共振器２０１Ｂの両端において、２つの回路部分は互いに短絡されている。 FIG. 9 is a perspective view showing a unit cell 10A including a unit resonator 201B according to a third comparative example of the first embodiment. The unit resonator 201B includes two circuit portions provided in parallel to each other, and both of these circuit portions are similar to the resonant element 21 (see FIG. 2) of the unit resonator 1 according to the first embodiment. That is, it is configured as a line including a plurality of series LC resonant circuits connected in series with one another. At both ends of the unit resonator 201B, the two circuit parts are shorted to each other.
　数値計算において、単位共振器２０１Ａの及び２０１Ｂの各構成パラメータには、第１の実施形態に係る単位共振器１の対応する部分のものと同じ値を設定した。 In the numerical calculation, the same value as that of the corresponding part of the unit resonator 1 according to the first embodiment is set to each of the configuration parameters of the unit resonators 201A and 201B.
　前述のように、第１の実施形態に係る単位共振器１を備えるメタマテリアル装置では、共振周波数２．４２ＧＨｚにおいて偏波回転角１２．５度が得られた。一方、図８の単位共振器２０１Ａを備える電磁波装置では、共振周波数３．１４ＧＨｚにおいて偏波回転角１．３３度が得られた。また、図９の単位共振器２０１Ｂを備える電磁波装置では、共振周波数３．８６ＧＨｚにおいて偏波回転角１．８６度が得られた。以上のことから、第１の実施形態に係るメタマテリアル装置、すなわち、電流が同時に逆向きに流れる並列回路部分を含まない単位共振器１を備えるメタマテリアル装置では、電流が同時に逆向きに流れる並列回路部分を含む単位共振器２０１Ａ及び２０１Ｂを備える電磁波装置に比べて、数倍大きな偏波回転角が得られることがわかった。 As described above, in the metamaterial device including the unit resonator 1 according to the first embodiment, the polarization rotation angle of 12.5 degrees is obtained at the resonance frequency of 2.42 GHz. On the other hand, in the electromagnetic wave apparatus provided with the unit resonator 201A of FIG. 8, the polarization rotation angle of 1.33 degrees was obtained at the resonance frequency of 3.14 GHz. Moreover, in the electromagnetic wave apparatus provided with the unit resonator 201B of FIG. 9, the polarization rotation angle of 1.86 degrees was obtained at the resonance frequency of 3.86 GHz. From the above, in the metamaterial device according to the first embodiment, that is, the metamaterial device including the unit resonator 1 not including the parallel circuit portion in which the current flows in the reverse direction simultaneously, the current flows in the reverse direction simultaneously It has been found that the polarization rotation angle several times larger can be obtained as compared with the electromagnetic wave apparatus including the unit resonators 201A and 201B including the circuit portion.
　ここで、３種類の単位共振器１、２０１Ａ、及び２０１Ｂをそれぞれ備えたメタマテリアル装置及び電磁波装置の共振周波数が互いに異なることに注意する。このうち、単位共振器１を備えるメタマテリアル装置の共振周波数が最も小さく、他の単位共振器２０１Ａ及び２０１Ｂを備える電磁波装置の共振周波数はより高い。波長比で換算すると、相対的に、単位共振器２０１Ａ及び２０１Ｂのサイズが単位共振器１よりも大きいので、より大きな偏波回転が起きるはずであると考えられる。しかしながら、実際には、単位共振器２０１Ａ及び２０１Ｂを備える電磁波装置では、第１の実施形態の第１の比較例に係る単位共振器２０１を備える電磁波装置の場合と同程度の偏波回転角しか得られていない。以上のことから、第１の実施形態に係る単位共振器１を備えるメタマテリアル装置の構造を採用することにより、偏波回転角を増大させる効果は明らかである。第１の実施形態に係る単位共振器１を備えるメタマテリアル装置では、図８の単位共振器２０１Ａ及び図９の単位共振器２０１Ｂを備える電磁波装置とは異なり、電流が同時に逆向きに流れる並列回路部分を除去しているので、より大きな偏波回転角が得られている。 Here, it should be noted that the resonance frequencies of the metamaterial device and the electromagnetic wave device provided with the three types of unit resonators 1, 201A and 201B are different from each other. Among these, the resonance frequency of the metamaterial device provided with the unit resonator 1 is the smallest, and the resonance frequency of the electromagnetic wave device provided with the other unit resonators 201A and 201B is higher. In terms of wavelength ratio, it is considered that, since the sizes of the unit resonators 201A and 201B are relatively larger than that of the unit resonator 1, larger polarization rotation should occur. However, in practice, in the electromagnetic wave apparatus having the unit resonators 201A and 201B, only the polarization rotation angle similar to that of the electromagnetic wave apparatus having the unit resonator 201 according to the first comparative example of the first embodiment. Not obtained. From the above, by adopting the structure of the metamaterial device including the unit resonator 1 according to the first embodiment, the effect of increasing the polarization rotation angle is clear. The metamaterial device including the unit resonator 1 according to the first embodiment differs from the electromagnetic wave device including the unit resonator 201A of FIG. 8 and the unit resonator 201B of FIG. Since the part is removed, a larger polarization rotation angle is obtained.
　次に、螺旋状に巻回された単位共振器の螺線半径及び螺線角を変化させたときの偏波回転角の変化について説明する。 Next, the change of the polarization rotation angle when the spiral radius and the spiral angle of the spirally wound unit resonator are changed will be described.
　図１０は、第１の実施形態の第１の比較例に係る単位共振器２０１を備える電磁波装置の螺線半径に対する偏波回転角の変化を示すグラフである。図１１は、第１の実施形態に係る単位共振器１を備えるメタマテリアル装置の螺線半径に対する偏波回転角の変化を示すグラフである。図１０及び図１１の数値計算では、螺線角はθ＝２５度に固定し、螺線半径のみを４ｍｍから２０ｍｍまで変化させた。他の構成パラメータは、上述の数値計算で用いたものと同じ値に設定した。図１１によれば、螺線半径ｒ＝１０ｍｍのとき、偏波回転角が極大となることがわかる。 FIG. 10 is a graph showing a change in polarization rotation angle with respect to the spiral radius of the electromagnetic wave device provided with the unit resonator 201 according to the first comparative example of the first embodiment. FIG. 11 is a graph showing a change in polarization rotation angle with respect to the spiral radius of the metamaterial device provided with the unit resonator 1 according to the first embodiment. In the numerical calculation of FIGS. 10 and 11, the spiral angle is fixed at θ = 25 degrees, and only the spiral radius is changed from 4 mm to 20 mm. The other configuration parameters were set to the same values as those used in the above-described numerical calculation. According to FIG. 11, it can be seen that the polarization rotation angle is maximum when the spiral radius r = 10 mm.
　図１２は、第１の実施形態の第１の比較例に係る単位共振器２０１を備える電磁波装置の螺線角に対する偏波回転角の変化を示すグラフである。図１３は、第１の実施形態に係る単位共振器１を備えるメタマテリアル装置の螺線角に対する偏波回転角の変化を示すグラフである。図１２及び図１３の数値計算では、螺線半径をｒ＝１０ｍｍに固定し、螺線角のみを変化させた。他の構成パラメータは、上述の数値計算で用いたものと同じ値に設定した。図１３によれば、螺線角θ＝２５度のとき、偏波回転角が極大となることがわかる。 FIG. 12 is a graph showing the change in polarization rotation angle with respect to the spiral angle of the electromagnetic wave device provided with the unit resonator 201 according to the first comparative example of the first embodiment. FIG. 13 is a graph showing the change in the polarization rotation angle with respect to the spiral angle of the metamaterial device provided with the unit resonator 1 according to the first embodiment. In the numerical calculation of FIG. 12 and FIG. 13, the spiral radius is fixed to r = 10 mm, and only the spiral angle is changed. The other configuration parameters were set to the same values as those used in the above-described numerical calculation. According to FIG. 13, it can be seen that the polarization rotation angle is maximal when the screw angle θ = 25 degrees.
　第１の実施形態の第１の比較例に係る単位共振器２０１を備える電磁波装置では、螺線半径及び螺線角を変化させても、偏波回転角は最大で３度程度である。一方、第１の実施形態に係る単位共振器１を備えるメタマテリアル装置では、螺線半径及び螺線角を最適に設定すれば、偏波回転角の大きさを最大２０度まで増加できることがわかる。 In the electromagnetic wave apparatus including the unit resonator 201 according to the first comparative example of the first embodiment, the polarization rotation angle is at most about 3 degrees even if the spiral radius and the spiral angle are changed. On the other hand, in the metamaterial device provided with the unit resonator 1 according to the first embodiment, it can be understood that the size of the polarization rotation angle can be increased up to a maximum of 20 degrees by optimally setting the spiral radius and the spiral angle. .
　次に、上述したものより大きな偏波回転角を有するように設定された代替の単位共振器１のモデルについて説明する。 Next, a model of an alternative unit resonator 1 configured to have a polarization rotation angle larger than that described above will be described.
　図１４は、第１の実施形態（実施例）に係る単位共振器１を備えるメタマテリアル装置と、第１の実施形態の第１の比較例に係る単位共振器２０１を備える電磁波装置とについて、偏波回転角の周波数特性を示すグラフである。図１４の数値計算では、図１と同様に、螺線状の単位共振器の軸が電磁波の伝搬方向に一致する単位セル１０Ａを用いた。 FIG. 14 shows a metamaterial device including the unit resonator 1 according to the first embodiment (example) and an electromagnetic wave device including the unit resonator 201 according to the first comparative example of the first embodiment, It is a graph which shows the frequency characteristic of a polarization rotation angle. In the numerical calculation of FIG. 14, similarly to FIG. 1, the unit cell 10A in which the axis of the spiral unit resonator coincides with the propagation direction of the electromagnetic wave was used.
　図１４の数値計算では、単位共振器１の構成パラメータは、以下の通りであった。 In the numerical calculation of FIG. 14, the configuration parameters of the unit resonator 1 were as follows.
単位セル１０Ａのサイズ：ｄ１＝ｄ２＝２５ｍｍ
ストリップ導体２３の長さ：ｌ＝６ｍｍ
ストリップ導体２３の幅：ｗ＝２ｍｍ
ストリップ導体２３の厚さ：ｔ＝１８μｍ
キャパシタ２４の容量：Ｃ＝１．７ｐＦ
反射素子２２の全長：１５ｍｍ
反射素子２２の幅：１．０ｍｍ
螺線半径：ｒ＝１０ｍｍ
螺旋角：θ＝２５度 Size of unit cell 10A: d1 = d2 = 25 mm
Length of strip conductor 23: l = 6 mm
Width of strip conductor 23: w = 2 mm
Thickness of strip conductor 23: t = 18 μm
Capacitance of capacitor 24: C = 1.7 pF
Total length of reflective element 22: 15 mm
Reflective element 22 width: 1.0 mm
Spiral radius: r = 10 mm
Spiral angle: θ = 25 degrees
　また、図１４の数値計算では、単位共振器２０１の構成パラメータは、以下の通りであった。 Further, in the numerical calculation of FIG. 14, the configuration parameters of the unit resonator 201 are as follows.
単位セル１０Ａのサイズ：ｄ１＝ｄ２＝２５ｍｍ
共振素子の全長：６９．５ｍｍ
共振素子の幅：２ｍｍ
螺線半径：ｒ＝１０ｍｍ
螺旋角：θ＝２５度 Size of unit cell 10A: d1 = d2 = 25 mm
Total length of resonant element: 69.5 mm
Width of resonant element: 2 mm
Spiral radius: r = 10 mm
Spiral angle: θ = 25 degrees
　図１４によれば、第１の実施形態の第１の比較例に係る単位共振器２０１を備える電磁波装置では、周波数２．８ＧＨｚにおいて偏波回転角７．３１度が得られた。一方、第１の実施形態（実施例）に係る単位共振器１を備えるメタマテリアル装置では、周波数２．４４ＧＨｚにおいて偏波回転角３３．６度が得られた。従って、この場合もまた、０次共振器である単位共振器１を備えるメタマテリアル装置の偏波回転角は、半波長共振器である単位共振器２０１を備える電磁波装置の偏波回転角に比べて約４．６倍に増大した。 According to FIG. 14, in the electromagnetic wave apparatus including the unit resonator 201 according to the first comparative example of the first embodiment, a polarization rotation angle of 7.31 degrees is obtained at a frequency of 2.8 GHz. On the other hand, in the metamaterial device provided with the unit resonator 1 according to the first embodiment (example), a polarization rotation angle of 33.6 degrees was obtained at a frequency of 2.44 GHz. Therefore, also in this case, the polarization rotation angle of the metamaterial device provided with the unit resonator 1 which is the zero-order resonator is compared with the polarization rotation angle of the electromagnetic wave device provided with the unit resonator 201 which is the half wavelength resonator. Increased about 4.6 times.
　図１５は、第１の実施形態（実施例）に係る単位共振器１を備えるメタマテリアル装置と、第１の実施形態の第１の比較例に係る単位共振器２０１を備える電磁波装置とについて、偏波回転角の周波数特性を示すグラフである。図１５の数値計算では、図５と同様に、螺線状の単位共振器の軸が電磁波の伝搬方向に直交する単位セル１０Ｂを用いた。 FIG. 15 shows a metamaterial device including the unit resonator 1 according to the first embodiment (example) and an electromagnetic wave device including the unit resonator 201 according to the first comparative example of the first embodiment, It is a graph which shows the frequency characteristic of a polarization rotation angle. In the numerical calculation of FIG. 15, as in FIG. 5, the unit cell 10B in which the axis of the spiral unit resonator is orthogonal to the propagation direction of the electromagnetic wave was used.
　図１５の数値計算では、単位共振器１の構成パラメータは、以下の通りであった。 In the numerical calculation of FIG. 15, the configuration parameters of the unit resonator 1 were as follows.
単位セル１０Ｂのサイズ：ｄ１×ｄ２＝２５ｍｍ×５５ｍｍ
ストリップ導体２３の長さ：ｌ＝６ｍｍ
ストリップ導体２３の幅：ｗ＝２ｍｍ
ストリップ導体２３の厚さ：ｔ＝１８μｍ
キャパシタ２４の容量：Ｃ＝０．７ｐＦ
反射素子２２の全長：１４ｍｍ
反射素子２２の幅：１．０ｍｍ
螺線半径：ｒ＝１０ｍｍ
螺旋角：θ＝２５度 Size of unit cell 10B: d1 x d2 = 25 mm x 55 mm
Length of strip conductor 23: l = 6 mm
Width of strip conductor 23: w = 2 mm
Thickness of strip conductor 23: t = 18 μm
Capacitance of capacitor 24: C = 0.7 pF
Total length of reflective element 22: 14 mm
Reflective element 22 width: 1.0 mm
Spiral radius: r = 10 mm
Spiral angle: θ = 25 degrees
　また、図１５の数値計算では、単位共振器２０１の構成パラメータは、以下の通りであった。 Further, in the numerical calculation of FIG. 15, the configuration parameters of the unit resonator 201 are as follows.
単位セル１０Ｂのサイズ：ｄ１×ｄ２＝２５ｍｍ×３５ｍｍ
共振素子の全長：６９．５ｍｍ
共振素子の幅：２ｍｍ
螺線半径：ｒ＝１０ｍｍ
螺旋角：θ＝２５度 Size of unit cell 10B: d1 x d2 = 25 mm x 35 mm
Total length of resonant element: 69.5 mm
Width of resonant element: 2 mm
Spiral radius: r = 10 mm
Spiral angle: θ = 25 degrees
　図１５によれば、第１の実施形態の第１の比較例に係る単位共振器２０１を備える電磁波装置では、周波数２．４８ＧＨｚにおいて偏波回転角１．４８度が得られた。一方、第１の実施形態（実施例）に係る単位共振器１を備えるメタマテリアル装置では、周波数２．６８ＧＨｚにおいて偏波回転角３２．１度が得られた。従って、図１５の場合もまた、０次共振器である単位共振器１を備えるメタマテリアル装置の偏波回転角は、図１４の場合と同程度に増大していることがわかる。 According to FIG. 15, in the electromagnetic wave apparatus provided with the unit resonator 201 according to the first comparative example of the first embodiment, a polarization rotation angle of 1.48 degrees was obtained at a frequency of 2.48 GHz. On the other hand, in the metamaterial device including the unit resonator 1 according to the first embodiment (example), a polarization rotation angle of 32.1 degrees was obtained at a frequency of 2.68 GHz. Accordingly, also in the case of FIG. 15, it is understood that the polarization rotation angle of the metamaterial device provided with the unit resonator 1 which is the zero-order resonator is increased to the same extent as in the case of FIG. 14.
　次に、図１６～図２２を参照して、第１の実施形態に係るメタマテリアル装置を実際に作成し、その特性を実際に測定した結果について説明する。 Next, with reference to FIGS. 16 to 22, the metamaterial device according to the first embodiment is actually created, and the results of actually measuring the characteristics thereof will be described.
　図１６は、第１の実施形態に係る単位共振器１を備えるメタマテリアル装置の測定システムを示す概略図である。図１６のメタマテリアル装置１００は、Ｘ方向及びＹ方向に沿って２次元アレイとして配列された複数の単位共振器１を備える。送信アンテナ３１及び受信アンテナ３２はネットワークアナライザに接続され、メタマテリアル装置１００は、送信アンテナ３１及び受信アンテナ３２の間に測定試料として配置される。送信アンテナ３１及び受信アンテナ３２は、例えばホーンアンテナである。送信アンテナ３１及び受信アンテナ３２の偏波方向を変更しながら電波を送受信することにより、メタマテリアル装置１００の直線偏波の透過特性Ｔｘｘ、Ｔｙｘ、Ｔｘｙ、及びＴｙｙを測定した。これにより、メタマテリアル装置１００の偏波回転角を実際に測定した。 FIG. 16 is a schematic view showing a measurement system of a metamaterial device provided with the unit resonator 1 according to the first embodiment. The metamaterial device 100 of FIG. 16 includes a plurality of unit resonators 1 arranged as a two-dimensional array along the X direction and the Y direction. The transmitting antenna 31 and the receiving antenna 32 are connected to a network analyzer, and the metamaterial device 100 is disposed as a measurement sample between the transmitting antenna 31 and the receiving antenna 32. The transmitting antenna 31 and the receiving antenna 32 are, for example, horn antennas. The transmission characteristics T xx , T yx , T xy , and T yy of the linearly polarized light of the metamaterial device 100 were measured by transmitting and receiving radio waves while changing the polarization directions of the transmitting antenna 31 and the receiving antenna 32. Thus, the polarization rotation angle of the metamaterial device 100 was actually measured.
　図１７は、第１の実施形態の第１の実施例に係る単位共振器１を備えるメタマテリアル装置を示す図である。図１７のメタマテリアル装置は、複数の単位共振器１、複数の円柱部材２、及びベース部材３を備えた。複数の単位共振器１は、複数の円柱部材２の周りにそれぞれ螺旋状に巻回された。複数の単位共振器１及び複数の円柱部材２は、螺線状の単位共振器の軸が電磁波の伝搬方向（Ｚ方向）に一致するように、板状のベース部材３の上に配置された。図１７の例では、５個×４個の単位共振器１及び円柱部材２を、ｄ１１×ｄ１２＝１２５ｍｍ×１００ｍｍの範囲に配置した。図１７の各単位共振器１には、図１４を参照して説明したものと同じ構成パラメータを設定した。 FIG. 17 is a view showing a metamaterial device provided with the unit resonator 1 according to the first example of the first embodiment. The metamaterial device of FIG. 17 includes a plurality of unit resonators 1, a plurality of cylindrical members 2, and a base member 3. The plurality of unit resonators 1 are spirally wound around the plurality of cylindrical members 2 respectively. The plurality of unit resonators 1 and the plurality of cylindrical members 2 are disposed on the plate-like base member 3 such that the axes of the spiral unit resonators coincide with the propagation direction (Z direction) of the electromagnetic wave. . In the example of FIG. 17, 5 × 4 unit resonators 1 and cylindrical members 2 are disposed in the range of d11 × d12 = 125 mm × 100 mm. The same configuration parameters as those described with reference to FIG. 14 were set in each unit resonator 1 of FIG.
　図１８は、第１の実施形態の第２の実施例に係る単位共振器１を備えるメタマテリアル装置を示す図である。図１８のメタマテリアル装置は、複数の単位共振器１、複数の円柱部材２、及びベース部材３を備えた。複数の単位共振器１及び複数の円柱部材２は、螺線状の単位共振器の軸が電磁波の伝搬方向（Ｚ方向）に直交するように、板状のベース部材３の上に配置された。図１８の例では、３個×４個の単位共振器１及び円柱部材２を、ｄ１１×ｄ１２＝１６５ｍｍ×１００ｍｍの範囲に配置した。図１８の各単位共振器１には、図１５を参照して説明したものと同じ構成パラメータを設定した。 FIG. 18 is a view showing a metamaterial device provided with a unit resonator 1 according to a second example of the first embodiment. The metamaterial device of FIG. 18 includes a plurality of unit resonators 1, a plurality of cylindrical members 2, and a base member 3. The plurality of unit resonators 1 and the plurality of cylindrical members 2 are disposed on the plate-like base member 3 such that the axes of the spiral unit resonators are orthogonal to the propagation direction (Z direction) of the electromagnetic wave. . In the example of FIG. 18, 3 × 4 unit resonators 1 and cylindrical members 2 are disposed in the range of d11 × d12 = 165 mm × 100 mm. The same configuration parameters as those described with reference to FIG. 15 were set in each unit resonator 1 of FIG. 18.
　図１９は、第１の実施形態の第４の比較例に係る単位共振器２０１を備える電磁波装置を示す図である。図１９の電磁波装置は、複数の単位共振器２０１、複数の円柱部材２０２、及びベース部材２０３を備えた。複数の単位共振器２０１は、複数の円柱部材２０２の周りにそれぞれ螺旋状に巻回された。複数の単位共振器２０１及び複数の円柱部材２０２は、螺線状の単位共振器の軸が電磁波の伝搬方向（Ｚ方向）に一致するように、板状のベース部材２０３の上に配置された。図１９の例では、５個×４個の単位共振器２０１及び円柱部材２０２を、ｄ１１×ｄ１２＝１２５ｍｍ×１００ｍｍの範囲に配置した。図１９の各単位共振器２０１には、図１４を参照して説明したものと同じ構成パラメータを設定した。 FIG. 19 is a view showing an electromagnetic wave apparatus provided with a unit resonator 201 according to a fourth comparative example of the first embodiment. The electromagnetic wave device of FIG. 19 includes a plurality of unit resonators 201, a plurality of cylindrical members 202, and a base member 203. The plurality of unit resonators 201 are spirally wound around the plurality of cylindrical members 202, respectively. The plurality of unit resonators 201 and the plurality of cylindrical members 202 are disposed on the plate-like base member 203 such that the axes of the spiral unit resonators coincide with the propagation direction (Z direction) of the electromagnetic wave. . In the example of FIG. 19, 5 × 4 unit resonators 201 and cylindrical members 202 are disposed in the range of d11 × d12 = 125 mm × 100 mm. The same configuration parameters as those described with reference to FIG. 14 were set in each unit resonator 201 of FIG.
　図２０は、第１の実施形態の第５の比較例に係る単位共振器２０１を備える電磁波装置を示す図である。図２０の電磁波装置は、複数の単位共振器２０１、複数の円柱部材２０２、及びベース部材２０３を備えた。複数の単位共振器２０１及び複数の円柱部材２０２は、螺線状の単位共振器の軸が電磁波の伝搬方向（Ｚ方向）に直交するように、板状のベース部材２０３の上に配置された。図２０の例では、４個×４個の単位共振器２０１及び円柱部材２０２を、ｄ１１×ｄ１２＝１４０ｍｍ×１００ｍｍの範囲に配置した。図２０の各単位共振器２０１には、図１５を参照して説明したものと同じ構成パラメータを設定した。 FIG. 20 is a diagram showing an electromagnetic wave apparatus provided with a unit resonator 201 according to a fifth comparative example of the first embodiment. The electromagnetic wave device in FIG. 20 includes a plurality of unit resonators 201, a plurality of cylindrical members 202, and a base member 203. The plurality of unit resonators 201 and the plurality of cylindrical members 202 are disposed on the plate-like base member 203 such that the axes of the spiral unit resonators are orthogonal to the propagation direction (Z direction) of the electromagnetic wave. . In the example of FIG. 20, 4 × 4 unit resonators 201 and cylindrical members 202 are disposed in the range of d11 × d12 = 140 mm × 100 mm. The same configuration parameters as those described with reference to FIG. 15 were set in each unit resonator 201 of FIG.
　図１７～図２０の円柱部材２，２０２及びベース部材３，２０３として、例えばスチロールからなるものを用いた。単位共振器１，２０１は、ストリップ導体２３として両面テープ上に配置された銅薄膜を備え、さらに、互いに隣接する銅薄膜の間にハンダで接続されたチップキャパシタをキャパシタ２４として備えた。 As the cylindrical members 2 and 202 and the base members 3 and 203 in FIGS. 17 to 20, for example, those made of polystyrene are used. The unit resonators 1, 201 each include a copper thin film disposed on a double-sided tape as a strip conductor 23, and further include a chip capacitor connected by solder between adjacent copper thin films as a capacitor 24.
　図２１は、第１の実施形態の第１の実施例に係る単位共振器１を備えるメタマテリアル装置と、第１の実施形態の第４の比較例に係る単位共振器２０１を備える電磁波装置とについて、偏波回転角の周波数特性を示すグラフである。すなわち、図２１は、螺線状の単位共振器の軸が電磁波の伝搬方向に一致する場合である、図１７のメタマテリアル装置（第１の実施例）と、図１９の電磁波装置（第４の比較例）とについて、偏波回転角の周波数特性を示す。第４の比較例では、周波数２．６８ＧＨｚにおいて偏波回転角９．１度が得られた。なお、図１９の電磁波装置と同じ構成パラメータを設定して数値計算を行った場合、図１４を参照して前述したように周波数２．８ＧＨｚにおいて共振周波数７．３１度が得られたので、偏波回転角の周波数特性は、数値計算と実際の測定とで比較的に良く一致していることがわかる。一方、第１の実施例では、周波数２．３７ＧＨｚにおいて偏波回転角３２．５度が得られた。なお、図１７のメタマテリアル装置と同じ構成パラメータを設定して数値計算を行った場合、図１４を参照して前述したように２．４４ＧＨｚにおいて偏波回転角３３．６度が得られたので、偏波回転角の周波数特性は、数値計算と実際の測定とで同程度になることがわかる。以上のことから、０次共振器である単位共振器１を備える第１の実施例のメタマテリアル装置の偏波回転角は、半波長共振器である単位共振器２０１を備える第４の比較例の電磁波装置の偏波回転角に比べて大幅に増大することが実験でも実証された。 FIG. 21 shows a metamaterial device provided with the unit resonator 1 according to the first example of the first embodiment, and an electromagnetic wave device provided with the unit resonator 201 according to the fourth comparative example of the first embodiment Is a graph showing the frequency characteristics of the polarization rotation angle. That is, FIG. 21 is the case where the axis of the spiral unit resonator coincides with the propagation direction of the electromagnetic wave, and the metamaterial device (first embodiment) of FIG. 17 and the electromagnetic wave device (fourth example) of FIG. And the frequency characteristics of the polarization rotation angle. In the fourth comparative example, a polarization rotation angle of 9.1 degrees was obtained at a frequency of 2.68 GHz. When numerical values are calculated by setting the same configuration parameters as those of the electromagnetic wave device shown in FIG. 19, a resonant frequency of 7.31 degrees is obtained at a frequency of 2.8 GHz as described above with reference to FIG. It can be seen that the frequency characteristics of the wave rotation angle are relatively well matched between the numerical calculation and the actual measurement. On the other hand, in the first embodiment, a polarization rotation angle of 32.5 degrees was obtained at a frequency of 2.37 GHz. In addition, when numerical parameters are calculated by setting the same configuration parameters as the metamaterial device of FIG. 17, the polarization rotation angle of 33.6 degrees is obtained at 2.44 GHz as described above with reference to FIG. It can be seen that the frequency characteristics of the polarization rotation angle are comparable between numerical calculation and actual measurement. From the above, the polarization rotation angle of the metamaterial device of the first example provided with the unit resonator 1 which is a zero-order resonator is the fourth comparative example provided with the unit resonator 201 which is a half-wave resonator. Experiments have also demonstrated that the polarization rotation angle of the electromagnetic wave device significantly increases.
　図２２は、第１の実施形態の第２の実施例に係る単位共振器１を備えるメタマテリアル装置と、第１の実施形態の第５の比較例に係る単位共振器２０１を備える電磁波装置とについて、偏波回転角の周波数特性を示すグラフである。すなわち、図２２は、螺線状の単位共振器の軸が電磁波の伝搬方向に直交する場合である、図１８のメタマテリアル装置（第２の実施例）と、図２０の電磁波装置（第５の比較例）とについて、偏波回転角の周波数特性を示す。第５の比較例では、周波数２．４２ＧＨｚにおいて偏波回転角３．５６度が得られた。なお、図２０の電磁波装置と同じ構成パラメータを設定して数値計算を行った場合、図１５を参照して前述したように周波数２．４８ＧＨｚにおいて偏波回転角１．４８度が得られたので、偏波回転角の周波数特性は、数値計算と実際の測定とで同程度になることがわかる。一方、第２の実施例では、周波数２．５９５ＧＨｚにおいて偏波回転角３１．９度が得られた。なお、図１８のメタマテリアル装置と同じ構成パラメータを設定して数値計算を行った場合、図１５を参照して前述したように周波数２．６８ＧＨｚにおいて偏波回転角３２．１度が得られたので、偏波回転角の周波数特性は、数値計算と実際の測定とで比較的に良く一致していることがわかる。以上のことから、０次共振器である単位共振器１を備える第２の実施例のメタマテリアル装置の偏波回転角は、半波長共振器である単位共振器２０１を備える第５の比較例の電磁波装置の偏波回転角に比べて大幅に増大することが実験でも実証された。 FIG. 22 shows a metamaterial device including the unit resonator 1 according to the second example of the first embodiment, and an electromagnetic wave device including the unit resonator 201 according to the fifth comparative example of the first embodiment Is a graph showing the frequency characteristics of the polarization rotation angle. That is, FIG. 22 is the case where the axis of the spiral unit resonator is orthogonal to the propagation direction of the electromagnetic wave, and the metamaterial device (second example) of FIG. 18 and the electromagnetic wave device (fifth example of FIG. And the frequency characteristics of the polarization rotation angle. In the fifth comparative example, a polarization rotation angle of 3.56 degrees was obtained at a frequency of 2.42 GHz. In addition, when numerical parameters are calculated by setting the same configuration parameters as the electromagnetic wave device of FIG. 20, a polarization rotation angle of 1.48 degrees is obtained at a frequency of 2.48 GHz as described above with reference to FIG. It can be seen that the frequency characteristics of the polarization rotation angle are comparable between numerical calculation and actual measurement. On the other hand, in the second embodiment, a polarization rotation angle of 31.9 degrees was obtained at a frequency of 2.595 GHz. In addition, when numerical parameters are calculated by setting the same configuration parameters as the metamaterial device of FIG. 18, a polarization rotation angle of 32.1 degrees is obtained at a frequency of 2.68 GHz as described above with reference to FIG. Therefore, it can be seen that the frequency characteristics of the polarization rotation angle are relatively well matched between the numerical calculation and the actual measurement. From the above, the polarization rotation angle of the metamaterial device of the second embodiment including the unit resonator 1 which is a zero-order resonator is the fifth comparative example including the unit resonator 201 which is a half-wave resonator. Experiments have also demonstrated that the polarization rotation angle of the electromagnetic wave device significantly increases.
　図２３は、第１の実施形態の第１の変形例に係る単位共振器１Ａを示す斜視図である。図１の単位共振器１では、反射素子２２のサイズを小さくするために、ミアンダ形状を有するストリップ導体を用いたが、反射素子２２の形状はこれに限定されない。反射素子２２は、動作波長の４分の１の長さを有し、共振素子２１の両端において短絡する条件を満足しさえすれば、任意の形状を有してもよい。例えば、図２３の単位共振器１Ａのように、渦巻き形状を有する反射素子２２Ａを備えてもよい。また、反射素子２２，２２Ａは、金属材料で構成される必要はなく、誘電体で構成されてもよい。 FIG. 23 is a perspective view showing a unit resonator 1A according to a first modified example of the first embodiment. In the unit resonator 1 of FIG. 1, in order to reduce the size of the reflective element 22, a strip conductor having a meander shape is used, but the shape of the reflective element 22 is not limited to this. The reflective element 22 may have any shape as long as it has a length of 1⁄4 of the operating wavelength and satisfies the short circuit condition at both ends of the resonant element 21. For example, as in the unit resonator 1A of FIG. 23, a reflective element 22A having a spiral shape may be provided. Further, the reflective elements 22 and 22A do not have to be made of a metal material, and may be made of a dielectric.
　図２４は、第１の実施形態の第２の変形例に係る単位共振器１Ｂを示す斜視図である。単位共振器１Ｂは、チップキャパシタである図２のキャパシタ２４に代えて、インターディジタルキャパシタのように分布定数キャパシタであるキャパシタ２４Ｂを備えてもよい。単位共振器１Ｂの共振素子２１Ｂにおいて、各直列ＬＣ共振回路はストリップ導体２３Ｂを備え、各直列ＬＣ共振回路のストリップ導体２３Ｂの端部は、隣接する直列ＬＣ共振回路のストリップ導体２３Ｂの端部と容量結合するように形成される。図２４の単位共振器１Ｂによれば、チップキャパシタを単位共振器に実装する必要がなく、導体パターンのみで単位共振器１Ｂを製造できるので、その製造を簡単化することができる。 FIG. 24 is a perspective view showing a unit resonator 1B according to a second modified example of the first embodiment. The unit resonator 1B may include a capacitor 24B which is a distributed constant capacitor such as an interdigital capacitor, instead of the capacitor 24 of FIG. 2 which is a chip capacitor. In the resonance element 21B of the unit resonator 1B, each series LC resonance circuit includes a strip conductor 23B, and an end of the strip conductor 23B of each series LC resonance circuit is an end of the strip conductor 23B of the adjacent series LC resonance circuit. It is formed to be capacitively coupled. According to the unit resonator 1B of FIG. 24, there is no need to mount the chip capacitor on the unit resonator, and the unit resonator 1B can be manufactured only with the conductor pattern, so that the manufacture can be simplified.
　また、図２の単位共振器１では、共振素子２１の各直列ＬＣ共振回路は、所定のインダクタンスを有するストリップ導体２３を備えていたが、インダクタンスを有する素子はこれに限定されない。ストリップ導体２３に代えて、チップインダクタを用いてもよい。 Further, in the unit resonator 1 of FIG. 2, each series LC resonant circuit of the resonant element 21 includes the strip conductor 23 having a predetermined inductance, but the element having the inductance is not limited to this. A chip inductor may be used instead of the strip conductor 23.
　また、第１の実施形態に係る単位共振器は、螺線以外の形状を有してもよい。単位共振器は、カイラリティを生じることができるのであれば、例えば渦巻き形状など、平面形状を有してもよい。 Further, the unit resonator according to the first embodiment may have a shape other than a spiral. The unit resonator may have a planar shape, such as a spiral shape, as long as chirality can be generated.
　以上説明したように、第１の実施形態に係るメタマテリアル装置によれば、螺旋状に巻回された０次共振器である単位共振器１を備えたことにより光学活性を増大し、この０次共振により、従来の半波長共振器を備える電磁波装置と比べて偏波回転度が大きく増大したことを確認した。これにより、カイラル構造を利用した様々なデバイスの特性改善が期待される。 As described above, according to the metamaterial device of the first embodiment, the optical activity is increased by providing the unit resonator 1 which is a zero-order resonator wound in a spiral shape. It was confirmed that the degree of polarization rotation was greatly increased by the next resonance as compared with the electromagnetic wave device provided with the conventional half-wave resonator. This is expected to improve the characteristics of various devices using chiral structures.
第２の実施形態．
　図２５は、第２の実施形態に係る偏波選択板の動作を示す概略図である。図２５に示すように、第１の実施形態に係るメタマテリアル装置１００は、入射する電磁波のエネルギーの一部を電磁波の偏波面に応じて選択的に透過又は反射する偏波選択板として動作してもよい。 Second embodiment.
FIG. 25 is a schematic view showing the operation of the polarization selection plate according to the second embodiment. As shown in FIG. 25, the metamaterial device 100 according to the first embodiment operates as a polarization selection plate that selectively transmits or reflects a part of the energy of the incident electromagnetic wave according to the polarization plane of the electromagnetic wave. May be
　ここで、図２６及び図２７を参照して、単位共振器による電磁波の透過及び反射について説明する。 Here, transmission and reflection of an electromagnetic wave by a unit resonator will be described with reference to FIG. 26 and FIG.
　図２６は、第２の実施形態の実施例に係る単位共振器を備えるメタマテリアル装置の、異なる偏波面を有する電磁波の透過係数を示すグラフである。図２６では、電磁波の伝搬方向に対して垂直な基板に沿って、図２と同様の単位共振器１を形成し、共振素子２１の長手方向に直交する偏波面を有する平面波（Ｔｘ）と、共振素子２１の長手方向に沿った偏波面を有する平面波（Ｔｙ）とを単位共振器１に向けて放射した場合を示す。 FIG. 26 is a graph showing transmission coefficients of electromagnetic waves having different polarization planes of a metamaterial device provided with unit resonators according to an example of the second embodiment. In FIG. 26, a unit resonator 1 similar to that of FIG. 2 is formed along a substrate perpendicular to the propagation direction of the electromagnetic wave, and a plane wave (Tx) having a polarization plane orthogonal to the longitudinal direction of the resonant element 21; The case where a plane wave (Ty) having a polarization plane along the longitudinal direction of the resonant element 21 is emitted toward the unit resonator 1 is shown.
　図２７は、第２の実施形態の比較例に係る単位共振器を備えるメタマテリアル装置の、異なる偏波面を有する電磁波の透過係数を示すグラフである。図２７では、電磁波の伝搬方向に対して垂直な基板に沿って、直線状のストリップ導体からなる半波長共振器を形成し、半波長共振器の長手方向に直交する偏波面を有する平面波（Ｔｘ）と、半波長共振器の長手方向に沿った偏波面を有する平面波（Ｔｙ）とを半波長共振器に向けて放射した場合を示す。 FIG. 27 is a graph showing transmission coefficients of electromagnetic waves having different polarization planes of a metamaterial device provided with unit resonators according to a comparative example of the second embodiment. In FIG. 27, a half-wave resonator formed of a linear strip conductor is formed along a substrate perpendicular to the propagation direction of the electromagnetic wave, and a plane wave (Tx having a polarization plane orthogonal to the longitudinal direction of the half-wave resonator) And a plane wave (Ty) having a polarization plane along the longitudinal direction of the half-wave resonator toward the half-wave resonator.
　図２６及び図２７によれば、共振素子２１又は半波長共振器の長手方向に直交する偏波面を有する平面波（Ｔｘ）は、いずれも、よく透過している。一方、図２７によれば、半波長共振器の長手方向に沿った偏波面を有する平面波（Ｔｙ）は、半波長共振器によって反射されて－４６．３ｄＢまで減衰しているのに対して、図２６によれば、共振素子２１の長手方向に沿った偏波面を有する平面波（Ｔｙ）は、単位共振器１によって反射されて－４８．２ｄＢまで減衰している。従って、半波長共振器に代えて単位共振器１を用いることにより、半波長共振器よりも良好に電磁波を反射することができる。 According to FIGS. 26 and 27, all plane waves (Tx) having polarization planes orthogonal to the longitudinal direction of the resonant element 21 or the half-wave resonator are well transmitted. On the other hand, according to FIG. 27, a plane wave (Ty) having a polarization plane along the longitudinal direction of the half-wave resonator is reflected by the half-wave resonator and attenuated to -46.3 dB, According to FIG. 26, a plane wave (Ty) having a polarization plane along the longitudinal direction of the resonant element 21 is reflected by the unit resonator 1 and attenuated to -48.2 dB. Therefore, by using the unit resonator 1 instead of the half wavelength resonator, it is possible to reflect the electromagnetic wave better than the half wavelength resonator.
　図２６及び図２７を参照して説明した結果は、図１等に示すように単位共振器１を巻回した場合にも同様にあてはまる。 The results described with reference to FIGS. 26 and 27 also apply to the case where the unit resonator 1 is wound as shown in FIG. 1 and the like.
　第１の実施形態に係るメタマテリアル装置１００を用いることにより、半波長共振器及び一波長共振器などを備えたメタマテリアル装置よりも、入射する電磁波のエネルギーを良好に反射する偏波選択板を提供することができる。 By using the metamaterial device 100 according to the first embodiment, a polarization selection plate that reflects the energy of the incident electromagnetic wave better than the metamaterial device provided with a half wavelength resonator, a single wavelength resonator, etc. Can be provided.
第３の実施形態．
　図２８は、第３の実施形態に係る偏波回転板の動作を示す概略図である。図２８に示すように、第１の実施形態に係るメタマテリアル装置１００は、入射する電磁波の偏波面を角度φにわたって回転させる偏波回転板として動作してもよい。第１の実施形態に係るメタマテリアル装置１００を用いることにより、半波長共振器及び一波長共振器などを備えたメタマテリアル装置よりも、入射する電磁波の偏波面を良好に回転する偏波回転板を提供することができる。 Third embodiment.
FIG. 28 is a schematic view showing the operation of the polarization rotating plate according to the third embodiment. As shown in FIG. 28, the metamaterial device 100 according to the first embodiment may operate as a polarization rotation plate that rotates the polarization plane of an incident electromagnetic wave across an angle φ. A polarization rotation plate that rotates the polarization plane of incident electromagnetic waves better by using the metamaterial device 100 according to the first embodiment than a metamaterial device provided with a half wavelength resonator, a single wavelength resonator, etc. Can be provided.
第４の実施形態．
　図２９は、第４の実施形態に係る周波数選択板の動作を示す概略図である。図２９に示すように、第１の実施形態に係るメタマテリアル装置１００は、入射する電磁波のエネルギーの一部を透過させ、入射する電磁波のエネルギーの残りの一部を反射する周波数選択板として動作してもよい。メタマテリアル装置１００は、入射する電磁波のエネルギーの一部を透過させるとき、その偏波面を角度φ１にわたって回転させる。また、メタマテリアル装置１００は、入射する電磁波のエネルギーの残りの一部を反射するとき、その偏波面を角度φ２にわたって回転させる。第１の実施形態に係るメタマテリアル装置１００を用いることにより、半波長共振器及び一波長共振器などを備えたメタマテリアル装置よりも、入射する電磁波の周波数成分を良好に分離する周波数選択板を提供することができる。 Fourth Embodiment
FIG. 29 is a schematic view showing the operation of the frequency selection plate according to the fourth embodiment. As shown in FIG. 29, the metamaterial device 100 according to the first embodiment operates as a frequency selection plate that transmits part of the energy of the incident electromagnetic wave and reflects the remaining part of the energy of the incident electromagnetic wave. You may When transmitting part of the energy of the incident electromagnetic wave, the metamaterial device 100 rotates its polarization plane through an angle φ1. Further, when the metamaterial device 100 reflects a part of the energy of the incident electromagnetic wave, the metamaterial device 100 rotates its polarization plane through an angle φ2. By using the metamaterial device 100 according to the first embodiment, a frequency selection plate that can better separate the frequency components of the incident electromagnetic wave than the metamaterial device provided with a half wavelength resonator, a single wavelength resonator, etc. Can be provided.
第５の実施形態．
　第１の実施形態では、カイラリティを得るために、単位共振器を螺旋状に巻回した。しかしながら、前述のように、卍字形及び渦巻きなどの平面構造物もカイラル構造を有する。第５の実施形態では、カイラル構造を有する平坦な単位共振器を備えるメタマテリアル装置について説明する。 Fifth Embodiment
In the first embodiment, the unit resonator is spirally wound in order to obtain chirality. However, as mentioned above, planar structures such as V-shaped and spiral also have chiral structures. In the fifth embodiment, a metamaterial device provided with a flat unit resonator having a chiral structure will be described.
　図３０は、第５の実施形態に係る単位共振器１Ｃを含む第３の単位セル１０Ｃを示す斜視図である。単位共振器１Ｃは、平坦な基板２０Ｃ上に形成される。図３０は、単位セル１０Ｃにおいて基板２０Ｃの面（ＸＹ面に平行な面）が電磁波の伝搬方向（－Ｚ方向）に直交する場合を示す。基板２０Ｃは、例えば誘電体からなる。また、単位セル１０Ｃは、Ｘ方向、Ｙ方向、及びＺ方向に沿って、長さｄ１、ｄ２、及びｄ３をそれぞれ有する。 FIG. 30 is a perspective view showing a third unit cell 10C including the unit resonator 1C according to the fifth embodiment. The unit resonator 1C is formed on a flat substrate 20C. FIG. 30 shows the case where the surface (surface parallel to the XY plane) of the substrate 20C in the unit cell 10C is orthogonal to the propagation direction (-Z direction) of the electromagnetic wave. The substrate 20C is made of, for example, a dielectric. Further, unit cell 10C has lengths d1, d2 and d3 along the X direction, Y direction and Z direction, respectively.
　本明細書では、単位共振器が形成された基板の面が電磁波の伝搬方向に直交する単位セルを、符号「１０Ｃ」により示す。 In the present specification, a unit cell in which the surface of the substrate on which the unit resonator is formed is orthogonal to the propagation direction of the electromagnetic wave is indicated by a symbol “10C”.
　図３１は、図３０の単位共振器１Ｃの構成を示す平面図である。単位共振器１Ｃは、１つの共振素子２１Ｃ及び複数の反射素子２２を備える。 FIG. 31 is a plan view showing a configuration of the unit resonator 1C of FIG. The unit resonator 1 </ b> C includes one resonant element 21 </ b> C and a plurality of reflective elements 22.
　共振素子２１Ｃは、少なくとも１つのストリップ形状の部分素子を含み、電流が同時に逆向きに流れる並列回路部分を含まない経路を有する。共振素子２１Ｃは、基板２０Ｃの面内において屈曲又は湾曲したストリップ形状をそれぞれ有する複数の部分素子、図３１の例では４つのアーム２６を含む。図３１の例では、共振素子２１Ｃは卍字形に形成される。各アーム２６は、図２の共振素子２１と同様に、ストリップ導体２３及びキャパシタ２４を含む。各アーム２６の一端は、複数の反射素子２２のうちの１つに接続され、各アーム２６の他端は、中心導体２５を介して他のアーム２６に接続される。共振素子２１Ｃは、中心Ｏの周りにおいて実質的に回転対称に形成される。これにより、共振素子２１Ｃは、基板２０Ｃの面内の任意の直線に対して非対称に形成される。 The resonant element 21C includes at least one strip-shaped subelement and has a path that does not include a parallel circuit part through which current flows simultaneously in the opposite direction. The resonant element 21C includes a plurality of subelements each having a bent or curved strip shape in the plane of the substrate 20C, four arms 26 in the example of FIG. In the example of FIG. 31, the resonant element 21C is formed in a wedge shape. Each arm 26 includes a strip conductor 23 and a capacitor 24 as with the resonant element 21 of FIG. One end of each arm 26 is connected to one of the plurality of reflective elements 22, and the other end of each arm 26 is connected to the other arm 26 via the central conductor 25. The resonant element 21C is formed substantially rotationally symmetric around the center O. Thereby, the resonant element 21C is formed asymmetrically with respect to any straight line in the plane of the substrate 20C.
　図３１の各反射素子２２は、図２の反射素子２２と同様に構成される。各反射素子２２は、共振素子２１Ｃの各アーム２６の各端部にそれぞれ接続され、各アーム２６から各反射素子２２Ｃを見たときのインピーダンスが実質的にゼロになるように構成される。 Each reflective element 22 of FIG. 31 is configured in the same manner as the reflective element 22 of FIG. Each reflective element 22 is connected to each end of each arm 26 of the resonant element 21C, and is configured such that the impedance when viewing each reflective element 22C from each arm 26 is substantially zero.
　単位共振器１Ｃもまた、図１等の単位共振器１と同様に０次共振器として動作する。従って、単位共振器１Ｃを備えるメタマテリアル装置もまた、半波長共振器又は一波長共振器を単位共振器として備えた従来の電磁波装置よりも、電磁波と強く相互作用することができる。また、共振素子２１Ｃが基板２０Ｃの面内の任意の直線に対して非対称に形成されたことにより、単位共振器１Ｃを備えるメタマテリアル装置もまた、カイラルメタマテリアルとして動作することができる。 The unit resonator 1C also operates as a zero-order resonator as in the unit resonator 1 of FIG. Therefore, the metamaterial device including the unit resonator 1C can also interact more strongly with the electromagnetic wave than the conventional electromagnetic wave device including the half wavelength resonator or the single wavelength resonator as the unit resonator. Further, by forming the resonant element 21C asymmetrically with respect to any straight line in the plane of the substrate 20C, the metamaterial device provided with the unit resonator 1C can also operate as a chiral metamaterial.
　次に、図３２～図３３を参照して、第５の実施形態に係るメタマテリアル装置について行った数値計算の結果について説明する。 Next, with reference to FIGS. 32 to 33, the results of numerical calculation performed for the metamaterial device according to the fifth embodiment will be described.
　数値計算において、単位共振器１Ｃを備えるメタマテリアル装置の構成パラメータは、以下の通りであった。 In the numerical calculation, configuration parameters of the metamaterial device provided with the unit resonator 1C were as follows.
単位セル１０Ｃのサイズ：ｄ１×ｄ２＝４５ｍｍ×４５ｍｍ（動作波長の０．３４倍）
基板２０Ｃの厚さ：０．８ｍｍ
単位共振器１Ｃの導体の厚さ：０．５ｍｍ Unit cell 10C size: d1 x d2 = 45 mm x 45 mm (0.34 times the operating wavelength)
Thickness of substrate 20C: 0.8 mm
Thickness of conductor of unit resonator 1C: 0.5 mm
　図３２は、第５の実施形態の比較例に係る単位共振器２０１Ｃを含む第３の単位セル１０Ｃを示す斜視図である。単位共振器２０１Ｃは、卍字形のストリップ導体のみを含む。数値計算において、単位共振器２０１Ｃの構成パラメータは、以下の通りであった。 FIG. 32 is a perspective view showing a third unit cell 10C including a unit resonator 201C according to a comparative example of the fifth embodiment. Unit resonator 201C includes only a wedge-shaped strip conductor. In the numerical calculation, configuration parameters of the unit resonator 201C were as follows.
単位セル１０Ｃのサイズ：ｄ１×ｄ２＝３５ｍｍ×３５ｍｍ（動作波長の０．２４倍）
基板２０Ｃの厚さ：０．８ｍｍ
単位共振器１Ｃの導体の厚さ：０．５ｍｍ Unit cell 10C size: d1 x d2 = 35 mm x 35 mm (0.24 times the operating wavelength)
Thickness of substrate 20C: 0.8 mm
Thickness of conductor of unit resonator 1C: 0.5 mm
　図３３は、第５の実施形態に係る単位共振器１Ｃを備えるメタマテリアル装置と、第５の実施形態の比較例に係る単位共振器２０１Ｃを備える電磁波装置とについて、偏波回転角の周波数特性を示すグラフである。図３３によれば、第５の実施形態の比較例に係る単位共振器２０１Ｃを備える電磁波装置では、周波数２．０８ＧＨｚにおいて偏波回転角０．４４度が得られた（図３３の点線）。一方、第５の実施形態（実施例）に係る単位共振器１Ｃを備えるメタマテリアル装置では、周波数２．２８ＧＨｚにおいて偏波回転角３．４９度が得られた（図３３の実線）。従って、この場合、０次共振器である単位共振器１Ｃを備えるメタマテリアル装置の偏波回転角は、単位共振器２０１を備える電磁波装置の偏波回転角に比べて約７．９倍に増大した。 FIG. 33: The frequency characteristic of a polarization rotation angle about the metamaterial apparatus provided with unit resonator 1C which concerns on 5th Embodiment, and the electromagnetic wave apparatus provided with unit resonator 201C which concerns on the comparative example of 5th Embodiment. Is a graph showing According to FIG. 33, in the electromagnetic wave apparatus provided with the unit resonator 201C according to the comparative example of the fifth embodiment, the polarization rotation angle of 0.44 degrees was obtained at a frequency of 2.08 GHz (dotted line in FIG. 33). On the other hand, in the metamaterial device including the unit resonator 1C according to the fifth embodiment (example), a polarization rotation angle of 3.49 degrees was obtained at a frequency of 2.28 GHz (solid line in FIG. 33). Therefore, in this case, the polarization rotation angle of the metamaterial device including the unit resonator 1C, which is a zero-order resonator, is increased by about 7.9 times in comparison with the polarization rotation angle of the electromagnetic wave device including the unit resonator 201. did.
　第５の実施形態によれば、平坦な単位共振器１Ｃを用いることにより、第１の実施形態の場合よりもメタマテリアル装置の製造を簡単化することができる。 According to the fifth embodiment, by using the flat unit resonator 1C, the manufacture of the metamaterial device can be simplified as compared with the first embodiment.
　図３０の例では、単位共振器１Ｃは、４つのアーム２６を有し、卍字形（又はテトラスケリオン（tetraskelion）ともいう）に形成された共振素子２１Ｃを備えていたが、他の形状に形成された共振素子を用いてもよい。例えば、３つのアームを有するトリスケリオン（triskelion）、５つのアームを有するペンタスケリオン（pentaskelion）、６つのアームを有するヘキサスケリオン（hexaskelion）、及び同様の形状を有する共振素子を使用可能である。 In the example of FIG. 30, the unit resonator 1C includes the resonance element 21C having four arms 26 and formed in a wedge shape (or also referred to as tetraskelion), but has another shape. The formed resonant element may be used. For example, triskelions having three arms, pentaskelions having five arms, hexaskelions having six arms, and resonant elements having similar shapes can be used.
　図３０の例では、共振素子２１Ｃの各アーム２６が９０度に屈曲する場合を示したが、各アームは他の角度に屈曲してもよく、図４０～図４１と同様に湾曲していてもよい。 Although the example of FIG. 30 shows the case where each arm 26 of the resonant element 21C is bent at 90 degrees, each arm may be bent at another angle, and is curved as in FIGS. 40 to 41. It is also good.
第６の実施形態．
　第６の実施形態でもまた、カイラル構造を有する平坦な単位共振器を備えるメタマテリアル装置について説明する。 Sixth embodiment.
The sixth embodiment also describes a metamaterial device provided with a flat unit resonator having a chiral structure.
　図３４は、第６の実施形態に係る単位共振器１Ｄの構成を示す平面図である。基板２０Ｄは、少なくとも１つの誘電体層及び複数の導体層を有する多層基板である。単位共振器１Ｄは、基板２０Ｄの互いに異なる複数の導体層にそれぞれ形成され、共振素子２１Ｄ及び複数の反射素子２２をそれぞれ備える複数の部分共振器１Ｄａ～１Ｄｃを含む。複数の部分共振器１Ｄａ～１Ｄｃの各共振素子２１Ｄは、互いに同じ形状を有し、各共振素子２１Ｄの回転対称の中心Ｏを通る軸の周りに互いに所定角度φだけずれて形成される。 FIG. 34 is a plan view showing the configuration of a unit resonator 1D according to the sixth embodiment. The substrate 20D is a multilayer substrate having at least one dielectric layer and a plurality of conductor layers. The unit resonator 1D includes a plurality of partial resonators 1Da to 1Dc that are respectively formed on a plurality of different conductor layers of the substrate 20D and each include a resonant element 21D and a plurality of reflective elements 22. Resonant elements 21D of the plurality of partial resonators 1Da to 1Dc have the same shape, and are formed so as to be offset from each other by a predetermined angle φ around an axis passing through the center O of rotational symmetry of each resonant element 21D.
　図３４の例では、各部分共振器１Ｄａ～１Ｄｃは図３１の単位共振器１Ｃと同様に構成され、共振素子２１Ｄは図３１の共振素子２１Ｃと同様に構成される。 In the example of FIG. 34, the partial resonators 1Da to 1Dc are configured the same as the unit resonator 1C of FIG. 31, and the resonant element 21D is configured the same as the resonant element 21C of FIG.
　単位共振器１Ｄのカイラリティは、部分共振器１Ｄａ～１Ｄｃの相対角度φに応じて変化する。また、単位共振器１Ｄの０次共振の状態は、反射素子２２の全長に応じて変化する。次に、これらのパラメータを変化させることにより、単位共振器１Ｄを備えるメタマテリアル装置の偏波回転角を最大化することについて説明する。 The chirality of the unit resonator 1D changes in accordance with the relative angle φ of the partial resonators 1Da to 1Dc. Further, the state of the zero-order resonance of the unit resonator 1 D changes according to the total length of the reflecting element 22. Next, maximizing the polarization rotation angle of the metamaterial device provided with the unit resonator 1D by changing these parameters will be described.
　最初のステップとして、部分共振器１Ｄａ～１Ｄｃの相対角度φを変化させ、偏波回転角を最大化する角度φを求める。このステップは、螺旋状に巻回された単位共振器の場合における単位共振器の螺線角（又はピッチ）を調整することに対応する。この角度φを固定し、次のステップとして、反射素子２２の全長を変化させ、偏波回転角を最大化する長さを求める。このステップは、角度φを調整した結果、単位共振器１Ｄの全体の実効的なパラメータが変化したので、最適な０次共振を実現するように反射素子２２を再調整することが必要になったので実行される。反射素子２２の全長は、前述のように、メタマテリアル装置の動作波長の４分の１の長さを実効的に有するように決められる。 As the first step, the relative angle φ of the partial resonators 1Da to 1Dc is changed to find the angle φ that maximizes the polarization rotation angle. This step corresponds to adjusting the spiral angle (or pitch) of the unit resonator in the case of the spirally wound unit resonator. The angle φ is fixed, and in the next step, the total length of the reflecting element 22 is changed to obtain the length that maximizes the polarization rotation angle. In this step, as a result of adjusting the angle φ, the entire effective parameter of the unit resonator 1D has changed, so it becomes necessary to readjust the reflective element 22 so as to realize an optimum zero-order resonance. Because it is executed. The total length of the reflective element 22 is determined to effectively have a length of one quarter of the operating wavelength of the metamaterial device, as described above.
　次に、図３５～図３６を参照して、単位共振器１Ｄを備えるメタマテリアル装置の偏波回転角を最大化するように行った数値計算の結果について説明する。 Next, with reference to FIGS. 35 to 36, the results of numerical calculation performed to maximize the polarization rotation angle of the metamaterial device provided with the unit resonator 1D will be described.
　数値計算において、各単位セル１０Ｃのサイズは、ｄ１×ｄ２＝４０ｍｍ×４０ｍｍであった。また、単位共振器１Ｄの構成パラメータは以下の通りであった。 In the numerical calculation, the size of each unit cell 10C was d1 × d2 = 40 mm × 40 mm. The configuration parameters of the unit resonator 1D were as follows.
各共振素子２１Ｄのストリップ導体２３の長さ：ｌ＝３ｍｍ
各共振素子２１Ｄのストリップ導体２３の幅：ｗ＝１ｍｍ
各共振素子２１Ｄのストリップ導体２３の厚さ：ｔ＝１８μｍ
各共振素子２１Ｄのキャパシタ２４の容量：Ｃ＝２ｐＦ
部分共振器１Ｄａ～１Ｄｃ間の間隔：２ｍｍ
基板２０Ｄの比誘電率：εｒ＝２．６ Length of strip conductor 23 of each resonant element 21D: l = 3 mm
Width of strip conductor 23 of each resonance element 21D: w = 1 mm
Thickness of strip conductor 23 of each resonant element 21D: t = 18 μm
Capacitance of the capacitor 24 of each resonant element 21D: C = 2 pF
Distance between partial resonators 1Da to 1Dc: 2 mm
Relative permittivity of substrate 20D: ε r = 2.6
　図３５は、第６の実施形態に係る単位共振器１Ｄを備えるメタマテリアル装置の部分共振器１Ｄａ～１Ｄｃの相対角度φに対する偏波回転角の変化を示すグラフである。図３５は、部分共振器１Ｄａ～１Ｄｃの相対角度φを８度から１６度まで変化させたときの偏波回転角の変化を示す。図３５によれば、角度φ＝１１度のとき、偏波回転角は最大化されることがわかる。この角度φを固定し、次に、反射素子２２の全長を調整した。 FIG. 35 is a graph showing a change in polarization rotation angle with respect to the relative angle φ of the partial resonators 1Da to 1Dc of the metamaterial device including the unit resonator 1D according to the sixth embodiment. FIG. 35 shows changes in the polarization rotation angle when the relative angle φ of the partial resonators 1Da to 1Dc is changed from 8 degrees to 16 degrees. According to FIG. 35, it can be seen that the polarization rotation angle is maximized when the angle φ is 11 degrees. The angle φ was fixed, and then the total length of the reflective element 22 was adjusted.
　図３６は、第６の実施形態に係る単位共振器１Ｄを備えるメタマテリアル装置の反射素子２２の幅ｗｍに対する偏波回転角の変化を示すグラフである。図３４の例では、反射素子２２はミアンダライン構造を有するので、反射素子２２の外形寸法ｌｍ×ｗｍのうち、長さｌｍ＝５ｍｍを固定し、幅ｗｍのみを変化させることによって、反射素子２２の全長を調整した。ミアンダライン構造の折り返し回数は、図３４に示す通り、５回のまま維持された。図３６は、反射素子２２の幅ｗｍを６．４ｍｍから７．２ｍｍまで変化させたときの偏波回転角の変化を示す。図３６によれば、幅ｗｍ＝６．６４ｍｍのとき、偏波回転角は最大値６７．９度になることがわかる。 FIG. 36 is a graph showing a change in polarization rotation angle with respect to the width wm of the reflective element 22 of the metamaterial device provided with the unit resonator 1D according to the sixth embodiment. In the example of FIG. 34, since the reflective element 22 has a meander line structure, the length lm = 5 mm of the outer dimensions lm × wm of the reflective element 22 is fixed, and only the width wm is changed. Adjusted the overall length of the The number of turns of the meander line structure was maintained at 5 as shown in FIG. FIG. 36 shows a change in polarization rotation angle when the width wm of the reflective element 22 is changed from 6.4 mm to 7.2 mm. According to FIG. 36, it can be seen that the polarization rotation angle has a maximum value of 67.9 degrees when the width wm = 6.64 mm.
　図３５及び図３６によれば、偏波回転角を最大化するように、部分共振器１Ｄａ～１Ｄｃの最適な相対角度φと、各反射素子２２の最適な全長とを求めることができる。 According to FIGS. 35 and 36, the optimum relative angle φ of the partial resonators 1Da to 1Dc and the optimum total length of each reflecting element 22 can be determined so as to maximize the polarization rotation angle.
　単位共振器１Ｄもまた、図１等の単位共振器１と同様に０次共振器として動作する。従って、単位共振器１Ｄを備えるメタマテリアル装置もまた、半波長共振器又は一波長共振器を単位共振器として備えた従来の電磁波装置よりも、電磁波と強く相互作用することができる。また、複数の部分共振器１Ｄａ～１Ｄｃの各共振素子２１Ｄが互いに所定角度φだけずれて形成されることにより、単位共振器１Ｄを備えるメタマテリアル装置もまた、カイラルメタマテリアルとして動作することができる。 The unit resonator 1D also operates as a zero-order resonator as in the unit resonator 1 of FIG. Therefore, the metamaterial device provided with the unit resonator 1D can also interact more strongly with the electromagnetic wave than the conventional electromagnetic wave device provided with the half wavelength resonator or the single wavelength resonator as the unit resonator. Further, by forming the respective resonant elements 21D of the plurality of partial resonators 1Da to 1Dc mutually offset by a predetermined angle φ, the metamaterial device provided with the unit resonator 1D can also operate as a chiral metamaterial .
　次に、図３７～図４２を参照して、第６の実施形態の変形例に係る単位共振器を備えたメタマテリアル装置について説明する。 Next, with reference to FIG. 37 to FIG. 42, a metamaterial device provided with a unit resonator according to a modification of the sixth embodiment will be described.
　図３７は、第６の実施形態の第１の変形例に係る単位共振器１ＤＡの構成を示す平面図である。単位共振器１ＤＡは、基板２０Ｄの互いに異なる複数の導体層にそれぞれ形成され、共振素子及び複数の反射素子をそれぞれ備える部分共振器１ＤＡａ～１ＤＡｂを含む。図３７の例では、各部分共振器１ＤＡａ～１ＤＡｂの共振素子は、直線状に、すなわち線対称に形成される。従って、各部分共振器１ＤＡａ～１ＤＡｂ自体はカイラリティを持たない。ただし、部分共振器１ＤＡａ～１ＤＡｂの各共振素子が、各共振素子の回転対称の中心Ｏを通る軸の周りに互いに所定角度だけずれて形成されることにより、単位共振器１ＤＡの全体はカイラリティを有する。 FIG. 37 is a plan view showing a configuration of a unit resonator 1DA according to a first modified example of the sixth embodiment. The unit resonator 1DA is formed on a plurality of different conductor layers of the substrate 20D, and includes partial resonators 1DAa to 1DAb each including a resonant element and a plurality of reflective elements. In the example of FIG. 37, the resonance elements of each of the partial resonators 1DAa-1DAb are formed linearly, that is, axisymmetrically. Therefore, each partial resonator 1DAa to 1DAb itself has no chirality. However, since the respective resonant elements of the partial resonators 1DAa to 1DAb are formed mutually offset by a predetermined angle around an axis passing through the rotational symmetry center O of each resonant element, the entire unit resonator 1DA is made chiral. Have.
　図３８は、第６の実施形態の第２の変形例に係る単位共振器１ＤＢの構成を示す平面図である。単位共振器１ＤＢは、基板２０Ｄの互いに異なる複数の導体層にそれぞれ形成され、共振素子及び複数の反射素子をそれぞれ備える部分共振器１ＤＢａ～１ＤＢｂを含む。図３７の例では、各部分共振器１ＤＢａ～１ＤＢｂの共振素子は、十字形に、すなわち線対称に形成される。従って、各部分共振器１ＤＢａ～１ＤＢｂ自体はカイラリティを持たない。ただし、部分共振器１ＤＢａ～１ＤＢｂの各共振素子が、各共振素子の回転対称の中心Ｏを通る軸の周りに互いに所定角度だけずれて形成されることにより、単位共振器１ＤＢの全体はカイラリティを有する。 FIG. 38 is a plan view showing a configuration of a unit resonator 1DB according to a second modified example of the sixth embodiment. The unit resonators 1DB are respectively formed on a plurality of different conductor layers of the substrate 20D, and include partial resonators 1DBa to 1DBb each including a resonant element and a plurality of reflective elements. In the example of FIG. 37, the resonance elements of the partial resonators 1DBa to 1DBb are formed in a cross shape, that is, in line symmetry. Therefore, each of the partial resonators 1 DBa to 1 DBb itself has no chirality. However, since the respective resonant elements of the partial resonators 1DBa to 1DBb are formed mutually offset by a predetermined angle around an axis passing through the rotational symmetry center O of each resonant element, the whole unit resonator 1DB is made chiral. Have.
　図３９は、第６の実施形態の第３の変形例に係る単位共振器１ＤＣの構成を示す平面図である。単位共振器１ＤＣは、基板２０Ｄの互いに異なる複数の導体層にそれぞれ形成され、共振素子及び複数の反射素子をそれぞれ備える複数の部分共振器１ＤＣａ～１ＤＣｂを含む。各部分共振器１ＤＣａ～１ＤＣｂは図３１の単位共振器１Ｃと同様に構成される。従って、図３１の単位共振器１Ｃと同様に、部分共振器１ＤＣａ～１ＤＣｂ自体がカイラリティを有する。ただし、部分共振器１ＤＣａ～１ＤＣｂの各共振素子が、各共振素子の回転対称の中心Ｏを通る軸の周りに互いに所定角度だけずれて形成されることにより、単位共振器１ＤＣの全体は、各部分共振器１ＤＣａ～１ＤＣｂのものよりも大きなカイラリティを有する。 FIG. 39 is a plan view showing a configuration of a unit resonator 1DC according to a third modified example of the sixth embodiment. The unit resonator 1DC is respectively formed on a plurality of different conductor layers of the substrate 20D, and includes a plurality of partial resonators 1DCa to 1DCb each including a resonant element and a plurality of reflective elements. Each partial resonator 1 DCa to 1 DCb is configured in the same manner as the unit resonator 1 C of FIG. Therefore, as in the unit resonator 1C of FIG. 31, the partial resonators 1DCa to 1DCb themselves have chirality. However, the respective resonator elements of the partial resonators 1 DCa to 1 DCb are formed mutually offset by a predetermined angle around an axis passing through the rotational symmetry center O of each resonator element, whereby the entire unit resonator 1 DC is It has a chirality greater than that of the partial resonators 1 DCa to 1 DCb.
　図４０は、第６の実施形態の第４の変形例に係る単位共振器１ＤＤの構成を示す平面図である。単位共振器１ＤＤは、基板２０Ｄの互いに異なる複数の導体層にそれぞれ形成され、共振素子及び複数の反射素子をそれぞれ備える複数の部分共振器１ＤＤａ～１ＤＤｂを含む。各部分共振器１ＤＤａ～１ＤＤｂは、図３１の単位共振器１Ｄのように屈曲した４つのアームに代えて、湾曲した４つのアームを備える。従って、図３１の単位共振器１Ｄと同様に、部分共振器１ＤＤａ～１ＤＤｂ自体がカイラリティを有する。ただし、部分共振器１ＤＤａ～１ＤＤｂの各共振素子が、各共振素子の回転対称の中心Ｏを通る軸の周りに互いに所定角度だけずれて形成されることにより、単位共振器１ＤＤの全体は、各部分共振器１ＤＤａ～１ＤＤｂのものよりも大きなカイラリティを有する。 FIG. 40 is a plan view showing a configuration of a unit resonator 1DD according to a fourth modified embodiment of the sixth embodiment. The unit resonator 1DD is respectively formed on a plurality of different conductor layers of the substrate 20D, and includes a plurality of partial resonators 1DDa to 1DDb each including a resonant element and a plurality of reflective elements. Each of the partial resonators 1DDa to 1DDb includes four curved arms instead of the four arms bent as in the unit resonator 1D of FIG. Therefore, as in the unit resonator 1D of FIG. 31, the partial resonators 1DDa to 1DDb themselves have chirality. However, the respective resonator elements of the partial resonators 1DDa to 1DDb are formed offset from each other by a predetermined angle around an axis passing through the rotational symmetry center O of each resonator element, so that the entire unit resonator 1DD is It has a chirality greater than that of the partial resonators 1DDa-1DDb.
　図４１は、第６の実施形態の第５の変形例に係る単位共振器１ＤＥの構成を示す平面図である。単位共振器１ＤＥは、基板２０Ｄの互いに異なる複数の導体層にそれぞれ形成され、共振素子及び複数の反射素子をそれぞれ備える複数の部分共振器１ＤＥａ～１ＤＥｂを含む。各部分共振器１ＤＥａ～１ＤＥｂは、図４０の単位共振器１ＤＤの湾曲した４つのアームに代えて、湾曲した６つのアームを備える。従って、図４０の単位共振器１ＤＤと同様に、部分共振器１ＤＥａ～１ＤＥｂ自体がカイラリティを有する。ただし、部分共振器１ＤＥａ～１ＤＥｂの各共振素子が、各共振素子の回転対称の中心Ｏを通る軸の周りに互いに所定角度だけずれて形成されることにより、単位共振器１ＤＥの全体は、各部分共振器１ＤＥａ～１ＤＥｂのものよりも大きなカイラリティを有する。 FIG. 41 is a plan view showing the configuration of a unit resonator 1DE according to a fifth modification of the sixth embodiment. The unit resonator 1DE is formed on a plurality of different conductor layers of the substrate 20D, and includes a plurality of partial resonators 1DEa to 1DEb each including a resonant element and a plurality of reflective elements. Each of the partial resonators 1DEa to 1DEb has six curved arms instead of the four curved arms of the unit resonator 1DD shown in FIG. Therefore, like the unit resonator 1DD of FIG. 40, the partial resonators 1DEa to 1DEb themselves have chirality. However, the respective resonator elements of the partial resonators 1DEa to 1DEb are formed so as to be offset from each other by a predetermined angle around an axis passing through the rotational symmetry center O of each resonator element, so that the whole unit resonator 1DE is It has larger chirality than that of the partial resonators 1DEa-1DEb.
　単位共振器１ＤＡ～１ＤＥもまた、図３４の単位共振器１Ｄと同様に０次共振器として動作する。従って、単位共振器１ＤＡ～１ＤＥのいずれかを備えるメタマテリアル装置もまた、半波長共振器又は一波長共振器を単位共振器として備えた従来の電磁波装置よりも、電磁波と強く相互作用することができる。また、複数の部分共振器の各共振素子が互いに所定角度だけずれて形成されることにより、単位共振器１ＤＡ～１ＤＥのいずれかを備えるメタマテリアル装置もまた、カイラルメタマテリアルとして動作することができる。 The unit resonators 1DA to 1DE also operate as zeroth-order resonators, similarly to the unit resonator 1D of FIG. Therefore, the metamaterial device provided with any of the unit resonators 1DA to 1DE can also interact more strongly with the electromagnetic wave than the conventional electromagnetic wave device provided with the half wavelength resonator or the single wavelength resonator as the unit resonator. it can. In addition, the metamaterial devices provided with any of the unit resonators 1DA to 1DE can also operate as chiral metamaterials by forming the respective resonant elements of the plurality of partial resonators to be offset from each other by a predetermined angle. .
　次に、図４２を参照して、単位共振器１ＤＡ～１ＤＥのいずれかを備えるメタマテリアル装置について行った数値計算の結果について説明する。単位共振器１ＤＡ～１ＤＥをそれぞれ備える５つのメタマテリアル装置の偏波回転角を比較した。 Next, with reference to FIG. 42, the result of the numerical calculation performed on the metamaterial device provided with any of the unit resonators 1DA to 1DE will be described. The polarization rotation angles of five metamaterial devices respectively provided with unit resonators 1DA to 1DE were compared.
　動作波長に対する単位共振器１ＤＡ～１ＤＥのサイズをそろえるため、単位セル１０Ｃのサイズを４５～５５ｍｍの範囲において、また、動作周波数を約２．２～約２．４ＧＨｚの付近において、できるだけ同じ値になるように選択した。単位共振器１ＤＡの単位セル１０Ｃのサイズは、ｄ１×ｄ２＝５０ｍｍ×５０ｍｍであった。単位共振器１ＤＢの単位セル１０Ｃのサイズは、ｄ１×ｄ２＝５５ｍｍ×５５ｍｍであった。単位共振器１ＤＣの単位セル１０Ｃのサイズは、ｄ１×ｄ２＝４０ｍｍ×４０ｍｍであった。単位共振器１ＤＤの単位セル１０Ｃのサイズは、ｄ１×ｄ２＝４０ｍｍ×４０ｍｍであった。単位共振器１ＤＥの単位セル１０Ｃのサイズは、ｄ１×ｄ２＝４５ｍｍ×４５ｍｍであった。各単位共振器１ＤＡ～１ＤＥの２つの部分共振器の相対角度は、１０度であった。０次共振の周波数を合わせるようにキャパシタ２４の容量を調整し、最適な０次共振の状態を達成するように反射素子２２の全長を調整した。 In order to make the sizes of the unit resonators 1DA to 1DE equal to the operating wavelength, the unit cell 10C has the same size as possible in the range of 45 to 55 mm and the operating frequency in the vicinity of about 2.2 to about 2.4 GHz. I chose to be. The size of the unit cell 10C of the unit resonator 1DA was d1 × d2 = 50 mm × 50 mm. The size of the unit cell 10C of the unit resonator 1DB was d1 × d2 = 55 mm × 55 mm. The size of the unit cell 10C of the unit resonator 1DC was d1 × d2 = 40 mm × 40 mm. The size of the unit cell 10C of the unit resonator 1DD was d1 × d2 = 40 mm × 40 mm. The size of the unit cell 10C of the unit resonator 1DE was d1 × d2 = 45 mm × 45 mm. The relative angle of the two partial resonators of each unit resonator 1DA to 1DE was 10 degrees. The capacitance of the capacitor 24 was adjusted to match the frequency of the zeroth resonance, and the total length of the reflective element 22 was adjusted to achieve the optimum zeroth resonance state.
　図４２は、図３７～図４１の単位共振器１ＤＡ～１ＤＥをそれぞれ備える５つのメタマテリアル装置について、偏波回転角の周波数特性を示すグラフである。 FIG. 42 is a graph showing frequency characteristics of polarization rotation angle for five metamaterial devices provided with the unit resonators 1DA to 1DE of FIGS. 37 to 41, respectively.
　まず、図３７の単位共振器１ＤＡ及び図３８の単位共振器１ＤＢをそれぞれ備えるメタマテリアル装置の偏波回転角を比較する。前述のように、単位共振器１ＤＡ，１ＤＢの各部分共振器の共振素子は線対称に形成されるので、それ自体ではカイラリティを持たない。部分共振器の各共振素子が、各共振素子の回転対称の中心Ｏを通る軸の周りに互いに所定角度だけずれて形成されることにより、単位共振器１ＤＡ，１ＤＢの全体がカイラリティを有する。単位共振器１ＤＡ，１ＤＢの違いは、単位共振器１ＤＡの各部分共振器１ＤＡａ～１ＤＡｂが直線状の（すなわち、中心Ｏに接続された２つのアームを有する）共振素子を備えるのに対して、単位共振器１ＤＢの各部分共振器１ＤＢａ～１ＤＢｂが十字形の（すなわち、４つのアームを有する）共振素子を備える、ということにある。図４２によれば、単位共振器１ＤＡを備えるメタマテリアル装置は、２．４８ＧＨｚの動作周波数において４．２５度の偏波回転角を達成する。一方、単位共振器１ＤＢを備えるメタマテリアル装置は、２．２ＧＨｚの動作周波数において１０．３度の偏波回転角を達成する。この結果から、共振素子のアームの個数を増やすことにより偏波回転角が増大することがわかる。 First, the polarization rotation angles of the metamaterial devices provided with the unit resonator 1DA of FIG. 37 and the unit resonator 1DB of FIG. 38 are compared. As described above, since the resonant elements of the partial resonators of the unit resonators 1DA and 1DB are formed in line symmetry, they themselves have no chirality. The respective resonator elements of the partial resonators are formed offset from each other by a predetermined angle around an axis passing through the rotational symmetry center O of each resonator element, whereby the entire unit resonators 1DA and 1DB have chirality. The difference between the unit resonators 1DA and 1DB is that each of the partial resonators 1DAa to 1DAb of the unit resonator 1DA is provided with linear (that is, having two arms connected to the center O) resonant elements, Each partial resonator 1DBa to 1DBb of the unit resonator 1DB is provided with a cruciform (that is, having four arms) resonant elements. According to FIG. 42, the metamaterial device provided with unit resonator 1DA achieves a polarization rotation angle of 4.25 degrees at an operating frequency of 2.48 GHz. On the other hand, the metamaterial device including the unit resonator 1DB achieves a polarization rotation angle of 10.3 degrees at an operating frequency of 2.2 GHz. From this result, it is understood that the polarization rotation angle is increased by increasing the number of arms of the resonant element.
　次に、図３８の単位共振器１ＤＢ及び図３９の単位共振器１ＤＣをそれぞれ備えるメタマテリアル装置の偏波回転角を比較する。前述のように、単位共振器１ＤＢの各部分共振器の共振素子は線対称に形成されるので、それ自体ではカイラリティを持たない。一方、単位共振器１ＤＢの各部分共振器の共振素子は、基板２０Ｄの面内の任意の直線に対して非対称に形成されるので、それ自体でカイラリティを有する。図４２によれば、単位共振器１ＤＢを備えるメタマテリアル装置は、２．２ＧＨｚの動作周波数において１０．３度の偏波回転角を達成する。一方、単位共振器１ＤＣを備えるメタマテリアル装置は、２．３４ＧＨｚの動作周波数において１７．２度の偏波回転角を達成する。単位共振器１ＤＣを備えるメタマテリアル装置では、部分共振器１ＤＣａ～１ＤＣｂの相対角度に起因するカイラリティに加えて、部分共振器１ＤＣａ～１ＤＣｂの共振素子自体のカイラリティが存在することにより、単位共振器１ＤＢを備えるメタマテリアル装置よりも偏波回転角が増大している。 Next, the polarization rotation angles of the metamaterial devices provided with the unit resonator 1DB of FIG. 38 and the unit resonator 1DC of FIG. 39 are compared. As described above, since the resonant elements of the partial resonators of the unit resonator 1DB are formed in line symmetry, they themselves have no chirality. On the other hand, since the resonant elements of the partial resonators of the unit resonator 1DB are formed asymmetrically with respect to any straight line in the plane of the substrate 20D, they have chirality by themselves. According to FIG. 42, the metamaterial device provided with the unit resonator 1DB achieves a polarization rotation angle of 10.3 degrees at an operating frequency of 2.2 GHz. On the other hand, the metamaterial device provided with unit resonator 1DC achieves a polarization rotation angle of 17.2 degrees at an operating frequency of 2.34 GHz. In the metamaterial device including the unit resonator 1DC, in addition to the chirality due to the relative angle of the partial resonators 1DCa to 1DCb, the chirality of the resonant elements themselves of the partial resonators 1DCa to 1DCb is present, thereby the unit resonator 1DB The polarization rotation angle is increased compared to the metamaterial device provided with
　次に、図３９の単位共振器１ＤＣ及び図４０の単位共振器１ＤＤをそれぞれ備えるメタマテリアル装置の偏波回転角を比較する。図４２によれば、単位共振器１ＤＣを備えるメタマテリアル装置は、２．３４ＧＨｚの動作周波数において１７．２度の偏波回転角を達成する。一方、単位共振器１ＤＤを備えるメタマテリアル装置は、２．２４ＧＨｚの動作周波数において２０．７度の偏波回転角を達成する。これは、単位共振器１ＤＤを備えるメタマテリアル装置では、各部分共振器１ＤＤａ～１ＤＤｂの共振素子が湾曲したアームを備えたことにより、単位共振器１ＤＣを備えるメタマテリアル装置よりも、共振素子自体のカイラリティが増大し、偏波回転の効果が増大したからであると考えられる。 Next, the polarization rotation angles of the metamaterial devices provided with the unit resonator 1DC of FIG. 39 and the unit resonator 1DD of FIG. 40 are compared. According to FIG. 42, the metamaterial device provided with unit resonator 1DC achieves a polarization rotation angle of 17.2 degrees at an operating frequency of 2.34 GHz. On the other hand, the metamaterial device provided with the unit resonator 1DD achieves a polarization rotation angle of 20.7 degrees at an operating frequency of 2.24 GHz. This is because, in the metamaterial device including the unit resonator 1DD, the resonant element of each of the partial resonators 1DDa to 1DDb includes the curved arm, so that the resonant element itself is more than the metamaterial device including the unit resonator 1DC. This is considered to be because the chirality is increased and the effect of polarization rotation is increased.
　次に、図４０の単位共振器１ＤＤ及び図４１の単位共振器１ＤＥをそれぞれ備えるメタマテリアル装置の偏波回転角を比較する。図４２によれば、単位共振器１ＤＤを備えるメタマテリアル装置は、２．２４ＧＨｚの動作周波数において２０．７度の偏波回転角を達成する。一方、単位共振器１ＤＥを備えるメタマテリアル装置は、２．１６ＧＨｚの動作周波数において２２．８度の偏波回転角を達成する。単位共振器１ＤＡ，１ＤＢをそれぞれ備えるメタマテリアル装置の場合と同様に、各共振素子が屈曲したアームに代えて湾曲したアームを備える場合でも、共振素子のアームの個数を増やすことにより偏波回転角が増大することがわかる。 Next, the polarization rotation angles of the metamaterial devices provided with the unit resonator 1DD of FIG. 40 and the unit resonator 1DE of FIG. 41 are compared. According to FIG. 42, the metamaterial device provided with the unit resonator 1DD achieves a polarization rotation angle of 20.7 degrees at an operating frequency of 2.24 GHz. On the other hand, the metamaterial device comprising the unit resonator 1DE achieves a polarization rotation angle of 22.8 degrees at an operating frequency of 2.16 GHz. As in the case of the metamaterial device including the unit resonators 1DA and 1DB, even in the case where each resonant element includes a curved arm instead of the curved arm, the polarization rotation angle is increased by increasing the number of arms of the resonant element. Is seen to increase.
　図４２によれば、単位共振器１ＤＡ～１ＤＥをそれぞれ備える５つのメタマテリアル装置の偏波回転角を比較すると、これらのメタマテリアル装置は、昇順に増大する偏波回転角度を有する。 According to FIG. 42, when comparing polarization rotation angles of five metamaterial devices respectively provided with unit resonators 1DA to 1DE, these metamaterial devices have polarization rotation angles that increase in ascending order.
　なお、単位共振器１ＤＥ，１ＤＥをそれぞれ備えるメタマテリアル装置について、アームの個数の増加に伴う偏波回転角の増大の効果が小さいのは、すべてのアームにおいて電磁界が集中せず、アームの個数を増やしてもカイラリティを増大させる効果が小さくなっていることに起因する。つまり、アームの個数の増大に伴う偏波回転角の増大には限りがある。従って、所望の偏波回転角に応じて、アームの適切な個数を決定することができる。 In the metamaterial devices respectively provided with unit resonators 1DE and 1DE, the effect of the increase in the polarization rotation angle with the increase in the number of arms is small because the electromagnetic field is not concentrated in all the arms, and the number of arms The effect of increasing the chirality is diminishing even if That is, the increase in the polarization rotation angle with the increase in the number of arms is limited. Thus, depending on the desired polarization rotation angle, the appropriate number of arms can be determined.
第７の実施形態．
　第１の実施形態で説明した０次共振する単位共振器１の構造は、線状アンテナにも適用可能である。これにより、線状アンテナの放射利得及び指向性を従来技術よりも改善することができる。 Seventh Embodiment
The structure of the zeroth-resonant unit resonator 1 described in the first embodiment is also applicable to a linear antenna. This allows the radiation gain and directivity of the linear antenna to be improved over the prior art.
　図４３は、第７の実施形態の第１の実施例に係るアンテナ装置４０の構成を示す斜視図である。図４３のアンテナ装置４０は、接地導体４２の上に、共振素子２１及び反射素子２２を備える１つの単位共振器を備える。共振素子２１は、ストリップ形状を有し、その両端の間で電流が同時に逆向きに流れる並列回路部分を含まない経路を有し、かつ、実質的にゼロの実効透磁率を有する。共振素子２１は、ストリップ導体２３及びキャパシタ２４をそれぞれ備える、互いに直列接続された複数の直列ＬＣ共振回路を含む。共振素子２１は直線状に形成される。反射素子２２は、共振素子２１の一方の端部に接続され、共振素子２１から反射素子２２を見たときのインピーダンスが実質的にゼロになるように構成される。共振素子２１の他方の端部には給電点が設けられ、給電点は同軸ケーブルを介して無線信号源４１に接続される。アンテナ装置４０は、第１の実施形態に係る単位共振器１と同様に０次共振器として動作し、これにより、高い効率で電磁波を送受信することができる。 FIG. 43 is a perspective view showing a configuration of an antenna apparatus 40 according to a first example of the seventh embodiment. The antenna device 40 of FIG. 43 includes one unit resonator including the resonant element 21 and the reflective element 22 on the ground conductor 42. The resonant element 21 has a strip shape, has a path that does not include a parallel circuit portion between which the current flows simultaneously in the opposite direction, and has a substantially zero effective permeability. The resonant element 21 comprises a plurality of series LC resonant circuits connected in series with one another, each comprising a strip conductor 23 and a capacitor 24. The resonant element 21 is formed linearly. The reflective element 22 is connected to one end of the resonant element 21 and is configured such that the impedance when the reflective element 22 is viewed from the resonant element 21 is substantially zero. A feeding point is provided at the other end of the resonant element 21, and the feeding point is connected to the radio signal source 41 via a coaxial cable. The antenna device 40 operates as a zero-order resonator as in the unit resonator 1 according to the first embodiment, and can thereby transmit and receive electromagnetic waves with high efficiency.
　次に、図４３のアンテナ装置４０について行った数値計算の結果について説明する。数値計算において、アンテナ装置４０の構成パラメータは、以下の通りであった。 Next, the result of the numerical calculation performed about the antenna apparatus 40 of FIG. 43 is demonstrated. In the numerical calculation, the configuration parameters of the antenna device 40 were as follows.
アンテナ装置４０の動作周波数：０．９６ＧＨｚ
ストリップ導体２３の長さ：ｌ＝４．６ｍｍ
キャパシタ２４の容量：Ｃ＝４ｐＦ
直列ＬＣ共振回路の個数：１５個
共振素子２１の全長：ｄ２１＝７５ｍｍ＝０．２４λ０（λ０：動作波長） Operating frequency of the antenna device 40: 0.96 GHz
Length of strip conductor 23: l = 4.6 mm
Capacitance of capacitor 24: C = 4 pF
Number of series LC resonant circuits: 15 total length of resonant element 21: d21 = 75 mm = 0.24λ 0 (λ 0 : operating wavelength)
　図４５は、図４３のアンテナ装置４０のＨ面利得を示すグラフである。図４６は、図４３のアンテナ装置４０のＥ面利得を示すグラフである。水平面内における平均の放射利得（図４５）は５．７９ｄＢｉであり、ビーム半値幅（図４６）は６８度であった。ＶＳＷＲ＝２以下の帯域（すなわち、リターンロスが－１０ｄＢ以下になる帯域）は０．０８ＧＨｚであった（比帯域８．３％）。 FIG. 45 is a graph showing the H-plane gain of the antenna device 40 of FIG. FIG. 46 is a graph showing the E-plane gain of the antenna device 40 of FIG. The average radiation gain (FIG. 45) in the horizontal plane was 5.79 dBi and the half beam width (FIG. 46) was 68 degrees. The band in which VSWR = 2 or less (that is, the band in which the return loss is −10 dB or less) was 0.08 GHz (relative band 8.3%).
　図４４は、第７の実施形態の第１の比較例に係るアンテナ装置の構成を示す斜視図である。図４４のアンテナ装置は、接地導体４２の上に設けられた４分の１波長の線状導体からなるアンテナ素子２４０を備える。アンテナ素子２４０の一端には給電点が設けられ、給電点は同軸ケーブルを介して無線信号源４１に接続される。 FIG. 44 is a perspective view showing a configuration of an antenna apparatus according to a first comparative example of the seventh embodiment. The antenna device of FIG. 44 includes an antenna element 240 formed of a quarter-wave linear conductor provided on the ground conductor 42. A feed point is provided at one end of the antenna element 240, and the feed point is connected to the radio signal source 41 via a coaxial cable.
　図４４のアンテナ装置についても数値計算を行った。数値計算において、アンテナ素子２４０の全長ｄ２２＝７５ｍｍを設定し、アンテナ装置の動作周波数を０．９６ＧＨｚに設定した。 Numerical calculation was also performed for the antenna device of FIG. In the numerical calculation, the total length d22 = 75 mm of the antenna element 240 was set, and the operating frequency of the antenna device was set to 0.96 GHz.
　図４７は、図４４のアンテナ装置のＨ面利得を示すグラフである。図４８は、図４４のアンテナ装置のＥ面利得を示すグラフである。水平面内における平均の放射利得は５．１６ｄＢｉであり、ビーム半値幅は７６度であった。ＶＳＷＲ＝２以下の帯域は０．１１ＧＨｚであった（比帯域１１．４ ％）。 FIG. 47 is a graph showing the H-plane gain of the antenna device of FIG. FIG. 48 is a graph showing an E-plane gain of the antenna device of FIG. The average radiation gain in the horizontal plane was 5.16 dBi, and the half beam width was 76 degrees. The band below VSWR = 2 was 0.11 GHz (ratio band 11.4%).
　図４５～図４８を比較すると、図４３のアンテナ装置４０は、０次共振するアンテナ装置４０の一様な電流分布のためにアンテナ装置４０の実効サイズが大きくなり、その結果、図４４のアンテナ装置に比較して放射利得及び指向性が改善したことがわかる。 Comparing FIG. 45 to FIG. 48, the antenna device 40 of FIG. 43 has a large effective size of the antenna device 40 due to the uniform current distribution of the antenna device 40 resonating at zero order, and as a result, the antenna of FIG. It can be seen that the radiation gain and directivity have improved compared to the device.
　次に、モノポールアンテナの低姿勢化を目的として、第１の実施形態で説明した０次共振する単位共振器１の構造をヘリカルアンテナに適用することについて説明する。この場合も、ヘリカルアンテナの放射利得を従来技術よりも改善することができる。 Next, for the purpose of reducing the attitude of the monopole antenna, application of the structure of the zeroth-resonant unit resonator 1 described in the first embodiment to a helical antenna will be described. Also in this case, the radiation gain of the helical antenna can be improved over the prior art.
　図４９は、第７の実施形態の第２の実施例に係るアンテナ装置４０Ａの構成を示す斜視図である。図４９のアンテナ装置４０Ａは、接地導体４２の上に、共振素子２１及び反射素子２２を備える１つの単位共振器を備える。共振素子２１は、ストリップ形状を有し、その両端の間で電流が同時に逆向きに流れる並列回路部分を含まない経路を有し、かつ、実質的にゼロの実効透磁率を有する。共振素子２１は、ストリップ導体２３及びキャパシタ２４をそれぞれ備える、互いに直列接続された複数の直列ＬＣ共振回路を含む。共振素子２１は螺線状に巻回される。反射素子２２は、共振素子２１の一方の端部に接続され、共振素子２１から反射素子２２を見たときのインピーダンスが実質的にゼロになるように構成される。共振素子２１の他方の端部には給電点が設けられ、給電点は無線信号源４１に接続される。アンテナ装置４０Ａは、第１の実施形態に係る単位共振器１と同様に０次共振器として動作し、これにより、高い効率で電磁波を送受信することができる。 FIG. 49 is a perspective view showing a configuration of an antenna apparatus 40A according to a second example of the seventh embodiment. The antenna device 40A of FIG. 49 includes one unit resonator including the resonant element 21 and the reflective element 22 on the ground conductor 42. The resonant element 21 has a strip shape, has a path that does not include a parallel circuit portion between which the current flows simultaneously in the opposite direction, and has a substantially zero effective permeability. The resonant element 21 comprises a plurality of series LC resonant circuits connected in series with one another, each comprising a strip conductor 23 and a capacitor 24. The resonant element 21 is spirally wound. The reflective element 22 is connected to one end of the resonant element 21 and is configured such that the impedance when the reflective element 22 is viewed from the resonant element 21 is substantially zero. A feeding point is provided at the other end of the resonant element 21, and the feeding point is connected to the wireless signal source 41. The antenna device 40A operates as a zero-order resonator as in the unit resonator 1 according to the first embodiment, and can thereby transmit and receive electromagnetic waves with high efficiency.
　次に、図４９のアンテナ装置４０Ａについて行った数値計算の結果について説明する。数値計算において、アンテナ装置４０Ａの構成パラメータは、以下の通りであった。 Next, the results of numerical calculation performed for the antenna device 40A of FIG. 49 will be described. In the numerical calculation, configuration parameters of the antenna device 40A were as follows.
アンテナ装置４０Ａの動作周波数：２．５６ＧＨｚ
ストリップ導体２３の長さ：ｌ＝１ｍｍ
キャパシタ２４の容量：Ｃ＝４ｐＦ
直列ＬＣ共振回路の個数：３２個
反射素子の全高：ｄ３１＝０．３２３λ０（λ０：動作波長）
螺線の直径：ｄ３２＝１．８ｍｍ
螺線のピッチ：ｄ３３＝３ｍｍ
螺線の巻数：Ｎ＝３ Operating frequency of antenna device 40A: 2.56 GHz
Length of strip conductor 23: l = 1 mm
Capacitance of capacitor 24: C = 4 pF
The number of the series LC resonant circuit: the 32 reflective element Height: d31 = 0.323λ 0 (λ 0 : operating wavelength)
Screw diameter: d32 = 1.8 mm
Spiral pitch: d33 = 3 mm
Number of turns of screw: N = 3
　図５１は、図４９のアンテナ装置４０ＡのＨ面利得を示すグラフである。図５２は、図４９のアンテナ装置４０ＡのＥ面利得を示すグラフである。水平面内における平均の放射利得（図５１）は４．５３ｄＢｉであり、ビーム半値幅（図５２）は８６度であった。 FIG. 51 is a graph showing the H-plane gain of the antenna device 40A of FIG. FIG. 52 is a graph showing the E-plane gain of the antenna device 40A of FIG. The average radiation gain (FIG. 51) in the horizontal plane was 4.53 dBi, and the half beam width (FIG. 52) was 86 degrees.
　図５０は、第７の実施形態の第２の比較例に係るアンテナ装置の構成を示す斜視図である。図５０のアンテナ装置は、接地導体４２の上において螺線形に巻回されたストリップ導体からなるアンテナ素子２４０Ａを備える。アンテナ素子２４０Ａの一端には給電点が設けられ、給電点は同軸ケーブルを介して無線信号源４１に接続される。 FIG. 50 is a perspective view showing a configuration of an antenna apparatus according to a second comparative example of the seventh embodiment. The antenna device of FIG. 50 includes an antenna element 240A made of a strip conductor spirally wound on the ground conductor 42. A feed point is provided at one end of the antenna element 240A, and the feed point is connected to the radio signal source 41 via a coaxial cable.
　図５０のアンテナ装置についても数値計算を行った。数値計算において、アンテナ装置２４０Ａの構成パラメータは、以下の通りであった。 Numerical calculation was also performed for the antenna device of FIG. In the numerical calculation, configuration parameters of the antenna device 240A were as follows.
アンテナ装置２４０Ａの動作周波数：２．５６ＧＨｚ
アンテナ素子２４０Ａの幅：０．２ｍｍ
アンテナ素子２４０Ａの厚さ：１．８μｍ
反射素子の全高：ｄ３１＝０．３２３λ０（λ０：動作波長）
螺線の直径：ｄ３２＝１．８ｍｍ
螺線のピッチ：ｄ３３＝３ｍｍ
螺線の巻数：Ｎ＝３ Operating frequency of antenna device 240A: 2.56 GHz
Antenna element 240A width: 0.2 mm
Thickness of antenna element 240A: 1.8 μm
Height of the reflective elements: d31 = 0.323λ 0 (λ 0 : operating wavelength)
Screw diameter: d32 = 1.8 mm
Spiral pitch: d33 = 3 mm
Number of turns of screw: N = 3
　図５３は、図５０のアンテナ装置のＨ面利得を示すグラフである。図５４は、図５０のアンテナ装置のＥ面利得を示すグラフである。水平面内における平均の放射利得は４．３４ｄＢｉであり、ビーム半値幅は８６度であった。 FIG. 53 is a graph showing the H-plane gain of the antenna device of FIG. 50. FIG. 54 is a graph showing an E-plane gain of the antenna device of FIG. The average radiation gain in the horizontal plane was 4.34 dBi, and the half beam width was 86 degrees.
　図５１～図５４を比較すると、図４９のアンテナ装置４０Ａもまた、０次共振するアンテナ装置４０Ａの一様な電流分布のためにアンテナ装置４０Ａの実効サイズが大きくなり、その結果、図５０のアンテナ装置に比較して放射利得が改善したことがわかる。 Comparing FIG. 51 to FIG. 54, the antenna device 40A of FIG. 49 also increases the effective size of the antenna device 40A due to the uniform current distribution of the antenna device 40A that resonates at zero order, and as a result, FIG. It can be seen that the radiation gain is improved compared to the antenna device.
　第７の実施形態によれば、０次共振する単位共振器の構造を線状アンテナに適用することにより、アンテナ素子の長さ全体にわたって、アンテナ素子に流れる電流の振幅及び位相の分布を一様にすることができる。これにより、アンテナの放射利得を増大させることができる。アンテナのサイズを増大すれば、放射利得も増大する。また、動作周波数を固定したまま、アンテナのサイズを自由に変更することができる。 According to the seventh embodiment, by applying the structure of a zeroth-order resonating unit resonator to a linear antenna, the distribution of the amplitude and phase of the current flowing in the antenna element is uniform over the entire length of the antenna element. Can be This can increase the radiation gain of the antenna. Increasing the size of the antenna also increases the radiation gain. In addition, with the operating frequency fixed, the size of the antenna can be freely changed.
　本発明の一態様に係るメタマテリアル装置は、例えば、人工衛星及び自動車のためのアンテナ装置に適用可能である。 A metamaterial device according to an aspect of the present invention is applicable to, for example, an antenna device for a satellite and a car.
１，１Ａ～１Ｄ，１ＤＡ～１ＤＥ…単位共振器、
１Ｄａ～１Ｄｃ，１ＤＡａ～１ＤＥｂ…部分共振器、
２…円柱部材、
３…ベース部材、
１０Ａ，１０Ｂ，１０Ｃ…単位セル、
２０…フレキシブル基板、
２０Ｃ，２０Ｄ…基板、
２１，２１Ｂ，２１Ｃ…共振素子、
２２，２２Ａ…反射素子、
２３，２３Ｂ…ストリップ導体、
２４，２４Ｂ…キャパシタ、
２５…中心導体、
２６…アーム、
３１…送信アンテナ、
３２…受信アンテナ、
４０，４０Ａ…アンテナ装置、
４１…無線信号源、
４２…接地導体、
１００…メタマテリアル装置。 1, 1A to 1D, 1DA to 1DE: unit resonators,
1Da to 1Dc, 1DAa to 1DEb ... partial resonator,
2 ... cylindrical member,
3 ... Base member,
10A, 10B, 10C ... unit cell,
20 ... flexible substrate,
20C, 20D ... board,
21, 21 B, 21 C: resonant elements,
22, 22A ... reflective element,
23, 23 B: Strip conductor,
24, 24 B ... capacitor,
25 ... central conductor,
26 ... arm,
31 ... Transmitting antenna,
32 ... Receiving antenna,
40, 40A: antenna device,
41 ... wireless signal source,
42 ... grounding conductor,
100 ... metamaterial device.

Claims (14)

  1. 　少なくとも１つの単位共振器を備えるメタマテリアル装置であって、
    　前記単位共振器は、
    　少なくとも１つのストリップ形状の部分素子を含む共振素子であって、電流が同時に逆向きに流れる並列回路部分を含まない経路を有し、かつ、実質的にゼロの実効透磁率を有する共振素子と、
    　前記共振素子の前記部分素子の各端部にそれぞれ接続された複数の反射素子であって、前記部分素子から前記各反射素子を見たときのインピーダンスが実質的にゼロになる複数の反射素子とを備え、
    　前記単位共振器は０次共振器として動作する、
    メタマテリアル装置。     A metamaterial device comprising at least one unitary resonator, wherein
    The unit resonator is
    A resonant element comprising at least one strip-shaped subelement, having a path without parallel circuit parts through which current flows simultaneously in the reverse direction, and having substantially zero effective permeability;
    A plurality of reflective elements respectively connected to respective end portions of the partial elements of the resonant element, wherein the impedance when viewed from the partial elements is substantially zero; Equipped with
    The unit resonator operates as a zero-order resonator,
    Metamaterial device.
  2. 　前記共振素子は、互いに直列接続された複数の直列ＬＣ共振回路を含み、
    　前記各直列ＬＣ共振回路の共振周波数は、前記メタマテリアル装置の動作周波数に一致するように設定される、
    請求項１記載のメタマテリアル装置。     The resonant element includes a plurality of series LC resonant circuits connected in series with one another,
    The resonant frequency of each series LC resonant circuit is set to match the operating frequency of the metamaterial device.
    The metamaterial device according to claim 1.
  3. 　前記各直列ＬＣ共振回路は、ストリップ導体と、互いに隣接する直列ＬＣ共振回路のストリップ導体の間に設けられたキャパシタとを備える、
    請求項２記載のメタマテリアル装置。     Each of the series LC resonant circuits includes a strip conductor and a capacitor provided between the strip conductors of series LC resonant circuits adjacent to each other.
    The metamaterial device according to claim 2.
  4. 　前記各直列ＬＣ共振回路はストリップ導体を備え、
    　前記各直列ＬＣ共振回路のストリップ導体の端部は、隣接する直列ＬＣ共振回路のストリップ導体の端部と容量結合するように形成される、
    請求項２記載のメタマテリアル装置。     Each series LC resonant circuit comprises a strip conductor,
    The end of the strip conductor of each series LC resonant circuit is formed to capacitively couple with the end of the strip conductor of the adjacent series LC resonant circuit.
    The metamaterial device according to claim 2.
  5. 　前記反射素子は、前記メタマテリアル装置の動作波長の４分の１の長さを有し、ミアンダ形状又は渦巻き形状を有する、
    請求項１～４のうちの１つに記載のメタマテリアル装置。     The reflective element has a quarter length of the operating wavelength of the metamaterial device and has a meander shape or a spiral shape.
    A metamaterial device according to any one of the preceding claims.
  6. 　前記単位共振器は、カイラリティを有するように形成される、
    請求項１～５のうちの１つに記載のメタマテリアル装置。     The unit resonator is formed to have chirality.
    A metamaterial device according to one of the preceding claims.
  7. 　前記共振素子は、第１及び第２の端部を有するストリップ形状を有し、
    　前記単位共振器は螺線状に巻回される、
    請求項６記載のメタマテリアル装置。     The resonant element has a strip shape having first and second ends,
    The unit resonator is spirally wound,
    The metamaterial device according to claim 6.
  8. 　前記単位共振器は、平坦な基板上に形成され、
    　前記共振素子は、前記基板の面内の任意の直線に対して非対称に形成される、
    請求項６記載のメタマテリアル装置。     The unit resonators are formed on a flat substrate,
    The resonant element is formed asymmetrically with respect to any straight line in the plane of the substrate.
    The metamaterial device according to claim 6.
  9. 　前記共振素子は、前記基板の面内において屈曲又は湾曲したストリップ形状をそれぞれ有する複数の部分素子を含み、
    　前記各部分素子の一端は、前記複数の反射素子のうちの１つに接続され、前記各部分素子の他端は、他の前記部分素子に接続され、
    　前記共振素子は実質的に回転対称に形成される、
    請求項８記載のメタマテリアル装置。     The resonant element includes a plurality of subelements each having a bent or curved strip shape in the plane of the substrate,
    One end of each of the partial elements is connected to one of the plurality of reflective elements, and the other end of each of the partial elements is connected to the other partial element,
    The resonant element is formed substantially rotationally symmetric,
    The metamaterial device according to claim 8.
  10. 　前記単位共振器は、平坦な基板上に形成され、
    　前記単位共振器は、前記基板の互いに異なる複数の導体層にそれぞれ形成され、前記共振素子及び前記複数の反射素子をそれぞれ備える複数の部分共振器を含み、
    　前記複数の部分共振器の前記各共振素子は、互いに同じ形状を有し、前記各共振素子の回転対称の中心を通る軸の周りに互いに所定角度だけずれて形成される、
    請求項６～９のうちの１つに記載のメタマテリアル装置。     The unit resonators are formed on a flat substrate,
    The unit resonator includes a plurality of partial resonators respectively formed on a plurality of different conductor layers of the substrate and including the resonant element and the plurality of reflective elements.
    The resonant elements of the plurality of partial resonators have the same shape, and are formed offset from each other by a predetermined angle around an axis passing through the centers of rotational symmetry of the resonant elements.
    A metamaterial device according to one of the claims 6-9.
  11. 　前記メタマテリアル装置は、２次元アレイに配列された複数の単位共振器を含む、
    請求項１～１０のうちの１つに記載のメタマテリアル装置。     The metamaterial device includes a plurality of unit resonators arranged in a two-dimensional array,
    A metamaterial device according to one of the preceding claims.
  12. 　前記メタマテリアル装置は、入射する電磁波の偏波面を回転させる、
    請求項１１記載のメタマテリアル装置。     The metamaterial device rotates the polarization plane of the incident electromagnetic wave.
    The metamaterial device according to claim 11.
  13. 　前記メタマテリアル装置は、入射する電磁波のエネルギーの一部を透過させ、前記入射する電磁波のエネルギーの残りの一部を反射する、
    請求項１１記載のメタマテリアル装置。     The metamaterial device transmits a portion of the energy of the incident electromagnetic wave and reflects a portion of the energy of the incident electromagnetic wave.
    The metamaterial device according to claim 11.
  14. 　１つの単位共振器を備えるアンテナ装置であって、
    　前記単位共振器は、
    　第１及び第２の端部を有するストリップ形状を有する共振素子であって、前記第１及び第２の端部の間で電流が同時に逆向きに流れる並列回路部分を含まない経路を有し、かつ、実質的にゼロの実効透磁率を有する共振素子と、
    　前記共振素子の第１の端部に接続された反射素子であって、前記共振素子から前記反射素子を見たときのインピーダンスが実質的にゼロになる反射素子とを備え、
    　前記共振素子の第２の端部に給電点が設けられ、
    　前記単位共振器は０次共振器として動作する、
    アンテナ装置。     An antenna apparatus comprising one unit resonator, the antenna apparatus comprising:
    The unit resonator is
    A resonant element having a strip shape having first and second ends, the path not including a parallel circuit portion in which current flows simultaneously in the opposite direction between the first and second ends, And a resonant element having an effective permeability of substantially zero.
    A reflective element connected to the first end of the resonant element, the reflective element having a substantially zero impedance when viewed from the resonant element;
    A feed point is provided at the second end of the resonant element,
    The unit resonator operates as a zero-order resonator,
    Antenna device.
PCT/JP2018/008402 2017-08-28 2018-03-05 Meta-material device and antenna device WO2019044000A1 (en)

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CN113806975B (en) * 2021-08-12 2023-07-18 上海工程技术大学 Structural design method of chiral acoustic metamaterial plate

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