JP2017152878A - Antenna device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna device using a non-reciprocal metamaterial transmission line device which operates highly efficiently in relative to the prior arts and makes a sharp beam width possible.SOLUTION: An antenna device comprises a non-reciprocal metamaterial transmission line device having a structure which is spontaneously magnetized or magnetized by an external magnetic field by magnetizing a microstrip line in a direction that is different from a propagation direction of the microstrip line. In the microstrip line, capacitive elements are inserted into circuits of series branches and inductive short-circuit stubs are inserted into circuits of a parallel branches cyclically. In the antenna device, parameters of the circuits are set in such a manner that the microstrip line operates in a waveguide region, and reflection elements are connected to both ends of the microstrip line and operated in a resonant state. Further, the antenna device comprises a power supply line that is connected to one end of the microstrip line.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an antenna device using a nonreciprocal metamaterial transmission line device in which a forward propagation constant and a reverse propagation constant are different from each other.

  One conventional beam scanning antenna is a leaky wave antenna. A leaky wave antenna uses the phenomenon that a part of a signal propagating along a transmission line radiates outside as a leaky wave when the absolute value of the effective refractive index of the transmission line constituting the antenna is smaller than 1. (See, for example, Patent Documents 1 to 3).

  Since the radiation beam angle is determined by the spatial phase gradient of the electromagnetic field distribution generated on the transmission line, the leakage wave beam angle can be scanned by changing the phase gradient on the line. In such a conventional leaky wave antenna, a signal is input from one end of the line. If there is a component that does not contribute to leakage wave radiation in the input signal and it reaches the other line termination, it is reflected at the termination and propagates in the same direction in the opposite direction, and is unnecessary due to secondary leakage wave radiation. Cause side lobes. As a means for solving this problem, it is necessary to unnecessarily increase the antenna size (line length) or to suppress reflection by inserting an impedance matching circuit at the end of the line. If the size of the leaky wave antenna is compact, signal components that do not contribute to radiation are consumed at the end, and radiation efficiency cannot be increased.

  One of the new technologies for maintaining high radiation efficiency while keeping the antenna size compact is the use of nonreciprocal metamaterials. Non-reciprocal metamaterials are metamaterials with different transmission coefficients in the forward and reverse directions.For example, in the case of forward propagation, a positive refractive index is shown. It is possible to indicate the refractive index. When this nonreciprocal line is applied to a leaky wave antenna, the leaky wave radiation direction can be directed in the same direction even if the propagation direction of the signal is switched along the line. In order not to reduce the radiation efficiency of leakage waves from this nonreciprocal line, a pair of reflective elements are inserted at both ends of the line, and multiple reflections are actively used, so that most of the input signal is directed to a specific direction. It can be considered to contribute to the leakage wave radiation.

  In other words, in the prior art, the power that has been wasted at the end can be effectively utilized by using the nonreciprocal line, and the radiation efficiency can be improved by the resonance structure. Such a nonreciprocal metamaterial resonant structure is called a pseudo traveling wave resonator and has several characteristics.

  The first feature is that the resonance frequency does not depend on the resonator size. When this is used, the antenna shape and size can be freely changed while the resonance frequency is fixed. Another feature is that the electromagnetic field distribution in the pseudo traveling wave resonator automatically becomes uniform in amplitude, while the phase distribution has a constant phase gradient. This phase gradient is an amount determined by the non-reciprocity of the line, and is a parameter that can be controlled independently regardless of the resonance condition.

  Therefore, highly efficient leaky wave beam scanning can be achieved by changing the nonreciprocity of the line while maintaining the resonance state. When there is no nonreciprocity in the line, the effective refractive index in the line becomes 0 and the phase is the same everywhere on the line, so that leakage waves radiate in the broadside (vertical) direction with respect to the line. As the nonreciprocity of the line increases, the slope of the leaky wave beam angle increases.

Japanese Patent No. 5234667 Japanese Patent No. 5655256 International Publication No. 2012/115245

  When the nonreciprocity is increased and the absolute value of the effective refractive index of the line approaches 1, ideally, the beam angle should increase in inclination to nearly 90 degrees from the broad side. However, in practice, the beam angle is not so inclined, and the beam width is greatly increased and the directivity is lowered in both cases where the beam direction is forward radiation or backward radiation. Further, when the nonreciprocity is increased and the waveguide region is larger than 1 in terms of the effective refractive index, the leakage gain is not generated, so that the radiation gain is lowered.

  As already explained, for antenna applications of nonreciprocal metamaterials, the antenna operation in the leaky wave region has been used so far. Even when reflective elements are inserted on both sides of the line and high-efficiency radiation is realized by actively using multiple reflections, the radiation principle is based on leakage wave radiation.

  An object of the present invention is to solve the above problems and to provide an antenna device using a nonreciprocal metamaterial transmission line device that can operate with higher efficiency than the prior art.

In the antenna device according to the present invention, a microstrip line in which a capacitive element is periodically inserted in a series branch circuit and an inductive short stub is periodically inserted in a parallel branch circuit is different from the propagation direction of the microstrip line. An antenna device comprising a nonreciprocal metamaterial transmission line device having a structure magnetized in a direction and having spontaneous magnetization or magnetized by an external magnetic field,
The parameters of each circuit are set so that the microstrip line operates in the waveguide region, and reflection elements are connected to both ends of the microstrip line, respectively, so that the microstrip line operates in a resonance state.

  The antenna device may further include a feed line connected to one end of the microstrip line.

  The antenna device includes a plurality of the antenna devices, each end of the plurality of antenna devices is connected to each other, and the plurality of antenna devices are arranged radially.

  Furthermore, the antenna device further includes a feed line connected to a point where one ends of the plurality of antenna devices are connected.

  Therefore, according to this invention, the antenna apparatus using the nonreciprocal metamaterial transmission line apparatus which can operate | move with high efficiency compared with a prior art can be provided.

It is a perspective view which shows the structure of the nonreciprocal metamaterial transmission line apparatus which concerns on Embodiment 1 of this invention. It is an enlarged view of the track | line part of FIG. 1A. It is a perspective view which shows the structure of the antenna apparatus using the pseudo | simulation traveling wave resonator which concerns on Embodiment 2 of this invention. It is a graph which shows a dispersion curve when effective magnetization is 130 mT in the nonreciprocal metamaterial transmission line apparatus of FIG. 1A and FIG. 1B. It is a graph which shows a dispersion curve when effective magnetization is 170 mT in the nonreciprocal metamaterial transmission line apparatus of FIG. 1A and FIG. 1B. In the nonreciprocal metamaterial transmission line device of FIG. 1A and FIG. 1B in which the number of unit cells 20 is 30, FIG. 7B is a pattern diagram showing a radiation pattern on the YZ plane during forward propagation at a frequency of 5.83 GHz when the effective magnetization is 130 mT is there. In the nonreciprocal metamaterial transmission line device of FIG. 1A and FIG. 1B in which the number of unit cells 20 is 30, FIG. 5B is a pattern diagram showing a radiation pattern on the YZ plane during reverse propagation at a frequency of 5.83 GHz when effective magnetization is 130 mT. is there. In the nonreciprocal metamaterial transmission line device of FIG. 1A and FIG. 1B in which the number of unit cells 20 is 30, the effective magnetization is 170 mT, and the pattern diagram showing the radiation pattern on the YZ plane during forward propagation at a frequency of 6.05 GHz. is there. In the nonreciprocal metamaterial transmission line device of FIG. 1A and FIG. 1B in which the number of unit cells 20 is 30, FIG. 7B is a pattern diagram showing a radiation pattern on the YZ plane during reverse propagation at a frequency of 6.05 GHz when effective magnetization is 170 mT. is there. 3 is a pattern diagram showing a radiation pattern on the YZ plane at a frequency of 5.88 GHz when the effective magnetization is 130 mT in the antenna device of FIG. 2 using a nonreciprocal metamaterial transmission line device in which the number of unit cells 20 is 30. FIG. 3 is a spectrum diagram showing reflection characteristics when effective magnetization is 130 mT in the antenna device of FIG. 2 using a nonreciprocal metamaterial transmission line device in which the number of unit cells 20 is 30. FIG. FIG. 3 is a pattern diagram showing a radiation pattern on the YZ plane at a frequency of 6.06 GHz when the effective magnetization is 170 mT in the antenna device of FIG. 2 using the nonreciprocal metamaterial transmission line device in which the number of unit cells 20 is 30. FIG. 3 is a spectrum diagram showing reflection characteristics when effective magnetization is 170 mT in the antenna device of FIG. 2 using a nonreciprocal metamaterial transmission line device in which the number of unit cells 20 is 30. It is a table | surface which shows the absolute gain and beam half value width in the non-reciprocal metamaterial transmission line apparatus of FIG. 1A and FIG. 1B. It is a table | surface which shows the absolute gain in the antenna apparatus using the quasi-traveling wave resonator of FIG. It is a top view which shows the structure of the antenna apparatus which concerns on Embodiment 3 of this invention. FIG. 15B is an enlarged view of a portion of the NCRLH line 30 in FIG. 15A. FIG. 16 is a spectrum diagram showing reflection characteristics when effective magnetization is 130 mT in the antenna device of FIGS. 15A and 15B. FIG. 16 is a spectrum diagram showing reflection characteristics when the effective magnetization is 170 mT in the antenna device of FIGS. 15A and 15B. FIG. 16 is a pattern diagram showing a radiation pattern on the XZ plane at a frequency of 5.83 GHz when the effective magnetization is 130 mT in the antenna device of FIGS. 15A and 15B. FIG. 16 is a pattern diagram showing a radiation pattern on the XZ plane at a frequency of 6.0 GHz when the effective magnetization is 170 mT in the antenna device of FIGS. 15A and 15B. FIG. 16 is a pattern diagram showing a radiation pattern on the XY plane at a frequency of 5.83 GHz when the effective magnetization is 130 mT in the antenna device of FIGS. 15A and 15B. FIG. 16 is a pattern diagram showing a radiation pattern on the XY plane at a frequency of 6.0 GHz when the effective magnetization is 170 mT in the antenna device of FIGS. 15A and 15B.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In addition, in each following embodiment, the same code | symbol is attached | subjected about the same component.

  In the present embodiment, a highly efficient directional antenna is proposed that resonates a nonreciprocal metamaterial transmission line device in a waveguide region and radiates in a horizontal direction. In the operation in the leaky wave region according to the conventional technique, the beam angle does not face the horizontal direction, and the beam width is further increased. In this embodiment, the nonreciprocal metamaterial line device is resonated in the waveguiding region to form a pseudo traveling wave resonator and realize forward radiation or backward radiation in a horizontal plane, thereby making the beam sharper than before. A highly efficient directional antenna with a width is realized. In addition, by adopting a structure in which a plurality of nonreciprocal metamaterial transmission line devices are arranged radially, an antenna that emits a sharp beam in a low orientation and in a horizontal direction can be configured.

  FIG. 1A is a perspective view showing a configuration of a nonreciprocal metamaterial transmission line device according to Embodiment 1 of the present invention. FIG. 1B is an enlarged view of the line portion of FIG. 1A. Here, the non-reciprocal metamaterial transmission line device is configured using a non-reciprocal phase-shifting right / left-handed composite transmission line (hereinafter referred to as an NCRLH line).

  1A and 1B, the NCRLH line 30 according to the first embodiment includes a strip conductor 12 on a perpendicular magnetization ferrite square bar 10 sandwiched between a pair of dielectric substrates 13 and 14 having a ground conductor 11 on the back surface. For the microstrip line composed of the ground conductor 11 and the ground conductor 11, a series capacitor Cs (however, 2Cs at both ends of the line) is inserted into the series branch circuit, and an inductor is periodically inserted into the parallel branch circuit. The plurality of unit cells 20 are connected in cascade. In the NCRLH line 30 of FIG. 1, for example, a chip capacitor is inserted as the series capacitor Cs of the serial branch, and an inductive short-circuit stub inserted only on one side with respect to the propagation direction of the electromagnetic wave is adopted as the parallel branch inductor. . Here, each inductive short-circuit stub is formed as an inductive short-circuit stub in which the strip conductor 16 is grounded via the via conductor 17, for example. One end of the NCRLH line 30 is connected to the port P1 via a strip conductor 12P1 on the dielectric substrates 13 and 14, and the other end of the NCRLH line 30 is a strip conductor on the dielectric substrates 13 and 14. 12P2 is connected to the port P2.

  Further, the ferrite square bar 10 is magnetized in a vertical direction (a direction perpendicular to the surfaces of the dielectric substrates 13 and 14, for example, a direction from the lower surface to the upper surface) by the permanent magnet 40 immediately below the line. .

In addition, the circuit parameters when simulating the nonreciprocal metamaterial transmission line apparatus of FIG. 1A and FIG. 1B are as follows.
―――――――――――――――――――――
Series capacitor Cs = 0.6pF
Width w of strip conductor 12 = 4.0 mm
Cell cycle p = 3.5mm
Dielectric constant of ferrite rod 10 ε _f = 15
Dielectric constant ε _d = 2.6 of dielectric substrates 13 and 14
Stub length l _stub = 0.2mm
Stub width w _stub = 1.6mm
―――――――――――――――――――――

  In the above embodiment, the ferrite square bar 10 is magnetized in the vertical direction by the permanent magnet 40 (FIG. 1A) provided immediately below the line. However, the present invention is not limited to this, and the ferrite square bar 10 is magnetized in advance. May be.

  The configuration of the ladder-type NCRLH line that is the nonreciprocal metamaterial transmission line is a ladder-type transmission line configuration in which, for example, at least one unit cell 20 is formed as shown in FIG. 1A. Here, the configuration of the unit cell 20 includes a transmission line portion having a nonreciprocal phase transition phenomenon having different propagation constants in the forward direction and the reverse direction, a capacitive element in a series branch circuit, and an inductive element in a parallel branch circuit. Are equivalently inserted (see FIGS. 1A and 1B). Circuits or devices targeted as the above transmission line configurations include printed circuit boards, waveguides, dielectrics used in microwaves, millimeter waves, quasi-millimeter waves, terahertz waves, such as strip lines, microstrip lines, slot lines, and coplanar lines. This includes not only body lines but also all configurations that support guided modes or attenuation modes including plasmons, polaritons, magnons, etc., or combinations thereof, and free space that can be described as an equivalent circuit.

  The transmission line having the irreversible phase transition phenomenon includes a material having gyro anisotropy in part or in whole in the transmission line configuration shown above, and a magnetization direction (different from the propagation direction of electromagnetic waves) More preferably, the transmission line is composed of a transmission line that is magnetized in a direction orthogonal to the propagation direction and has an asymmetry with respect to a plane formed by the propagation direction and the magnetization direction. As the transmission line having the nonreciprocal phase transition phenomenon, in addition to the transmission line, a lumped constant element having an equivalent nonreciprocal phase transition function and sufficiently smaller than the wavelength is also targeted. As the material having the above gyro anisotropy, a dielectric constant tensor or a magnetic permeability tensor representing the characteristics of the material by spontaneous magnetization, magnetization induced by a direct-current or low-frequency magnetic field applied from the outside, or circular motion of free charge, or Both include all cases expressed as states having gyro anisotropy. Specific examples include ferrimagnetic materials such as ferrite used in microwaves and millimeter waves, ferromagnetic materials, solid plasmas (semiconductor materials, etc.) and liquids, gas plasma media, and microfabrication. Examples include magnetic artificial media that are configured.

  Capacitive elements inserted in the above-mentioned series branch circuit include not only distributed constant type capacitive elements used in capacitors, microwaves, millimeter wave circuits, etc. often used in electric circuits, but equivalently, in transmission lines It may be a circuit or a circuit element in which the effective permeability of the electromagnetic wave mode propagating through the channel has a negative value. Specific examples of negative effective permeability include a split ring resonator made of metal, a spatial arrangement including at least one magnetic resonator such as a spiral configuration, or a dielectric resonator in a magnetic resonance state All microwave circuits operating in the waveguide mode or attenuation mode with negative effective magnetic permeability, such as the edge mode propagating along the ferrite substrate microstrip line, as an equivalent circuit It can be used because the circuit is described as a line that operates predominantly as a capacitive element. In addition to the above, the capacitive element inserted into the series branch circuit may be a series connection, a parallel connection, or a combination of a capacitive element and an inductive element. The element or circuit of the part to be inserted may be capacitive as a whole.

  As an inductive element inserted into the above-mentioned parallel branch circuit, only a lumped constant type element such as a coil used in an electric circuit or a distributed constant type inductive element such as a short-circuit stub used in a microwave or millimeter wave circuit is used. Alternatively, a circuit or element having a negative effective dielectric constant of the electromagnetic wave mode propagating through the transmission line can be used. Specifically, a spatial arrangement including at least one electric resonator such as a thin metal wire or a metal sphere, or a spatial arrangement of a dielectric resonator in an electric resonance state as well as a metal, or a TE mode is cut off. Transmission in which the parallel branch is dominantly operated as an inductive element as an equivalent circuit for all microwave circuits operating in the waveguide mode or attenuation mode having a negative effective dielectric constant, such as waveguides and parallel plate lines in the region It can be used because it is described as a track. In addition to the above, the inductive element inserted into the parallel branch circuit may be a series connection, a parallel connection, or a combination of a capacitive element and an inductive element. The part to be inserted may be a circuit or an element that exhibits inductivity as a whole.

  FIG. 2 is a perspective view showing a configuration of an antenna device using a pseudo traveling wave resonator according to Embodiment 2 of the present invention. 2 and subsequent drawings, the width direction of the microstrip line is taken as the X direction, the longitudinal direction thereof is taken as the Y direction, and the vertical direction from the lower surface to the upper surface of the microstrip line is taken as the Z direction.

  In the second embodiment shown in FIG. 2, the pseudo traveling wave resonator short-circuits both ends of the NCRLH line 30 shown in FIGS. 1A and 1B in order to impose a resonance condition. In order to satisfy the short-circuit condition at the terminal end, a microstrip line strip conductor 21 having a line length corresponding to ¼ wavelength of the operating frequency is inserted as a reflective element on the power supply line side of the port P1, and the port P2 side The strip conductor 23 is grounded via the via conductor 32. Further, the strip conductor 22 of the feed line is inserted at a position of the strip conductor 21 that can be matched with a reflector of ¼ wavelength at 50Ω, and the end of the strip conductor 22 receives a microwave signal or It becomes port P3 for output.

  FIG. 3 is a graph showing a dispersion curve when the effective magnetization is 130 mT in the nonreciprocal metamaterial transmission line device of FIGS. 1A and 1B. FIG. 4 is a graph showing a dispersion curve when the effective magnetization is 170 mT in the nonreciprocal metamaterial transmission line device of FIGS. 1A and 1B. The case of FIG. 3 is a dispersion curve when the effective magnetization of the ferrite rod 10 is 130 mT, and the intersection of the dispersion curves is on the air line, and corresponds to the case where the effective refractive index is 1. This corresponds to forward or backward radiation when the leaky wave radiation angle is inclined by 90 ° from the broad side. On the other hand, the case of FIG. 4 shows a dispersion curve when the effective magnetization is 170 mT. The intersection of the dispersion curves when the effective magnetization is 130 mT operates in the fast wave (leakage wave) region inside the air line, whereas the intersection of the dispersion curves when the effective magnetization is 170 mT is the waveguide outside the air line. Operates in the (non-radiating) region.

  FIG. 5 shows the radio wave radiation pattern on the YZ plane during forward propagation at a frequency of 5.83 GHz when the effective magnetization is 130 mT in the nonreciprocal metamaterial transmission line device of FIGS. 1A and 1B in which the number of unit cells 20 is 30. FIG. Further, FIG. 6 shows radio wave radiation on the YZ plane during reverse propagation at a frequency of 5.83 GHz when the effective magnetization is 130 mT in the nonreciprocal metamaterial transmission line device of FIG. 1A and FIG. It is a pattern figure which shows a pattern. In the case of forward propagation in FIG. 5, the maximum value of the radiation gain (hereinafter expressed as absolute gain) is 9.71 dBi at the radiation beam angle θ = 90 degrees on the YZ plane, and the radiation half-value width is 37 degrees. became. In the case of reverse propagation in FIG. 6, the maximum value of the radiation gain is 8.70 dBi at the beam angle θ = 90 degrees on the YZ plane, and the beam half width is 26 degrees.

  FIG. 7 shows the radio wave radiation pattern on the YZ plane during forward propagation at a frequency of 6.05 GHz when the effective magnetization is 170 mT in the nonreciprocal metamaterial transmission line device of FIGS. 1A and 1B in which the number of unit cells 20 is 30. FIG. Further, FIG. 8 shows radio wave radiation on the YZ plane during reverse propagation at a frequency of 6.05 GHz when the effective magnetization is 170 mT in the nonreciprocal metamaterial transmission line device of FIGS. 1A and 1B in which the number of unit cells 20 is 30. It is a pattern figure which shows a pattern. In the case of forward propagation in FIG. 7, the maximum value of the radiation gain is 7.23 dBi at the beam angle θ = 90 degrees on the YZ plane, and the beam half width is 19.5 degrees. In the case of reverse propagation in FIG. 8, the maximum value of the radiation gain is −0.75 dBi at the beam angle θ = 90 degrees on the YZ plane, and the beam half width is 15 degrees.

  FIG. 9 is a pattern diagram showing a radiation pattern on the YZ plane at a frequency of 5.88 GHz when the effective magnetization is 130 mT in the antenna device of FIG. 2 using the nonreciprocal metamaterial transmission line device having 30 unit cells 20. It is. FIG. 10 is a spectrum diagram showing the reflection characteristics when the effective magnetization is 130 mT in the antenna device of FIG. 2 using the nonreciprocal metamaterial transmission line device in which the number of unit cells 20 is 30, and the horizontal axis is the frequency. The vertical axis represents the S parameter S11. In the radiation pattern of FIG. 9, the maximum value of the radiation gain is 12.66 dBi at the beam angle θ = 90 degrees on the YZ plane, and the beam half width is 36 degrees. In the reflection characteristics of the pseudo traveling wave resonator shown in FIG. 10, the zeroth-order resonance frequency appears at 5.88 GHz, and the ratio band is 0.78%.

  FIG. 11 is a pattern diagram showing a radiation pattern on the YZ plane at a frequency of 6.06 GHz when the effective magnetization is 170 mT in the antenna device of FIG. 2 using the nonreciprocal metamaterial transmission line device having 30 unit cells 20. It is. FIG. 12 is a spectrum diagram showing reflection characteristics when the effective magnetization is 170 mT in the antenna apparatus of FIG. 2 using the nonreciprocal metamaterial transmission line apparatus in which the number of unit cells 20 is 30. In the radiation pattern of FIG. The maximum value of the radiation gain was 9.42 dBi at the beam angle θ = 90 degrees on the YZ plane, and the beam half width was 18 degrees. In the reflection characteristic of FIG. 12, the zeroth-order resonance frequency appeared at 6.06 GHz, and the specific band was 0.69%.

  A summary of simulation results by the present inventors is shown in FIGS. FIG. 13 is a table showing absolute gains and beam half-value widths in the nonreciprocal metamaterial transmission line device of FIGS. 1A and 1B. FIG. 14 is a table showing the absolute gain, beam half width, and ratio band in the antenna device using the pseudo traveling wave resonator of FIG.

  As described above, according to the present embodiment, a microstrip line in which a capacitive element is periodically inserted in a series branch circuit and an inductive element is periodically inserted in a parallel branch circuit is used as a propagation direction of the microstrip line. Antenna device having a nonreciprocal metamaterial transmission line device that is magnetized in a different direction and has a spontaneous magnetization or a structure magnetized by an external magnetic field, wherein the microstrip line operates in the waveguide region In this way, the parameters of each circuit are set, reflection elements are connected to both ends of the microstrip line, and the circuit operates in a resonance state. Here, a feed line connected to one end of the microstrip line is further provided.

  Therefore, according to the present embodiment, by operating a pseudo traveling wave resonator antenna device composed of a nonreciprocal metamaterial transmission line device in the waveguide region, the electromagnetic field attenuation effect of the propagation signal on the line due to leakage wave radiation can be reduced. It can suppress, operate | moves with high radiation efficiency compared with a prior art, can obtain more uniform electromagnetic field distribution, and can form a sharp beam.

  FIG. 15A is a plan view showing a configuration of an antenna apparatus according to Embodiment 3 of the present invention. FIG. 15B is an enlarged view of the portion of the NCRLH line 30 in FIG. 15A. The antenna device according to the third embodiment is a horizontal omnidirectional radiating antenna device including the pseudo traveling wave resonator according to the second embodiment.

  15A and 15B, the antenna device according to the third embodiment includes, for example, 10 NCRLH lines 30 radially from via conductors 33 (connected to the power feeding circuit via the power feeding line) at the power feeding point in the center of the apparatus. This is a pseudo traveling wave resonance antenna apparatus in which -1 to 30-10 are arranged on the dielectric substrate 13 at an equal angle of, for example, 36 degrees. Here, in order to impose a resonance condition on each NCRLH line 30, via conductors 31 and 32 having a short circuit to the ground are inserted at both ends of each NCRLH line 30. The feed point is connected by a 50Ω feed line, and the length of the microstrip line from the feed point to the via conductor 32 inserted at the end of the port P2 side of each NCRLH line 30 is adjusted to 50Ω. Impedance matching is taken for the feed line.

  FIG. 16 is a spectrum diagram showing reflection characteristics when the effective magnetization is 130 mT in the antenna device of FIGS. 15A and 15B. FIG. 17 is a spectrum diagram showing reflection characteristics when the effective magnetization is 170 mT in the antenna device of FIGS. 15A and 15B. Each resonance point in FIGS. 16 and 17 matches the frequency of the intersection of the dispersion curves shown in FIGS.

  FIG. 18 is a pattern diagram showing a radiation pattern on the XZ plane at a frequency of 5.83 GHz when the effective magnetization is 130 mT in the antenna device of FIGS. 15A and 15B. FIG. 19 is a pattern diagram showing a radiation pattern on the XZ plane at a frequency of 6.0 GHz when the effective magnetization is 170 mT in the antenna device of FIGS. 15A and 15B. As is apparent from FIG. 18, the radiation gain when the effective magnetization is 130 mT is 4.29 dBi at a beam angle θ = 90 degrees on the XZ plane corresponding to the horizontal plane, and the beam half width is 40 degrees. As is clear from FIG. 19, when the effective magnetization is 170 mT, the radiation gain is 3.39 dBi at a beam angle θ = 90 degrees on the XZ plane, and the beam half width is 35 degrees.

  FIG. 20 is a pattern diagram showing a radiation pattern on the XY plane at a frequency of 5.83 GHz when the effective magnetization is 130 mT in the antenna device of FIGS. 15A and 15B. FIG. 21 is a pattern diagram showing a radiation pattern on the XY plane at a frequency of 6.0 GHz when the effective magnetization is 170 mT in the antenna device of FIGS. 15A and 15B. As is clear from FIG. 20, when the effective magnetization is 130 mT, the radiation is omnidirectional in the horizontal direction, and the average horizontal radiation gain is 4.29 dBi. As is clear from FIG. 21, even when the effective magnetization was 170 mT, the radiation was omnidirectional in the horizontal direction, and the average horizontal radiation gain was 3.39 dBi.

  As described above, by arranging a plurality of antenna devices according to Embodiment 2 in a radial manner, the antenna device has higher radiation efficiency than the conventional technology, provides a sharp beam width in the elevation direction, and is omnidirectional in the horizontal direction. Can be realized.

  In the above embodiment, the ten NCRLH lines 30 are provided. However, the present invention is not limited to this. For example, the omnidirectional antenna apparatus can be configured by arranging four or more NCRLH lines 30 radially. It may be configured.

  As described in detail above, according to the present invention, it is possible to provide an antenna device using a nonreciprocal metamaterial transmission line device that operates with higher efficiency than the prior art and provides a sharp beam width in the elevation direction. it can.

10 ... Ferrite square bar,
11: Ground conductor,
12, 12P1, 12P2 ... strip conductors,
13, 14 ... dielectric substrate,
16: Strip conductor,
17 ... via conductor,
20: Unit cell,
21, 22, 23 ... strip conductors,
30, 30-1 to 30-10 ... NCRLH line,
31, 32, 33 ... via conductors,
40 ... Permanent magnet,
Cs: Series capacitor,
P1-P3 ... port
P1E, P2E: Line ends.

Claims (4)

A microstrip line in which a capacitive element is inserted in a series branch circuit and an inductive element is inserted in a parallel branch circuit is magnetized in a direction different from the propagation direction of the microstrip line to have spontaneous magnetization. An antenna device comprising a nonreciprocal metamaterial transmission line device having a structure magnetized by an external magnetic field,
An antenna device, wherein the parameters of each circuit are set so that the microstrip line operates in a waveguide region, reflection elements are connected to both ends of the microstrip line, and the antenna device operates in a resonance state.   2. The antenna device according to claim 1, further comprising a feed line connected to one end of the microstrip line.   An antenna device comprising a plurality of the antenna devices according to claim 1, wherein one end of each of the plurality of antenna devices is connected to each other, and the plurality of antenna devices are arranged radially.   4. The antenna device according to claim 3, further comprising a feed line connected to a point where one ends of the plurality of antenna devices are connected.

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