JP2014096726A - Antenna device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna device that makes operation frequency variable without using an active component, that restricts occurrence of unnecessary scattered wave, and that eliminates the need for a design in which isolation is taken into account.SOLUTION: An antenna device comprises: a ground plate 3 formed from a conductor; a hollow dielectric plate 1 arranged on the ground plate 3 in laminated structure and having a hollow structure in which a gas can be sealed; a radiation conductor 2 arranged parallel to the ground plate 3 on an internal wall of a side of the hollow dielectric plate 1, which side is opposite the laminated side with the ground plate 3; an electric power supply pin 4 whose one end is exposed to the outside of the device and whose other end supplies electric power to a connected radiation conductor 2; and electric plates 5a and 5b arranged in a place where they do not conduct with the ground plate 3 of the hollow dielectric plate 1 and the radiation conductor 2. Plasma is generated by applying a specific voltage to the electrode plates 5a and 5b and exciting the gas sealed in the hollow dielectric plate 1. At least the voltage applied to the electrode plates 5a and 5b or the concentration of the gas sealed in the hollow dielectric plate 1 is adjusted, and the electric characteristic of plasma is changed.

Description

  The present invention relates to an antenna device used for communication and radar in the microwave band.

  As a communication device used for transmission / reception of a microwave band, various antennas using the principle of a Micro Strip resonator, such as a Micro Strip Antenna (hereinafter referred to as MSA) and a reflect array antenna, are used.

FIG. 7 is a diagram showing a configuration of a conventional MSA. The MSA shown in FIG. 7 includes a dielectric substrate 91, a radiating conductor 92 that is a radiating element affixed on the dielectric substrate 91, a power supply pin 93 that supplies power to the radiating conductor 92, It is comprised with the conductor ground plane 94 contact | abutted to the bottom face side. The power feed pin 93 and the conductor ground plane 94 are not conductive.
The operating frequency band of the MSA as shown in FIG. 7 includes the dielectric constant, the number of layers and the size of the dielectric constituting the dielectric substrate 91, the size and shape of the radiation conductor 92, the feeding position to the radiation conductor 92, etc. It depends on. By providing the radiating conductor 92 with a notch shape or a slot, it is possible to operate in a plurality of frequency bands and generate circularly polarized waves. Further, MSA has an advantage that it can be easily manufactured at a relatively low cost by etching a printed circuit board.

  FIG. 8 is a diagram showing a configuration of a conventional reflectarray antenna. The reflectarray antenna shown in FIG. 8 includes a dielectric substrate 91, a plurality of radiation conductors 92 'pasted on the dielectric substrate 91', a conductor substrate 94 ', and a primary radiator 100 such as a horn antenna. It is configured. By adjusting the reflection phase of the plurality of radiation conductors 92 ′ constituting the reflectarray antenna, the radio wave 101 having the phase distribution irradiated from the primary radiator 100 installed in the vicinity is converted into the plane wave 102. Thus, the reflecting surface of the reflectarray antenna functions in the same manner as the main reflector of a reflector antenna such as a parabolic antenna. Since the reflector array antenna can be flattened, it has a feature that it is not as wide as a reflector antenna having a curved surface, and can be easily placed in places where space for mounting is limited, such as a satellite-mounted antenna.

  Such MSA and reflectarray antennas began with passive research and development in which the transmission direction of radio waves and the frequency band used are constant, and in recent years, with the aim of expanding their application range and improving functionality, Active research and development that can switch the reflection direction is also becoming popular. The configurations of active MSA and reflectarray antenna are shown below.

  As one of MSAs capable of switching the operating frequency, there is one using an active element. Non-Patent Document 1 discloses an MSA using a diode as an active element. In the MSA disclosed in Non-Patent Document 1, a slot is provided in the radiation conductor of the MSA, a PIN diode is arranged so as to cross the slot, and the PIN diode is turned on by applying a voltage to the arranged PIN diode. A conduction path is formed in a part of the slot. Thereby, the path of the surface current of the radiation conductor is changed, and the resonance frequency is changed.

  Similar to MSA, there is also a reflectarray antenna configured using an antenna element using an active element. As described above, the radio wave radiation direction of the reflectarray antenna depends on the reflection phase of the antenna elements constituting the antenna. Therefore, if the reflection phase is changed, the radiation direction is changed. For this purpose, an antenna element using an active element is used. The antenna element of the reflectarray antenna described in Non-Patent Document 2 changes the reflection phase by changing the electrical length of the radiation conductor of the antenna element using a PIN diode. For the same purpose, Non-Patent Document 3 describes a reflectarray antenna using MEMS (Micro Electro Mechanical System) as an active element.

Other than antennas, there are devices using plasma in order to make the frequency of electromagnetic wave transmission variable. The complex relative permittivity of plasma has frequency dependence and changes depending on the internal gas density and electric field. In addition, when an external magnetic field is applied, the relative dielectric constant has anisotropy. Therefore, the direction of the electromagnetic wave incident on the plasma can be controlled by changing the plasma state.
Patent Document 1 discloses an electromagnetic wave control device that controls the direction of an electromagnetic wave incident on a space by adjusting the refractive index of the gas sealed in a certain space by using a large number of electrodes to adjust the refractive index. It is disclosed.

International Publication No. 2007/000989

MS Nishamol, VP Sarin, D. Tony, CK Aananda, P. Mohanan, and K. Vasudevan, “An Electronically Reconfigurable Microstrip Antenna With Switchable Slots for Polarization Diversity”, IEEE Trans. Antennas Propag., Vol. 59, No. 9 , 2011 X. Delestre, T. Dousset, M. Labeyrie, and C. Renard, “New Challenges for Active Reflect Arrays”, Radar Conference-Surveillance for a Safer World, 2009. RADAR. International, 2009 J. Perruisseau-Carrier, and A. K. Skrivervik, “Monolithic MEMS-Based Reflectarray Cell Digitally Reconfigurable Over a 360 ° Phase Range” S, IEEE Antennas and Wireless Propagation Letters, Vol. 7, 2008

  However, the above-described active antenna technology has a problem that the structure of the antenna becomes very complicated when many active elements are used as the antenna elements of the MSA or the reflect array antenna. It is necessary to create a current distribution for obtaining a desired resonance frequency on the surface of the radiation conductor, and when switching to many frequency bands, it is necessary to mount a plurality of diodes on one radiation conductor. is there. In addition, when a plurality of active elements are mounted, the number of conductive wires connected to control each active element also increases. When an electromagnetic wave is incident in a state where a huge number of wirings exist on the radiation surface, there is a problem that a large current is excited on the wirings to generate unnecessary scattered waves. Further, in order to prevent loss due to active and prevent a current from flowing through the diode bias circuit, there is a problem that the design must be performed in consideration of isolation.

  In addition, the technique disclosed in Patent Document 1 has a problem in that the structure of the antenna device is complicated because it is necessary to arrange a large number of electrodes for supplying power for generating plasma.

  The present invention has been made to solve the above-described problems, and requires a design that considers isolation by making the operating frequency variable without using active elements, further suppressing the generation of unnecessary scattered waves. An object of the present invention is to provide an antenna device that does not.

  The antenna device according to the present invention is opposed to a laminated surface of a ground plate made of a conductor, a dielectric plate laminated on the ground plate and having a hollow structure capable of enclosing gas therein, and the ground plate of the dielectric plate. A radiation conductor disposed on the inner wall of the surface to be parallel to the ground plate, a power supply pin for supplying power to the radiation conductor having one end exposed to the outside of the device and the other end connected thereto, a ground plate and a radiation conductor of the derivative plate, An electrode plate disposed at a non-conducting position, applying a predetermined voltage to the electrode plate to excite the gas enclosed in the dielectric plate to generate plasma, and applying the voltage to the electrode plate and the dielectric plate It adjusts at least one of the densities of the gas sealed inside to change the electrical characteristics of the plasma.

  According to the present invention, it is possible to realize an MSA in which the operating frequency is variable without using an active element. In addition, it is possible to provide an antenna device that suppresses the generation of unnecessary scattered waves on the radiation surface of the radiation element and does not require a design that considers the isolation of the bias circuit.

1 is a diagram showing a configuration of an antenna device according to Embodiment 1. FIG. 3 is a three-sided view illustrating a configuration of an antenna element according to Embodiment 1. FIG. It is a figure which shows the structure of the antenna apparatus by Embodiment 2. FIG. FIG. 6 is a trihedral view illustrating a configuration of an antenna element according to a second embodiment. FIG. 10 is a diagram illustrating a configuration of an antenna device according to a third embodiment. FIG. 10 is an explanatory diagram showing an array antenna according to a fourth embodiment. It is a figure which shows the structure of the conventional MSA. It is a figure which shows the structure of the conventional reflectarray antenna.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of an antenna apparatus according to Embodiment 1 of the present invention. In FIG. 1, the antenna element 10 is shown in a transparent perspective view. 2A and 2B are three views showing the configuration of the antenna element according to Embodiment 1 of the present invention. FIG. 2A is a transparent top view of the antenna element, and FIG. 2B is AA in FIG. A sectional view taken along the line ′, and FIG. 2C is a sectional view taken along the line BB ′ in FIG.
The antenna device includes an antenna element 10, a power supply device 20, a conducting wire 21, a gas density adjusting device 30, a gas cylinder 40, and a control device 50. The antenna element 10 includes a hollow dielectric plate 1, a radiation conductor 2, a ground plate 3, a feed pin 4, and a pair of electrode plates 5a and 5b.

  The hollow dielectric plate 1 is formed of a hollow thin cube, has a structure capable of enclosing a gas filled from the gas cylinder 40, and functions as a discharge tube. Any dielectric material can be used for the hollow dielectric plate 1, but a low dielectric loss and low dielectric constant material such as polyethylene, polyethylene terephthalate, polycarbonate, and polytetrafluoroethylene can be used. desirable. The hollow dielectric plate 1 has a hole portion (power supply hole portion) 1a into which the power supply pin 4 is inserted on the bottom surface, and a hole portion 1b and electrode plate 5b into which the electrode plate 5a is inserted on each of the three side surfaces. And a hole (gas introduction hole) 1d into which a tube for connecting to the gas density adjusting device 30 is inserted.

  The radiation conductor 2 is arranged at the center of the top surface in the hollow portion of the hollow dielectric plate 1. The ground plate 3 is formed of a conductor and is disposed in contact with the outer bottom surface of the hollow dielectric plate 1 so that the normal direction of the radiation conductor 2 and the normal direction of the ground plate 3 are substantially the same. Yes. The ground plate 3 has a similar hole portion 3 a formed at a location that coincides with the hole portion 1 a provided on the bottom surface of the hollow dielectric plate 1. One end of the power supply pin 4 is connected to the radiation conductor 2 and supplies power to the radiation conductor 2. On the other hand, the other end of the power feed pin 4 passes through the hole 1 a of the hollow dielectric plate 1 and the hole 3 a of the ground plate 3 and is exposed to the outside of the hollow dielectric plate 1. The power feed pin 4 is disposed so as not to contact the ground plate 3.

  The pair of electrode plates 5a and 5b are inserted into the hole 1bb and the hole 1c respectively provided on the opposing side surfaces of the hollow dielectric plate 1, and the electrode plates 5a and 5b are provided inside and outside the hollow dielectric plate 1 respectively. Arranged to be exposed. Further, the pair of electrode plates 5a and 5b are connected to the power supply device 20 via the conducting wires 21a and 21b, respectively. The pair of electrode plates 5a and 5b are arranged so as not to contact the radiation conductor 2 and the ground plate 3, respectively.

  The power supply device 20 applies a predetermined voltage to the conductive plates 5a and 5b connected via the conducting wires 21a and 21b. The gas density adjusting device 30 is connected to the gas cylinder 40 and adjusts the gas density when the gas in the gas cylinder 40 is filled in the hollow portion of the hollow dielectric plate 1. The other end of the tube 31 connected to the hole 1 d formed on one side surface of the hollow dielectric plate 1 is connected to the gas density adjusting device 30. The gas in the gas cylinder 40 is filled into the hollow portion of the hollow dielectric plate 1 through the tube 18.

The gas cylinder 40 is filled with a Group 18 element (rare gas), nitrogen, oxygen, fluorine, or the like. Further, a mixed gas of a rare gas and nitrogen, or a gas (such as air) having a high ratio including these may be filled.
Since the four holes 1a, 1b, 1c, 1d provided in the hollow dielectric plate 1 are completely closed by the power feed pin 4, the pair of conducting wires 21a, 21b and the tube 31, respectively, the hollow dielectric plate The gas enclosed in the hollow portion of 1 does not leak to the outside.

  When the power supply device 20 applies a voltage to the pair of electrode plates 5a and 5b exposed to the inside and outside of the hollow dielectric plate 1, for example, a rare gas sealed in the hollow portion of the hollow dielectric plate 1 is supplied. When excited, it enters a plasma state. The complex relative permittivity of plasma has frequency dependence and varies depending on the gas density and electric field in the hollow portion of the hollow dielectric plate 1. Therefore, the electrical properties of the plasma generated in the hollow portion of the hollow dielectric plate 1 can be changed by adjusting the applied voltage of the power supply device 20 and the gas density setting of the gas density adjusting device 30.

  The control device 50 calculates an applied voltage and a gas density so as to have a frequency specified via an input unit (not shown), and adjusts the applied voltage of the power supply device 20 and the gas density of the gas density adjusting device 30. I do. The controller 50 is configured to directly input an application voltage and a gas density and to control the power supply device 20 and the gas density adjusting device 30 so that the specified application voltage and gas density are obtained. Also good.

・参考文献１
C. A. Balanies, Antenna Theory: Analysis & Design, 2^nd edition, John Wiley & Sons, Inc., 1997 Next, control of the resonance frequency using generated plasma in the antenna element 10 using the hollow dielectric plate 1 functioning as a discharge tube will be described below.
First, calculation of the resonance frequency of the MSA will be described. For simplicity of explanation, an MSA having a simple structure including a dielectric substrate 91, a radiating conductor 92 having a square shape, a feed pin 93, and a conductor grounding plate 94 shown as a conventional antenna device in FIG. 7 is taken as an example. Give an explanation.
Using the following formulas (1) to (3) related to the rectangular MSA described in Reference 1, the resonance frequency of the MSA is obtained.

・ Reference 1
CA Balanies, Antenna Theory: Analysis & Design, 2 nd edition, John Wiley & Sons, Inc., 1997

For example, if the length a of one side of the radiation conductor 92 is 15.172 mm, the thickness t of the dielectric substrate 91 is 1 mm, the relative dielectric constant ε _r is 0.8, and the dielectric loss tangent is 0.01, the resonance of the MSA The frequency is required to be about 10 GHz.

Next, a configuration in which the antenna device of the present invention shown in FIG. 1 realizes the dielectric constant calculated as described above using plasma will be described.
When a magnetic field does not exist outside the plasma generated in the hollow dielectric plate 1 and the electron temperature is low, the complex relative permittivity ε _r of the plasma is _expressed by the Drude dispersion formula described in Reference 2. It is represented by the following formula (4).

In Equation (4), ω represents the angular frequency [rad / s] of the electromagnetic wave, and ν represents the frequency of collision of electrons with the atom per unit time (collision frequency [Hz]).
・ Reference 2
RJ Vidmar, “On the use of Atmospheric Pressure Plasmas as Electromagnetic Reflections and Absorbers”, IEEE Trans. Plasma Sci., Vol. 18, No. 4, 1990

式（５）において、ｅは電子の電荷［ｑ］、ｍｅは電子質量、ε_０は真空の比誘電率［Ｆ／ｍ］、そして、ｎ_ｅは電子の密度［ｍ^−３］を表している。 Further, ω _p is a frequency of fluctuation when the plasma becomes electrically neutral, and is called a plasma angular frequency [rad / s], and is expressed by the following formula (5 ).

In the formula (5), e is the electron charge [q], me is the electron mass, epsilon ₀ is the vacuum dielectric constant [F / m], and, _{n e} is representative of the electron density ^{[m -3]} Yes.

式（６）において、実部がプラズマの比誘電率、実部と虚部の比が誘電正接となる。式（６）により、誘電率は最大でも１未満となり、１以上の値は取りえないことが分かる。 From the above equations (4) and (5), it can be seen that the electrical properties of plasma with respect to electromagnetic waves of a certain frequency are determined by the electron density and the collision frequency. When Formula (4) is further developed, the following Formula (6) described in Reference Document 2 described above is shown.

In Equation (6), the real part is the relative dielectric constant of the plasma, and the ratio of the real part to the imaginary part is the dielectric loss tangent. From the equation (6), it can be seen that the dielectric constant is less than 1 at the maximum and cannot take a value of 1 or more.

A dielectric having a relative dielectric constant of 0.8 and a dielectric loss tangent of 0.01 when the angular frequency ω is 10 × 2π rad / s (electromagnetic wave frequency: 10 GHz) according to the equations (4) to (6) described above. In order to control the plasma to behave as follows, the electron density may be 2.5 × 10 17 m ⁻³ and the collision frequency may be 2.5 GHz. Both of these values are realizable values.

The control device 50 controls the applied voltage of the power supply device 20 of the antenna device shown in FIG. 1 and the gas density of the gas density adjusting device 30 so that the electron density and the collision frequency calculated as described above are obtained. Thereby, the electron density and the collision frequency in the hollow part of the hollow dielectric plate 1 can be controlled to desired values, and a predetermined plasma state can be obtained.
The calculation of the electron density and the collision frequency described above may be performed by the control device 50, or may be performed by a calculation processing device (not shown) and the calculation result may be set in the control device 50. Good.

As described above, the antenna element 10 includes the hollow dielectric plate 1 that functions as a discharge tube, changes the electrical properties of the plasma by changing the plasma state of the gas sealed in the hollow portion of the hollow dielectric plate 1. Therefore, it is possible to realize an MSA that can change the resonance frequency without using an active element such as a diode or MEMS used in a conventional active antenna device.
In addition, since it is not necessary to use an active element, it is possible to reduce the elements that transmit and receive waves are lost, and it is not necessary to perform design in consideration of isolation of the bias circuit. In addition, since it is not necessary to arrange a plurality of active elements, it is possible to avoid a state in which an enormous number of wirings exist on the radiation surface of the radiation element 2, and it is possible to reduce the generation of unnecessary scattered waves.

  Further, according to the first embodiment, the power source device 20 for adjusting the voltage applied to the hollow dielectric plate 1, the gas density adjusting device 30 for adjusting the gas density in the hollow dielectric plate 1, and plasma are used. Since the power supply device 20 and the control device 50 for controlling the gas density adjusting device 30 are provided on the basis of the electron density and the collision frequency calculated to achieve a desired dielectric constant, Alternatively, an antenna device that can change the resonance frequency using plasma can be configured.

Embodiment 2. FIG.
In this Embodiment 2, the structure which changed the arrangement position of an electrode plate and the connection position of a gas density adjusting device is shown.
FIG. 3 is a diagram showing the configuration of the antenna device according to Embodiment 1 of the present invention. In FIG. 3, the antenna element 10 ′ is shown in a transparent perspective view. 4A and 4B are three views showing the configuration of the antenna element according to Embodiment 1 of the present invention. FIG. 4A is a transparent top view of the antenna element 10 ', and FIG. 4B is A in FIG. -A 'sectional view, FIG.4 (c) is BB' sectional drawing in Fig.4 (a).

  As shown in FIGS. 4B and 4C, the pair of electrode plates 5a ′ and 5b ′ provided at the tips of the conducting wires 21a and 21b are the top and bottom surfaces in the hollow portion of the hollow dielectric plate 1, respectively. And it arrange | positions so that neither of side and a side surface may be contacted. Furthermore, the conducting wires 21 a and 21 b are inserted into the hollow portion from the bottom surface of the hollow dielectric plate 1. Similarly, a pipe 31 connecting the hollow dielectric plate 1 and the gas density adjusting device 30 is also inserted into the hollow portion from the bottom surface of the hollow dielectric plate 1.

  With the change of the insertion position of conducting wire 21a, 21b and the pipe | tube 18, the formation position of hole 1b, 1c, 1d shown in FIG. 1 and FIG. 2 of Embodiment 1 is changed. As shown in FIGS. 3 and 4, the hollow dielectric plate 1 has a hole 1a into which the power feed pin 4 is inserted in the bottom surface, and a hole (in which the conductive wires 21a and 21b connected to the electrode plates 5a and 5b are inserted ( A hole 1d ′ into which a pipe 31 for connecting to the wiring hole) 1b ′, the hole 1c ′ and the gas density adjusting device 30 is inserted is formed.

  The ground plate 3 has similar holes 3 a, 3 b, 3 c, 3 d formed at positions corresponding to the holes 1 a, 1 b ′, 1 c ′, 1 d ′ provided on the bottom surface of the hollow dielectric plate 1. . The feed pin 4 passes through the hole 1 a of the hollow dielectric plate 1 and the hole 3 a of the ground plate 3 and is exposed to the outside of the hollow dielectric plate 1. The power feed pin 4 is disposed so as not to contact the ground plate 3. The conducting wires 21a and 21b connected to the electrode plates 5a ′ and 5b ′ are connected to the power supply device 20 through the holes 1b ′ and 1c ′ and the holes 3b and 3c. The conducting wires 21 a and 21 b are arranged so as not to contact the ground plate 3. The pipe 31 is connected to the hole 1d ′ and is connected to the gas density adjusting device 30 via the hole 3d.

  In addition, the four holes 1a, 1b ′, 1c ′, and 1d ′ provided in the hollow dielectric plate 1 are completely closed by the power feed pin 4, the conductive wires 21a and 21b, and the tube 31, respectively. The gas sealed in the hollow part of the body plate 1 does not leak out.

  By forming all of the holes 1b 'and 1c' into which the conducting wires 21a and 21b are inserted and the hole 1d 'to which the tube 31 is connected on the bottom surface side of the hollow dielectric plate 1, the electrode plates 5a' and 5b are formed. Conductive wires 21a, 21b and a pipe 31 connected to ′ can be inserted into the hollow dielectric plate 1 from the bottom surface side of the ground plate 3, that is, from the bottom side of the antenna element 10 ′. Normally, there is a problem that unnecessary scattered waves are generated by the wirings of the conducting wires 21a and 21b. Generation of unnecessary scattered waves can be reduced. Further, by inserting the conducting wires 21a and 21b and the tube 31 into the hollow dielectric plate 1 from the bottom side of the ground plate 3, it becomes easy to place the plurality of antenna elements 10 close to each other.

  As described above, according to the second embodiment, the electrode plates 5a ′ and 5b ′ are arranged in the hollow portion of the hollow dielectric plate 1, and the conductive wires 21a and 21b connected to the electrode plates 5a ′ and 5b ′. Since the holes 1b ', 1c', 3b, 3c for inserting the wires are formed on the bottom side of the antenna element 10 ', the conductive wires 21a, 21b are viewed from the rear surface of the ground plate 3 when viewed from the installation plane of the radiation conductor 2. It is possible to reduce the occurrence of unnecessary scattered waves on the surface of the radiation conductor 2.

  Further, according to the second embodiment, in addition to the conducting wires 21a and 21b, the holes 1c ′ and 3c for connecting the pipe 31 connected to the gas density adjusting device 30 are formed on the bottom side of the antenna element 10 ′. Since it comprised so, the some antenna element 10 can be arrange | positioned closely.

Embodiment 3 FIG.
FIG. 5 is a diagram showing a configuration of an antenna apparatus according to Embodiment 3 of the present invention.
In the example of FIG. 5, an antenna device configured using the antenna element 10 ′ shown in the second embodiment is shown, but the antenna element 10 shown in the first embodiment can also be applied.
The antenna device according to the third embodiment includes an antenna element 10 ', a power supply device 20, a distributor 60, a plurality of gas density adjusting devices 30a, 30b, 30c, 30d, a plurality of gas cylinders 40a, 40b, 40c, 40d, and a control. The apparatus 50 is comprised.

  Of the gas cylinders 40a, 40b, 40c, and 40d, one gas cylinder (for example, the gas cylinder 40d) is an exhaust gas cylinder used when exhausting the gas sealed in the hollow portion of the hollow dielectric plate 1, and the remaining three gas cylinders. Reference numerals 40a, 40b, and 40c denote ordinary gas cylinders filled with different kinds of gases. Note that it is possible to appropriately set which gas cylinders 40a, 40b, 40c, and 40d are used for exhaust. The gas density adjusting devices 30a, 30b, 30c and 30d adjust the gas density of the gas output from the gas cylinders 40a, 40b, 40c and 40d connected thereto. For example, in FIG. 5, when the gas cylinder 40d is always used only for exhaust, the arrangement of the gas density adjusting device 30d may be omitted.

  The distributor 60 distributes the gas output from each cylinder 40a, 40b, 40c based on a predetermined mixing ratio of each gas whose gas density is adjusted by the gas density adjusting devices 30a, 30b, 30c, 30d. A mixed gas is produced. The generated mixed gas is fed into the hollow portion of the hollow dielectric plate 1. The control device 50 performs control to adjust the applied voltage of the power supply device 20, the gas density of the gas density adjusting device 30, and the distribution ratio of the distributor 60.

Plasma density and collision frequency depend on applied voltage and gas type. Electrons move by receiving acceleration due to an electric field generated by applying a voltage. The average number of times per second that the moving electrons collide with other particles and disappear is the collision frequency. The collision frequency ν is defined by the following equation (7).

In equation (7), it can be seen that as the size of other particles that collide with the moving electrons increases, the collision cross-sectional area increases, and the collision frequency increases.
The control device 50 applies the voltage applied to the power supply device 20 of the antenna device shown in FIG. 5, the gas density of the gas density adjusting device 30, and the distributor 60 so that the collision frequency and electron density calculated as described above are obtained. The mixing ratio of each gas is controlled. Thereby, the electron density and the collision frequency in the hollow part of the hollow dielectric plate 1 can be controlled to desired values, and a predetermined plasma state can be obtained.
The calculation of the electron density and the collision frequency described above may be performed by the control device 50, or may be performed by a calculation processing device (not shown) and the calculation result may be set in the control device 50. Good.

  Further, since the exhaust gas cylinder 40d is provided, the mixed gas filled in the hollow portion of the hollow dielectric plate 1 can be completely extracted into the exhaust cylinder. Therefore, the plasma state can be easily changed.

  As described above, according to the third embodiment, a plurality of gas cylinders 40 filled with different gases, and a plurality of gases for adjusting the pressure of the gas filled into the hollow portion of the hollow dielectric plate 1 from each gas cylinder 40. A density adjusting device 30; a distributor 60 that distributes each gas whose gas density has been adjusted by the plurality of gas density adjusting devices 30 based on a specified mixing ratio; and a power supply device 20, a gas density Since the adjustment device 30 and the control device 50 for controlling the distributor 60 are provided, various gas particles are mixed so as to have a predetermined collision frequency in the plasma state in the hollow portion of the hollow dielectric plate 1. Therefore, the degree of freedom for adjusting the collision frequency can be further increased.

  Further, according to the third embodiment, since the exhaust gas cylinder 40d is provided in addition to the gas cylinders 40a, 40b, 40c filled with a plurality of different types of gases, the hollow portion of the hollow dielectric plate 1 is provided. The mixed gas sealed in the gas can be completely extracted, and the mixed gas mixed at a new mixing ratio can be filled in the hollow portion of the hollow dielectric plate 1 so that the collision frequency can be easily adjusted.

Embodiment 4 FIG.
In the fourth embodiment, a configuration of a reflectarray antenna configured using the antenna elements described above will be described.
FIG. 6 is an explanatory diagram showing a reflectarray antenna according to Embodiment 4 of the present invention. Note that a reflectarray antenna can be configured using the antenna elements 10 and 10 'shown in the first to third embodiments. However, when arranging a plurality of antenna elements in alignment as in the example of FIG. 6, it is necessary to form a hole for inserting the conducting wires 21 a and 21 b and the pipe 31 at the bottom of the antenna element. The case where the antenna element 10 ′ of the second embodiment and the third embodiment is applied will be described as an example.

  Each antenna element 10 ′ forming the reflectarray antenna does not include the feed pin 2 shown in FIGS. 3 and 4, but includes the hole 1a in the hollow dielectric plate 1 and the hole 3a in the ground plate 3. Not. Further, the ground plates 3 of the plurality of antenna elements 10 ′ are electrically connected to each other.

  The reflect array antenna 70 is configured by arranging a plurality of antenna elements 10 ′ in parallel in the plane direction of the antenna element 10 ′. The reflect array antenna 70 adjusts the reflection phase of the radiating conductor 2 of each antenna element 10 ′, thereby causing a plane wave 102 to generate a radio wave 101 having a phase distribution emitted from a primary radiator 100 such as a horn antenna installed in the vicinity. Convert to The primary radiator 100 is disposed at a position where all the radiation conductors 2 of the antenna elements 10 ′ are visible.

In general, in order to control the light beam direction in a reflectarray antenna, it is necessary to adjust the reflection phase of the radiation conductor provided in each antenna element. In order to obtain the desired plane wave 102 by reflecting the primary radiator 100 to be used and the radio wave 101 radiated from the primary radiator 100, a plurality of different antenna elements are required each time.
On the other hand, by using the antenna element 10 ′ using plasma shown in the second embodiment, one type of antenna element 10 ′ may be manufactured. By adjusting the applied voltage and gas density of each antenna element 10 ′, the plasma element The reflection phase of the radiation conductor 2 can be adjusted by changing the relative dielectric constant.

  As described above, according to the fourth embodiment, in the reflect array antenna 70 configured by arranging a plurality of antenna elements 10 ', the plasma dielectric constant of each antenna element is changed to change the reflection phase of each antenna element. Since it is configured to adjust, it can be operated as a different reflectarray antenna only by changing the complex relative dielectric constant of the plasma without changing the structure of the antenna element. This makes it possible to form a reflectarray antenna having different reflection phases without producing several types of antenna elements having a desired radiation direction and radiation conductors corresponding to the primary radiator 100 to be used.

  In the first to fourth embodiments described above, the configuration in which the applied voltage of the power supply device 20 and the gas density of the gas density adjusting device 30 are both adjusted has been described. However, either the applied voltage or the gas density is adjusted. If a desired plasma state can be obtained by doing this, either the applied voltage or the gas density may be adjusted.

  In the present invention, within the scope of the invention, any combination of the embodiments, or any modification of any component in each embodiment, or omission of any component in each embodiment is possible. .

  DESCRIPTION OF SYMBOLS 1 Hollow dielectric board, 1a, 1b, 1c, 1d, 1b ', 1c', 1d ', 3a, 3b, 3c, 3d Hole part, 2 Radiation conductor, 3 Grounding board, 4 Feeding pin, 5a, 5b, 5a ', 5b' electrode plate, 10, 10 'antenna element, 20 power supply device, 21a, 21b conducting wire, 30, 30a, 30b, 30c, 30d gas density adjusting device, 40, 40a, 40b, 40c, 40d gas cylinder, 50 control Device, 60 distributor, 70 reflectarray antenna, 100 primary radiator, 101 radio wave, 102 plane wave.

Claims (6)

A ground plate made of a conductor;
A dielectric plate laminated on the ground plate and having a hollow structure capable of enclosing gas inside;
A radiation conductor arranged in parallel with the ground plate on the inner wall of the surface facing the laminated surface of the dielectric plate with the ground plate;
A feed pin that feeds power to the radiation conductor, one end of which is exposed to the outside of the device and the other end of which is connected;
An electrode plate disposed at a position not conducting with the ground plate and the radiation conductor of the dielectric plate,
A predetermined voltage is applied to the electrode plate to excite the gas sealed inside the dielectric plate to generate plasma, and the voltage applied to the electrode plate and the gas sealed inside the dielectric plate are An antenna device that adjusts at least one of the densities to change the electrical characteristics of the plasma.   A power supply hole portion into which one end of the power supply pin is inserted, a wiring hole portion into which a conductive wire connected to the electrode plate is inserted, and the dielectric, on the laminated surface of the ground plate and the dielectric plate with the ground plate The antenna device according to claim 1, further comprising a gas introduction hole for introducing the gas into the body plate. An antenna device comprising a plurality of antenna elements that reflect radio waves transmitted from a radio wave transmitter,
Each antenna element includes a ground plate made of a conductor, a dielectric plate laminated on the ground plate and having a hollow structure capable of enclosing gas therein, and a laminated surface of the ground plate of the dielectric plate. A radiation conductor disposed in parallel with the ground plate on the inner wall of the opposing surface, an electrode plate disposed at a position not conducting to the ground plate and the radiation conductor of the dielectric plate, the ground plate and the dielectric plate A wiring hole portion into which a conductive wire connected to the electrode plate is inserted, and a gas introduction hole portion for introducing the gas into the dielectric plate;
The ground plates of the antenna elements are electrically connected to each other,
A predetermined voltage is applied to the electrode plate to excite the gas sealed inside the dielectric plate to generate plasma, and the voltage applied to the electrode plate and the gas sealed inside the dielectric plate are An antenna device characterized in that at least one of the densities is adjusted to change the electric characteristics of the plasma to control the reflection phase of the radiation conductor.   The gas filled in the dielectric plate is any of rare gas, nitrogen, oxygen, and fluorine, or a mixed gas containing any of rare gas, nitrogen, oxygen, and fluorine. The antenna device according to any one of claims 1 to 3. A power supply device for applying a voltage to the electrode plate;
A gas density adjusting device for adjusting the density of the gas sealed in the dielectric plate;
A control device that controls at least one of an applied voltage of the power supply device and an adjustment value of a gas density of the gas density adjusting device according to an electrical characteristic of the plasma generated inside the dielectric plate. The antenna device according to any one of claims 1 to 4, wherein the antenna device is provided. A power supply device for applying a voltage to the electrode plate;
A plurality of gas density adjusting devices that adjust the densities of a plurality of types of the gases enclosed in the dielectric plate;
A distributor for distributing each gas whose density is adjusted by the plurality of gas density adjusting devices to generate a mixed gas having a predetermined mixing ratio and introducing the mixed gas into the dielectric;
According to the electrical characteristics of the plasma generated inside the dielectric plate, at least one of an applied voltage of the power supply device and a gas density adjustment value of the gas density adjusting device and each gas of the distributor The antenna device according to any one of claims 1 to 4, further comprising a control device that controls a distribution ratio of the antenna.

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