JP2008067017A - Magnetic communication antenna and apparatus - Google Patents
Magnetic communication antenna and apparatus Download PDFInfo
- Publication number
- JP2008067017A JP2008067017A JP2006242188A JP2006242188A JP2008067017A JP 2008067017 A JP2008067017 A JP 2008067017A JP 2006242188 A JP2006242188 A JP 2006242188A JP 2006242188 A JP2006242188 A JP 2006242188A JP 2008067017 A JP2008067017 A JP 2008067017A
- Authority
- JP
- Japan
- Prior art keywords
- coil
- frequency
- magnetic
- circuit
- resonance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000004891 communication Methods 0.000 title claims abstract description 105
- 230000005540 biological transmission Effects 0.000 claims abstract description 19
- 238000005259 measurement Methods 0.000 claims description 16
- 239000000696 magnetic material Substances 0.000 claims description 5
- 230000004907 flux Effects 0.000 description 24
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 20
- 238000002474 experimental method Methods 0.000 description 8
- 238000009375 geological disposal Methods 0.000 description 8
- 239000003990 capacitor Substances 0.000 description 7
- 230000008878 coupling Effects 0.000 description 6
- 238000010168 coupling process Methods 0.000 description 6
- 238000005859 coupling reaction Methods 0.000 description 6
- 238000009434 installation Methods 0.000 description 6
- 238000000034 method Methods 0.000 description 5
- 239000011162 core material Substances 0.000 description 4
- 238000012544 monitoring process Methods 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000002689 soil Substances 0.000 description 3
- 229910000976 Electrical steel Inorganic materials 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 239000002901 radioactive waste Substances 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 239000011435 rock Substances 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910000808 amorphous metal alloy Inorganic materials 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 238000009933 burial Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000009429 electrical wiring Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- 229910000889 permalloy Inorganic materials 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000011343 solid material Substances 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Landscapes
- Near-Field Transmission Systems (AREA)
Abstract
Description
本発明は磁気通信アンテナ及び装置に関し、とくに磁界を搬送波として用いる磁気通信アンテナ及び装置に関する。本発明の磁気通信アンテナ及び装置は、土中、水中又は土木・建築構造物内に埋設する計測器からの無線通信に利用することができる。 The present invention relates to a magnetic communication antenna and apparatus, and more particularly to a magnetic communication antenna and apparatus using a magnetic field as a carrier wave. INDUSTRIAL APPLICABILITY The magnetic communication antenna and apparatus of the present invention can be used for wireless communication from measuring instruments embedded in soil, underwater, or in civil engineering / building structures.
例えばフィルダムや堤防等の土木構造物やコンクリート建物等の建築構造物を構築する場合に、その構造物の内部又は周辺にセンサその他の計測器を埋設して各種の物理量（変形量、力学的挙動、水圧、土圧等）を計測し、その計測値により土木・建築構造物の安全性・健全性のモニタリング（例えば土木構造物の老朽化診断や建築構造物の地震被災度評価等）をすることがある。また最近では、例えば図６に示すように、原子力発電所から生じる放射性廃棄物その他の不要な物質を地下深部の岩盤中に構築した処分坑道（地下空洞）36に閉じ込めて処分する地層処分施設30等の地下施設の建設が計画されており、そのような地下施設の建設中及び供用中における安全性を確保するため、地下施設内部又はその周辺の地盤内部（例えば図６に示す処分坑道36から周辺地盤中に穿ったボーリング孔37の内部）に計測器を埋設して力学的挙動、水理環境、地質環境等をモニタリングすることが求められることがある。 For example, when building a civil structure such as a fill dam or embankment or a building structure such as a concrete building, various physical quantities (deformation amount, mechanical behavior) are embedded inside or around the structure. , Water pressure, earth pressure, etc.), and monitoring the safety and soundness of civil engineering and building structures based on the measured values (for example, aging diagnosis of civil engineering structures and earthquake damage assessment of building structures) Sometimes. Recently, as shown in FIG. 6, for example, as shown in FIG. 6, a geological disposal facility 30 in which radioactive waste and other unnecessary materials generated from a nuclear power plant are confined and disposed in a disposal tunnel (underground cavity) 36 built in a deep underground rock. In order to ensure safety during construction and operation of such underground facilities, the underground facilities or the surrounding ground (for example, from the disposal tunnel 36 shown in FIG. 6) It may be required to embed a measuring instrument in the borehole 37 drilled in the surrounding ground to monitor the mechanical behavior, hydraulic environment, geological environment, and the like.
従来、このように土中又は水中に埋設した計測器の計測信号は、ケーブルを用いて地上又は水上まで有線通信する方法が一般的である。しかし有線通信には、ケーブルの敷設に手間やコストがかかり、ケーブルの切断や絶縁不良による故障が生じやすく、構造物内部に埋設したケーブルが強度上の弱部や水みちの原因となりうる等の問題点がある。そこで、例えば特許文献１及び２が開示するように、土中又は水中の計測器の計測信号を数Hz〜10kHz程度の低周波電磁波に乗せて無線通信する方法が開発されている。地上の移動体通信等の無線通信で用いられる数百MHz〜数GHzの高周波数電磁波は、地中又は水中のように導電率の高い媒体中では減衰が大きく、地中又は水中の無線通信に用いることは難しい。これに対し数Hz〜10kHz程度の低周波電磁波は磁界成分が卓越しており、導電率の高い媒質中でも小さな減衰で伝播させることができる特徴を有している。 Conventionally, a measurement signal of a measuring instrument buried in the soil or in the water as described above is generally a method of performing wired communication to the ground or water using a cable. However, wired communication is time consuming and expensive to lay cables, and is prone to failure due to cable cutting and insulation failure. Cables embedded in the structure can cause weakness in the structure and water spots. There is a problem. In view of this, for example, as disclosed in Patent Documents 1 and 2, a method of performing wireless communication by placing a measurement signal of a measuring instrument in soil or in water on a low frequency electromagnetic wave of about several Hz to 10 kHz has been developed. High-frequency electromagnetic waves of several hundred MHz to several GHz used in wireless communications such as terrestrial mobile communications are highly attenuated in a medium with high electrical conductivity such as in the ground or in the water. It is difficult to use. On the other hand, a low frequency electromagnetic wave of about several Hz to 10 kHz has an excellent magnetic field component and can be propagated with small attenuation even in a medium having high conductivity.
特許文献２に開示された低周波電磁波（以下、磁界ということがある）利用の無線通信装置を、図７を参照して、本発明の理解に必要な程度において説明する。図示例の通信装置は、水底に向けて送信指令を発すると共に水底からの地盤情報を受信する水上側通信装置40と、その送信指令に応答して水底に設置した計測器17からの地盤情報を水上に向けて伝送する水底側通信装置50とを有する。水上側通信装置40は、容器43に収容されたソレノイドコイル42と、そのコイル42の内側に配置された中空磁性体（例えば円筒形の珪素鋼板製ボビン）44と、中空磁性体44内に配置された通信回路41とを有し、通信回路41において所定搬送波信号をコンピュータ45からの送信指令で変調（例えば２値位相変調又は２値周波数変調）し、変調された電気信号をソレノイドコイル42で低周波の磁気信号に変換して放射する。水上側通信装置40から放射された磁気信号は水中を小さな減衰で伝播して水底側通信装置50に到達する。 A wireless communication device using low-frequency electromagnetic waves (hereinafter sometimes referred to as a magnetic field) disclosed in Patent Document 2 will be described to the extent necessary for understanding the present invention with reference to FIG. The communication device in the illustrated example sends a transmission command to the bottom of the water and receives ground information from the bottom of the water, and receives ground information from the measuring instrument 17 installed on the bottom of the water in response to the transmission command. And a bottom-side communication device 50 for transmitting toward the surface of the water. The waterside communication device 40 includes a solenoid coil 42 housed in a container 43, a hollow magnetic body (for example, a cylindrical silicon steel bobbin) 44 disposed inside the coil 42, and a hollow magnetic body 44. The communication circuit 41 modulates a predetermined carrier wave signal with a transmission command from the computer 45 (for example, binary phase modulation or binary frequency modulation), and the modulated electric signal is transmitted by the solenoid coil 42. It is converted into a low-frequency magnetic signal and emitted. The magnetic signal radiated from the waterside communication device 40 propagates through the water with small attenuation and reaches the waterside communication device 50.
図７の水底側通信装置50は、耐圧容器54に収容されたソレノイドコイル53と、そのコイル53の内側に配置された中空磁性体55と、中空磁性体55内に配置された通信回路52及び電源（図示せず）とを有し、水上から到着した磁気信号をソレノイドコイル53で吸収して電気信号に変換し、その電気信号を通信回路52において復調して送信指令を得る。通信回路52は、計測器17からの地盤情報で所定搬送波信号を変調（例えば２値位相変調又は２値周波数変調）する変調回路を有し、送信指令を入力すると地盤情報で変調した電気信号をソレノイドコイル53に出力する。変調された電気信号は、コイル53において低周波の磁気信号に変換されて水中に放射される。水底側通信装置50から放射された磁気信号は、送信指令と同様に水中を伝播して水上側通信装置40に到達し、通信装置40のコイル53に吸収されて電気信号に変換され、通信回路41により地盤情報に復調されてコンピュータ45に出力される。 7 includes a solenoid coil 53 housed in a pressure vessel 54, a hollow magnetic body 55 disposed inside the coil 53, a communication circuit 52 disposed in the hollow magnetic body 55, A magnetic power signal (not shown) is included, and a magnetic signal arriving from the water is absorbed by the solenoid coil 53 and converted into an electric signal, and the electric signal is demodulated in the communication circuit 52 to obtain a transmission command. The communication circuit 52 has a modulation circuit that modulates a predetermined carrier wave signal (for example, binary phase modulation or binary frequency modulation) with the ground information from the measuring instrument 17, and when the transmission command is input, the electrical signal modulated with the ground information is received. Output to solenoid coil 53. The modulated electric signal is converted into a low-frequency magnetic signal in the coil 53 and radiated into the water. The magnetic signal radiated from the water-bottom communication device 50 propagates underwater, reaches the water-side communication device 40, is absorbed by the coil 53 of the communication device 40, and is converted into an electric signal, as in the transmission command. 41 is demodulated into ground information and output to the computer 45.
図７の通信装置のように磁界を搬送波として用いることにより、地中又は水中の例えば100ｍ程度に埋設した計測器17の計測信号を地上又は水上まで無線通信することができる。また図示例のように地中又は水中の通信装置50を地上又は水上からの送信指令に応答して駆動することにより、常時連続的に駆動する方法に比して消費電力を小さく抑え、通信装置50の電源寿命の長期化を図ることができる。更に、ソレノイドコイル42、53を中空磁性体44、55の外側に配置すると共に、通信回路41、52を中空磁性体44、55の内側に配置することにより、コイル42、53の発生する強い磁界から通信回路41、52を保護し、通信回路41、52による磁気信号から電気信号への変換時における信号対雑音比の低下を避けることが期待できる。 By using a magnetic field as a carrier wave as in the communication device of FIG. 7, it is possible to wirelessly communicate the measurement signal of the measuring instrument 17 embedded in, for example, about 100 m in the ground or underwater to the ground or water. In addition, as shown in the illustrated example, by driving the underground or underwater communication device 50 in response to a transmission command from the ground or water, the power consumption can be reduced compared to the method of continuously driving the communication device 50. 50 power supply life can be extended. Further, the solenoid coils 42 and 53 are arranged outside the hollow magnetic bodies 44 and 55, and the communication circuits 41 and 52 are arranged inside the hollow magnetic bodies 44 and 55, whereby a strong magnetic field generated by the coils 42 and 53 is obtained. Therefore, it can be expected that the communication circuits 41 and 52 are protected from each other and that the signal-to-noise ratio is not lowered when the communication circuits 41 and 52 convert the magnetic signal into the electric signal.
例えば図６のような地層処分施設30は地下300〜1000ｍ程度の深部に構築することが想定されており、そのような地下深部の施設内部又は周辺に埋設した計測器の計測信号を地上まで無線通信するためには、図７のソレノイドコイル42、53に大きな磁界（磁束）を発生させて無線通信装置40、50の通信距離を延ばす必要がある。一般にコイルの発生する磁束を大きくするためには、コイルの入力電力を大きくするか又はコイルの断面積Ｓ、巻数Ｎ、長さＥによりインダクタンスＬ（Ｌ＝μＳＮ2／Ｅ、μは透磁率）を大きくすればよい。ただし、入力電力を大きくすると電源寿命が短くなることから、電池交換等が容易でない地中又は水中に埋設する無線通信装置では、断面積Ｓ等の増加すなわちコイル自体を大きくすることで通信距離を延ばす方法が選択されている。 For example, it is assumed that the geological disposal facility 30 as shown in FIG. 6 is constructed in a depth of about 300 to 1000 m underground, and measurement signals of measuring instruments embedded in or around the deep underground facility are wirelessly transmitted to the ground. In order to communicate, it is necessary to generate a large magnetic field (magnetic flux) in the solenoid coils 42 and 53 of FIG. 7 and extend the communication distance of the wireless communication devices 40 and 50. In general, in order to increase the magnetic flux generated by the coil, the input power of the coil is increased or the inductance L (L = μSN 2 / E, μ is the magnetic permeability) depending on the cross-sectional area S, the number of turns N, and the length E of the coil. Should be increased. However, if the input power is increased, the life of the power supply is shortened. Therefore, in a wireless communication device embedded in the ground or underwater where it is not easy to replace the battery, the communication distance can be increased by increasing the cross-sectional area S or the like, that is, by increasing the coil itself. A method of extending is selected.
しかし、地下施設内の設置スペースが限られている場合は、大きなコイルを含む無線通信装置50（図７参照）を地下施設に設置できない場合がある。例えば図６の地層処分施設30において地下深部の処分坑道36のモニタリングが要求される場合に、モニタリング用計測器17とそれに接続した無線通信装置50とを処分坑道36の内部又は周辺に設置する必要があるが、処分坑道36の形状・規模は岩盤の力学的安定性等により設定されるので、コイル53が大き過ぎると通信装置50が処分坑道36内又はその周辺に穿ったボーリング孔37内に入らなくなり、無線通信によるモニタリングができなくなる。地下深部の施設の安全性等を磁界利用の無線通信によりモニタリングするためには、長い通信距離を有し且つ限られたスペースに設置できる磁気通信アンテナを開発する必要がある。 However, when the installation space in the underground facility is limited, the wireless communication device 50 (see FIG. 7) including a large coil may not be installed in the underground facility. For example, in the case of the geological disposal facility 30 in FIG. 6, when monitoring of the deep underground disposal mine 36 is required, it is necessary to install the monitoring measuring instrument 17 and the wireless communication device 50 connected thereto in or around the disposal mine 36. However, since the shape and scale of the disposal tunnel 36 are set by the dynamic stability of the rock mass, if the coil 53 is too large, the communication device 50 will be in the borehole 37 drilled in or around the disposal tunnel 36. It becomes impossible to enter and monitoring by wireless communication becomes impossible. In order to monitor the safety of deep underground facilities by radio communication using a magnetic field, it is necessary to develop a magnetic communication antenna that has a long communication distance and can be installed in a limited space.
そこで本発明の目的は、限られたスペースに設置できる通信距離の長い磁気通信アンテナ及び装置を提供することにある。 Therefore, an object of the present invention is to provide a magnetic communication antenna and apparatus having a long communication distance that can be installed in a limited space.
本発明者は、磁気通信アンテナを単独のコイルではなく独立した一対のコイルにより構成し、その一対のコイルを相互誘導により磁気的に結合して等価的な１つの共振回路を形成し、その共振回路により磁束を放射又は吸収することに着目した。一対のコイルを用いた場合、一方のコイルのみを計測器17（図７参照）に接続し、他方のコイルを計測器17から離すことができるので、アンテナの形状及び大きさを計測器17の設置環境に応じて変更することができる。また、各コイルの形状、大きさ、相互間隔等を適切に選択して磁束の放射又は吸収効率を高めれば、設計の自由度を残しつつ、アンテナの通信距離を十分延ばすことが期待できる。本発明は、この着想に基づく研究開発により完成に至ったものである。 The present inventor forms a magnetic resonance antenna by a pair of independent coils instead of a single coil, and magnetically couples the pair of coils by mutual induction to form an equivalent resonance circuit. We focused on radiating or absorbing magnetic flux by the circuit. When a pair of coils is used, only one of the coils can be connected to the measuring instrument 17 (see FIG. 7) and the other coil can be separated from the measuring instrument 17. It can be changed according to the installation environment. Moreover, if the shape, size, mutual interval, etc. of each coil are appropriately selected to increase the radiation or absorption efficiency of the magnetic flux, it can be expected that the communication distance of the antenna is sufficiently extended while leaving the degree of freedom of design. The present invention has been completed by research and development based on this idea.
図１（Ａ）の実施例を参照するに、本発明による磁気通信アンテナは、信号源（例えば同図（Ｂ）の送信回路14）に接続する給電端子12と第１コイル３とを含む所定共振周波数f0の直列共振回路２、及び第１コイル３に磁気的に結合する第２コイル６を含む所定共振周波数f0の直列共振閉回路５を備え、信号源からの電気信号を所定共振周波数f0の磁界Ｂに変換して放射してなるものである。第１コイル３には、軟質磁性材料製の芯材16を含めることができる。 Referring to the embodiment of FIG. 1A, a magnetic communication antenna according to the present invention includes a power supply terminal 12 connected to a signal source (for example, the transmission circuit 14 of FIG. 1B) and a first coil 3. A series resonance closed circuit 5 having a predetermined resonance frequency f 0 including a series resonance circuit 2 having a resonance frequency f 0 and a second coil 6 magnetically coupled to the first coil 3 is provided to resonate an electric signal from a signal source with a predetermined resonance. It is converted into a magnetic field B of frequency f 0 and radiated. The first coil 3 can include a core material 16 made of a soft magnetic material.
好ましくは、第２コイル６の軸線を第１コイル３の軸線と平行に配置する。例えば図示例のように、第２コイル６を第１コイル３と同軸線上に配置することができ、第２コイル６と第１コイル３とを軸線方向に隔てて配置することができる。この場合は、第２コイル６と第１コイル３との軸線方向間隔Ｗを、放射又は吸収する磁界Ｂのピーク周波数が所定共振周波数f0と一致するように定めることができる。更に好ましくは、第２コイル６を第１コイル３より大径とする。この場合は、第２コイル６の径δと第１コイル３の径Ｄとの比（＝δ／Ｄ）を、放射又は吸収する磁界Ｂのピーク周波数が所定共振周波数f0と一致するように定めることができる。 Preferably, the axis of the second coil 6 is arranged parallel to the axis of the first coil 3. For example, as in the illustrated example, the second coil 6 can be arranged on the same axis as the first coil 3, and the second coil 6 and the first coil 3 can be arranged apart from each other in the axial direction. In this case, can be a second coil 6 an axial distance W between the first coil 3, the peak frequencies of the magnetic field B that emit or absorb determined to coincide with the predetermined resonant frequency f 0. More preferably, the second coil 6 has a larger diameter than the first coil 3. In this case, the ratio (= δ / D) between the diameter δ of the second coil 6 and the diameter D of the first coil 3 is set so that the peak frequency of the radiated or absorbed magnetic field B coincides with the predetermined resonance frequency f 0. Can be determined.
また図１（Ｂ）の実施例を参照するに、本発明による磁気通信装置は、計測器17に接続されその計測器17の計測信号で所定低周波数f0の搬送波を変調して出力する送信回路14、送信回路14に接続する給電端子12と第１コイル３とを含み共振周波数が所定低周波数f0に調整された直列共振回路２、及び第１コイル３と磁気的に結合する第２コイル６を含み共振周波数が所定低周波数f0に調整された直列共振閉回路５を備え、計測器17の計測信号を所定低周波数f0の磁界Ｂに乗せて放射してなるものである。 1B, the magnetic communication device according to the present invention is connected to a measuring instrument 17 and modulates and outputs a carrier wave having a predetermined low frequency f 0 with a measurement signal of the measuring instrument 17. The circuit 14, the series resonance circuit 2 including the power supply terminal 12 connected to the transmission circuit 14 and the first coil 3, the resonance frequency of which is adjusted to a predetermined low frequency f 0 , and the second magnetically coupled to the first coil 3. A series resonance closed circuit 5 including a coil 6 and having a resonance frequency adjusted to a predetermined low frequency f 0 is provided, and the measurement signal of the measuring instrument 17 is radiated on a magnetic field B of the predetermined low frequency f 0 .
好ましくは、第１コイル３と第２コイル６とを同軸線上に配置し、第１コイル３及び第２コイル６の軸線方向間隔Ｗ及び／又は径の比（＝δ／Ｄ）を、放射又は吸収する磁界Ｂのピーク周波数が所定共振周波数f0と一致するように定める。更に好ましくは、図３に示すように、送信回路14と第１コイル３を含む直列共振回路２とを計測器17と共に地中（例えば同図（Ａ）のような地層処分施設30の処分坑道36又はボーリング孔37の内部）又は構造物39内（例えば同図（Ｂ）のような土木・建築構造物39の内部）に埋設し、第２コイル６を含む直列共振閉回路５を地表又は構造物表面に配置する。 Preferably, the first coil 3 and the second coil 6 are arranged on a coaxial line, and the axial distance W and / or the diameter ratio (= δ / D) of the first coil 3 and the second coil 6 is radiated or The peak frequency of the magnetic field B to be absorbed is determined so as to coincide with the predetermined resonance frequency f 0 . More preferably, as shown in FIG. 3, the transmitter circuit 14 and the series resonant circuit 2 including the first coil 3 together with the measuring instrument 17 are disposed in the ground (for example, the disposal tunnel of the geological disposal facility 30 as shown in FIG. 3A). 36 or the inside of the boring hole 37) or in the structure 39 (for example, in the civil engineering / building structure 39 as shown in FIG. 5B), the series resonant closed circuit 5 including the second coil 6 is provided on the surface or Place on the surface of the structure.
本発明による磁気通信アンテナは、給電端子12及び第１コイル３を含む所定共振周波数f0の直列共振回路２と、第１コイル３に磁気的に結合する第２コイル６を含む所定共振周波数f0の直列共振閉回路５とを備え、電気信号を入力し所定共振周波数f0の磁界Ｂに変換して放射するので、次の顕著な効果を奏する。 The magnetic communication antenna according to the present invention includes a series resonance circuit 2 having a predetermined resonance frequency f 0 including a feeding terminal 12 and a first coil 3, and a predetermined resonance frequency f including a second coil 6 magnetically coupled to the first coil 3. Since the zero series resonance closed circuit 5 is provided and an electric signal is input and converted into a magnetic field B having a predetermined resonance frequency f 0 , the following remarkable effects are obtained.
（イ）磁気通信アンテナを一対の独立した第１コイル３及び第２コイル６により形成するので、両コイル３、６の形状や大きさ、相互間隔をそれぞれ選択することにより、設置環境やスペースの制約に応じて多彩な形状及び大きさのアンテナを設計することができる。
（ロ）また、第１コイル３を含む直列共振回路２の共振周波数f0と第２コイル６を含む直列共振閉回路５の共振周波数f0とを一致させ、アンテナから放射される磁界Ｂのピーク周波数をその共振周波数f0と一致させることにより、電気信号を効率的に磁界Ｂに変換して放射する磁束密度を大きくすることができ、第１コイル３のみを用いた場合に比し通信距離を長くすることができる。
（ハ）アンテナのピーク周波数を両共振回路２、５の共振周波数f0と一致させることにより、従来のコイル１個の磁気通信アンテナに比し小さな電流で磁束密度の大きな磁界Ｂを放射することができ、省電力で電源寿命が長くメンテナンスの少ない又は不要なアンテナとすることができる。
（ニ）地中に埋設する計測器17の計測信号を無線通信する場合に、第１コイル３のみを計測器と共に埋設すれば足り、第２コイル５は計測器から分離して地表に配置できるので、埋設スペースが限られた地下空洞やボーリング孔等にも設置可能なアンテナとすることができる。
（ホ）また、土木・建築構造物等の内部に埋設する計測器17の計測信号を無線通信する場合にも、第１コイル３のみを計測器と共に埋設すれば足りるので、第１コイル３の小型化を図ることでアンテナの埋設に伴う構造物の断面欠損等を小さく抑えることができる。
(A) Since the magnetic communication antenna is formed by a pair of independent first coil 3 and second coil 6, by selecting the shape, size, and mutual distance between the coils 3, 6, the installation environment and the space can be reduced. Various shapes and sizes of antennas can be designed according to the constraints.
(B) Further, the resonance frequency f 0 of the series resonance circuit 2 including the first coil 3 is matched with the resonance frequency f 0 of the series resonance closed circuit 5 including the second coil 6, and the magnetic field B radiated from the antenna is By matching the peak frequency with the resonance frequency f 0 , it is possible to increase the density of the magnetic flux to be radiated by efficiently converting the electric signal into the magnetic field B, and communication is possible as compared with the case where only the first coil 3 is used. The distance can be increased.
(C) By radiating the magnetic field B having a large magnetic flux density with a smaller current than the conventional magnetic communication antenna with one coil by matching the peak frequency of the antenna with the resonance frequency f 0 of both the resonance circuits 2 and 5. Therefore, it is possible to provide an antenna that saves power, has a long power supply life, requires little maintenance, or is unnecessary.
(D) When wirelessly communicating the measurement signal of the measuring instrument 17 embedded in the ground, it is sufficient to embed only the first coil 3 together with the measuring instrument, and the second coil 5 can be separated from the measuring instrument and placed on the ground surface. Therefore, it can be set as the antenna which can be installed also in an underground cavity, a borehole, etc. with a limited burial space.
(E) Also, when wirelessly communicating the measurement signal of the measuring instrument 17 embedded in the civil engineering / building structure, etc., it is sufficient to embed only the first coil 3 together with the measuring instrument. By reducing the size, it is possible to reduce the cross-sectional defect of the structure accompanying the embedment of the antenna.
図１（Ａ）は本発明の磁気通信アンテナ１の一実施例を示し、同図（Ｂ）はその回路図を示す。磁気通信アンテナ１は、径Ｄの第１コイル３、コンデンサ４、及び給電端子12を含む直列共振回路２と、径δの第２コイル６及びコンデンサ７を含む直列共振閉回路５とからなる一対の共振回路により構成される。直列共振回路２は、第１コイル３のインダクタンスL1とコンデンサ４の容量C1とで所定共振周波数f0（＝１／２π（L1・C1）1/2）となるように調整され、直列共振閉回路５も、その第２コイル６のインダクタンスL2とコンデンサ７の容量C2とで直列共振回路２と同じ所定共振周波数f0（＝１／２π（L2・C2）1/2）となるように調整されている。給電は、第１コイル３を含む直列共振回路２に対してのみ行う。 FIG. 1 (A) shows an embodiment of the magnetic communication antenna 1 of the present invention, and FIG. 1 (B) shows a circuit diagram thereof. The magnetic communication antenna 1 includes a pair of a series resonance circuit 2 including a first coil 3 having a diameter D, a capacitor 4, and a power supply terminal 12, and a series resonance closed circuit 5 including a second coil 6 having a diameter δ and a capacitor 7. It is comprised by the resonance circuit. The series resonance circuit 2 is adjusted so that the inductance L1 of the first coil 3 and the capacitance C1 of the capacitor 4 have a predetermined resonance frequency f 0 (= 1 / 2π (L1 · C1) 1/2 ), and the series resonance closed The circuit 5 is also adjusted such that the inductance L2 of the second coil 6 and the capacitance C2 of the capacitor 7 have the same predetermined resonance frequency f 0 (= ½π (L2 · C2) 1/2 ) as that of the series resonance circuit 2. Has been. Power is fed only to the series resonant circuit 2 including the first coil 3.
図示例の磁気通信アンテナ１は、直列共振回路２の給電端子12を信号源に接続し、直列共振回路２の第１コイル３と直列共振閉回路５の第２コイル６とを磁気的に結合して等価的な１つの共振回路を形成し、その等価的な共振回路により信号源からの電気信号を磁界Ｂに変換して放射する。独立した共振回路２と共振回路５とを磁気的に結合させたアンテナ１の放射する磁界Ｂのピーク周波数（以下、アンテナ１のピーク周波数ということがある）は両共振回路２、５に共通の共振周波数f0と一致するとは限らないが、本発明者の実験的知見によれば、第１コイル３の径Ｄと第２コイル６の径δと両コイル３、６の相互間隔Ｗとを適当に調整することにより、アンテナ１のピーク周波数を両共振回路２、５の共振周波数f0と一致させることができる（後述の実験例１及び２参照）。アンテナ１のピーク周波数を両共振回路２、５の共振周波数f0と一致させることにより、その共振周波数f0において電気信号から磁界Ｂへの変換効率を高め、一対の共振回路２、５を含む磁気通信アンテナ１の通信距離を一方の共振回路２だけの場合に比して延ばすことができる。 In the illustrated magnetic communication antenna 1, the power supply terminal 12 of the series resonance circuit 2 is connected to a signal source, and the first coil 3 of the series resonance circuit 2 and the second coil 6 of the series resonance closed circuit 5 are magnetically coupled. Thus, one equivalent resonance circuit is formed, and an electric signal from the signal source is converted into a magnetic field B and radiated by the equivalent resonance circuit. The peak frequency of the magnetic field B radiated from the antenna 1 in which the independent resonance circuit 2 and the resonance circuit 5 are magnetically coupled (hereinafter sometimes referred to as the peak frequency of the antenna 1) is common to both the resonance circuits 2 and 5. Although not necessarily coincident with the resonance frequency f 0 , according to the inventor's experimental knowledge, the diameter D of the first coil 3, the diameter δ of the second coil 6, and the mutual interval W between the coils 3 and 6 are determined. By appropriately adjusting, the peak frequency of the antenna 1 can be matched with the resonance frequency f 0 of both the resonance circuits 2 and 5 (see Experimental Examples 1 and 2 described later). By making the peak frequency of the antenna 1 coincide with the resonance frequency f 0 of both the resonance circuits 2 and 5, the conversion efficiency from the electric signal to the magnetic field B is increased at the resonance frequency f 0 , and a pair of resonance circuits 2 and 5 are included. The communication distance of the magnetic communication antenna 1 can be extended as compared with the case of only one resonance circuit 2.
図１（Ｂ）の回路図に示すように、磁気通信アンテナ１の給電端子12に所定低周波数f0（例えば、上述した数Hz〜10kHz程度の低周波数）の搬送波を発生して変調する送信回路14を接続し、アンテナ１の共振回路２、５の共振周波数をそれぞれ搬送波周波数f0と一致するように調整し、更にアンテナ１のピーク周波数が搬送波周波数f0と一致するように第１コイル３の径Ｄ、第２コイル６の径δ、及び両コイル３、６の相互間隔Ｗを調整することにより、計測器17の計測信号を磁界Ｂに乗せて通信する磁気通信装置を形成することができる。第１コイル３及び第２コイル６のインダクタンスL1、L2はコイル径Ｄ、δ（すなわちコイルの断面積）に応じて変化するが、コンデンサ４、７の容量C1、C2を適当に選択することにより、両共振回路２、５の共振周波数を所定低周波数f0となるように調整することができる。図示例の送信回路14は、計測回路18を介して地中又は構造物内に埋設する計測器17と接続されており、その計測器17からの計測信号で低周波数f0の搬送波信号を変調して磁気通信アンテナ１の給電端子12に供給する。低周波数f0において磁界Ｂへの変換効率（磁束発生効率）が高いアンテナ１を用いることにより、低周波数f0の磁界Ｂに乗せて計測器17の計測信号の長距離通信が実現できる。 As shown in the circuit diagram of FIG. 1B, a transmission that generates and modulates a carrier wave of a predetermined low frequency f 0 (for example, the above-described low frequency of several Hz to 10 kHz) at the power supply terminal 12 of the magnetic communication antenna 1. connect the circuit 14, the first coil so that the resonance frequency of the resonant circuit 2,5 of the antenna 1 respectively adjusted to match the carrier frequency f 0, further the peak frequency of the antenna 1 to match the carrier frequency f 0 By adjusting the diameter D of 3, the diameter δ of the second coil 6, and the mutual distance W between the two coils 3, 6, a magnetic communication device for communicating the measurement signal of the measuring instrument 17 on the magnetic field B is formed. Can do. The inductances L1 and L2 of the first coil 3 and the second coil 6 change according to the coil diameters D and δ (that is, the cross-sectional area of the coil), but by appropriately selecting the capacitances C1 and C2 of the capacitors 4 and 7 The resonance frequency of both resonance circuits 2 and 5 can be adjusted to be a predetermined low frequency f 0 . Transmission circuit 14 of the illustrated embodiment is connected to the measuring instrument 17 embedded in the ground or structures through the measuring circuit 18, modulates a carrier signal of a low frequency f 0 in the measurement signal from the measuring instrument 17 And supplied to the power feeding terminal 12 of the magnetic communication antenna 1. By using the antenna 1 having a high conversion efficiency (magnetic flux generation efficiency) to the magnetic field B at the low frequency f 0 , it is possible to realize long-distance communication of the measurement signal of the measuring instrument 17 on the magnetic field B at the low frequency f 0 .
なお、図示例の磁気通信アンテナ１では、第１コイル３に軟質磁性材料製の芯材16を含めている。軟質磁性材料は保磁力が極端に小さく透磁率μが大きな磁性体であり、そのような芯材16を第１コイル３に含めてインダクタンスL1を大きくすることにより、磁気通信アンテナ１による磁束発生効率を更に高めることができる。軟質磁性材料の一例は、ケイ素鋼板（鉄とシリコン数％の合金）、フェライト、ファインメット、パーマロイ、アモルファス金属合金等の薄泊又は無垢材である。 In the illustrated magnetic communication antenna 1, the first coil 3 includes a core material 16 made of a soft magnetic material. The soft magnetic material is a magnetic body having an extremely small coercive force and a large permeability μ. By including such a core material 16 in the first coil 3 and increasing the inductance L1, the magnetic flux generation efficiency of the magnetic communication antenna 1 is increased. Can be further increased. An example of the soft magnetic material is a thin or solid material such as a silicon steel plate (an alloy of several percent of iron and silicon), ferrite, fine met, permalloy, and amorphous metal alloy.
［実験例１］
本発明の磁気通信アンテナ１による電気信号から磁界Ｂへの変換効率を確認するため、径Ｄ＝100mm、コイル長さＥ＝250mmの第１コイル３を含む共振周波数f0＝1250Hzの直列共振回路２と、径δ1＝400mm、コイル長さＥ＝50mmの第２コイル６を含む共振周波数f0＝1250Hzの直列共振閉回路５とを用いて実験を行った。本実験では、先ず図４（Ａ）に示すように共振回路２のみを用い、その給電端子12に信号発生器21（例えば周波数シンセサイザ）から増幅器22経由で振幅一定・周波数可変の電圧を周波数掃引しながら印加し、共振回路２の駆動電流Ｉ（ｍＡ）を電流計23で計測すると共に、第１コイル３の軸線（ｚ軸）上の距離Ｐ（＝1.5ｍ）隔てた位置に設置した磁気センサ24で共振回路２から放射される磁束密度Ｂ（μＧ、ｚ軸方向のみ）を計測した。この実験結果を図５の電流Ｉ（Ａ）及び磁束密度Ｂ（Ａ）のグラフに示す。同図のグラフＩ（Ａ）及びグラフＢ（Ａ）は、単独の共振回路２を用いた場合に、共振周波数f0において電流Ｉ及び放射磁束密度Ｂが共に最大（ピーク）となることを示している。
[Experimental Example 1]
In order to confirm the conversion efficiency from the electric signal to the magnetic field B by the magnetic communication antenna 1 of the present invention, a series resonance circuit having a resonance frequency f 0 = 1250 Hz including the first coil 3 having a diameter D = 100 mm and a coil length E = 250 mm. 2 and a series resonant closed circuit 5 having a resonance frequency f 0 = 1250 Hz including a second coil 6 having a diameter δ 1 = 400 mm and a coil length E = 50 mm. In this experiment, first, as shown in FIG. 4 (A), only the resonance circuit 2 is used, and a voltage of a constant amplitude and a variable frequency is swept through the amplifier 22 from a signal generator 21 (for example, a frequency synthesizer) at its power supply terminal 12. While being applied, the drive current I (mA) of the resonance circuit 2 is measured by the ammeter 23 and the magnet is installed at a position separated by a distance P (= 1.5 m) on the axis (z axis) of the first coil 3. The magnetic flux density B radiated from the resonance circuit 2 by the sensor 24 (μG, only in the z-axis direction) was measured. The experimental results are shown in the graph of current I (A) and magnetic flux density B (A) in FIG. Graphs I (A) and B (A) in the figure show that the current I and the radiated magnetic flux density B both become maximum (peak) at the resonance frequency f 0 when the single resonance circuit 2 is used. ing.
次に、図４（Ｃ）に示すように共振回路２と共振回路５とを第１コイル３及び第２コイル６とが同軸線上で入れ子状に重なるように（軸線方向間隔Ｗ＝０となるように）配置し、上記と同様に振幅一定・周波数可変の電流を印加しながら、共振回路２の駆動電流Ｉと、コイル軸線方向の距離Ｐ（＝1.5ｍ）隔てた位置の磁束密度Ｂとを計測した。この実験結果を図５の電流Ｉ（Ｃ）及び磁束密度Ｂ（Ｃ）のグラフに示す。グラフＩ（Ｃ）及びグラフＢ（Ｃ）は、アンテナ１の両共振回路２、５を図４（Ｃ）のように配置した場合に、アンテナ１から放射される磁束密度Ｂのピーク周波数（1050Hz付近）が両共振回路２、５の共振周波数f0と異なることを示している。 Next, as shown in FIG. 4C, the resonance circuit 2 and the resonance circuit 5 are arranged so that the first coil 3 and the second coil 6 are nested on the coaxial line (the axial interval W = 0). In the same manner as described above, while applying a constant amplitude and variable frequency current, the drive current I of the resonance circuit 2 and the magnetic flux density B at a position separated by a distance P (= 1.5 m) in the coil axis direction Was measured. The experimental results are shown in the graph of current I (C) and magnetic flux density B (C) in FIG. Graphs I (C) and B (C) show the peak frequency (1050 Hz) of the magnetic flux density B radiated from the antenna 1 when both the resonance circuits 2 and 5 of the antenna 1 are arranged as shown in FIG. (Near) shows that the resonance frequency f 0 of both resonance circuits 2 and 5 is different.
そこで、第１コイル３及び第２コイル６を同軸線上に配置したまま、両コイル３、６の軸線方向の軸線方向間隔Ｗを大きくして両コイル３、６の磁気的結合を弱めながら駆動電流Ｉ及び磁束密度Ｂを計測する実験を繰り返したところ、図４（Ｂ）に示すように、両コイル３、６の軸線方向間隔Ｗを17cm程度とすることによりアンテナ１のピーク周波数を両共振回路２、５の共振周波数f0と一致させることができた。この実験から、本発明の磁気通信アンテナ１の放射する磁界Ｂのピーク周波数は、第１コイル３及び第２コイル６の軸線方向間隔Ｗの調整により、両共振回路２、５の共振周波数f0と一致させることができることを確認できた。 Therefore, while the first coil 3 and the second coil 6 are arranged on the coaxial line, the axial current W between the coils 3 and 6 is increased to weaken the magnetic coupling between the coils 3 and 6 while reducing the magnetic coupling. When the experiment of measuring I and the magnetic flux density B was repeated, the peak frequency of the antenna 1 was set to both resonance circuits by setting the axial distance W between the coils 3 and 6 to about 17 cm as shown in FIG. It was possible to match the resonance frequencies f 0 of 2 and 5. From this experiment, the peak frequency of the magnetic field B radiated by the magnetic communication antenna 1 of the present invention is determined by adjusting the axial distance W between the first coil 3 and the second coil 6 and the resonance frequency f 0 of both the resonance circuits 2 and 5. It was confirmed that it can be matched with.
また、両コイル３、６の軸線方向間隔Ｗを17cmとしたときの実験結果を示す図５のグラフＩ（Ｂ）及びグラフＢ（Ｂ）は、アンテナ１のピーク周波数を両共振回路２、５の共振周波数f0と一致させた場合に、その共振周波数f0において電流Ｉが極小になると共に放射磁束密度Ｂが最大となることを示す。その電流Ｉの極小値は共振回路２のみを用いたグラフＩ（Ａ）の電流Ｉより小さく、磁束密度Ｂの最大値（ピーク値）はグラフＢ（Ａ）の磁束密度Ｂより大きい。すなわち、アンテナ１のピーク周波数を両共振回路２、５の共振周波数f0と一致させることにより、共振回路２のみを用いた場合に比してアンテナ１の磁束発生効率を飛躍的に高め、小さな消費電力で通信距離の長いアンテナ１が得られることを確認できた。 Also, graphs I (B) and B (B) in FIG. 5 showing the experimental results when the axial distance W between the coils 3 and 6 is 17 cm indicate the peak frequency of the antenna 1 as the resonance circuits 2 and 5. When the resonance frequency f 0 coincides with the resonance frequency f 0 , the current I becomes minimum and the radiation flux density B becomes maximum at the resonance frequency f 0 . The minimum value of the current I is smaller than the current I of the graph I (A) using only the resonance circuit 2, and the maximum value (peak value) of the magnetic flux density B is larger than the magnetic flux density B of the graph B (A). That is, by making the peak frequency of the antenna 1 coincide with the resonance frequency f 0 of both the resonance circuits 2 and 5, the magnetic flux generation efficiency of the antenna 1 is remarkably increased compared with the case where only the resonance circuit 2 is used, and is small. It was confirmed that the antenna 1 having a long communication distance with power consumption can be obtained.
［実験例２］
更に、図４（Ｃ）に示す両共振回路２、５の配置において、同図（Ｄ）に示すように共振回路５の径δ1のコイル６をより小さい径δ2（＝300mm）のコイル６に交換したところ、図５のグラフＩ（Ｄ）及びグラフＢ（Ｄ）に示す実験結果が得られた。グラフＩ（Ｄ）及びグラフＢ（Ｄ）は、両コイル３、６の径の比（＝δ／Ｄ）を小さくして磁気的結合を強めた場合に、グラフＩ（Ｃ）及びグラフＢ（Ｃ）に比してアンテナ１のピーク周波数と両共振回路２、５の共振周波数f0との差が拡大したことを示している。このことは逆に、両コイル３、６の径の比（＝δ／Ｄ）を大きくして磁気的結合を弱めることにより、アンテナ１のピーク周波数と両共振回路２、５の共振周波数f0との差が小さくし、両者を一致させることができることを示唆している。
[Experiment 2]
Further, in the arrangement of the two resonance circuits 2 and 5 shown in FIG. 4C, as shown in FIG. 4D, the coil 6 having the diameter δ 1 of the resonance circuit 5 is replaced with a coil having a smaller diameter δ 2 (= 300 mm). As a result, the experimental results shown in graphs I (D) and B (D) in FIG. 5 were obtained. Graphs I (D) and B (D) show graphs I (C) and B (() when the ratio of the diameters of the coils 3 and 6 (= δ / D) is reduced to increase the magnetic coupling. It shows that the difference between the peak frequency of the antenna 1 and the resonance frequency f 0 of both the resonance circuits 2 and 5 is larger than C). Conversely, by increasing the ratio of the diameters of the coils 3 and 6 (= δ / D) to weaken the magnetic coupling, the peak frequency of the antenna 1 and the resonance frequency f 0 of both the resonance circuits 2 and 5 are reduced. This suggests that the difference between the two can be reduced and the two can be matched.
そこで本発明者は、図４（Ｃ）における共振回路５の径δ1のコイル６をより大きい径δ3のコイル６（図示せず）に交換して駆動電流Ｉ及び磁束密度Ｂを計測する実験を行ったところ、両コイル３、６の径の比（＝δ／Ｄ）を大きくして磁気的結合を弱めることにより、アンテナ１のピーク周波数と両共振回路２、５の共振周波数f0との差が小さくなることを確認することができた。アンテナ１のピーク周波数と両共振回路２、５の共振周波数f0とが一致するような両コイル３、６の径の比（＝δ／Ｄ）を見出すまでには至らなかったが、この実験により、本発明の磁気通信アンテナ１が放射する磁界Ｂのピーク周波数は、両コイル３、６の軸線方向間隔Ｗの調整だけでなく、両コイル３、６の径の比（＝δ／Ｄ）の調整によっても、両共振回路２、５の共振周波数f0と一致させることができることを確認できた。 Therefore, the present inventor replaces the coil 6 having the diameter δ 1 of the resonance circuit 5 in FIG. 4C with a coil 6 (not shown) having a larger diameter δ 3 and measures the drive current I and the magnetic flux density B. When an experiment was performed, the peak frequency of the antenna 1 and the resonance frequency f 0 of both resonance circuits 2 and 5 were reduced by increasing the ratio of the diameters of the coils 3 and 6 (= δ / D) to weaken the magnetic coupling. It was confirmed that the difference between and became smaller. Although it was not possible to find the ratio of the diameters of the coils 3 and 6 (= δ / D) such that the peak frequency of the antenna 1 and the resonance frequency f 0 of both the resonance circuits 2 and 5 coincided with each other, this experiment Thus, the peak frequency of the magnetic field B radiated by the magnetic communication antenna 1 of the present invention is not only the adjustment of the axial distance W between the coils 3 and 6, but also the ratio of the diameters of the coils 3 and 6 (= δ / D). It can be confirmed that the resonance frequency f 0 of both the resonance circuits 2 and 5 can be made to coincide with this adjustment.
上述したように本発明の磁気通信アンテナは、一対の独立した第１コイル３及び第２コイル６により構成されているので、両コイル３、６の形状や大きさ、軸線方向間隔をそれぞれ選択することができ、設置環境や設置スペースに応じて形状及び大きさを適当に設計することが可能である。例えば、設置スペースが限られたボーリング孔等に埋設する第１コイル３は小型化を図り、第２コイル６はボーリング孔の外部に配置して大型化を図ることができる。また、たとえ第１コイル３を小型化した場合でも、第１コイル３を含む共振回路２の共振周波数f0と第２コイル６を含む共振回路５の共振周波数f0とを一致させると共にアンテナのピーク周波数を共振周波数f0と一致させることにより、磁束発生効率を高めてアンテナ１の通信距離を十分長くすることができる。 As described above, since the magnetic communication antenna of the present invention is composed of a pair of independent first coil 3 and second coil 6, the shape and size of both coils 3, 6 and the axial distance are selected. It is possible to design the shape and size appropriately according to the installation environment and installation space. For example, the first coil 3 embedded in a boring hole or the like having a limited installation space can be reduced in size, and the second coil 6 can be arranged outside the boring hole to increase the size. Even if the first coil 3 is downsized, the resonance frequency f 0 of the resonance circuit 2 including the first coil 3 is matched with the resonance frequency f 0 of the resonance circuit 5 including the second coil 6 and the antenna By making the peak frequency coincide with the resonance frequency f 0 , the magnetic flux generation efficiency can be increased and the communication distance of the antenna 1 can be made sufficiently long.
なお、上述した実験例では第２コイル６の軸線と第１コイル３の軸線とを平行とし且つ同軸線上に重なるように配置しているが、設置環境やスペースに制限があって両コイル３、６の軸線を同軸線上に配置できない場合は、多少の伝送損失が発生するものの、両コイル３、６の軸線を平行にずらして又は交差するように配置してもよい。本発明者は、このように両コイル３、６の軸線をずらして又は交差するように配置した場合でも、上述したように両コイル３、６の相互間隔Ｗ（例えばコイル中心の相互間隔）及び径の比（＝δ／Ｄ）を調整することにより、磁気通信アンテナ１のピーク周波数を両共振回路２、５の共振周波数f0と一致させることができることを実験的に確認することができた。 In the above-described experimental example, the axis of the second coil 6 and the axis of the first coil 3 are arranged so as to be parallel and overlap on the coaxial line. If the six axes cannot be arranged on the coaxial line, some transmission loss may occur, but the axes of the coils 3 and 6 may be arranged so as to be shifted or crossed in parallel. Even when the present inventor arranges the axes of the coils 3 and 6 so as to be shifted or intersecting with each other as described above, the mutual distance W between the coils 3 and 6 (for example, the mutual distance between the coil centers) and It was experimentally confirmed that the peak frequency of the magnetic communication antenna 1 can be matched with the resonance frequency f 0 of both the resonance circuits 2 and 5 by adjusting the ratio of diameters (= δ / D). .
こうして本発明の目的である「限られたスペースに設置できる通信距離の長い磁気通信アンテナ及び装置」を達成することができる。 Thus, the “magnetic communication antenna and apparatus having a long communication distance that can be installed in a limited space”, which is an object of the present invention, can be achieved.
以上、本発明の磁気通信アンテナを送信回路に接続する実施例について説明したが、本発明の磁気通信アンテナを磁気信号の受信に利用することも可能である。ただし受信アンテナとして利用する場合は、図２（Ａ）に示すように、受電端子13及び第１コイル３を含む所定共振周波数f0の並列共振回路８と、第１コイル３に磁気的に結合する第２コイル６を含む所定共振周波数f0の直列共振閉回路６とにより磁気通信アンテナ１を構成し、所定共振周波数f0の磁界Ｂを吸収して受電端子13に電気信号を出力する。この場合も、第１コイル３と第２コイル６とを例えば同軸線上に配置し、第１コイル３及び第２コイル６の軸線方向間隔Ｗ及び径の比（＝δ／Ｄ）を調整することにより、アンテナ１の吸収する磁界Ｂのピーク周波数を両共振回路２、５の共振周波数f0と一致させることができる。図２（Ｂ）は、受電端子13に受信回路13及びコンピュータ45を接続した磁気通信装置の回路図を示す。直列共振回路２に代えて並列共振回路８を用いることにより、共振周波数f0において吸収する磁界Ｂの選択性を高めると共に、受電端子13に出力する誘導起電力を大きくすることができる。 Although the embodiment in which the magnetic communication antenna of the present invention is connected to the transmission circuit has been described above, the magnetic communication antenna of the present invention can also be used for receiving a magnetic signal. However, when it is used as a receiving antenna, as shown in FIG. 2A, it is magnetically coupled to the first coil 3 and the parallel resonance circuit 8 having a predetermined resonance frequency f 0 including the power receiving terminal 13 and the first coil 3. The magnetic communication antenna 1 is configured by the series resonant closed circuit 6 having the predetermined resonance frequency f 0 including the second coil 6 that absorbs the magnetic field B having the predetermined resonance frequency f 0 and outputs an electric signal to the power receiving terminal 13. Also in this case, the first coil 3 and the second coil 6 are arranged on a coaxial line, for example, and the axial distance W and the diameter ratio (= δ / D) of the first coil 3 and the second coil 6 are adjusted. Thus, the peak frequency of the magnetic field B absorbed by the antenna 1 can be matched with the resonance frequency f 0 of both the resonance circuits 2 and 5. FIG. 2B shows a circuit diagram of a magnetic communication device in which the receiving circuit 13 and the computer 45 are connected to the power receiving terminal 13. By using the parallel resonance circuit 8 in place of the series resonance circuit 2, the selectivity of the magnetic field B absorbed at the resonance frequency f 0 can be enhanced and the induced electromotive force output to the power receiving terminal 13 can be increased.
図３（Ａ）は、本発明による磁気通信アンテナ１を、地層処分施設30の処分坑道36又はボーリング孔37（図６参照）の内部に埋設する計測器17の計測信号の通信に適用した実施例を示す。上述したように地層処分施設30の処分坑道36は地下300〜1000ｍ程度の深部に構築することが想定され、しかも放射性廃棄物等を閉じ込めるため止水プラグ38等で密閉しなければならない場合がある。本発明のアンテナ１は、電気的な配線等を必要としない独立した第１コイル３及び第２コイル６の相互間隔Ｗ及び径の比（＝δ／Ｄ）を調整することで通信距離を延ばすことができるので、例えば第１コイル３のみを計測器17と共に処分坑道36の内側に埋設し、止水プラグ38を介して処分坑道36の反対側（外側又は地表）に第２コイル６を配置することができる。両コイル３、６の間に止水プラグ38を貫くような配線ケーブル等を設ける必要はない。その上で、両コイル３、６の大きさ及び形状を適当に選択すると共に磁気的結合の最適化を図ることで、地下深部から地上まで届くような長い通信距離を確保することが期待できる。 FIG. 3 (A) shows an implementation in which the magnetic communication antenna 1 according to the present invention is applied to communication of measurement signals of a measuring instrument 17 embedded in a disposal mine 36 or a borehole 37 (see FIG. 6) of a geological disposal facility 30. An example is shown. As described above, the disposal mine 36 of the geological disposal facility 30 is assumed to be built in a depth of about 300 to 1000m underground, and may need to be sealed with a water stop plug 38 or the like in order to confine radioactive waste. . The antenna 1 of the present invention extends the communication distance by adjusting the mutual spacing W and the ratio of the diameters (= δ / D) of the independent first coil 3 and second coil 6 that do not require electrical wiring or the like. Therefore, for example, only the first coil 3 is embedded inside the disposal tunnel 36 together with the measuring instrument 17, and the second coil 6 is arranged on the opposite side (outside or ground) of the disposal tunnel 36 through the water stop plug 38. can do. There is no need to provide a wiring cable or the like that penetrates the water stop plug 38 between the coils 3 and 6. In addition, by appropriately selecting the sizes and shapes of the coils 3 and 6 and optimizing the magnetic coupling, it can be expected to secure a long communication distance that reaches from the deep underground to the ground.
図３（Ｂ）は、本発明による磁気通信アンテナ１を、コンクリート建物や土構造物等の土木・建築構造物39の内部に埋設する計測器17の計測信号の通信に適用した実施例を示す。この場合も、第１コイル３のみを計測器17と共に構造物39の内部に埋設し、第２コイル６は構造物39の表面又は外部に配置することができる。埋設機器は構造物39に対する異物として作用するので、構造物39の安定を図るためには埋設機器をできるだけ小さくすることが望ましい。本発明のアンテナ１によれば、構造物39に埋設する第１コイル３の小型化を図り、構造物39の表面又は外部に配置した第２コイル６との相互間隔Ｗや径の比（＝δ／Ｄ）を調整して通信距離を延ばすことにより、構造物39の安定性の欠損を最小限に抑えつつ構造物39の安全性・健全性等を無線通信によりモニタリングすることができる。 FIG. 3B shows an embodiment in which the magnetic communication antenna 1 according to the present invention is applied to communication of measurement signals of a measuring instrument 17 embedded in a civil engineering / building structure 39 such as a concrete building or earth structure. . Also in this case, only the first coil 3 can be embedded in the structure 39 together with the measuring instrument 17, and the second coil 6 can be arranged on the surface of the structure 39 or outside. Since the embedded device acts as a foreign object to the structure 39, in order to stabilize the structure 39, it is desirable to make the embedded device as small as possible. According to the antenna 1 of the present invention, the first coil 3 embedded in the structure 39 is reduced in size, and the mutual distance W and the diameter ratio (=) of the second coil 6 arranged on the surface of the structure 39 or on the outside (= By adjusting (δ / D) and extending the communication distance, it is possible to monitor the safety and soundness of the structure 39 by wireless communication while minimizing the loss of stability of the structure 39.
１…磁気通信アンテナ ２…直列共振回路
３…第１コイル ４…コンデンサ
５…直列共振閉回路 ６…第２コイル
７…コンデンサ ８…並列共振回路
12…給電端子 13…受電端子
14…送信回路 15…受信回路
16…芯材 17…計測器
18…計測回路 19…送受切替回路
21…信号発生器（周波数シンセサイザ）
22…増幅器 23…電流計
24…磁気センサ
30…地層処分施設 31…地表
32…地上設備 32…アクセス立孔
33…アクセス斜孔 35…連絡坑道
36…処分坑道（空洞） 37…ボーリング孔
38…止水プラグ 39…土木・建築構造物
40…水上側通信装置 41…通信回路
42…ソレノイドコイル 43…容器
44…中空磁性体 45…コンピュータ
50…水底側通信装置 52…通信回路
53…ソレノイドコイル 54…容器
55…中空磁性体
Ｂ…磁界 Ｃ…容量
Ｄ…コイル径 δ…コイル径
Ｅ…コイル長さ f0…所定共振周波数
Ｌ…インダクタンス Ｎ…コイル巻数
Ｐ…距離 Ｓ…コイル断面積
Ｗ…コイル相互間隔（軸線方向間隔）
DESCRIPTION OF SYMBOLS 1 ... Magnetic communication antenna 2 ... Series resonance circuit 3 ... 1st coil 4 ... Capacitor 5 ... Series resonance closed circuit 6 ... 2nd coil 7 ... Capacitor 8 ... Parallel resonance circuit
12 ... Power supply terminal 13 ... Power reception terminal
14 ... Transmission circuit 15 ... Reception circuit
16 ... Core 17 ... Measuring instrument
18 ... Measurement circuit 19 ... Transmission / reception switching circuit
21 ... Signal generator (frequency synthesizer)
22 ... Amplifier 23 ... Ammeter
24… Magnetic sensor
30… Geological disposal facility 31… Surface
32 ... ground equipment 32 ... access hole
33 ... Access oblique hole 35 ... Connection tunnel
36 ... Disposal tunnel (cavity) 37 ... Boring hole
38 ... Water plug 39 ... Civil engineering / building structures
40 ... Water side communication device 41 ... Communication circuit
42 ... solenoid coil 43 ... container
44 ... Hollow magnetic body 45 ... Computer
50 ... Submarine communication device 52 ... Communication circuit
53 ... Solenoid coil 54 ... Container
55 ... hollow magnetic B ... field C ... capacitance D ... coil diameter [delta] ... coil diameter E ... coil length f 0 ... predetermined resonant frequency L ... inductance N ... number of coil turns P ... distance S ... coil sectional area W ... coil spacing (Axial direction spacing)
Claims (12)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006242188A JP4915849B2 (en) | 2006-09-06 | 2006-09-06 | Magnetic communication antenna and apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006242188A JP4915849B2 (en) | 2006-09-06 | 2006-09-06 | Magnetic communication antenna and apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2008067017A true JP2008067017A (en) | 2008-03-21 |
| JP4915849B2 JP4915849B2 (en) | 2012-04-11 |
Family
ID=39289328
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2006242188A Expired - Fee Related JP4915849B2 (en) | 2006-09-06 | 2006-09-06 | Magnetic communication antenna and apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4915849B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010203079A (en) * | 2009-02-27 | 2010-09-16 | Mitsubishi Heavy Industries Bridge & Steel Structures Engineering Co Ltd | Movable breakwater and movable wave breaking facility |
| JP2012088144A (en) * | 2010-10-19 | 2012-05-10 | National Agriculture & Food Research Organization | Landslide observation system |
| CN102611214A (en) * | 2012-04-06 | 2012-07-25 | 天津工业大学 | EMSR (electromagnetic & mechanical synchronous resonance) electromagnetic energy transmitting and receiving system |
| KR20180073425A (en) * | 2016-12-22 | 2018-07-02 | 현대자동차주식회사 | Wireless charging system for electric vehicle with adjustable flux angle |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000216715A (en) * | 1999-01-26 | 2000-08-04 | Hitachi Maxell Ltd | Communication system utilizing noncontact information medium and communication auxiliary equipment used for such communication system |
| JP2004029873A (en) * | 2002-06-21 | 2004-01-29 | Hitachi Ltd | Information processing apparatus, mobile information device, and non-contact information medium to be used therefor |
| JP2005110131A (en) * | 2003-10-01 | 2005-04-21 | Sony Corp | Repeater and communication system |
| JP2005323019A (en) * | 2004-05-07 | 2005-11-17 | Pegasus Net Kk | Booster antenna for rfid tag |
-
2006
- 2006-09-06 JP JP2006242188A patent/JP4915849B2/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000216715A (en) * | 1999-01-26 | 2000-08-04 | Hitachi Maxell Ltd | Communication system utilizing noncontact information medium and communication auxiliary equipment used for such communication system |
| JP2004029873A (en) * | 2002-06-21 | 2004-01-29 | Hitachi Ltd | Information processing apparatus, mobile information device, and non-contact information medium to be used therefor |
| JP2005110131A (en) * | 2003-10-01 | 2005-04-21 | Sony Corp | Repeater and communication system |
| JP2005323019A (en) * | 2004-05-07 | 2005-11-17 | Pegasus Net Kk | Booster antenna for rfid tag |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010203079A (en) * | 2009-02-27 | 2010-09-16 | Mitsubishi Heavy Industries Bridge & Steel Structures Engineering Co Ltd | Movable breakwater and movable wave breaking facility |
| JP2012088144A (en) * | 2010-10-19 | 2012-05-10 | National Agriculture & Food Research Organization | Landslide observation system |
| CN102611214A (en) * | 2012-04-06 | 2012-07-25 | 天津工业大学 | EMSR (electromagnetic & mechanical synchronous resonance) electromagnetic energy transmitting and receiving system |
| KR20180073425A (en) * | 2016-12-22 | 2018-07-02 | 현대자동차주식회사 | Wireless charging system for electric vehicle with adjustable flux angle |
| KR102406107B1 (en) | 2016-12-22 | 2022-06-07 | 현대자동차 주식회사 | Wireless charging system for electric vehicle with adjustable flux angle |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4915849B2 (en) | 2012-04-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2282810C (en) | Drill string telemetry | |
| US3967201A (en) | Wireless subterranean signaling method | |
| JPH07294658A (en) | Signal transmission device and method | |
| CA2826376C (en) | Improved electro-magnetic antenna for wireless communication and inter-well electro-magnetic characterization in hydrocarbon production wells | |
| US6595285B2 (en) | Method and device for emitting radial seismic waves in a material medium by electromagnetic induction | |
| JP4915849B2 (en) | Magnetic communication antenna and apparatus | |
| EP2659496B1 (en) | Device for transfer of electrical signals and/or electrical energy | |
| MX2007006111A (en) | Methods and apparatus for communicating across casing. | |
| GB2146126A (en) | Drill stem logging system | |
| Ma et al. | Near-field magnetic induction communication device for underground wireless communication networks | |
| CN103726835A (en) | While-drilling reflecting sound wave measuring sound system | |
| CN102667530A (en) | Electromagnetic logging between a cased borehole and surface | |
| CN209979870U (en) | In-hole scanning detection device based on electromagnetic induction principle | |
| CN110767979A (en) | Borehole electromagnetic wave transmitting antenna for subway diaphragm wall leakage detection | |
| RU2611603C1 (en) | Communication system of very low and extremely low frequency range with deep-seated and distant objects | |
| US6968735B2 (en) | Long range data transmitter for horizontal directional drilling | |
| CN110725681A (en) | Near-bit measuring device | |
| US10502799B2 (en) | Fiber optic nuclear magnetic resonance sensor | |
| CN211144481U (en) | A nuclear magnetic resonance logging device is bored to position for geological orientation | |
| CN111697334A (en) | Borehole electromagnetic wave receiving antenna for subway diaphragm wall leakage detection | |
| Dang et al. | Multi-coil array for long-distance cross-well electromagnetic detection | |
| US10424027B1 (en) | Fiber optic magnetic induction (B-field) sensors | |
| AU2022361327A1 (en) | System and method/process for commercial blasting | |
| US20240141778A1 (en) | Downhole electromagnetic induction communication device | |
| JP3057563B2 (en) | Receiving electromagnetic coil |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20090403 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20101210 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20110207 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20110602 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20110902 |
|
| A911 | Transfer to examiner for re-examination before appeal (zenchi) |
Free format text: JAPANESE INTERMEDIATE CODE: A911 Effective date: 20110909 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20110928 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20111114 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20120119 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20120119 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20150203 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |