JP2007251819A - Antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna for radio-controlled watch, getting smaller with ease and superior impact resistance, and having stable high-sensitivity, regardless of the magnitudes of the intensity of waves. <P>SOLUTION: The antenna includes a plurality of magnetic wires 1 with isolation processed surfaces, a first shorting member 2 and second shorting member 3 connecting these magnetic wires 1 at both ends, a means for passing radio-frequency pulse current through the magnetic wires 1, and an impedance-detecting means for detecting impedance of the magnetic wires 1. The antenna provides an active antenna by using MI effect, and at least one of the plurality of magnetic wires 1 consists of a wound pick-up coil 4 and has a voltage-detecting means for detecting the voltage among the electrodes of the magnetic wires 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an antenna that increases a magnetic permeability by an MI effect (Magneto-Impedance effect) using a long magnetic material such as a plurality of amorphous thin films or wires.

  The application of radio timepieces is increasing due to the advantage of time correction by radio waves, but recently, they are implemented and provided in watches. However, since the frequency is a long wave band of 40 kHz and 60 kHz, it is difficult to reduce the size and the sensitivity of the antenna, and various ideas have been made.

For example, an antenna device is known that aims to reduce the size and improve the sensitivity by dividing the ferrite bar antenna structure in the longitudinal direction and arranging a permanent magnet in the middle to improve the permeability of the part through which the magnetic field passes. (See Patent Document 1). There is also known a Hall element type small antenna that amplifies a voltage change caused by a change in resistance of the Hall element due to a magnetic field and calibrates the conventional bar antenna to a surface state (see Patent Document 2). Furthermore, in the magnetic core member of an antenna, which is characterized by obtaining a high magnetic permeability by a material and obtaining an impact resistance against ferrite by laminating an amorphous thin film (see Patent Document 3), especially in a bar antenna, etc. There is also known an antenna device that is reduced in size by resonating at 40 kHz and 60 kHz of a standard radio wave with weak magnetic field strength (see Patent Document 4). There is also known a bar antenna that increases the amount of magnetic field absorption by increasing the open area at both ends of the bar antenna, and is small in size to improve sensitivity (see Patent Documents 5 to 6). A configuration is also known in which a solenoidal coil antenna is formed using this structure to capture a magnetic field passing through a circular surface of a wristwatch (see Patent Document 7). In this configuration, since the passage area is large, high sensitivity can be expected, and the exclusive area inside the watch is considered to be smaller than the linear bar antenna.
JP 2004-104430 A Japanese Patent Laid-Open No. 10-68785 JP 2003-110341 A JP 2004-120261 A JP 2004-125606 A JP 2004-274609 A JP-A-6-331759

  Various approaches have been taken as described above. However, in the above-mentioned Patent Document 1, it is necessary to dispose a permanent magnet, which may complicate assembly and may have insufficient impact resistance. Although the Hall element antenna described in Patent Document 2 is effective for miniaturization, it is necessary to increase the area of the Hall element that receives a magnetic field in order to achieve high sensitivity, and a Hall current is passed during reception. There was a need to worry about battery consumption.

  In Patent Document 3, the antenna magnetic core material has an amorphous laminated structure. However, in a small antenna, the space factor in the case of the laminated structure cannot be increased, and the effective area of magnetic flux passage with respect to the coil cross-sectional area is reduced. Even if an amorphous material having a high magnetic permeability is used, the effect may be halved.

The “antenna device and radio timepiece using the antenna device” of Patent Document 4 are characterized in that the resonance frequency is designed to be a standard radio frequency particularly under weak magnetic field conditions, but the gain is 0.02 μT to 1 μT. It becomes the maximum in. For this reason, although it is possible to reduce the size, there may be cases where sensitivity cannot be obtained with a magnetic field intensity other than the resonance condition. There is a concern that the structures of the bar antennas of Patent Documents 5 to 6 having an increased area at both ends basically increase in size. In Patent Document 7, it is possible to improve sensitivity and effectively use the inside of the watch structure, but it is necessary to embed the watch in a casing on the circumference of the wristwatch, and there are problems such as an increase in manufacturing cost and mounting accuracy.
As described above, the conventional antenna for a radio timepiece in the above patent application has various problems in miniaturization and high sensitivity.

    On the other hand, standard radio waves in Japan have two types of frequencies, 40 kHz and 60 kHz, and radio clock antennas need to be sensitive to these two types of radio waves, so optimal design is performed for one resonance frequency. There are difficult problems. Furthermore, there is a problem that high magnetic permeability cannot be obtained only with existing materials.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an antenna that has excellent radio wave sensitivity and can be miniaturized.

The inventors of the present application have made extensive studies in order to achieve the above object. As a result, a high-frequency pulse current is formed by bundling or laminating wires or thin films made of an amorphous magnetic material having a magnetic layer with a high saturation magnetic flux density on the surface layer or a magnetic material composed of nanocrystals, with the surfaces insulated. By controlling the surface fine magnetic domain of the amorphous wire or thin film due to the MI effect, the voltage change at both ends or the output voltage change of the winding due to the magneto-impedance effect of the amorphous wire or thin film due to the passage of an external magnetic field As a result, the inventors have found that the above object can be achieved, and have completed the present invention.
In order to improve the magnetic permeability in the circumferential surface direction of the material when a high-frequency current is passed due to the MI effect, and to further improve the permeability of the material surface when a high-frequency current is passed, , B-containing amorphous or nanocrystalline material containing Fe and Co as the main component is used. As a result, a long magnetic material such as a thin material or wire material made of a magnetic layer with a high saturation magnetic flux density is used on the surface, and the high frequency current is increased or decreased in synchronization with the frequency to change the permeability so that the standard radio wave is obtained. Can be tuned.
Magneto-Impedance Effect (MI effect) is that the impedance (inductance and resistance) at both ends of a wire is as low as several Oe to several tens of Oe when a high-frequency current of 1 MHz or more is passed through an amorphous magnetic wire (FeCoSiB, CoSiB). This is a phenomenon in which a large change of 10% to 80% occurs when an external magnetic field is applied. The change in magnetic impedance due to the MI effect is shown in the following equation.

Where Z: wire impedance, a: wire diameter, ρ: specific resistance (Ωm), Hex: external magnetic field (A / m)
R _DC : DC resistance (Ω), ω _μ : Angular frequency of current flow (rad / sec), μ: Permeability in circumferential direction (H / m)

In order to solve the above-described problem, the antenna according to claim 1 is configured such that a plurality of long magnetic bodies whose surfaces are insulated and the plurality of long magnetic bodies are respectively connected at or near both ends in the longitudinal direction. An electrode structure; a high-frequency pulse current passing means for passing a high-frequency pulse current to the plurality of long magnetic bodies; and an impedance detecting means for detecting the impedance of the both-end electrode structure. Yes.

  According to the above configuration, when an alternating current is applied, the circumferential magnetic domains on the surface of the long magnetic body are aligned, and a weak magnetic field in the direction of current flow causes a circumferential magnetic field vector and a perpendicular magnetic field vector. The change in impedance at both ends of the wire is large due to the direction of the combined vector, and it effectively functions as an antenna.

  In order to solve the above-described problem, in the antenna according to claim 2, a voltage for detecting a voltage between electrodes of the long magnetic body is formed by winding at least one of the long magnetic bodies around a pickup coil. It is characterized by comprising detection means.

    According to said structure, the magnetic field intensity by an electromagnetic wave can be detected with the voltage of a pick-up coil by MI effect, and when a some pick-up coil is connected in series, a big output can be obtained.

In order to solve the above-described problems, the antenna according to claim 3 has, as a core material, a first magnetic layer made of an amorphous or nanocrystalline structure in which the long magnetic material contains Fe and / or Co as a main component. And a wire or thin film ribbon having a second magnetic layer having a saturation magnetic flux density higher than that of the core material on the surface.
According to said structure, the magnetic domain of the circumferential direction of the wire surface is aligned by using the wire of an amorphous magnetic body or a nanocrystal magnetic body as a core material of a long magnetic body. In addition, even a weak magnetic field in the direction of current flow causes a large impedance change at both ends of the wire, and functions effectively as an antenna. In addition, when a thin ribbon magnetic material is used as the long magnetic material, the space factor is further increased with respect to the wire, and the magnetic field passing through the antenna opening area can be effectively used, improving sensitivity. Is possible.

  At this time, by forming the second magnetic layer having a higher saturation magnetic flux density outside the first magnetic layer, the core material and the magnetic layer on the surface form a strong interaction due to the magnetic exchange interaction with the central core material. The long magnetic material exhibits a magnetic characteristic reflecting the characteristics of the core material rather than the single characteristic of the magnetic layer on the surface. Here, an example in which a layer having a high saturation magnetic flux density was formed on the surface of a long magnetic material and an amorphous magnetic material or a nanocrystalline magnetic material was used as a core material was shown, but depending on the thickness and composition of the magnetic layer, In some cases, it is better to have a magnetic layer with a high saturation magnetic flux density at the center and to form an amorphous magnetic material or nanocrystalline magnetic material layer on the surface. In addition, as a method of forming the two kinds of magnetic layers, there are a method of stacking and a method of forming a layer by vapor deposition or electroplating.

By forming the second magnetic layer having a higher saturation magnetic flux density as in the present invention, an effect of obtaining a large voltage output to the pickup coil can be obtained.
As a comparison between amorphous magnetic material and nanocrystalline magnetic material, amorphous magnetic material has poor saturation magnetic properties and low maximum magnetic permeability, but amorphous magnetic material has weak magnetostriction because there is no magnetostriction in the magnetization direction. Tend to be magnetized against a strong magnetic field. For this reason, an amorphous magnetic material is used as a core material in the case of a very small magnetic field such as an antenna of a radio timepiece, and a nanocrystal layer is formed on the surface by crystallizing an amorphous magnetic layer by heat treatment. It is desirable. As described above, the same characteristics can be obtained even when the surface is an amorphous magnetic layer on the surface and a nanocrystalline magnetic layer as the central core material.

    The core material and the second magnetic layer constituting the first magnetic layer of the long magnetic body are not particularly limited as long as they are magnetic bodies made of an alloy mainly composed of Fe and / or Co. Accordingly, Nd, B, and Si may be included. Among these, it is more preferable that B is contained in an appropriate amount.

    As the formation state of the first magnetic layer and the second magnetic layer, for example, a structure in which a long first magnetic layer is used as a core and the periphery thereof is covered by a cylindrical second magnetic layer is most preferable.

  In order to solve the above-described problem, the voltage detection unit is configured so that the voltage detection means passes through two types of filters of a first frequency (for example, 40 kHz) and a second frequency (for example, 60 kHz). Output comparator means for comparing the output values of the two types of filters, an output value judging means for judging the magnitude of the output value, and a signal switched by a signal from the output value judging means Switching means; detection / amplification means for detecting and amplifying the output from the signal switching means; and modulation means for modulating the peak value of the high-frequency pulse signal according to the magnitude of the signal output from the signal switching means. It is characterized by that.

  According to the above configuration, the antenna itself has a resonance function, and a small antenna excellent in noise resistance can be obtained. In addition, since the sensitivity of the detected magnetic flux density in the MI effect is high but the saturation value is small, a signal cannot be detected when the magnetic flux density due to radio waves is high and saturated. Therefore, if the magnitude of the high-frequency pulse current is modulated so that the output of the pickup coil is within the saturation magnetic flux density in the MI effect, or if the modulation within the high-frequency pulse current cannot be controlled within the saturation magnetic flux density, the detected frequency It is possible to attenuate the magnetic flux itself by the external coil current synchronized with, and finally prevent saturation. Therefore, according to the above configuration, a stable received radio wave can be obtained in any radio wave strength environment.

  In order to solve the above-described problem, the antenna according to claim 5 includes a pickup coil output value determining unit that determines the magnitude of the output of the pickup coil, and an adjusting unit that adjusts the gain of the modulated high-frequency pulse signal. And a magnetic field application coil.

    As described above, in the antenna of the present invention, long magnetic bodies made of a plurality of amorphous wires or ribbons are coupled at their ends, and a high-frequency pulse current flows through the plurality of amorphous wires or ribbons.

By doing so, a magnetic impedance effect due to the MI effect is generated, and a change in magnetic field due to radio waves is captured with high sensitivity. Further, if the longitudinal direction of the wire is configured to be relatively short and the number of wires to be bundled is increased, the area through which the magnetic field passes is increased, so that the sensitivity is improved. Moreover, a planar antenna can be formed from the structure of a conventional bar-shaped bar antenna, and it is possible to reduce the size as well as to reduce the thickness. In addition, if microcoils are manufactured by microfabrication, they can be integrated into each amorphous wire or ribbon, which is a complicated and low reliability factor, such as winding a coil with polyurethane insulated wires like conventional bar antennas. The process with many is unnecessary.
In addition to simplifying the manufacturing process, it is possible to prevent deterioration of reliability due to a short circuit due to disconnection or damage to the insulating film, thereby reducing manufacturing costs. In addition, the peak value of the high-frequency pulse current to be supplied is changed in synchronization with the detection intensity of the radio wave, so that an active antenna that selectively receives synchronously is obtained. Furthermore, since the saturation magnetic flux density due to the MI effect is relatively low, when the magnetic flux density is high, the intensity of the high frequency pulse current is adjusted so that the received radio wave waveform is not saturated, or the magnetic flux synchronized with the radio wave signal from another coil To generate a feedback circuit that keeps the received magnetic flux density constant within the saturation magnetic flux density. By doing so, it is possible to obtain an effect that can stably maintain high sensitivity at any radio wave intensity, and to provide a standard radio wave antenna that is small and excellent in noise resistance, sensitivity stability, and interference ratio.

An embodiment of the present invention will be described below with reference to the drawings.
The antenna of the present invention includes a magnetic wire, a mechanism for electrically connecting and bundling the magnetic wire at both ends, a circuit for passing a high-frequency pulse current through the magnetic wire, and a circuit for detecting the magnetic wire connection end voltage. It is out.

[Example 1]
FIG. 1 shows a schematic diagram of a magnetic wire (long magnetic body) 1 used in the antenna of the present invention. As shown in FIGS. 1 to 2, the magnetic wires 1 are insulated and electrically coupled to each other at both ends by a first short-circuit member 2 and a second short-circuit member 3. As a matter of course, the magnetic wire 1 is not necessarily in the form of a wire, and the cross section of the magnetic ribbon or the like may be rectangular, and it can be replaced as long as the material can obtain a desired magnetoimpedance effect. Needless to say, you can. In FIG. 1 to FIG. 2, a short-circuit member is used, but it is not always necessary to short-circuit at both ends. Further, as shown in FIG. 2, the longitudinal direction of the magnetic wire 1 is configured to be relatively short and the number of wires to be bundled is increased, so that the area through which the magnetic field passes is increased, so that the sensitivity is improved and the conventional bar-shaped bar antenna A planar antenna can be formed from this structure, and it is possible to reduce the size as well as to reduce the thickness.

  FIG. 3 is a schematic diagram showing a state where the pickup coil 4 is applied to the magnetic wire 1. In the figure, the arrow 5 indicates the direction of the magnetic flux of the magnetic field applied from the outside. In principle, the MI effect can be detected by a change in impedance at both ends of the magnetic wire 1, but in general, sensing by the pickup coil 4 is performed in this way. If the induced voltage is detected using the pickup coil, only the imaginary part of Equation 1 is detected, the positive / negative discrimination of the magnetic field direction is possible, and the output characteristics are linear.

  FIG. 4 is a schematic diagram in which a plurality of magnetic wires 1 provided with a pickup coil 4 are connected in the same manner as shown in FIGS. 1 and 2, and a pulse current is applied to all the magnetic wires 1 from the high-frequency pulse power supply 6. It has become so.

  FIG. 5 is an explanatory diagram showing an embodiment of the present invention, in which pickup coils 4 of a plurality of magnetic wires 1 are connected in parallel and connected to an amplifier 7, and the output of the amplifier 7 is a first bandpass filter. 8 and the second bandpass filter 9. The outputs of the first bandpass filter 8 and the second bandpass filter 9 are connected to the input of the changeover switch 11 and the comparator / changeover switch control device 10, and the output of the comparator / changeover switch control device 10 is connected to the changeover switch 11. It is connected. The output of the changeover switch 11 is input to the receiving device 13 through the detection circuit 12. The output of the detection circuit 12 is connected to one negative input of the adder 18 via a waveform processing circuit 26 (not shown), and the output of the addition signal setting unit 17 is connected to the positive input of the adder 18. The output of the adder 18 is connected to one input of the multiplier 15 via the PI controller 14, the output of the high frequency pulse power supply 6 is connected to the other input of the multiplier 15, and the output of the multiplier 15 is connected to the amplifier 16. All the magnetic wires 1 are energized.

  FIG. 9 is a schematic diagram relating to modulation of standard radio waves. The standard radio wave is transmitted by modulating a signal of 40 kHz or 60 kHz from 10% to 100% with a pulse signal having a frequency of 1 Hz and pulse widths of 0.2 S, 0.5 S, and 0.8 S, respectively. In the figure, a radio wave waveform schematic diagram indicated by a waveform 29 (a schematic waveform of a radio wave waveform modulated by a time code pulse) passes through the magnetic wire 1 and is induced in the pickup coil. Here, the amplifier 7 amplifies it and inputs it to the first band-pass filter 8 and the second band-pass filter 9 having pass frequencies of 40 kHz and 60 kHz, respectively. The comparator / switch control device switches the changeover switch 11 to the bandpass filter having the stronger output of the received frequency among the outputs of the bandpass filters 8 and 9. The output signal that has passed through the change-over switch is detected inside the detection circuit 12, and the time code pulse shown in the waveform 28 (partial waveform of the time code pulse) in FIG. 9 is obtained. The time code pulse is processed inside the receiving apparatus 13 shown in FIG. 5, and is used as a time standard signal for time calibration by a clock or the like connected to the receiving apparatus as year / month / day / time data. On the other hand, the time code pulse waveform that is the output of the detection circuit 12 is added to the signal of the addition signal setting unit 17 by the adder 18 via the waveform processing circuit 26 and input to the PI controller 14. Here, 14 is expressed as a PI controller, but in the basic operation, there is almost no integral element, and it can be considered that the operation is only the proportional component. That is, an appropriate analog amount is added to a digital signal called a time code pulse by an addition signal setting device, and an output proportional to the analog amount is output from the PI controller, which is input to one input of the multiplier 15 as an analog amount and multiplied. A value obtained by modulating the high-frequency pulse power source connected to one input of the unit 15 is output from the multiplier 15, amplified by the amplifier 16, and applied to the magnetic wire 1 via the first short-circuit member 2 and the second short-circuit member 3. A high frequency pulse is energized. With this function, the magnetic wire 1 is excited by a high-frequency pulse only when a pulse transmitted every second is received, so that there is an advantage that unnecessary power loss is eliminated and erroneous reception due to noise is avoided.

  FIG. 7 does not modulate the excitation of the amorphous wire by the high frequency pulse in the operation of FIG. 5 with the received signal. An air-core coil 24 is provided outside so that the low-frequency magnetic flux among the magnetic flux passing through the magnetic wire 1 does not become large and saturation occurs, and the low-frequency is synchronized with the time code pulse output from the detection circuit 12. This is intended to cancel the external magnetic field. The output of the addition signal setting unit 17 is generally held at zero, and the target value of the PI controller 14 is zero. That is, the output of the low-pass filter 27 is a detected value of the low frequency component, and the PI controller 14 outputs a component that makes this zero, and the formed feedback loop is activated to excite the air-core coil 24. The low frequency component will be canceled. The multiplier 19 is configured to be excited only when the time code pulse of the output signal of the detection circuit 12 is output in order to prevent the air-core coil from being always excited and increasing power consumption. The waveform processing circuit 26 is for adjusting the offset voltage to zero when there is no time pulse code, or delaying the rise and fall of the pulse to make the operation of the multiplier 19 and the like smooth.

[Example 2]
Although the basic operation of FIG. 6 is the same as that of FIG. 5, the voltage of the signal input to the amplifier 7 is increased because the output of the pickup coil is serialized, and there is an advantage that a high S / N ratio can be obtained in terms of circuit. is there.

  In FIG. 6, the pickup coil 4 is different from the first embodiment in that the pickup coils 4 of the respective magnetic wires 1 are connected in series. In this series connection, not all the magnetic wires 1 are necessarily connected in series, but a plurality of magnetic wire 1 pickup coils connected in series may be connected in parallel. Other connections are the same as in the first embodiment.

Example 3
FIG. 7 shows a different embodiment of the present invention, in which a pickup coil 4 of a plurality of magnetic wires 1 is connected in series and connected to an amplifier 7. The output of the amplifier 7 is a first bandpass filter 8 and a second band. The output of the first band pass filter 8 and the second band pass filter 9 is connected to the pass filter 9, and is connected to the input of the changeover switch 11 and the comparator / changeover switch control device 10. Is connected to the changeover switch 11. The output of the changeover switch 11 is input to the receiving device 13 via the detection circuit 12. The output of the detection circuit 12 is connected to one input of the multiplier 19 via the waveform processing circuit 26. The output of the amplifier 7 is connected to the negative input of the adder 18 through the low-pass filter 27, and the output of the addition signal setting unit 17 is connected to the positive input of the adder 18. The output of the adder 18 is connected to one input of the multiplier 19 via the PI adjuster 14. The output of the multiplier 19 is connected to the coil 25 of the air-core coil 24 through the amplifier 23. The output of the high-frequency pulse power supply 6 is energized to the magnetic wire via the amplifier 16 via the first short-circuit member 2 and the second short-circuit member 3.

  FIG. 8 shows a specific oscillation circuit for applying a high-frequency pulse current to the magnetic wires 1a and 1b. The inverters 21a and 21b are connected in series, and the resistor 20a is connected in parallel to the inverter 21a. The inverter 21a and the capacitor 22a connected in parallel to the series circuit of the inverter 21b constitute an oscillation circuit, and the output of the inverter 21b is pulled up by the series circuit of the capacitor 22c and the resistor 20c via the inverter 21c and the inverter 21d. Has been. The connection point between the capacitor 22b and the resistor 20b is connected to the inputs of the inverters 21e and 21f. The outputs of the inverter 21e and the inverter 21f are connected to the magnetic wires 1a and 1b through the resistors 20d and 20e, respectively. Grounded. The output of the inverter 21b is pulled up to the power supply through a series circuit of the capacitor 22b and the resistor 20b, and the connection point between the capacitor 22b and the resistor 20b is input to the inverter 21e, which is not shown in this drawing, but is not shown in FIG. It is used as a detection timing signal with the unit. Here, the oscillation circuit constituted by the inverter 21a and the inverter 21b, that is, the high-frequency pulse power supply may have another configuration.

  FIG. 10 is an explanatory diagram showing a schematic configuration of a magnetic wire 51 according to another embodiment of the present invention. As shown in the figure, the magnetic wire 51 has a two-layer structure in which a surface material 31 (second magnetic layer) is arranged on the surface of a core material 30 (first magnetic layer) made of amorphous magnetic material or nanocrystalline magnetic material. Is done. With such a configuration, a larger voltage can be output.

    Applications of the antenna of the present invention include use as a radio timepiece, particularly as a radio timepiece antenna built in a wristwatch. The wristwatch antenna needs to be small and have high impact resistance. However, the standard radio frequency of 40 kHz and 60 kHz is long wave and long wavelength, so the conventional bar antenna using ferrite etc. is small. However, by using the antenna of the present invention that obtains the MI effect by exciting an amorphous wire, a high-sensitivity antenna having a small size and high impact resistance can be realized. It can also be applied to antenna applications where similar features are essential.

It is a structural example schematic diagram of the magnetic wire which concerns on one embodiment of this invention. It is a schematic diagram of a different configuration example of a magnetic wire according to an embodiment of the present invention. It is a schematic diagram of the magnetic wire which concerns on one embodiment of this invention. It is a block diagram of the structure of the magnetic wire which concerns on one embodiment of this invention. It is a block diagram which shows one embodiment of this invention. It is a block diagram of a different embodiment of the present invention. It is a block diagram which shows one embodiment of this invention. It is an example of the high frequency pulse oscillation circuit of a magnetic wire. It is a schematic diagram regarding the modulation | alteration of a standard radio wave. It is explanatory drawing which shows schematic structure of the magnetic wire which concerns on other embodiment of this invention.

Explanation of symbols

1 Magnetic wire (long magnetic material)
1a-1b Magnetic wire
2 First Short-Circuit Member 3 Second Short-Circuit Member 4 Pickup Coil 6 High Frequency Pulse Power Supply 7 Amplifier 8 First Band Pass Filter 9 Second Band Pass Filter 10 Comparator / Changeover Switch Control Device 11 Changeover Switch 12 Detection Circuit 13 Receiver 14 PI Adjuster 15 Multiplier 16 Amplifier 17 Addition signal setting device 18 Adder 19 Multiplier (gain adjuster)
20a-20e Resistors 21a-21e Inverters 22a-22c Capacitor 23 Amplifier 24 Air core coil 25 Coil 26 Waveform processing circuit 27 Low pass filter 28 Waveform 29 Schematic waveform 30 of radio wave waveform modulated by time code pulse 30 Core material (first magnetic layer)
31 Surface material (second magnetic layer)

Claims (5)

A plurality of long magnetic bodies whose surfaces are insulated, an electrode structure in which the plurality of long magnetic bodies are respectively connected at or near both ends in the longitudinal direction, and a high-frequency pulse current for the plurality of long magnetic bodies An antenna comprising: high-frequency pulse flow means for flowing through; and impedance detection means for detecting impedance of the electrode structure. 2. The antenna according to claim 1, wherein at least one of the long magnetic bodies is formed by winding a pickup coil, and further includes voltage detection means for detecting a voltage between the electrodes of the long magnetic body. . The second magnetic layer has a first magnetic layer made of an amorphous or nanocrystalline structure containing Fe and / or Co as a main component as a core material, and has a saturation magnetic flux density higher than that of the core material on the surface. 3. The antenna according to claim 1, wherein the antenna is a wire or a thin film ribbon provided with a magnetic layer. The voltage detection means detects the voltage through two types of filters of a first frequency and a second frequency, and compares the output values of the two types of filters with the magnitude of the output value. Output value judging means for judging the length, signal switching means switched by a signal from the output value judging means, detection / amplification means for detecting / amplifying the output from the signal switching means, and output from the signal switching means 4. The antenna according to claim 2, further comprising a modulation unit that modulates a peak value of the high-frequency pulse signal according to the magnitude of the signal. 5. A pickup coil output value determining means for determining the magnitude of the output of the pickup coil, and an adjusting means for adjusting the gain of the modulated high-frequency pulse signal or a magnetic field applying coil. The antenna according to any one of the above.