WO2022209782A1

WO2022209782A1 - Antenna

Info

Publication number: WO2022209782A1
Application number: PCT/JP2022/011039
Authority: WO
Inventors: 真一谷本; 浩国本; 新九郎藤野; 亮松原
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2021-03-31
Filing date: 2022-03-11
Publication date: 2022-10-06

Abstract

An antenna 10 comprises: a coil 3 spirally wound along a predetermined longitudinal direction, and a dielectric 4 coating the surface of at least a spirally wound portion of the coil 3.

Description

antenna

The present disclosure relates to antennas.

Patent Document 1 discloses an antenna for radiating or receiving radio waves, which is composed of an electric field antenna that responds to electric field components, a magnetic field antenna that responds to magnetic field components, and a splitter/combiner for splitting or combining the two. Disclosed is a standing wave tolerant antenna.

Japanese Patent Application Laid-Open No. 06-291705

An object of the present disclosure is to provide an antenna with improved electric field acquisition capability.

The present disclosure provides an antenna comprising a spirally wound coil along a predetermined longitudinal direction and a dielectric covering at least the surface of the spirally wound portion of the coil.

According to the present disclosure, it is possible to improve the electric field acquisition capability of the antenna.

FIG. 1 is a block diagram of a measurement system according to Embodiment 1 of the present disclosure. FIG. 2 is a block diagram of a measurement system according to Embodiment 2 of the present disclosure. 3 is a perspective view of an antenna used in the measurement system of the present disclosure; FIG. FIG. 4 is a cross-sectional view of an antenna used in the measurement system of the present disclosure; FIG. 5 is a graph showing the electric field strength of a conventional antenna without a dielectric and the antenna of the present disclosure with a dielectric.

(Background leading up to this disclosure)
At substations and the like, work and construction accompanying patrol and maintenance may be carried out. When performing such work, the worker will work in the vicinity of the relevant equipment. However, it is difficult for a worker (hereinafter referred to as a user) who performs maintenance and inspection of equipment or performs construction work to recognize the charging state or operating state of surrounding equipment during work.

In addition, regardless of whether or not the user is working, it is preferable for the user to check the presence or absence of high voltage in the power transmission line from the viewpoint of safety. Since it is dangerous for a user to directly touch power lines, non-contact detection is desired.

　One of the methods for realizing non-contact detection is to measure electromagnetic waves, which are emitted from energized transmission lines. That is, the user can confirm the presence or absence of energization by knowing the direction of the source of the leakage electric field leaking from the transmission line connected to the device and the direction of arrival of the leakage electric field.

By the way, the frequency of the voltage used is 50 Hz, 60 Hz, and its wavelength is several thousand kilometers, making it difficult to capture it as a wave. Therefore, even if a user inspects a transmission line at a height of about 10 m from the ground, for example, it is difficult to detect the phase change (phase difference) of the electric field wave that is generated due to the voltage start-up.

On the other hand, when power is transmitted from a distribution substation to a large-scale building, the voltage is transformed to, for example, about 6600V. Since this level of voltage is applied to the transmission line, it is possible to detect the magnitude of the electric field, but the directivity is poor, and it is difficult to detect whether or not a specific transmission line is energized. However, since the magnetic field generated from an energized transmission line has strong directivity, it is possible to detect whether or not a specific transmission line is energized. Therefore, by detecting both the electric field and the magnetic field, it becomes easy to detect the presence or absence of energization of a specific transmission line and the magnitude of the current.

A conventional device that detects both an electric field and a magnetic field includes antennas that detect the electric field and the magnetic field, respectively, as described in Patent Document 1. Therefore, the number of antennas provided in the device inevitably increases in units of even numbers, such as 2, 4, 6, .

Therefore, in each embodiment shown below, an example of a measurement system and a measurement method that makes it possible to observe electric and magnetic fields with a small number of antennas will be described.

Hereinafter, embodiments specifically disclosing the configuration and operation of the antenna according to the present disclosure will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and redundant descriptions of substantially the same configurations may be omitted. This is to avoid unnecessary verbosity in the following description and to facilitate understanding by those skilled in the art. It should be noted that the accompanying drawings and the following description are provided to allow those skilled in the art to fully understand the present disclosure and are not intended to limit the claimed subject matter.

(Embodiment 1)
The measurement system and measurement method according to the present disclosure will be described below with reference to the drawings. FIG. 1 is a block diagram of a measurement system according to Embodiment 1 of the present disclosure. The measurement system 100 can measure both an electric field and a magnetic field, and is a device for inspecting whether or not a transmission line, which is an object to be measured, is energized, for example.

The measurement system 100 includes an antenna 10a shown in the upper half of FIG. 1 as a basic configuration, a connection terminal 30 for inputting a selection signal for measuring either the electric field measurement or the magnetic field measurement, and the antenna 10a. and a switch 14a for opening and closing a part of the first circuit 1a. The measurement system 100 is connected to a PC (personal computer) 23 . The PC 23 can receive a user's operation to operate the PC 23 and output the selection signal described above to the measurement system 100 . The operation device for operating the measurement system 100 is not limited to the PC 23, and may be a smartphone, a tablet, a dedicated device for the measurement system 100, or the like, and is not particularly limited. Other components shown in the lower half of FIG. 1 will be described later.

Antenna 10a detects an electric field and a magnetic field. The antenna 10a is formed by winding a coil around a core, for example. When the core is made of ferrite, it is made of a ferrite antenna. A ferrite antenna is formed by winding an electric wire coil whose surface is coated with insulation around a rod-shaped core made of ferrite or the like with high magnetic permeability. With a ferrite antenna, when both ends of the coil are closed, magnetic lines of force pass through the inside of the antenna in response to changes in the surrounding magnetic field, and electromagnetic induction generates an electromotive force in the coil, making it possible to measure the magnetic field. (Loop antenna behavior). On the other hand, in a ferrite antenna, when one end of the coil is open, a voltage is induced in the coil according to the surrounding electric field, so that the electric field can be measured (monopole antenna operation).

A selection signal for measuring either the electric field or the magnetic field is input to the connection terminal 30, for example, by the antenna 10a. That is, connection terminal 30 receives a selection signal input from the outside. The user operates the PC 23 to select which of the electric field and the magnetic field is to be measured. The PC 23 generates a selection signal corresponding to this selection operation by the user and inputs it to the measurement system 100 via the connection terminal 30 . The connection terminal 30 not only receives the selection signal, but also has a function of outputting a predetermined signal to the PC 23 as will be described later, and functions as a signal input/output unit.

In other words, the selection signal output from the PC 23 is input to the first circuit 1 a and the second circuit 1 b of the measurement system 100 via the Lch chip 31 and Rch ring 32 of the measurement system 100 . Moreover, the measurement result by the antenna 10a is input to the PC 23 via the sleep 34. FIG.

The connection terminal 30 can be composed of, for example, a connection terminal having at least an audio output terminal and a microphone input terminal (audio input terminal). In this embodiment, the connection terminal 30 is configured by a 4-pole CTIA (Cellular Telephone Industry Association) terminal including four poles, and includes an Lch chip 31 and an Rch ring 32, which are audio output terminals for outputting an audio signal as a selection signal. , an insulating ring (GND) 33 and a sleep (MIC) 34 which is a microphone input terminal. A selection signal for selecting electric field measurement or magnetic field measurement is output from the Lch chip 31 and the Rch ring 32 . However, as will be described later, even when no audio signal is output from the Lch chip 31 and the Rch ring 32, it is included in the output of the selection signal whose output is zero. A measurement result by the antenna 10 a is input to the sleep 34 .

The first circuit 1a can connect both ends of the coil of the antenna 10a and the connection terminal 30. The first circuit 1a includes a capacitor 12a, a diode 13a, and an amplifier 20a. The diode 13a and the capacitor 12a are connected to the Lch chip 31 of the connection terminal 30, and convert the audio signal from the Lch chip 31 to direct current (DC).

The switch 14a is a part of the first circuit 1a and has a function of opening and closing the first circuit 1a. The switch 14a is composed of, for example, an NPN transistor, and the output sides of the diode 13a and the capacitor 12a are connected to the base of the transistor. The input side of the transistor forming the switch 14a, in this example the collector of the transistor, is connected to the coil of the antenna 10a. The output side of the transistor (the emitter of the transistor in this example) is connected to the amplifier 20a. With this configuration, as will be described later, the measurement system 100 switches the switch 14a on or off according to the selection signal input to the connection terminal 30 to close or open the first circuit 1a. As a result, the measurement system 100 can switch between magnetic field measurement and electric field measurement by the antenna 10a. However, the specific configuration of the switch 14a is not limited to an NPN transistor, and can be replaced by a semiconductor element or device having a switching function such as a PNP transistor or MOSFET.

The amplifier 20a is connected to the emitter of the transistor forming the switch 14a and amplifies the output of the switch 14a. The output of the amplifier 20 a is the magnetic field measurement result or the electric field measurement result of the antenna 10 a and is input to the sleep 34 that is the microphone input terminal of the connection terminal 30 .

In other words, the magnetic field measurement result or the electric field measurement result by the antenna 10 a is input to the PC 23 via the sleep 34 .

Next, operations (1) to (3) of the measurement system 100 having the basic configuration described above will be described. (1) The user operates the keyboard, mouse, etc. of the PC 23 to open the operation screen of the measurement system 100 and selects a magnetic field measurement operation. In response to the selection operation by the user, the PC 23 outputs an audio signal (for example, 10 kHz, 1 V), which is a selection signal for selecting magnetic field measurement, to the Lch chip 31 of the measurement system 100. do. The audio signal input to the Lch chip 31 is input to the first circuit 1a, the diode 13a and the capacitor 12a of the first circuit 1a convert the audio signal into a DC signal, and the switch 14a is turned on. In the first circuit 1a, the collector and emitter of the switch 14a are electrically connected at this time, one side of the antenna 10a is connected to the minus terminal of the amplifier 20a, and both ends of the coil of the antenna 10a are closed. As a result, the measurement system 100 can measure the magnetic field because the lines of magnetic force pass through the inside of the antenna 10a according to changes in the surrounding magnetic field, and electromagnetic induction generates an electromotive force in the coil.

(2) Next, the user operates the keyboard, mouse, etc. of the PC 23 to open the operation screen of the measurement system 100, and selects the electric field measurement operation. In response to the selection operation by the user, the processor in the PC 23 does not output the audio signal, which is the selection signal for selecting magnetic field measurement. In other words, the processor in the PC 23 outputs a selection signal with zero output to the Lch chip 31 of the measurement system 100 . At this time, the switch 14a is turned off and one side of the antenna 10a is opened. Accordingly, when one end of the coil of the antenna 10a is open, the measurement system 100 can measure the electric field because a voltage is induced in the coil according to the surrounding electric field.

(3) The output of the amplifier 20a that amplifies the signal obtained by the antenna 10a is input to the sleep 34, which is the microphone input terminal (audio input terminal) of the connection terminal 30. FIG. In other words, the output of the amplifier 20 a is input to the PC 23 via the sleep 34 . The input data input here is the data of the measurement result. The PC 23 handles this input data in a data format such as WAV (Waveform Audio File Format). Based on the data, the PC 23 generates and displays a screen (not shown) including the measurement result, or performs processing such as saving the data of the measurement result. The PC 23 switches between the operations (1) and (2) manually by the user, or automatically switches between the operations (1) and (2) at predetermined time intervals, so that both the electric field and the magnetic field are generated. can be detected and recorded. Thereby, the user can inspect whether or not the power transmission line, which is the object to be measured, is energized.

Conventional devices require at least two antennas to detect both the electric field and the magnetic field, but according to this embodiment, one antenna can detect both the electric field and the magnetic field. As a result, it is possible to reduce the number of antennas, specifically to halve the number of antennas, to suppress an increase in the number of antennas, to reduce the size and weight of the device, and to simplify the configuration. and can help reduce costs. Also, when an antenna for detecting an electric field and an antenna for detecting a magnetic field are separately provided, interference between the two may become a problem, but such a problem can also be solved.

The above description relates to the configuration and operation of the measurement system 100 including the antenna 10a, the connection terminal 30, the first circuit 1a, and the switch 14a shown in the upper half of FIG. Furthermore, the measurement system 100 may also comprise an antenna 10b, a second circuit 1b and a switch 14b shown in the lower half of FIG.

The antenna 10b has a configuration equivalent to that of the antenna 10a. Antenna 10a can be regarded as a first antenna. Also, the antenna 10b can be regarded as a second antenna. However, the antenna 10b is arranged so as to face the direction in which the antenna 10a is rotated by 90 degrees, for example. That is, the axial directions of the cores of the

antennas

10a and 10b are in a relationship of intersecting each other at 90 degrees. The second circuit 1b has a configuration equivalent to that of the first circuit 1a, and includes a capacitor 12b, a diode 13b, and an amplifier 20b. The switch 14b has the same configuration as the switch 14a.

Although the number of components increases in this configuration, it is possible to use a first antenna (antenna 10a) and a second antenna (antenna 10b) facing two different physical directions. That is, the two antennas can receive electromagnetic waves in different postures (directions) with respect to the direction from which the electromagnetic waves arrive. Therefore, the measurement system 100 can capture electromagnetic waves arriving from different directions with each of the two antennas, and can further improve measurement accuracy.

On the other hand, in this configuration, the Lch chip 31 of the connection terminal 30 receives not only the input corresponding to the output of the amplifier 20a but also the input corresponding to the output of the amplifier 20b. The measurement system 100 needs to distinguish between these two inputs (measurement results) in order to more accurately capture the measurement results obtained by the

antennas

10a and 10b respectively.

In other words, both the output of the amplifier 20 a and the output of the amplifier 20 b are input to the PC 23 via the Lch chip 31 of the connection terminal 30 . Therefore, the PC 23 needs to distinguish whether the input measurement result is the measurement result of the antenna 10a or the antenna 10b.

Therefore, the measurement system 100 in this embodiment includes a frequency conversion circuit 24 to separate the output of the first circuit 1a and the output of the second circuit 1b. The frequency conversion circuit 24 is a separation circuit capable of outputting the output of the amplifier 20b, which is the output of the second circuit 1b, to the Lch chip 31 of the connection terminal 30. FIG. The frequency conversion circuit 24 is connected between the amplifier 20 b and the Lch chip 31 of the connection terminal 30 . The frequency conversion circuit 24 converts the frequency of the output of the amplifier 20b, which is the output of the second circuit 1b, so that it can be distinguished from the output of the amplifier 20a, which is the output of the first circuit 1a. That is, the frequency conversion circuit 24 separates both outputs and outputs them to the Lch chip 31 of the connection terminal 30 . The frequency conversion circuit 24 may be connected between the amplifier 20a and the Lch chip 31 of the connection terminal 30, and may convert the frequency of the output of the amplifier 20a, which is the output of the first circuit 1a.

Next, the operation of the measurement system 100 having the overall configuration of FIG. 1 described above will be described. The operation of the measurement system 100 includes the following (4) to (6) in addition to the above (1) to (3). (4) At the same time as the processing of (1) of the basic configuration is performed, the processor in the PC 23 sends an audio signal (for example, 10 kHz, 1 V), which is a selection signal for selecting magnetic field measurement, to the Rch ring 32 of the measurement system 100. Output. The audio signal input to the Rch ring 32 is input to the second circuit 1b and converted to a DC signal by the diode 13b and the capacitor 12b of the second circuit 1b. The DC signal turns on switch 14b. At this time, in the second circuit 1b, the collector and emitter of the switch 14b are electrically connected, one side of the antenna 10b is connected to the minus terminal of the amplifier 20b, and both ends of the coil of the antenna 10b are closed. As a result, the measurement system 100 can measure the magnetic field because the lines of magnetic force pass through the inside of the antenna 10b according to changes in the surrounding magnetic field, and electromagnetic induction generates an electromotive force in the coil.

(5) At the same time as the processing of (2) of the basic configuration is performed, the processor in the PC 23 does not output the audio signal, which is the selection signal for selecting the measurement of the magnetic field. In other words, the processor in the PC 23 outputs a selection signal with an output of zero to the second circuit 1b. At this time, the switch 14b is turned off, and one side of the antenna 10b is open. When one end of the coil of the antenna 10b is open, the measurement system 100 can measure the electric field because a voltage is induced in the coil according to the surrounding electric field.

(6) At the same time as the processing of (3) of the basic configuration is performed, the output of the amplifier 20b that amplifies the signal obtained by the antenna 10b is input to the frequency conversion circuit 24 and frequency conversion is performed. The frequency-converted output is superimposed on the output of the amplifier 20 a and input to the sleep 34 that is the microphone input terminal (audio input terminal) of the connection terminal 30 . In other words, a signal obtained by synthesizing the output obtained by frequency-converting the output of the amplifier 20 b by the frequency conversion circuit 24 and the output of the amplifier 20 a is input to the PC 23 via the sleep 34 . This input is the data of the measurement results. The PC 23 handles this input data in a data format such as WAV (Waveform Audio File Format). The PC 23 displays the measurement result to the user based on the data, or performs processing such as saving the data. The measurement system 100 switches between operations (1) and (4) and (2) and (5) by manual operation by the user, and switches operations (1) and (4), (2) and (2) at predetermined time intervals. By automatically switching the operation of (5), both the electric field and the magnetic field can be detected and recorded. This allows the user to check whether or not the power transmission line, which is the object of measurement, is energized.

As described above, in the conventional device, at least 2×2=4 antennas were required to detect both the electric field and the magnetic field from two different directions. According to this embodiment, the measurement system 100 can detect both electric and magnetic fields with two antennas. As a result, the measurement system 100 can reduce the number of antennas, specifically, halve the number of antennas to suppress an increase in the number of antennas. In addition, the measurement system 100 can contribute to reducing the size and weight of the device, simplifying the configuration, and reducing the cost. Moreover, if the measurement system 100 is provided with separate antennas for electric field detection and magnetic field detection, interference between the two may become a problem, but such a problem can also be resolved.

In addition, the measurement system 100 has a mechanism for physically rotating the antenna 10a by 90 degrees, and by switching the outputs of the Lch chip 31 and the Rch ring 32 according to the rotation angle, only one antenna 10a is used. It is possible to perform the processes (1) to (6).

In other words, the PC 23 switches the selection signal according to the rotation angle of the antenna 10a of the measurement system 100, and the selection signal output by the PC 23 is transmitted to the measurement system 100 via the Lch chip 31 and the Rch ring 32 of the measurement system 100. are input to the first circuit 1a and the second circuit 1b.

(Embodiment 2)
FIG. 2 is a block diagram of a measurement system according to Embodiment 2 of the present disclosure. The measurement system 100 of the second embodiment includes a time division circuit 25 instead of the frequency conversion circuit 24 of the first embodiment. The time division circuit 25 is a separation circuit capable of separating the output of the first circuit 1 a and the output of the second circuit 1 b and outputting them to the Lch chip 31 of the connection terminal 30 in the same way as the frequency conversion circuit 24 . The time-division circuit 25 is connected between the

amplifiers

20a and 20b and the Lch chip 31 of the connection terminal 30, and outputs the output of the amplifier 20a, which is the output of the first circuit 1a, and the output of the amplifier 20b, which is the output of the second circuit 1b. and the output of , are time-divided and distributed to distinguish between the two.

The capacitor 12a and the diode 13a of the first circuit 1a are connected not only to the switch 14a but also to the base of the switch 14b, and the capacitor 12b and the diode 13b of the second circuit 1b are connected to the time division circuit 25 instead of the switch 14b. It is connected to the.

Next, operations (7) to (10) of the measurement system 100 of this embodiment will be described.
(7) The user operates the keyboard, mouse, etc. of the PC 23 to open the operation screen of the measurement system 100, and selects a magnetic field measurement operation. In response to the user's selection operation, the processor in the PC 23 outputs an audio signal (for example, 10 kHz, 1 V), which is a selection signal for selecting magnetic field measurement, to the Lch chip 31 of the measurement system 100 . The audio signal input to the Lch chip 31 is input to the first circuit 1a, the diode 13a and the capacitor 12a of the first circuit 1a convert the audio signal into a DC signal, and the

switches

14a and 14b are turned on. At this time, in the measurement system 100, the collectors and emitters of the

switches

14a and 14b are electrically connected, one of the

antennas

10a and 10b is connected to the negative terminals of the

amplifiers

20a and 20b, and both ends of the coils of the

antennas

10a and 10b are connected. will close. As a result, the measuring system 100 can measure the magnetic field because the lines of magnetic force pass through the

antennas

10a and 10b in response to changes in the surrounding magnetic field, and electromotive force is generated in the coils by electromagnetic induction.

(8) Next, the user operates the keyboard, mouse, etc. of the PC 23 to open the operation screen of the measurement system 100, and selects the electric field measurement operation. In response to the selection operation by the user, the processor in the PC 23 does not output the audio signal, which is the selection signal for selecting magnetic field measurement. In other words, the processor in the PC 23 outputs a selection signal with zero output to the Lch chip 31 of the measurement system 100 . At this time, in the measurement system 100, the

switches

14a and 14b are turned off, and one of the

antennas

10a and 10b is open. When one end of the coils of the

antennas

10a and 10b is open, the measurement system 100 can measure the electric field because a voltage is induced in the coils according to the surrounding electric field.

(9) On the other hand, the processor in the PC 23 has a switching function of switching the output of either the amplifier 20a or the amplifier 20b and inputting it to the sleep 34 of the connection terminal 30 in the processes of (7) and (8). have That is, the processor in the PC 23 can output an audio signal (for example, 10 kHz, 1 V) to the time division circuit 25 via the Rch ring 32 of the connection terminal 30, the capacitor 12b of the second circuit 1b, and the diode 13b. When an audio signal is output (so-called Hi output), the time division circuit 25 sets the time during which the output of the amplifier 20a of the first circuit 1a is valid, and only the amplifier 20a outputs the amplified measurement result in the sleep 34. On the other hand, when the processor in the PC 23 does not output an audio signal (so-called Low output), the time division circuit 25 sets the time during which the output of the amplifier 20b of the second circuit 1b is valid, and only the amplifier 20b is put into sleep 34. Output the amplified measurement result.

(10) The outputs of the

amplifiers

20a and 20b for amplifying the signals obtained by the

antennas

10a and 10b are input to the sleep 34 which is the microphone input terminal of the connection terminal 30 . The sleep 34 is when the audio signal of the Lch chip 31 is on (Hi) or off (Low), and when the audio signal of the Rch ring 32 is on (Hi) or off (Low), a total of 4 patterns of data. is input to the PC 23. The PC 23 handles this input data in a data format such as WAV (Waveform Audio File Format). The PC 23 displays the measurement result to the user based on the data, or performs processing such as saving the data. The measurement system 100 switches between the operations (7) and (8) manually by the user, and the PC 23 automatically switches between the operations (7) and (8) at predetermined time intervals. Both magnetic fields can be detected and recorded. This allows the user to check whether or not the power transmission line, which is the object of measurement, is energized.

Also in this embodiment, the measurement system 100 reduces the number of antennas, specifically by halving the number of antennas to suppress an increase in the number of antennas, thereby reducing the size and weight of the device, The configuration can be simplified, which can contribute to cost reduction. Moreover, if the measurement system 100 is provided with separate antennas for electric field detection and magnetic field detection, interference between the two may become a problem, but such a problem can also be resolved.

Also, in the measurement system 100 according to

Embodiments

1 and 2, the connection terminal 30 is configured by a connection terminal having an audio output terminal and a microphone input terminal such as a 4-pole CTIA terminal. However, the connection terminal 30 can also be configured by an audio interface capable of so-called analog/digital conversion. An example of an audio interface is a device that can be connected to the PC 23 via a USB (Universal Serial Bus) interface. The audio interface is arranged at the position of the connection terminal 30 in FIG. 1, for example. The PC 23 outputs audio output 1 to the first circuit 1a and audio output 2 to the second circuit 1b via the audio interface. The output of the amplifier 20a is input to the audio interface as an audio input 1, and the output of the amplifier 20b is input as an audio input 2 to the audio interface. Operations (11) to (15) of the measurement system 100 having such a configuration will be described.

(11) The user operates the keyboard, mouse, etc. of the PC 23 to open the operation screen of the measurement system 100 and selects a magnetic field measurement operation. In response to the user's selection operation, the processor in the PC 23 outputs audio output 1, which is an audio signal (for example, 10 kHz, 1 V), to the audio interface of the measurement system 100 . The audio output 1 input to the audio interface is input to the first circuit 1a, the diode 13a and the capacitor 12a of the first circuit 1a convert the audio output 1 into a DC signal, and the switch 14a is turned on. At this time, in the measurement system 100, the collector and emitter of the switch 14a are electrically connected, one side of the antenna 10a is connected to the negative terminal of the amplifier 20a, and both ends of the coil of the antenna 10a are closed. As a result, the measurement system 100 can measure the magnetic field because the lines of magnetic force pass through the inside of the antenna 10a according to changes in the surrounding magnetic field, and electromagnetic induction causes the coil to generate an electromotive force.

(12) Simultaneously with the processing of (11), the processor in the PC 23 outputs audio output 2, which is a voice signal, to the audio interface of the measurement system 100. FIG. The audio output 2 input to the audio interface is input to the second circuit 1b, the diode 13b and the capacitor 12b of the second circuit 1b convert the audio output 2 into a DC signal, and the switch 14b is turned on. At this time, in the measurement system 100, the collector and emitter of the switch 14b are electrically connected, one side of the antenna 10b is connected to the minus terminal of the amplifier 20b, and both ends of the coil of the antenna 10b are closed. As a result, the measurement system 100 can measure the magnetic field because the lines of magnetic force pass through the inside of the antenna 10b according to changes in the surrounding magnetic field, and electromagnetic induction generates an electromotive force in the coil.

(13) Next, the user operates the keyboard, mouse, etc. of the PC 23 to open the operation screen of the measurement system 100, and selects the electric field measurement operation. In response to the selection operation by the user, the processor in the PC 23 does not output the audio signal, which is the selection signal. In other words, the processor in the PC 23 outputs a selection signal with an output of zero to the audio interface, the first circuit 1a. At this time, the switch 14a is turned off, and one side of the antenna 10a is open. When one end of the coil of the antenna 10a is open, the measurement system 100 can measure the electric field because a voltage is induced in the coil according to the surrounding electric field.

(14) Simultaneously with the processing of (13), the processor in the PC 23 outputs a selection signal with no output to the audio interface and the second circuit 1b. At this time, the switch 14b is turned off, and one side of the antenna 10b is open. When one end of the coil of the antenna 10b is open, the measurement system 100 can measure the electric field because a voltage is induced in the coil according to the surrounding electric field.

(15) In the first circuit 1a, the signal obtained by the antenna 10a is amplified by the amplifier 20a and input as the audio input 1 to the audio interface. In the second circuit 1b, the signal obtained by the antenna 10b is amplified by the amplifier 20b and input as the audio input 2 to the audio interface. The PC 23 processes this input data and records the measurement results. The measurement system 100 switches the operations (11) to (14) by manual operation by the user, or the PC 23 automatically switches the operations (11) to (14) at predetermined time intervals. Both magnetic fields can be detected and recorded. This allows the user to check whether or not the power transmission line, which is the object of measurement, is energized.

Also in this form, the measurement system 100 can reduce the number of antennas, specifically, halve the number of antennas to suppress an increase in the number of antennas. In addition, the measurement system 100 can be made smaller and lighter, and the configuration can be simplified and the cost can be reduced. Moreover, if the measurement system 100 is provided with separate antennas for electric field detection and magnetic field detection, interference between the two may become a problem, but such a problem can also be resolved.

The measurement system 100 is composed of, for example, one housing, and this housing and an operation device such as the PC 23 are connected by a connection cable. Alternatively, the measurement system 100 may be equipped with a circuit, module, or the like having a wireless communication function instead of the connection terminal 30, and may be connected to an operation device having a wireless communication function by wireless communication. That is, the measurement system 100 receives the selection signal transmitted by wireless communication from the operation device. Also, the operation device receives the measurement result transmitted from the measurement system 100 by wireless communication. Here, for wireless communication, a wireless LAN, Wi-Fi (registered trademark), Bluetooth (registered trademark), or the like can be used. Moreover, the measuring system 100 and the operating device may be configured as an integrated device.

3 and 4 show an example of an embodiment of an

antenna

10a or 10b (hereinafter referred to as "antenna 10") applicable to the measurement system 100. FIG. FIG. 3 is a perspective view of antenna 10 used in measurement system 100 of the present disclosure. FIG. 4 is a cross-sectional view of antenna 10 used in measurement system 100 of the present disclosure. The antenna 10 of the embodiment includes the core 2, the coil 3 wound along the longitudinal direction L of the core 2, the entire surface of the core 2 and the entire surface of at least the portion of the coil 3 wound around the core 2. and a dielectric 4 covering the . In this embodiment, the dielectric 4 is formed to cover the entire surface of the core 2 and at least the entire surface of the portion of the coil 3 wound around the core 2, but the antenna is not limited to such an antenna. That is, the dielectric 4 may be formed so as to cover part of the surface of the core 2 and/or part of the surface of at least the part of the coil 3 wound around the core 2 . However, as described in the present embodiment, the dielectric 4 is formed so as to cover the entire surface of the core 2 and at least the entire surface of the portion of the coil 3 wound around the core 2, thereby obtaining an electric field. You can improve your abilities.

The core 2 is a member forming the core of the antenna 10, and is a member for supporting the spirally wound coil 3 portion. Although the material of the core 2 is not particularly limited, it can be composed of a magnetic material such as ferrite, for example. The antenna 10 can improve the magnetic flux density interlinking the inside of the antenna 10 by configuring the core 2 with a magnetic material. As a result, the antenna 10 may have an enhanced ability to collect magnetic fields from the surroundings of the antenna 10 . However, as will be described later, the core 2 is not an essential member from the viewpoint of improving the electric field acquisition capability.

The coil 3 is spirally wound on the surface of the core 2 along the longitudinal direction L of the core 2 . As described above, in the measurement system 100 of FIGS. 1 and 2, one end of the coil 3 is connected to the switch 14a or the switch 14b, so that the switch 14a or the switch 14b is switched on and off, and the first circuit is switched. It can be determined whether 1a or the second circuit 1b forms an open loop or a closed loop. The antenna 10 functions as an electric field antenna when the first circuit 1a or the second circuit 1b forms an open loop. The antenna 10 functions as a magnetic field antenna for measuring the surrounding magnetic field when the first circuit 1a or the second circuit 1b forms a closed loop.

The dielectric 4 is formed around the core 2 while covering the entire surface of the core 2 in this embodiment. Moreover, the dielectric 4 covers the entire surface of at least the portion of the coil 3 wound around the core 2 .

The dielectric 4 is made of a predetermined dielectric material. Due to its dielectric properties, the dielectric 4 can increase the electric flux density inside the antenna 10 including the coil 3 and increase the induced voltage induced in the coil 3 . In other words, since the dielectric 4 can amplify the electric flux density inside the antenna 10, the electric field acquisition capability of the antenna 10 can be improved.

As shown in FIG. 4, the dielectric 4 has a thickness T in a cross section orthogonal to the longitudinal direction L of the core 2. The thickness T is the distance between the surface of the core 2 and the surface of the dielectric 4, but in this embodiment the thickness T is constant on the cross section. Dielectric 4 has a doughnut-shaped cross section. If the thickness T is constant, the dielectric 4 can suppress the detectable bias of the electric field, making it possible to manufacture the antenna 10 more easily.

The core 2 has a circular cross-sectional shape in a cross section perpendicular to the longitudinal direction L, for example, as in this embodiment. If the cross-sectional shape of the antenna 10 is circular, the directivity of the antenna 10 in a specific direction can be suppressed, and the isotropy in the cross section can be improved.

In the antenna 10, in a cross section orthogonal to the longitudinal direction L, the cross-sectional shape of the core 2 and the cross-sectional shape along the surface of the dielectric 4 are similar to each other, for example, as in this embodiment. In this embodiment, the cross-sectional shape of the core 2 and the cross-sectional shape along the surface of the dielectric 4 are circular, but both can be rectangular cross-sections. Thereby, the antenna 10 can suppress the directivity of the antenna 10 in a specific direction and improve the isotropy in the cross section.

The dielectric 4 is preferably made of a material having a dielectric constant (ε _r ) higher than 1. Barium titanate is an example of a material having a dielectric constant (ε _r ) higher than 1. Barium titanate has a dielectric constant (ε _r ) of about 4000 relative to the vacuum dielectric constant (ε ₀ ). By using barium titanate for all or part of the material of the dielectric 4, the electric field acquisition capability of the antenna 10 can be improved. Examples of materials other than barium titanate include ceramic materials such as alumina, zirconia, silicon nitride, lead zirconate titanate, and plastics. Among substances having a dielectric constant (ε _r ) higher than 1, it is preferable that the value of the dielectric loss tangent is 0.02 or less in the 50 Hz to 60 Hz band.

FIG. 5 shows a comparison of the field strength obtained with a conventional antenna without the dielectric 4 and the antenna of the present disclosure with the dielectric 4 . Both are the same except for the presence or absence of the dielectric 4 . As can be seen from the graph, the electric field strength of the conventional antenna without the dielectric 4 is -39.8 dB, and the electric field strength of the antenna of the present disclosure with the dielectric 4 is -32.9 dB. This graph shows that the strength of the acquired electric field can be improved by providing the dielectric 4 to the antenna, which means that the electric field acquisition capability of the antenna is improved.

It should be noted that the antenna 10 of this embodiment has a core 2 . The core 2 serves to support the helically wound portion around which the coil 3 is wound. As described above, when the core 2 is made of a magnetic material such as ferrite or an iron core, the antenna 10 can improve the magnetic flux density interlinking inside the antenna 10 . However, in this embodiment, the dielectric 4 plays a role of improving the electric field acquisition ability, and the core 2 is not an essential member when emphasizing the electric field acquisition ability. If the core 2 does not exist, the antenna 10 is formed by spirally winding the coil 3 along a predetermined longitudinal direction, and then spirally winding the dielectric 4 so as to cover the surface of the spirally wound portion. The portion wound into a shape may be embedded in the dielectric 4 . Even without the core 2, the antenna 10 can acquire the surrounding magnetic field by forming a closed loop with the coil 3 together with the first circuit 1a or the second circuit 1b.

As described above, the antenna includes a spirally wound coil along a predetermined longitudinal direction, and a dielectric covering at least the surface of the spirally wound portion of the coil. Thereby, the electric field acquisition capability of the antenna can be improved.

The antenna of the present disclosure further comprises a core around which the coil is wound to support the helically wound portion, the dielectric covering a surface of the core and at least a surface of the coil wound on the core. cover. Thereby, the magnetic field acquisition capability of the antenna can be improved.

The antenna of the present disclosure has a constant dielectric thickness in a cross section orthogonal to the longitudinal direction. As a result, it is possible to suppress the detectable bias of the electric field and to easily manufacture the antenna.

In the antenna of the present disclosure, the cross-sectional shape of the core is circular in a cross section perpendicular to the longitudinal direction. Thereby, the directivity of the antenna in a specific direction can be suppressed, and the isotropy can be improved.

In the antenna of the present disclosure, the cross-sectional shape of the core and the cross-sectional shape along the surface of the dielectric are similar to each other in the cross section orthogonal to the longitudinal direction. Thereby, the directivity of the antenna in a specific direction can be suppressed, and the isotropy can be improved.

In the antenna of the present disclosure, the dielectric contains a material with a relative dielectric constant (ε _r ) greater than one. Thereby, the electric field acquisition capability of the antenna can be improved.

Although various embodiments have been described above with reference to the accompanying drawings, the present disclosure is not limited to such examples. It is obvious that a person skilled in the art can conceive of various modifications, modifications, substitutions, additions, deletions, and equivalents within the scope of the claims. It is understood that it belongs to the technical scope of the present disclosure. In addition, the constituent elements of the various embodiments described above may be combined arbitrarily without departing from the gist of the invention.

This application is based on a Japanese patent application (Japanese Patent Application No. 2021-061317) filed on March 31, 2021, the contents of which are incorporated herein by reference.

The present disclosure is useful as an antenna with improved electric field acquisition capability.

1a First circuit 1b Second circuit 2 Core 3 Coil 4

Dielectric

10, 10a,

10b Antenna

12a,

12b Capacitor

13a,

13b Diode

14a,

14b Switch

20a, 20b Amplifier 23 PC
24 frequency conversion circuit 25 time division circuit 30 connection terminal 31 Lch chip 32 Rch ring 33 insulation ring (GND)
34 Sleep (MIC)
100 measurement system

Claims

a spirally wound coil along a predetermined longitudinal direction;
a dielectric covering the surface of at least the helically wound portion of the coil;
Antenna with
further comprising a core supporting the helically wound portion around which the coil is wound;
The dielectric covers the surface of the core and the surface of at least a portion of the coil wound around the core.
Antenna according to claim 1.
The thickness of the dielectric is constant in a cross section perpendicular to the longitudinal direction,
Antenna according to claim 2.
In a cross section orthogonal to the longitudinal direction, the core has a circular cross-sectional shape,
Antenna according to claim 2.
In a cross section orthogonal to the longitudinal direction, the cross-sectional shape of the core and the cross-sectional shape along the surface of the dielectric are similar to each other.
Antenna according to claim 2.
the dielectric contains a material with a relative permittivity (ε r ) greater than 1;
Antenna according to claim 1.