JP2009216625A - Vibration detection element, vibration measuring device, and vibration measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration detection element for detecting vibration in the noncontact state without laminating a reflection seal even on an object not having a characteristic for reflecting laser light, and taking out a sufficient signal from a received radio wave, and a vibration measuring device and a vibration measuring method for using properly the vibration detection element. <P>SOLUTION: A radio wave is transmitted to a measuring target object by a radio wave transmission means 2. A transmitted radio wave and a reflected radio wave are received by an antenna 4 arranged inside a radio wave reflection means 3 and near the radio wave transmission means 2, and a signal including information on phases of the transmitted radio wave and the reflected radio wave received by the antenna 4 is detected by a transistor 5. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vibration detecting element that can detect vibration of an object in a non-contact manner, a vibration measuring apparatus and a vibration measuring method that can suitably use the vibration detecting element.

Conventionally, when measuring vibration of an object such as a mechanical apparatus, a method of detecting vibration by bringing a vibration sensor such as an acceleration pickup into contact with the object is generally used.
The method of measuring by contacting the vibration sensor is also applied in the field of biological measurement, and various methods have been proposed. For example, in order to measure the internal quality of a living organism such as a fruit by vibration, it is performed by bringing a contact-type vibration detecting element (for example, a piezo element) into contact with the fruit.

However, the present inventors have found that the action itself of bringing such a contact-type vibrator into contact with a soft object such as a fruit causes a change in the characteristics of the measurement target, and accurate measurement cannot be performed.
Therefore, the present inventors measure the internal quality by using a laser Doppler vibrometer that has been conventionally used for industrial measurement in order to measure vibration without contact with the object to be measured. A laser Doppler method is proposed. (See Patent Document 1).
Furthermore, the present inventors have also proposed a technique for measuring vibrations by irradiating an object to be measured with microwaves, receiving the detected radio wave with a comb antenna, and detecting it (see Patent Document 2).
Japanese Patent Laid-Open No. 9-236587 Japanese Patent Laid-Open No. 20007-198787

However, in the technique described in Patent Document 1, in order to measure the vibration of an object that does not reflect laser light, it is necessary to apply a reflective sticker to the surface of the object. May not be able to accurately measure the vibration of the object.
In the technique described in Patent Document 2, the antenna is arranged at a position far from the signal source. Therefore, the signal strength of the received radio wave is weak and the reception sensitivity is low. As a result, a sufficient signal for vibration measurement may not be extracted from the received radio wave.

  The present invention has been made in view of the above problems, and can detect vibration without contact without sticking a reflective sticker to an object that does not have the property of reflecting laser light, and It is an object of the present invention to provide a vibration detecting element that can extract a sufficient signal from a received radio wave, a vibration measuring device and a vibration measuring method that can suitably use the vibration detecting element.

(1) A cylindrical radio wave reflecting means having at least one end opened, a radio wave transmitting means attached to one end of the radio wave reflecting means so that a transmitted radio wave is directed toward the open end, And an antenna that is disposed inside the radio wave reflecting means, receives the radio wave transmitted from the radio wave transmitting means, and receives the reflected radio wave reflected by the object to be measured.
A vibration detecting element comprising: a transistor for detecting a signal including information related to a phase between a transmitted radio wave and a reflected radio wave received by an antenna.
(2) The vibration detecting element according to item 1, wherein the antenna is comb-shaped.
(3) The vibration detecting element according to item 1 above, wherein the antenna is a folded dipole antenna.
(4) A cylindrical radio wave reflecting means having at least one end opened, a radio wave transmitting means attached to one end of the radio wave reflecting means so that a transmitted radio wave is directed toward the open end, and the vicinity of the radio wave transmitting means, The dipole antenna is disposed inside the radio wave reflecting means and receives the radio wave transmitted from the radio wave transmitting means, and receives the reflected radio wave reflected by the object to be measured, and the transmission received by the dipole antenna. A vibration detecting element comprising: a diode for detecting a signal including information on a phase between a radio wave and a reflected radio wave.
(5) A bridge of a cylindrical radio wave reflecting means having at least one open end, a radio wave transmitting means attached to one end of the radio wave reflecting means so that the transmitted radio wave is directed toward the open end, and four diodes The bridge circuit, the first tuning circuit connected to the input side of the bridge circuit, the second tuning circuit connected to the output side of the bridge circuit, the inside of the radio wave reflection means, and the vicinity of the radio wave transmission means A reflector formed in a U shape by a pair of conductor plates, the first tuning circuit is in a space where the angle formed by the reflector is an acute angle, and the second tuning circuit is an obtuse angle formed by the reflector A vibration detecting element arranged in each side space.
(6) The vibration detecting element according to any one of items 1 to 5, wherein the radio wave reflecting means is an electromagnetic horn antenna.
(7) The vibration detecting element according to any one of items 1 to 6, wherein the frequency of the radio wave transmitted from the radio wave transmitting means is in a range of 5 GHz to 30 GHz.
(8) The vibration detection element according to any one of (1) to (7), wherein the signal including information on the phase is a signal including information on a phase difference between the transmitted radio wave and the reflected radio wave.
(9) A vibration measuring apparatus comprising: the vibration detecting element according to any one of items 1 to 8; and a frequency analyzing unit that performs frequency analysis on a signal including information related to a phase.
(10) While receiving the radio wave transmitted in the first step by the first step of transmitting a radio wave to the object to be measured, and the antenna disposed in the vicinity of the radio wave transmitting unit and inside the radio wave reflecting unit, A second step of receiving a reflected radio wave reflected by an object to be measured, and a signal including information on the phase of the transmitted radio wave and the received radio wave received in the second step are detected by a transistor; And a fourth step of analyzing the frequency of a signal including information relating to the phase detected in the third step.
(11) The vibration measurement method according to item 10 above, wherein the signal including information on the phase is a signal including information on a phase difference between the transmission radio wave and the reception radio wave.

  According to the invention described in item (1) above, radio waves are transmitted from the radio wave transmitting means to the object to be measured, and the transmitted radio waves and the reflected radio waves are placed inside the radio wave reflecting means and in the vicinity of the radio wave transmitting means by the antenna. Received by a deployed antenna. Information on the phase between the transmitted radio wave and the reflected radio wave is detected by the transistor. Thereby, it is possible to detect vibration of the object in a non-contact manner without performing a complicated operation of applying a reflective seal even to an object having a characteristic of not reflecting the laser by using radio waves. In addition, since it is not necessary to attach a reflective seal, it is possible to eliminate the possibility that the vibration of the object cannot be measured accurately depending on how the reflective seal is applied. In addition, since the antenna is placed near the radio wave transmission means (signal source) and inside the radio wave reflection means where the reflected radio waves gather, the receiving intensity of the outgoing radio wave and the reflected radio wave is increased and the sensitivity is increased. It is possible to extract a sufficient signal for the vibration measurement. In addition, since a signal including information on the phase between the transmitted radio wave and the reflected radio wave is detected by the transistor, high demodulation efficiency can be obtained.

  According to the invention described in item (2) above, the antenna that receives the transmitted radio wave and the received wave can be formed in a comb shape.

  According to the invention described in item (3) above, the antenna that receives the transmission radio wave and the reception wave can be a folded dipole antenna.

  According to the invention described in item (4) above, since vibration measurement of an object to be measured using radio waves is possible, the trouble of applying a reflective sticker to an object that does not reflect a laser can be reduced. The vibration of the object can be detected in a non-contact manner without being applied. In addition, since it is not necessary to attach a reflective seal, it is possible to eliminate the possibility that the vibration of the object cannot be measured accurately depending on how the reflective seal is applied. In addition, since the dipole antenna is placed near the radio wave emitting means and inside the radio wave reflecting means, the receiving intensity of the outgoing radio wave and the reflected radio wave is increased and the sensitivity is high, and sufficient for measuring vibration from the received radio wave. The signal can be taken out. Further, by combining a dipole antenna and a diode, a signal including information on the phase between the transmitted radio wave and the reflected radio wave can be demodulated efficiently.

  According to the invention described in item (5) above, vibration measurement of an object to be measured using radio waves is possible. Therefore, it takes time and effort to put a reflective sticker on an object that does not reflect a laser. The vibration of the object can be detected without contact. In addition, since it is not necessary to attach a reflective seal, it is possible to eliminate the possibility that the vibration of the object cannot be measured accurately depending on how the reflective seal is applied. Further, by combining a reflector, two tuning circuits, and a bridge circuit to which the two tuning circuits are connected, it is possible to efficiently demodulate a signal including information on the phase of the transmitted radio wave and the reflected radio wave.

According to the invention described in item (6), the radio wave reflecting means can be an electromagnetic horn antenna.
According to the invention described in item (7) above, it is possible to detect the vibration of the object to be measured using radio waves in the range of 5 GHz to 30 GHz.
According to the invention described in item (8), the vibration of the object to be measured can be detected by a signal including information on the phase difference between the transmitted radio wave and the reflected radio wave.
According to the invention described in item (9) above, it is possible to analyze the frequency of vibration of the object to be measured based on a signal including information related to the phase between the transmitted radio wave and the reflected radio wave.

According to the invention described in the above item (10), since radio waves are used for measurement, vibration measurement of an object can be performed in a non-contact manner without performing a complicated operation such as attaching a reflective seal to an object that does not reflect a laser. It becomes possible. Further, since the antenna is disposed inside the radio wave reflection means and in the vicinity of the radio wave transmission means, the signal reception intensity is high and the sensitivity is high, and a sufficient signal for vibration measurement from the received radio wave can be extracted. As a result, highly accurate vibration measurement is possible.
According to the invention described in item (11) above, it is possible to analyze the frequency of vibration of the object to be measured based on a signal including information on the phase difference between the transmitted radio wave and the reflected radio wave.

Example 1
Hereinafter, a vibration detecting element and a vibration measuring apparatus according to Embodiment 1 of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of the vibration measuring apparatus 1.
As shown in FIG. 1, the vibration measuring apparatus 1 includes a radio wave transmission means 2, an electromagnetic horn antenna 3, a four comb antenna 4, a transistor 5, a reactance 6, a power supply voltage 7, and a frequency analysis means 8. The comb antenna 4, the transistor 5, and the reactance 6 are disposed inside the electromagnetic horn antenna 3.

The base of the transistor 5 is connected to the four comb antennas 4, the collector is connected to the reactance 6, and the emitter is grounded. The other end of the reactance 6 is connected to the positive side of the power supply voltage 7.
The radio wave transmitting means 2 is disposed at one end (base) of the electromagnetic horn antenna 3 so that the transmitted radio wave is directed toward the opening end of the electromagnetic horn antenna 3, and transmits a radio wave having a frequency of 10 GHz to the object to be measured. To do.

The electromagnetic horn antenna 3 is used as a radio wave reflecting means and efficiently collects radio waves.
The four comb antennas 4 receive outgoing radio waves and reflected radio waves.
The transistor 5 detects a signal including phase difference information between the received transmitted radio wave and the received radio wave.
The reactance 6 outputs the detected signal to the frequency analysis means 8.
The power supply voltage 7 is used to output a signal.
The frequency analysis means 8 performs known frequency analysis such as fast Fourier analysis on the output signal.
The radio wave transmitting means 2, the electromagnetic horn antenna 3, the four comb antenna 4, and the transistor 5 constitute a vibration detecting element.

The transmitted radio wave transmitted by the radio wave transmitting means 2 and the reflected radio wave reflected from the object to be measured are received by the four comb antennas 4. A signal including phase difference information between the transmitted radio wave and the reflected radio wave is detected by the transistor 5 and output to the frequency analysis means 8 using the power supply voltage 7.
Next, the relationship between the transmitted radio wave and the reflected radio wave when the radio wave is transmitted to the measurement target object 10 (hereinafter also simply referred to as an object) will be described with reference to FIG.

  When a radio wave 15 having a frequency of 10 GHz is transmitted from the radio wave transmission means 2 toward the object 10 (in this embodiment, an apple), it is received by the four comb antennas 4 and applied to the object 10. The transmitted radio wave 15 applied to the object 10 is reflected, and the reflected radio wave 16 that is the reflected wave is received by the four comb antennas 4.

Next, the measurement principle of the vibration measuring apparatus 1 will be described with reference to FIGS.
FIG. 3 is a diagram showing details of the four comb antenna 4.
In this embodiment, a radio wave having a frequency of 10 GHz is used. Since the wavelength of the radio wave having the frequency is about 3.0 cm, the antenna elements 30 to 33 are connected to the four comb antennas 4 in a ladder shape at intervals of a half wavelength (about 1.5 cm). The antenna elements 34 to 37 are connected in a ladder shape so as to face the antenna elements 30 to 33.

  When radio waves are transmitted from the radio wave transmitting means 2, the transmitted radio waves 15 are received by the four comb antennas 4 and simultaneously projected onto the object 10. The projected radio wave is reflected on the surface of the object 10, and the reflected radio wave 16 that is the reflected wave is received by the four comb antennas 4.

の信号が受信される。 When the transmission radio wave 15 is received by the four comb antennas 4, the antenna element 30

Are received.

の信号が受信される。 In the antenna element 31 separated by half a wavelength (about 1.5 cm),

Are received.

の信号が受信される。 In the antenna element 32 and the antenna element 33, respectively.

Are received.

で表される信号が得られる。 When the signals received by the antenna elements 31 to 33 are propagated to the position of the antenna element 30, the phases are delayed by π, 2π, and 3π, respectively.
Therefore, at the position of the antenna element 30, as shown in FIG.

Is obtained.

の信号が受信される。 On the other hand, when the transmission radio wave 15 is applied to the object 10, the reflected position changes due to the vibration of the object and receives a phase change. It is assumed that a change in phase represented by ψ is received at the position of the antenna element 34.
When the reflected radio wave 16 is received by the four comb antennas 4,
In the antenna element 34,

Are received.

の信号がそれぞれ受信される。 In the antenna elements 35, 36 and 37,

Are respectively received.

の信号が得られる。 When signals respectively received by the antenna elements 30 to 33 are propagated to the antenna element 34,
As the phase advances by π, 2π, and 3π, respectively, at the position of the antenna element 34, as shown in FIG.

Is obtained.

And the total I of the two signals is

とおくと、

となる。 here,

After all,

It becomes.

となり、出力効率をαとすると

となる。つまり、位相差（ψ）に従った出力（振動強度）が得られ、（a-b）＞０の場合、ψが２π毎に値が最低となる。 This is a signal including phase difference information, and this signal is detected (rectified) by the transistor 5.
The output after rectifying and smoothing the signal is as shown in FIG.

If the output efficiency is α

It becomes. That is, an output (vibration intensity) according to the phase difference (ψ) is obtained, and when (ab)> 0, ψ has the lowest value every 2π.

This is shown in FIG.
FIG. 6 is a graph in which the position of the radio wave transmitting means 2 is changed and the relationship between the position of the radio wave transmitting means 2 from the object (horizontal axis) and the vibration intensity (vertical axis) is measured. Since the radio wave goes back and forth, the phase 2π corresponds to a half wavelength as a distance. Therefore, since the frequency of the transmitted radio wave is 10 GHz, the value of the vibration intensity becomes the lowest every half wavelength (about 1.5 cm).
The amplitude of the rectified signal is proportional to a + b when ψ is zero, and is proportional to a−b when ψ is π.

  Finally, the vibration of the object 10 is analyzed by performing known frequency analysis such as fast Fourier analysis on the rectified and smoothed signal by the frequency analysis means 8.

Next, the measurement result when the vibration characteristic of the watermelon is measured using the vibration measuring device 1 will be described.
As shown in FIG. 7, the watermelon 40 is placed on the vibration exciter 41 and vibrations of 10 MHz to 100 MHz are applied, and the vibrations are measured by the vibration measuring device 1 to perform fast Fourier analysis.
FIG. 8 is a graph showing the vibration of the watermelon measured by the above method.
As can be seen from FIG. 8, the second, third, and fourth resonance peaks peculiar to watermelon were observed at the frequency 190 point 45, the frequency 230 point 46, and the frequency 350 MHz point 47.

In this embodiment, a four comb antenna is used as an antenna. However, the present invention is not limited to this. For example, a folded dipole antenna 50 shown in FIG. 9 or an antenna having another shape may be used.
In this embodiment, a radio wave having a frequency of 10 GHz is used. However, the present invention is not limited to this, and a radio wave having any frequency may be used as long as the frequency is in the range of 5 GHz to 30 GHz.
Further, although the transistor 5 and the reactance 6 are arranged inside the electromagnetic horn antenna 3, they may be arranged outside the electromagnetic horn antenna 3.

As described above, the vibration detecting element and the vibration measuring device according to the first embodiment have the following effects.
First, since radio waves are used for measurement, it is possible to detect and measure vibrations of an object in a non-contact manner without the trouble of attaching a reflective sticker to an object that does not reflect a laser.
Secondly, since it is not necessary to attach a reflective seal, it is possible to eliminate the possibility that the vibration of the object cannot be measured accurately depending on how the reflective seal is applied.

  Third, since a signal including information on the phase difference between the transmitted radio wave and the reflected radio wave is detected by the class C amplifier circuit of the transistor, high demodulation efficiency can be obtained.

Fourthly, since the receiving four comb antennas 4 are arranged in the vicinity of the radio wave transmitting means 2 and in the electromagnetic horn antenna 3 where the reflected radio waves gather, the reception intensity of the transmitted radio waves and the reflected radio waves is increased. High sensitivity. As a result, a sufficient signal for vibration measurement from the received radio wave can be extracted, so that vibration measurement with high accuracy is possible.
(Example 2)
Next, a vibration detecting element and a vibration measuring apparatus according to Embodiment 2 of the present invention will be described with reference to the drawings.

  In Example 1, the transmitted and reflected radio waves were received by the four comb antennas, and the detection was performed by the transistor. In the second embodiment, radio waves are received and detected using a bridge circuit in which four diodes are bridge-coupled and two tuning circuits.

  FIG. 10 is a diagram showing a configuration of a detection circuit provided in the vibration detection element used in this embodiment. As shown in FIG. 10, the detection circuit includes two tuning circuits 51 and 52 shared with the antenna in a bridge circuit 53 in which four diodes are bridge-coupled, and the tuning circuit 51 is input to the bridge circuit 53. The tuning circuit 52 is connected to the output side of the bridge circuit 53.

FIG. 11 is a diagram showing the configuration of the vibration detecting element used in this embodiment.
As shown in FIG. 11, a reflector 54 formed by making a pair of conductor plates into a U shape inside the electromagnetic horn antenna 3 is disposed, and the radio wave transmitting means 2 is disposed at one end (base) of the electromagnetic horn antenna 3. Is arranged.

  A tuning circuit 51 is disposed in a space where the angle formed by the reflector 54 is an acute angle, and a tuning circuit 52 is disposed in a space where the angle formed by the reflector is an obtuse angle. One end of the tuning circuit 51 is grounded to the reflector 54. The transmitted radio wave is used as a reference for phase detection, and the phase of the reflected signal with respect to that signal is detected by a detection circuit. The reflector 54 is arranged to isolate the control signal and the reflected signal.

A signal is input to one tuning circuit, a reference signal is input to the other tuning circuit, and a phase signal is extracted and output by a balanced demodulation circuit. The output signal is obtained from the midpoint of the two tuning circuits, and the output signal line is drawn in a direction perpendicular to the polarization of the radio wave so that there is no interference.
Note that the configuration of the vibration measuring device provided with the vibration detecting element and the method of vibration measurement using the vibration measuring device are the same as those in the first embodiment, and are omitted here.
As described above, the vibration detecting element and the vibration measuring apparatus according to the second embodiment have the following effects.

First, since radio waves are used for measurement, it is possible to detect and measure vibrations of an object without contact with an object that does not reflect a laser without a trouble of attaching a reflective seal.
Secondly, since it is not necessary to attach a reflective seal, it is possible to eliminate the possibility that the vibration of the object cannot be measured accurately depending on how the reflective seal is applied.
Third, by combining the reflector 54, the tuning circuits 51 and 52, and the bridge circuit 53, a high demodulation rate can be realized.

Fourthly, since the tuning circuit shared with the antenna is arranged in the vicinity of the radio wave transmitting means 2 and in the electromagnetic horn antenna 3 where the reflected radio waves are collected, the reception intensity of the received radio wave is increased and the sensitivity can be increased. As a result, a sufficient signal for vibration measurement from the received radio wave can be extracted, so that vibration measurement with high accuracy is possible.
(Example 3)
Next, a vibration detecting element and a vibration measuring apparatus according to Embodiment 3 of the present invention will be described with reference to the drawings.

In this embodiment, a multi-dipole antenna 60 is used as an antenna and a detection diode 61 is connected.
FIG. 12 is a diagram showing a configuration of a vibration detection element used in the present embodiment.
The vibration detection element includes a radio wave transmission means 2, an electromagnetic horn antenna 3, a multiple dipole antenna 60, and a diode 61. A multiple dipole antenna 60 and a diode 61 are disposed inside the electromagnetic horn antenna 3, and the radio wave emitting means 2 is disposed at one end (base) of the electromagnetic horn antenna 3.

Multiple dipole antenna 60 has multiple antennas in order to increase demodulation efficiency.
The transmitted radio wave and the reflected radio wave transmitted from the radio wave transmitting means 2 are received by the multiple dipole antenna 60, and a signal including phase difference information is detected (rectified) by the diode 61.
Note that the configuration of the vibration measuring device provided with the vibration detecting element and the method of vibration measurement using the vibration measuring device are the same as those in the first embodiment, and are omitted here.
In the present embodiment, the diode 61 is disposed inside the electromagnetic horn antenna 3. However, the diode 61 may be disposed outside the electromagnetic horn antenna 3.

The vibration detecting element and the vibration measuring device according to the third embodiment have the following effects.
First, since radio waves are used for the measurement, it is possible to detect and measure the vibration of the object in a non-contact manner without the trouble of attaching a reflective sticker to an object that does not reflect the laser.
Secondly, since it is not necessary to attach a reflective seal, it is possible to eliminate the possibility that the vibration of the object cannot be measured accurately depending on how the reflective seal is applied.

Third, a high demodulation rate can be obtained by combining the multiple dipole antenna 60 and the diode 61.
Fourthly, since the multiple dipole antenna 60 is disposed in the vicinity of the radio wave transmitting means 2 and in the electromagnetic horn antenna 3 where the reflected radio waves are collected, the receiving intensity of the transmitted radio waves and the reflected radio waves is increased and the sensitivity can be increased. As a result, a sufficient signal for vibration measurement from the received radio wave can be extracted, so that vibration measurement with high accuracy is possible.

  In the first embodiment, the second embodiment, and the third embodiment, detection is performed using a transistor, a diode, or the like. However, detection may be performed using an active element other than this.

  The vibration detecting element, the vibration measuring device and the vibration measuring method according to the present invention can measure the vibration of soft organisms such as fruits and vegetables, in particular, organisms that are difficult to reflect laser light, so that the quality of the fruits and vegetables is not contacted. It is useful as a sorting machine to be inspected and a growth monitoring sensor for growing fruits and vegetables. Moreover, it is useful also for the quality measuring device which can measure the quality of living organisms other than fruits and vegetables, such as a tree and wood, without contact. Furthermore, the application of measuring the internal deterioration and structure of an artificial building structure such as concrete is also possible.

It is the figure which showed the structure of the vibration detection element and vibration measuring apparatus which concern on Example 1. FIG. It is the figure which showed the positional relationship of the vibration measuring device which concerns on Example 1, and the object of a measuring object. It is the figure which showed the phase at the time of a transmission radio wave and a reflected radio wave being received by each antenna element. It is the figure which showed the phase of the synthesized signal in the position of a transistor. It is the figure which showed the output in the position of a transistor with the vector. It is the figure which showed the relationship between the position of a radio wave transmission means, and a vibration output. It is a figure at the time of measuring the vibration of a watermelon using the vibration measuring apparatus which concerns on Example 1. FIG. It is the figure which showed the vibration spectrum of the watermelon measured with the vibration measuring apparatus which concerns on Example 1. FIG. The antenna of the vibration detection element according to Example 1 is a folded dipole antenna. 6 is a diagram illustrating a detection circuit used in a vibration detection element according to Embodiment 2. FIG. 6 is a diagram illustrating a vibration detecting element according to Example 2. FIG. 6 is a diagram illustrating a vibration detection element according to Example 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vibration measuring apparatus 2 ... Radio wave transmission means 3 ... Electromagnetic horn antenna 4 ... 4 comb antenna 5 ... Transistor 6 ... Reactance 7 ... Power supply voltage 8 ... Frequency analysis means

Claims (11)

A cylindrical radio wave reflecting means having at least one end opened;
Radio wave transmission means attached to one end of the radio wave reflection means so that the transmitted radio wave is directed toward the opening end;
An antenna that is disposed in the vicinity of the radio wave transmission means and inside the radio wave reflection means, receives the radio waves transmitted from the radio wave transmission means, and receives the reflected radio waves reflected by the object to be measured.
A transistor for detecting a signal including information on the phase of the transmitted radio wave and the reflected radio wave received by the antenna;
A vibration detecting element comprising:   The vibration detecting element according to claim 1, wherein the antenna has a comb shape.   The vibration detecting element according to claim 1, wherein the antenna is a folded dipole antenna. A cylindrical radio wave reflecting means having at least one end opened;
Radio wave transmission means attached to one end of the radio wave reflection means so that the transmitted radio wave is directed toward the opening end;
A dipole antenna that is disposed in the vicinity of the radio wave transmission means and inside the radio wave reflection means, receives a radio wave transmitted from the radio wave transmission means, and receives a reflected radio wave reflected by the object to be measured.
A diode for detecting a signal including information on the phase of the transmitted radio wave and the reflected radio wave received by the dipole antenna;
A vibration detecting element comprising: A cylindrical radio wave reflecting means having at least one end opened;
Radio wave transmission means attached to one end of the radio wave reflection means so that the transmitted radio wave is directed toward the opening end;
A bridge circuit in which four diodes are bridge-coupled, a first tuning circuit connected to the input side of the bridge circuit, a second tuning circuit connected to the output side of the bridge circuit, the inside of the radio wave reflecting means, and radio wave transmission A reflector disposed in the vicinity of the means and formed in a U shape by a pair of conductor plates;
With
The vibration detecting element, wherein the first tuning circuit is disposed in a space on the side where the angle formed by the reflector is an acute angle, and the second tuning circuit is disposed in a space on the side where the angle formed by the reflector is an obtuse angle.   6. The vibration detecting element according to claim 1, wherein the radio wave reflecting means is an electromagnetic horn antenna.   The vibration detecting element according to any one of claims 1 to 6, wherein a frequency of a radio wave transmitted from the radio wave transmitting means is in a range of 5 GHz to 30 GHz.   The vibration detection element according to claim 1, wherein the signal including information on the phase is a signal including information on a phase difference between the transmitted radio wave and the reflected radio wave. The vibration detection element according to any one of claims 1 to 8,
A frequency analysis means for frequency analysis of a signal including information on the phase;
A vibration measuring apparatus comprising: A first step of transmitting radio waves to an object to be measured;
An antenna disposed in the vicinity of the radio wave transmission means and inside the radio wave reflection means receives the radio wave transmitted in the first step and receives the reflected radio wave reflected by the object to be measured. Two steps;
A third step of detecting, with a transistor, a signal including information on the phase of the transmitted radio wave and the received radio wave received in the second step;
A fourth step of performing frequency analysis on a signal including information on the phase detected in the third step;
A vibration measuring method comprising:   The vibration measurement method according to claim 10, wherein the signal including information on the phase is a signal including information on a phase difference between the transmission radio wave and the reception radio wave.

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