JP2000258529A - Movement detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a movement detecting device by which a very small movement can be detected with high accuracy. SOLUTION: A high-frequency signal is generated by an oscillation means 22 in synchronization with a reference signal which is generated by a reference- signal generation means 21. The high-frequency signal is radiated from an antenna 20 as high-frequency electromagnetic waves. Then, reflected waves which are reflected by an object are received by the antenna 20, and they are transmitted by a circulator 24 to a phase comparison means 23. The phase comparison means 23 is a phase comparator, of a superheterodyne system, by which the frequency of a local oscillator signal generated in such a way that the phase of the reference signal generated by the reference-signal generation means 21 is used as a reference is set as a local oscillation frequency. A phase comparison result is wavelet-conversion-processed by a signal processing means 25. A high-frequency noise component at a cycle which is sufficiently separated from the cycle of the movement of the object, a modulating signal component which is modulated by the movement of the object and a noise signal component at a frequency near the modulating signal component are separated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motion detecting device, and more particularly, to a motion detecting device for detecting a motion of an object using high-frequency electromagnetic waves.

[0002]

2. Description of the Related Art Conventionally, this kind of motion detecting apparatus has an antenna, and radiates a high-frequency electromagnetic wave from the antenna to a target object. The antenna receives reflected signals from a target object and objects around the target object. The motion detection device detects the motion of the target object by compensating for a reflected signal from an object that does not move around.

FIG. 7 shows an outline of the configuration of a conventionally proposed motion detecting device. In this motion detection device,
The high-frequency sine wave signal generated by the oscillator 10 is divided into equal powers by the first power divider 11 and supplied to the second power divider 12 and the phase comparator 13, respectively. The second power divider 12 further divides the sine wave signal supplied from the first power divider 11 into equal powers, and supplies the equal power to the circulator 14 and the amplitude / phase compensation circuit 15. The circulator 14 is connected to the antenna 16 and the adder 17, and can transmit the transmission power from the second power divider 12 to the antenna 13 and the reception power from the antenna 16 to the adder 17, respectively. It has become. The amplitude / phase compensation circuit 15 adjusts the amplitude and phase of the transmission sine wave so that the reception signal has the same amplitude and opposite phase, and supplies this to the adder 17. The antenna 16 radiates the transmission power supplied from the circulator 14 as high-frequency electromagnetic waves and receives the reflected waves. The adder 17 adds the transmission signal having the same amplitude and opposite phase to the reception signal supplied from the circulator 14 and the reception signal supplied from the amplitude / phase compensation circuit 15. The result of this addition is supplied to the phase comparator 13 where the phase of the addition result of the adder 17 is compared with the phase of the high-frequency sine wave equally divided by the first power divider 11. The fast Fourier transform means 18 performs a fast Fourier transform on the comparison result to obtain a signal spectrum. The spectrum display means 19 displays the signal spectrum.

[0004] A conventional motion detecting device having such a configuration is as follows.
The high-frequency sine wave signal generated by the oscillator 10 is emitted from the antenna 16 via the circulator 14, and the antenna 16 receives a reflected wave near the target. This reflected wave is input to the adder 17 via the circulator 14. The transmission high-frequency sine wave signal divided from the transmission side has the same amplitude as the reception signal in the adder 17.
It is input as an opposite phase, and by adding this to the reflected wave, the component of the reflected wave from the stationary object is removed, and the phase comparator 13 compares the phase with the transmitted high-frequency sine wave signal, thereby moving. Only the reflected wave component modulated upon hitting the object is extracted. The motion of the object extracted in this way is converted to the fast Fourier transform processing means 18.
, And is displayed on the spectrum display means 19 as a signal spectrum.

[0005] Techniques relating to such a motion detection device include:
For example, it is disclosed in Japanese Patent Application Laid-Open No. 9-304525, entitled "Moving Object Detection Device".

[0006]

However, the motion detecting apparatus proposed in the prior art requires a compensating circuit for compensating a reflected signal from an object which does not move around as described above. Even if the reflected signal is compensated for, if there are a plurality of moving objects, only a combination of modulated signals from the respective objects is detected. In other words, the use of a compensation circuit is useful because the dynamic range of the receiver does not need to be wide, but on the other hand, it can be used only as an additional circuit to extract signals from a moving object. Had been. Therefore, when there are a plurality of moving objects, the extracted signal cannot be displayed as a waveform or the spectrum display cannot be used to determine the movement of the target object, and only a low-reliability detection result is obtained. I couldn't. Also, when there are multiple objects that do not move and the distance from each antenna is different, the phase difference determined by the distance from the antenna and the wavelength is different for each reflected wave,
The received signal is a signal obtained by combining a plurality of sine wave signals having the same frequency but shifted in phase. Therefore, the phase of the received signal changes irregularly in a short time, and the compensation circuit cannot always follow this change effectively.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a motion detecting device which detects minute motion with high accuracy without using the above-mentioned compensation circuit.

[0008]

According to the first aspect of the present invention, there is provided (a) reference signal generating means for generating a reference signal;
(B) an oscillation signal generation means for generating an oscillation signal in synchronization with the phase of the reference signal generated by the reference signal generation means; and (c) a predetermined oscillation signal generated by the oscillation signal generation means as an electromagnetic wave. (D) comparing the phase of the reflected wave received by the antenna with the phase of the reference signal by radiating to the target and receiving the reflected wave of the electromagnetic wave reflected by the target; Phase comparison means for extracting a modulation signal component modulated by the movement of the object; and (e) a modulation signal component of the frequency of the movement of the target object by subjecting the modulation signal component extracted by the phase comparison means to a wavelet transform. And a signal processing means for separating the signal into noise signal components near the frequency.

In other words, according to the first aspect of the present invention, the oscillation signal generated by the oscillation signal generation means in synchronization with the phase of the reference signal generated by the reference signal generation means from the antenna is used as an electromagnetic wave for a predetermined target. The electromagnetic wave is radiated, and a reflected wave reflected by the electromagnetic wave hitting the target is received. Then, by comparing the phase of the reflected wave with the phase of the reference signal by the phase comparing means, a phase modulation component due to the movement of the target object is extracted. Further, a wavelet transform process is performed on the phase modulation component extracted by the signal processing means, and further, the frequency of the motion of the target object that cannot be removed by a normal filter and a noise component near the frequency are separated, and an accurate target Only the modulation signal component due to the movement of the object is detected.

According to the second aspect of the present invention, (a) reference signal generating means for generating a reference signal, and (b) an oscillation signal is generated in synchronization with the phase of the reference signal generated by the reference signal generating means. Oscillation signal generation means, (c) division means for dividing the oscillation signal generated by the oscillation signal generation means, and (d) one of the oscillation signals divided by the division means as an electromagnetic wave to a predetermined target. And (e) comparing the phase of the reflected wave received by this antenna with the phase of the other oscillation signal divided by the dividing means. Phase comparing means for extracting a modulated signal component modulated by the movement of the target object, and (f) extracting the modulated signal component extracted by the phase comparing means. And signal processing means for separating the modulated signal component of the frequency of the motion of the target and the noise signal component of the frequency neighborhood is provided to the motion detection device by Eburetto conversion.

That is, according to the second aspect of the present invention, the oscillation signal generated by the oscillation signal generation means is divided by the division means based on the reference signal generated by the reference signal generation means. Then, one of the oscillation signals split by the splitting means is radiated from the antenna to a predetermined target as an electromagnetic wave, and a reflected wave reflected by the electromagnetic wave hitting the target is received. The phase comparing means directly compares the phase of the reflected wave with the phase of the other oscillation signal divided by the dividing means,
The phase modulation component due to the movement of the target object is extracted. Further, by performing a wavelet transform process on the phase modulation component extracted by the signal processing means,
Further, the frequency of the movement of the target that cannot be removed by a normal filter and a noise component near the frequency are separated, and only the modulated signal component due to the accurate movement of the target is detected.

According to a third aspect of the present invention, in the motion detecting device according to the first aspect, the phase comparing means generates the first local oscillator signal in synchronization with the phase of the reference signal generated by the reference signal generating means. A first local oscillator for converting the frequency of the reflected wave received by the antenna into a first intermediate frequency based on the frequency of the first local oscillator signal generated by the first local oscillator; A first frequency converting means for extracting a component, and a frequency of the received signal from which the first intermediate frequency component is extracted by the first frequency converting means is converted to a second intermediate frequency based on the frequency of the reference signal. A second frequency converting means for extracting an intermediate frequency component.

That is, according to the third aspect of the present invention, the first local oscillator generates the first local oscillator signal in synchronization with the phase of the reference signal generated by the reference signal generator, and the first intermediate frequency converter generates the first local oscillator signal. By converting the frequency of the reflected wave received by the antenna to a first intermediate frequency based on the frequency of the first local oscillator signal generated by the first local oscillator, and extracting the first intermediate frequency component, High frequency noise components included in the signal received from the antenna are removed. Further, the frequency of the received signal from which the first intermediate frequency component has been extracted by the first frequency converting unit is converted into a second intermediate frequency based on the frequency of the reference signal by the second frequency converting unit, and this second intermediate frequency component is converted. By extracting, a modulation signal component due to the movement of the target is extracted.

According to a fourth aspect of the present invention, in the motion detection device according to the first aspect, the phase comparing means generates the first local oscillator signal in synchronization with the phase of the reference signal generated by the reference signal generating means. The first local oscillation means and the second local oscillation means synchronize with the phase of the reference signal generated by the reference signal generation means.
A second local oscillator for generating a local oscillator signal; and a frequency converter for converting a frequency of the reflected wave received by the antenna into a first intermediate frequency based on a frequency of the first local oscillator signal generated by the first local oscillator. First frequency converting means for extracting the first intermediate frequency component, and a second local oscillator for generating the frequency of the received signal from which the first intermediate frequency component has been extracted by the first frequency converting means by the second local transmitting means A second intermediate frequency for converting the frequency to a second intermediate frequency based on the frequency of the signal and extracting the second intermediate frequency component;
Frequency conversion means.

That is, in the present invention, the first and second local oscillators generate the first and second local oscillator signals in synchronization with the phase of the reference signal generated by the reference signal generator. (1) The frequency of the reflected wave received by the antenna by the intermediate frequency converting means is converted into a first intermediate frequency based on the frequency of the first local oscillator signal generated by the first local oscillator, and the first intermediate frequency component is converted. To extract high-frequency noise components included in the signal received from the antenna. Further, the frequency of the received signal from which the first intermediate frequency component has been extracted by the first frequency converting means is converted by the second frequency converting means into a second intermediate frequency based on the frequency of the second local oscillator signal. By extracting the frequency component, a modulation signal component due to the movement of the target is extracted. Thus, the frequency of the local oscillator signal can be set relatively freely. Therefore, design can be facilitated and cost can be reduced.

According to a fifth aspect of the present invention, in the motion detection device according to the first aspect, the phase comparing means generates the first local oscillator signal in synchronization with the phase of the reference signal generated by the reference signal generating means. The first local oscillation means and the second local oscillation means synchronize with the phase of the reference signal generated by the reference signal generation means.
A second local oscillator for generating a local oscillator signal; and a frequency converter for converting a frequency of the reflected wave received by the antenna into a first intermediate frequency based on a frequency of the first local oscillator signal generated by the first local oscillator. First frequency converting means for extracting the first intermediate frequency component, and a second local oscillator for generating the frequency of the received signal from which the first intermediate frequency component has been extracted by the first frequency converting means by the second local transmitting means A second intermediate frequency for converting the frequency to a second intermediate frequency based on the frequency of the signal and extracting the second intermediate frequency component;
Frequency converting means for converting the frequency of the received signal from which the second intermediate frequency component has been extracted by the second frequency converting means into a third intermediate frequency based on the frequency of the reference signal, and extracting the third intermediate frequency component And a third frequency conversion unit.

That is, in the present invention, the first and second local oscillators generate the first and second local oscillator signals in synchronization with the phase of the reference signal generated by the reference signal generator. (1) The frequency of the reflected wave received by the antenna by the intermediate frequency converting means is converted into a first intermediate frequency based on the frequency of the first local oscillator signal generated by the first local oscillator, and the first intermediate frequency component is converted. To extract high-frequency noise components included in the signal received from the antenna. Further, the frequency of the received signal from which the first intermediate frequency component has been extracted by the first frequency converting means is converted by the second frequency converting means into a second intermediate frequency based on the frequency of the second local oscillator signal. By extracting frequency components, frequency selectivity and detection sensitivity can be further improved. Further, the third frequency converter converts the frequency of the received signal from which the second intermediate frequency component is extracted by the second frequency converter into a third intermediate frequency based on the frequency of the reference signal, and converts the frequency into a third intermediate frequency. By extracting the modulation signal component due to the movement of the target.

According to a sixth aspect of the present invention, in the motion detecting device according to the second aspect, the phase comparing means divides the frequency of the reflected wave received by the antenna based on the frequency of the other oscillation signal divided by the dividing means. It is characterized in that the frequency is converted to a first intermediate frequency and the first intermediate frequency component is extracted.

That is, according to the present invention, the direct transmission signal and the reception signal are converted into the first intermediate frequency and the phases are compared with each other. A highly accurate modulated signal can be detected by the wavelet transform of the processing means, and the apparatus can be simplified and downsized.

According to a seventh aspect of the present invention, in the motion detection device according to the third aspect, the first and second frequency conversion means are first and second mixers, and the frequency of the oscillation signal and the first
The difference between the frequency of the local oscillator signal and the frequency of the reference signal is matched.

According to an eighth aspect of the present invention, in the motion detecting device according to the fourth aspect, the first and second frequency conversion means are first and second mixers, and the frequency of the oscillation signal and the first
The difference between the frequency of the local oscillator signal and the frequency of the second local oscillator signal reference signal is matched.

According to a ninth aspect of the present invention, in the motion detecting apparatus according to the fifth aspect, the third frequency converting means is a third mixer, and the second intermediate frequency component is extracted by the second frequency converting means. The frequency of the received signal and the frequency of the reference signal are matched.

In other words, in the inventions according to the seventh to ninth aspects, the phase modulation signal component is compared with each other so that the respective frequencies are substantially matched, so that the phase modulation signal component can be detected with higher sensitivity. it can.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments.

First Embodiment

FIG. 1 shows an outline of a principle configuration of a motion detecting apparatus according to a first embodiment of the present invention. The motion detection device includes an antenna 20, radiates a high-frequency electromagnetic wave from the antenna 20 around a target object, and receives a reflected wave from the object. Further, the motion detection device includes a reference signal generation unit 21 that generates a reference signal;
Oscillating means 22 for generating a high-frequency signal for radiating an electromagnetic wave to an object in synchronization with the phase of the reference signal generated by the reference signal generating means 21, and transmitting the high-frequency signal generated by the oscillating means 22 to the antenna 20. The phase comparing means 23 transmits and receives the signal from the antenna 20.
And a circulator 24 for transmission to the Further, a phase comparison unit 23 that performs a phase comparison of the received signal transmitted from the circulator 24 based on the reference signal generated by the reference signal generation unit 21, and performs signal processing on the phase comparison result of the phase comparison unit 23. And a signal processing means 25 for performing the processing.

In the motion detecting apparatus having such a configuration, a high-frequency signal is generated by an oscillating unit 22 in synchronization with the phase of a reference signal generated by a reference signal generating unit 21, and the high-frequency signal is converted to a high-frequency electromagnetic wave via a circulator 23. 2
Radiates from 0 to around the target object. The high-frequency electromagnetic wave radiated from the antenna 20 is reflected by a minute movement having a period of about several hertz (Hz), or an object having vibration or an object having no movement around the object. This motion detection device receives this as a reflected wave by the antenna 20. When a reflected wave is received by the antenna 20, the circulator 24 transmits the received signal to the phase comparing means 23. The phase comparison means 23 is a reference signal generation means 2
1 is a superheterodyne type phase comparator that uses the frequency of a local oscillator signal generated based on the phase of the reference signal generated by the reference signal 1 as a local oscillation frequency. A high frequency noise component having a distant cycle is removed, and this is detected as a modulated signal modulated by the movement of the target object. The modulated signal detected in this way is further processed by the signal processing means 2.
5, a wavelet transform process is performed to separate a modulated signal component modulated by the motion of the target object from a noise signal component that cannot be completely removed by normal filter processing at a frequency near the modulated signal component. Only the modulated signal component is effectively extracted. Accordingly, it is possible to effectively and accurately extract only a modulation signal component generated by a moving object without providing a conventional compensation circuit.

Hereinafter, the motion detecting apparatus according to the first embodiment will be described in detail.

FIG. 2 specifically shows the main components of the motion detecting apparatus according to the first embodiment. The motion detection device includes an antenna 30 that receives radiation of a high-frequency electromagnetic wave and a reflected wave thereof, an oscillator 31 that generates a high-frequency signal for generating a high-frequency electromagnetic wave radiated from the antenna 30, and an antenna 30 that receives the signal. Receiver 3 for detecting a modulated signal component modulated by the motion of an object from a reflected wave
2 is provided. Further, a circulator 33 is provided, and a high-frequency signal from the oscillator 31 is transmitted to the antenna 3.
0, and the reflected wave received by the antenna 30 can be transmitted to the receiver 32 as a reception signal. The receiver 32 has a superheterodyne phase comparator, and includes a second local oscillator 34 that generates a reference signal serving as a phase reference of a local oscillator signal having the local oscillation frequency. The reference signal generated by the second local oscillator 34 is supplied to the oscillator 31.

Further, the motion detecting device converts the modulated signal detected by the receiver 32 into a digital signal (Analog-Digital Converte).
r: hereinafter abbreviated as AD converter. ) 35 and this AD
A wavelet transform processing means 36 for performing a wavelet transform process on the digital signal converted by the converter 35;
Display means 37 for displaying a waveform of the result of the conversion process
And Further, the motion detection device includes a Fourier transform processing means 38 for performing a fast Fourier transform on the modulated signal component extracted by the wavelet transform processing means 36, and a spectrum display means for displaying a signal spectrum obtained by the fast Fourier transform processing means 38. 39.

The oscillator 31 includes a first oscillator 40 and a second phase-locked loop (hereinafter, abbreviated as PLL) circuit 41. Second PLL circuit 41
Receives the reference signal generated by the second local oscillator 34 of the receiver 32, synchronizes with the phase of the reference signal,
A first oscillator reference signal having the frequency of the reference signal is supplied to the first oscillator 40. The first oscillator 40 is synchronized with the phase of the first oscillator reference signal and generates a predetermined high-frequency sine wave signal according to the frequency. The high frequency sine wave signal generated by the first oscillator 40
And is radiated from the antenna 30 as high-frequency electromagnetic waves.

The receiver 32 includes a first PLL circuit 42 for generating a first local oscillator reference signal having the frequency of the reference signal in synchronization with the phase of the reference signal generated by the second local oscillator 34, and the first PLL circuit. A first local oscillator that is synchronized with the first local oscillator reference signal generated by the circuit and generates a local oscillator signal having a predetermined frequency according to the frequency. Also, the receiver 32
The first low noise amplifier 44 amplifies the received signal input from the circulator 33 with low noise, and the local oscillator signal generated by the first local oscillator 43 is input and amplified by the first low noise amplifier 44. A first mixer 45 for converting the frequency of the signal to a first intermediate frequency;
A first filter 46 is connected to the first mixer 45 and is a narrow band-pass filter having a first intermediate frequency as a pass band. Further, a second low-noise amplifier 47 amplifies the signal selected by the first filter 46 with low noise, and a signal to which a reference signal generated by the second local oscillator 34 is input and amplified by the second low-noise amplifier 47 For detecting a desired phase modulation signal from the
A mixer 48 and a second filter 49 that is connected to the second mixer 48 and that is a low-pass filter that uses a frequency of the motion of the target object as a pass band.

Next, the operation of the motion detecting device having such a configuration will be described.

The reference signal generated by the second local oscillator 34 of the receiver 32 is connected to the second PLL circuit 4 of the oscillator 31.
1 and the first PLL circuit 42 and the second mixer 48 of the receiver 32. The second PLL circuit 41 synchronizes the first oscillator reference signal with the first signal in synchronization with the phase of the reference signal.
It is supplied to the oscillator 40. The first oscillator 40 generates a high-frequency sine wave signal having a frequency f ₀ in synchronization with the first oscillator reference signal. That is, the high-frequency sine wave signal is synchronized with the phase of the reference signal generated by the second local oscillator 34. This high frequency sine wave signal is
_Is transmitted as a transmission signal _STX from the antenna 30 to the outside through the antenna. Here, it is assumed that the transmission signal S _TX is represented on the time axis as in the following equation (1).

S _TX = cos (2πf ₀ t) (1)

This transmission signal is reflected mainly by various objects in front of the antenna 30. Of these, the reflected wave received by the antenna 30 is a composite of these multiple reflected signals. Such a reflected wave is a reflected wave from an object having motion (vibration), the reflected wave of which amplitude and phase are modulated by the motion (vibration), and a reflected wave whose object does not move like a wall, for example. It can be distinguished from a reflected wave which is a reflected wave only from a transmitted signal and which has a phase difference uniquely determined by the distance from the antenna 30 to the object and the wavelength of the transmitted signal. The former is a modulated signal, and the latter is a non-modulated signal. Here, since it is more sensitive to detect the phase modulation signal than to detect the amplitude modulation signal among the modulation signals, attention is paid only to the phase modulation signal. This phase modulation signal S
_RX is represented by the following equation (2).

S _RX = cos (2πf ₀ t + θ (t)) + cos (2πf ₀ t + φ (t)) (2)

The phase modulation signal S represented by the equation (2)
The first term of _RX shows a phase modulation signal of a reflected wave from a moving object. θ (t) is a modulation signal component due to the motion of the object. The second term of the phase modulation signal S _RX is
9 shows a phase modulation signal as a result of combining a plurality of reflected waves from a stationary object. φ (t) is a random modulated signal component that is reflected from a plurality of objects and is received at various timings due to differences in distance from the antenna 30, and is a high-frequency noise signal component.

When the phase modulated signal S _RX represented by the equation (2) is received by the antenna 30 as a reflected wave,
It is transmitted to the receiver 32 by the circulator 33.
The receiver 32 is a superheterodyne phase comparator that uses a frequency of an oscillation signal synchronized with the phase of the reference signal generated by the second local oscillator 34 as a local oscillation frequency. The reflected wave input to the receiver 32 is first amplified by the first low noise amplifier 44 and input to the first mixer 45.

Here, generated by the first local oscillator 43
The frequency of the local oscillator signal _LO1, 2nd local oscillation
The frequency of the reference signal generated by the_LO2When
Then, the local oscillator generated by the first local oscillator 43
Vibrator signal S_LO1And the reference signal S_{L O2}Is the following (3), (4)
It is assumed to be represented by an equation.

S _LO1 = cos (2πf _LO1 t)
(3) S _LO2 = cos (2πf _LO2 t) (4)

The first mixer 45 includes a first low noise amplifier 44
The product of the modulated signal amplified by the above and the local oscillator signal S _LO1 generated by the first local oscillator 43 is calculated. Then, a modulation signal of the first intermediate frequency component is detected by selecting a difference frequency component from the product. The detected modulated signal S _IF1 is expressed by the following equation (5).

S _IF1 = (1/2) [cos {2π (f ₀ −f _LO1 ) t + θ (t)} + cos {2π (f ₀ −f _LO1 ) t + φ (t)}] (5)

The modulated signal thus converted into the first intermediate frequency component by the first mixer 45 is supplied to the first filter 4
6 is input. Here, φ (t) is random noise as described above and has a high frequency component as compared with θ (t), so that a band-pass filter having an appropriate pass band width is used for the first filter 46. By applying, high-frequency components including φ (t) can be easily removed. Therefore, the first filter 46 outputs only the first term of S _IF1 expressed by the equation (5). Thereafter, the signal is input to the second low noise amplifier 47 and amplified, and the second mixer 48
Is input to

The second mixer 48 includes a second low noise amplifier 47
The product of the modulated signal amplified by the above and the reference signal S _LO2 generated by the second local oscillator 34 is calculated.
Then, a modulation signal of the second intermediate frequency component is detected by selecting a difference frequency component from the product. Here, when the relationship represented by the following equation (6) holds,
The modulated signal of the second intermediate frequency component is expressed by the following equation (7).

F ₀ −f _LO1 = f _LO2 (6) S _IF2 = (１ ／) cos (θ (t)) (7)

That is, when the relationship of the expression (6) holds, the detection signal output from the second filter 49 is expressed by the following expression (7).
As represented by the equation, only the phase modulation component modulated by the motion of the object can be detected. Therefore, the signal is input to the second filter 49, which is a low-pass filter having a pass band of the frequency represented by this equation, and
Unnecessary noise components included in _IF2 are removed, and a modulated signal component representing the motion of the target object is detected. Thus, the phase of the first local oscillator 43 and the phase of the second local oscillator 34 are synchronized. Further, the phase of the first oscillator 40 and the first
The phase of the local oscillator 43 is the same as that of the second local oscillator 34.
Phase. Therefore, the second mixer 48
Is to compare the phase of the transmission signal from the antenna 30 with the phase of the reception signal to the antenna 30, and the result of this phase comparison can be detected as a modulated signal from a moving object. However, the difference between the frequency f ₀ of the sine wave generated by the first oscillator 40 and the frequency f _LO1 of the local oscillator signal generated by the first local oscillator 43 as expressed by the equation (6) is generated by the second local oscillator 34. It is not necessary to be the same as the frequency f _LO2 of the reference signal, but if it is the same, the detection accuracy can be increased.

In the motion detecting apparatus according to the first embodiment, the signal S _IF2 having the second intermediate frequency component detected via the second mixer 49 of the receiver 32 is converted into a modulated signal θ by the second filter 49. When noise components near the frequency of (t) are included, there are cases where these components cannot be removed by the filter processing used in the conventional motion detection device. For example, if the intensity of the modulation signal due to the movement of the target object is equal to or greater than the intensity of the noise component near the frequency of the modulation signal, the noise component should be removed by conventional filtering using Fourier transform processing. However, when the noise component is larger, the modulated signal having a small signal intensity cannot be detected because it is buried in the noise floor in the conventional Fourier transform processing.

Therefore, the motion detecting apparatus according to the first embodiment includes a wavelet transform processing means 36 and a fast Fourier transform processing means 38, and performs signal processing by wavelet transform processing to detect a minute motion of a target object. I have to. That is, the phase modulation signal based on the movement of the target object detected by the receiver 32 is input to the AD converter 35. The AD converter 35 samples the phase modulated signal, converts it into a digital signal, and outputs the output digital signal to the wavelet transform processing means 36. The wavelet transform processing means 36 performs a wavelet transform on the sampled 2 ⁿ (n is a natural number) digital signals.

In the wavelet transform, 2 ⁿ digital signals are converted so as to be decomposed into basic functions called basis functions, and the signals are converted into “n + 1” frequency components. At this time, the time information of each converted signal is kept as it is. Since the digital signal thus converted is converted by a basis function, by selecting an appropriate function as the basis function, the above-described modulated signal θ (t) is separated from a noise component near the frequency. be able to. When converted into “n + 1” frequency components by the wavelet transform processing means 36, a noise component near the frequency of the separated modulated signal θ (t) is removed from the conversion result on the frequency axis, and the target object Is extracted and displayed by the waveform display means 37. Further, the modulated signal subjected to the wavelet transform by the wavelet transform processing means 36 generates a signal spectrum on the frequency axis by fast Fourier transform by the fast Fourier transform processing means 38 and displays the signal spectrum on the spectrum display means 39 to obtain the conventional spectrum. A minute movement of the target object can be detected with higher accuracy than the display. Further, since the processing result after the wavelet transform covers the frequency domain and the time domain, a signal waveform of a necessary frequency component can be obtained. Only the information of the frequency can be obtained only by the conventional Fourier transform processing, and when the signal strength of the noise component included in the detection signal is large or when the detection signal includes a plurality of frequency components, the signal to be detected is Not only cannot be determined, but also from the information only in the frequency domain, it cannot be determined whether the detected signal is always generated from the target object, and only a result with poor reliability can be obtained. However, by performing the wavelet transform processing as described above, a desired signal can be obtained as a waveform in the time domain and the frequency domain, so that the motion of the target object can be easily determined, and the reliability of the detection signal can be improved. Can be improved step by step.

As described above, the motion detecting apparatus according to the first embodiment transmits a high-frequency electromagnetic wave from the oscillator 31 via the antenna 30 in synchronization with the reference signal generated by the second local oscillator 34. The transmitted high-frequency electromagnetic wave is reflected by the object and received by the antenna 30 as a composite reflected wave such as a modulated reflected wave from a moving object or various reflected waves from a non-moving object. Antenna 30
Is received by the receiver 32 as a modulated signal. The receiver 32 employs a superheterodyne phase comparator based on the local oscillation frequency of the local oscillator signal generated by the first local oscillator 43 in synchronization with the reference signal generated by the second local oscillator. First, the first mixer 45 to which the local oscillator signal generated by the first local oscillator 43 is input is converted into a first intermediate frequency to remove a high-frequency noise signal component having a cycle sufficiently separated from the frequency of the motion of the object. The second mixer 48 to which the reference signal generated by the second local oscillator 34 is input is converted into a second intermediate frequency, and only the phase modulation signal component modulated by the motion of the object is detected. By comparing the phases of the transmission signal and the reception signal in the second mixer 48 in this manner, a phase modulation signal component modulated by a moving object is detected without using a conventional compensation circuit. . Further, the detected phase modulation signal component is decomposed by a wavelet transform means into a basic function called a basis function, and the phase modulation signal is effectively separated from a noise component in the vicinity of its frequency, thereby minimizing the minuteness of the object. It also detects unnatural movements.

Second Embodiment

The motion detecting apparatus according to the first embodiment is based on the phase of the reference signal generated by the second local oscillator 34. However, the motion detecting apparatus according to the second embodiment is provided with a reference oscillator. The frequency of the local oscillator signal input to the mixer 48 can be freely set.

FIG. 3 shows the outline of the configuration of the motion detecting apparatus according to the second embodiment of the present invention. However,
The same parts as those of the motion detection device according to the first embodiment shown in FIG. The difference between the motion detecting device of the second embodiment and the motion detecting device of the first embodiment is that the motion detecting device includes a reference oscillator 50, a second local oscillator 51 inside a receiver, and a third PLL.
The circuit 52 is provided. That is, the reference signal generated by the reference oscillator 50
Is supplied to the receiver 53. The reference signal input to the oscillator 31 is input to the second PLL circuit 41,
The L circuit 41 synchronizes with the phase of the reference signal and outputs a first oscillator reference signal having the frequency of the reference signal to the first oscillator 4.
Supply 0. On the other hand, the reference signal supplied to the receiver 53 is input to the first and third PLL circuits 42 and 52. The first PLL circuit 42 generates a first local oscillator reference signal having the frequency of the reference signal in synchronization with the phase of the reference signal generated by the reference oscillator 50, and outputs the first local oscillator reference signal to the first local oscillator 43. Third PLL circuit 52
Generates a second local oscillator reference signal at the frequency of the reference signal in synchronization with the phase of the reference signal. The second local oscillator reference signal is input to the second local oscillator 51, generates a local oscillator signal having a predetermined frequency f _LO2 , and outputs it to the second mixer 48.

The outline of the operation of such a motion detecting device is the same as the outline of the operation of the motion detecting device in the first embodiment, and the method of supplying the local oscillator signal to the second mixer 48 is different. The motion detecting apparatus according to the second embodiment includes the reference oscillator 50 provided outside the receiver 53 as described above, and transmits a transmission signal from the oscillator 31 in synchronization with the reference signal generated thereby. And the local oscillator signals of the second mixers 45 and 48.

Focusing on the second mixer 48, the frequency of the local oscillator signal from the second local oscillator 51 input to the second mixer 48 matches the frequency of the amplified modulation signal of the second low noise amplifier 47. Sometimes, the detection sensitivity is most improved. However, since the frequency of the amplified modulation signal input to the second mixer 48 is determined by the frequency f _LO1 of the local oscillator signal generated by the first local oscillator 43 and the band of the first filter 46, the first filter 46 requires a narrow bandpass filter to improve frequency selectivity. In general, in a narrow band pass filter, a surface acoustic wave (Surface Acoustic Wave: hereinafter, abbreviated as SAW) can obtain an arbitrary high-precision frequency characteristic by changing the structure and position of its electrode.
Filters are often applied. However, since the frequency band of the low-cost SAW filter is limited, the frequency of the local oscillator signal of the second local oscillator 51 is adjusted to the filter band.

In this case, in the motion detecting device according to the first embodiment, since the second local oscillator is used as the reference oscillator, excellent low phase noise characteristics are required. this is,
In consideration of the fact that a lower oscillation frequency generally has better phase noise characteristics, it means that the selection range of frequencies that can be used as the second local oscillator is limited. It is not easy to match the frequency of the local oscillator signal. On the other hand, in the motion detection device according to the second embodiment, the third PLL circuit 52
Since the local oscillator signal is generated from the second local oscillator 51 based on the synchronization, the frequency of the local oscillator input to the second mixer can be set freely. Therefore, it is very easy to match the frequency of the first filter band with the frequency of the local oscillator signal of the second local oscillator.

Third Embodiment

In the motion detecting apparatus according to the second embodiment, the receiver 53 detects a modulation signal due to a minute motion of an object by a superheterodyne phase comparator using the second local oscillator 51. However, in the motion detection device according to the third embodiment, the detection sensitivity of the modulation signal is further improved.

FIG. 4 shows an outline of the configuration of a motion detecting device according to a third embodiment of the present invention. However,
The same parts as those of the motion detection device according to the second embodiment shown in FIG. 3 are denoted by the same reference numerals, and the description thereof will not be repeated. The difference between the motion detecting device according to the third embodiment and the motion detecting device according to the second embodiment is that the reference oscillator is removed and a third local oscillator 55 and a third mixer 56 are provided inside the receiver 54.
And the third filter 57 are provided. The third local oscillator 55 generates a reference signal, and the second local oscillator 55
PLL circuit 41 and first PLL circuit 42 of receiver 54
And the third PLL circuit 52. The second PLL circuit 41 supplies the first oscillator reference signal having the frequency of the reference signal to the first oscillator 40 in synchronization with the phase of the reference signal. The first PLL circuit 42 generates a first local oscillator reference signal having the frequency of the reference signal in synchronization with the phase of the input reference signal, and outputs the generated signal to the first local oscillator 43. The third PLL circuit 52 generates a second local oscillator reference signal having the frequency of the reference signal in synchronization with the phase of the reference signal. Further, the reference signal generated by the third local oscillator 55 is used as the local oscillator signal of the third mixer 56 to which the output signal of the second filter 49 is input. From the modulated signal converted to the third intermediate frequency by the third mixer 56, a component only of the frequency of the motion of the target object is extracted with higher accuracy by the third filter 57, which is a low-pass filter.

That is, in the motion detecting apparatus according to the third embodiment, the frequency comparison is further improved and the detection sensitivity of the modulation signal is further improved by the phase comparison of the superheterodyne method by the third local oscillator 55. In this case, the phases of the signals generated by the first oscillator 40, the first local oscillator 43, the second local oscillator, and the third local oscillator 55 need to be synchronized. In addition, since the phase comparison of the superheterodyne method is performed as described above, the frequency of the modulation signal output from the second filter 49 and the frequency of the local oscillator signal input from the third local oscillator 55 match. Is desirable.

Fourth Embodiment

In the first to third embodiments, the phase of the transmission signal and the phase of the reception signal are compared by the phase comparator of the superheterodyne system, and the modulation signal component included in the reception signal is extracted. However, the present invention is not limited to this. For example, in a motion detection device that achieves miniaturization by simplifying the configuration of the device as much as possible, by directly comparing the phases of a transmission signal and a reception signal without using a superheterodyne type phase comparator as described above. Also,
A modulated signal component can be extracted.

FIG. 5 shows an outline of the principle configuration of a motion detecting apparatus according to a fourth embodiment of the present invention. The motion detecting device according to the fourth embodiment includes an antenna 60
And radiates a high-frequency electromagnetic wave from the antenna 60 around the target object, and receives a reflected wave from the object. Further, the motion detecting device includes a reference signal generating means 61 for generating a reference signal, and an oscillating means for generating a high frequency signal for radiating an electromagnetic wave to an object in synchronization with the reference signal generated by the reference signal generating means 61 62, and a circulator 64 for transmitting the high-frequency signal generated by the oscillating means 62 to the antenna 60 and transmitting the received signal from the antenna 60 to the phase comparing means 63. Further, a phase comparing means 63 for comparing the phase of the received signal transmitted from the circulator 64 with the high-frequency transmission signal generated by the oscillating means 62, and for performing signal processing on the phase comparison result of the phase comparing means 63 And the signal processing means 65 of FIG.

In the motion detecting device having such a configuration, a high-frequency signal is generated by the oscillating means 62 in synchronization with the reference signal generated by the reference signal generating means 61, and the high-frequency signal is transmitted from the antenna 60 as a high-frequency electromagnetic wave via the circulator 63. Radiates around the target object. The high-frequency electromagnetic wave transmitted from the antenna 60 is reflected by a minute movement having a cycle of about several hertz (Hz), or an object having vibration or an object having no movement around the object. This motion detection device receives this as a reflected wave by the antenna 60. When the reflected wave is received by the antenna 60, the received signal is transmitted to the phase comparing means 24 by the circulator 64. The phase comparison unit 63 compares the phase of the high-frequency transmission signal generated by the oscillation unit 62 with the phase of the reception signal input from the circulator 64. As a result, high-frequency noise components having a cycle sufficiently separated from the cycle of the movement of the target object are removed, and this is detected as a modulated signal modulated by the movement of the target object. The modulated signal detected in this way is further subjected to wavelet transform processing by the signal processing means 65 to completely remove the modulated signal component modulated by the motion of the target object and the normal filter processing at a frequency in the vicinity thereof. A noise signal component that cannot be obtained is separated, and only a modulated signal component modulated by the movement of the target object is effectively extracted.

Hereinafter, the motion detecting apparatus according to the fourth embodiment will be specifically described.

FIG. 6 specifically shows a main part of the configuration of the motion detecting apparatus according to the fourth embodiment. Here, FIG.
The same reference numerals are given to the same portions as those of the motion detection device in the first embodiment shown in FIG. The motion detection device includes an antenna 30 that receives radiation of a high-frequency electromagnetic wave and a reflected wave thereof, and an oscillator 3 that generates a high-frequency signal for generating a high-frequency electromagnetic wave radiated from the antenna 30.
1 and a receiver 70 for detecting a modulated signal from a reflected wave received by the antenna 30. Further, a circulator 33 is provided, which transmits a high-frequency signal from the oscillator 31 to the antenna 30 and uses a reflected wave received by the antenna 30 as a reception signal as a receiver 70.
It can be transmitted to. Further, a power divider 71 is provided to divide the high-frequency signal generated by the oscillator 31 into equal powers,
Is supplied to the oscillator 70. In addition, reference oscillator 72
And a reference signal is generated and supplied to the oscillator 31.

The receiver 70 receives the first low-noise amplifier 44 for amplifying the reception signal input from the circulator 33 with low noise and the high-frequency transmission signal generated by the oscillator 31 and divided by the power divider 71. (1) A first mixer 45 that compares the phase of the signal amplified by the low noise amplifier 44 with the transmission signal, and a first filter 46 that is connected to the first mixer 45 and that is a low-pass filter that uses the frequency of the motion of the object as a pass band. And

In the motion detection device having such a configuration, the product of the high-frequency transmission signal and the received signal generated by the oscillator 31 in the first mixer 45 of the receiver 70 is calculated, and the difference frequency component is selected. A modulation signal due to the movement of the object is detected. Then, by applying a low-pass filter having an appropriate pass band width to the first filter 46, high-frequency components included in the modulated signal are removed.
As described above, the motion detection device according to the fourth embodiment includes more harmonic noise by an amount corresponding to the simplification of the device than the modulation signal detected by the receiver detected by the motion detection device according to the first embodiment. Will be. However, by selecting an appropriate basis function in the signal wavelet transform processing means 36 in the subsequent stage, it is possible to sufficiently separate the noise component and the modulation signal component.

In the motion detecting devices according to the first to fourth embodiments of the present invention, the signal is transmitted between the antenna and the antenna by the circulator. However, the present invention is not limited to this. For example, a directional coupler having a degree of coupling that does not affect the amplitude and phase characteristics of the transmission signal or the reception signal may be used.

In the motion detection apparatus according to the first to fourth embodiments of the present invention, the signal spectrum is displayed by the fast Fourier transform processing means 38, but the waveform is simply displayed by the wavelet transform processing means 36. Is sufficient, the fast Fourier transform means 38 is
And the spectrum display means 39 becomes unnecessary.

In the motion detecting apparatus according to the first to fourth embodiments of the present invention, the wavelet transform processing is not limited to one wavelet transform, and if the noise cannot be sufficiently separated, Alternatively, a plurality of wavelet transform processes may be performed. In this case, the basis function may be changed such as changing the wavelet coefficient matrix for each wavelet transform process.

[0074]

As described above, according to the first aspect of the present invention, a phase modulation signal component is extracted by phase comparison,
In addition, since the wavelet transform is performed, noise components that cannot be removed by a normal filter can be separated from the extracted components, and even if the intensity of the noise components is large, minute noise modulated by the movement of the target object The phase modulation signal component can be accurately detected. Further, since the wavelet transform only needs to multiply the coefficient matrix by the sampling data, the time required for signal processing can be reduced. In addition, by performing the wavelet transform processing in this manner, a desired signal can be obtained as a waveform in the time domain and the frequency domain, so that the motion of the target object can be easily determined, and the reliability of the detection signal can be increased in each stage. Can be improved.

According to the second aspect of the present invention, the phases of the direct transmission signal and the reception signal are compared, and the wavelet transform is performed by the signal processing means, so that the apparatus can be simplified and downsized. it can.

Further, according to the third aspect of the present invention, the first
The frequency is converted to an intermediate frequency to remove high-frequency noise components contained in a signal received from the antenna, and further converted to a second intermediate frequency to extract the second intermediate frequency component. An effective phase modulation signal can be extracted by improving the frequency selectivity and the detection sensitivity.

According to the fourth aspect of the present invention,
Since the frequency of the local oscillator signal can be set relatively freely, the design can be facilitated and the cost can be reduced.

According to the fifth aspect of the present invention, the third
Second by the frequency conversion means Second by the frequency conversion means
The invention according to claim 3 or 4, wherein the frequency of the received signal from which the intermediate frequency component has been extracted is converted into a third intermediate frequency based on the frequency of the reference signal, and the third intermediate frequency component is extracted. The frequency selectivity and the detection sensitivity can be further improved as compared with.

According to the present invention, the direct transmission signal and the received signal are converted into the first intermediate frequency and the phases are compared with each other, so that the conventional compensation circuit is not required. In addition, a highly accurate modulated signal can be detected by the wavelet transform of the signal processing means, and the device can be simplified and downsized.

Further, according to the present invention, the phase comparison is performed by the mixer and the frequencies are made to coincide with each other, whereby the phase modulation signal component can be detected with higher sensitivity. it can.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an outline of a basic configuration of a motion detection device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating an outline of a main part of a configuration of the motion detection device according to the first embodiment of the present invention.

FIG. 3 is a block diagram illustrating an outline of a main part of a configuration of a motion detection device according to a second embodiment of the present invention.

FIG. 4 is a block diagram illustrating an outline of a main configuration of a motion detection device according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram illustrating an outline of a basic configuration of a motion detection device according to a fourth embodiment of the present invention.

FIG. 6 is a block diagram illustrating an outline of a main part of a configuration of a motion detection device according to a fourth embodiment of the present invention.

FIG. 7 is a block diagram showing an outline of a configuration of a conventionally proposed motion detection device.

[Explanation of symbols]

 10, 31 Oscillator 11 First power divider 12 Second power divider 13 Phase comparator 14, 24, 33 Circulator 15 Amplitude / phase compensation circuit 16, 20, 30, 60 Antenna 17 Adder 18, 38 Fast Fourier Conversion processing means 19, 39 Spectrum display means 21, 61 Reference signal generation means 22, 62 Oscillation means 23, 63 Phase comparison means 25, 65 Signal processing means 32, 53, 54, 70 Receiver 34, 51 Second local oscillator 35 AD converter 36 Wavelet transform processing means 37 Waveform display means 40 First oscillator 41 Second PLL circuit 42 First PLL circuit 43 First local oscillator 44 First low noise amplifier 45 First mixer 46 First filter 47 Second low noise amplifier 48 Second 2 mixer 49 second filter 50, 72 reference oscillator 52 third PLL circuit 55 Third local oscillator 56 Third mixer 57 Third filter 71 Power divider

Claims (9)

[Claims] A reference signal generating means for generating a reference signal; an oscillation signal generating means for generating an oscillation signal in synchronization with a phase of the reference signal generated by the reference signal generating means; An antenna for radiating the generated oscillation signal as an electromagnetic wave to a predetermined target and receiving a reflected wave of the electromagnetic wave reflected by the target; a phase of the reflected wave received by the antenna and the reference signal; Phase comparison means for extracting a modulation signal component modulated by the motion of the target by comparing the phase of the target object with the phase of the target object by performing a wavelet transform on the modulation signal component extracted by the phase comparison means. Signal processing means for separating a modulated signal component having a frequency of Motion detection apparatus according to claim. 2. A reference signal generating means for generating a reference signal, an oscillation signal generating means for generating an oscillation signal in synchronization with a phase of the reference signal generated by the reference signal generating means, A dividing unit that divides the generated oscillation signal, and radiates one of the oscillation signals divided by the dividing unit as an electromagnetic wave to a predetermined target, and receives a reflected wave of the electromagnetic wave reflected by the target. And a phase for extracting a modulated signal component modulated by the movement of the target by comparing the phase of the reflected wave received by the antenna with the phase of the other oscillation signal divided by the dividing means. Comparing means for performing a wavelet transform on the modulated signal component extracted by the phase comparing means, thereby obtaining the target Motion detecting apparatus characterized by comprising a signal processing means for separating the modulated signal component of the frequency of the motion and the noise signal component of the frequency neighborhood. 3. The phase comparison means according to claim 1, wherein said first phase comparison means synchronizes with a phase of said reference signal generated by said reference signal generation means.
A first local oscillator for generating a local oscillator signal, and a frequency of the reflected wave received by the antenna is changed to a first intermediate frequency based on the frequency of the first local oscillator signal generated by the first local oscillator. Convert this first
First frequency conversion means for extracting an intermediate frequency component, and frequency conversion of the frequency of the received signal from which the first intermediate frequency component has been extracted by the first frequency conversion means to a second intermediate frequency based on the frequency of the reference signal 2. The motion detecting device according to claim 1, further comprising a second frequency converting unit that extracts the second intermediate frequency component. 4. The phase comparison means according to claim 1, wherein said phase comparison means synchronizes with a phase of said reference signal generated by said reference signal generation means.
A first local oscillator for generating a local oscillator signal; a second local oscillator for generating a second local oscillator signal in synchronization with a phase of the reference signal generated by the reference signal generator; First frequency converting means for converting the frequency of the reflected wave into a first intermediate frequency based on the frequency of the first local oscillator signal generated by the first local transmitting means, and extracting the first intermediate frequency component; The frequency of the received signal from which the first intermediate frequency component is extracted by the first frequency converting means is converted to a second intermediate frequency based on the frequency of the second local oscillator signal generated by the second local transmitting means. The motion detection device according to claim 1, further comprising a second frequency conversion unit that extracts a second intermediate frequency component. 5. The phase comparison means according to claim 1, wherein said phase comparison means synchronizes with a phase of said reference signal generated by said reference signal generation means.
A first local oscillator for generating a local oscillator signal; a second local oscillator for generating a second local oscillator signal in synchronization with a phase of the reference signal generated by the reference signal generator; First frequency converting means for converting the frequency of the reflected wave into a first intermediate frequency based on the frequency of the first local oscillator signal generated by the first local transmitting means, and extracting the first intermediate frequency component; The first frequency converter converts the frequency of the received signal from which the first intermediate frequency component is extracted into a second intermediate frequency based on the frequency of the second local oscillator signal generated by the second local oscillator. A second frequency converting means for extracting the second intermediate frequency component;
A third frequency converter for converting the frequency of the received signal from which the second intermediate frequency component is extracted by the frequency converter to a third intermediate frequency based on the frequency of the reference signal, and extracting the third intermediate frequency component; The motion detection device according to claim 1, further comprising: 6. The phase comparing means converts the frequency of the reflected wave received by the antenna into a first intermediate frequency based on the frequency of the other oscillation signal divided by the dividing means, and converts the frequency of the reflected wave to the first intermediate frequency. 3. The motion detection device according to claim 2, wherein components are extracted. 7. The first and second frequency conversion means are first and second mixers, and the difference between the frequency of the oscillation signal and the frequency of the first local oscillator signal, the frequency of the reference signal, 4. The motion detection device according to claim 3, wherein 8. The first and second frequency conversion means are first and second mixers, wherein a difference between a frequency of the oscillation signal and a frequency of the first local oscillator signal and a signal of the second local oscillator signal are provided. 5. The motion detection device according to claim 4, wherein the frequency of the reference signal is matched. 9. The third frequency conversion means is a third mixer, and makes the frequency of the received signal from which the second intermediate frequency component is extracted by the second frequency conversion means coincide with the frequency of the reference signal. 6. The method according to claim 5, wherein
The motion detection device according to claim 1.