JP6271872B2 - Frequency shift method for simulating moving objects - Google Patents

Description

  The present invention relates to a frequency shift method for simulating a moving body.

  A device that detects waves by emitting waves (sound waves, radio waves, etc.) to the water and space and receiving reflected waves reflected from the sea surface, moving bodies such as underwater navigational bodies and aircraft (hereinafter, detection) Known as a device). Ideally, such a test of the detection apparatus is carried out by actually moving the moving object to be detected. However, a test using a real moving body requires the arrangement of the moving body and increases the test scale, which increases the cost and time required for the test. Therefore, a test using a real moving object cannot be easily performed.

  Therefore, a simulation device that simulates a moving body is required. The simulation device needs to simulate a reflected wave reflected by the moving body so that the detection device can recognize the moving body and perform a required test. That is, the simulation device must simulate the frequency shift due to the well-known Doppler effect accompanying the movement of the moving body, and return the output wave of the detection device to the detection device at an appropriate level without changing its shape. Don't be.

  About the structure of such a simulation apparatus, it is proposed by patent documents 1 and 2, for example.

  Patent Document 1 describes a configuration in which a frequency-shifted signal is used to generate a signal that is frequency-shifted from an outgoing wave of a detection device, and the generated signal is sent to the detection device as a reflected wave of a moving body.

  In Patent Document 2, a frequency signal equal to an outgoing wave of a detection device and a frequency shift amount (hereinafter sometimes referred to as “Doppler frequency”) is multiplied using a multiplier, and the frequency of the outgoing wave and the Doppler frequency are multiplied. A configuration is described in which only the frequency component after frequency shift is extracted from the output signal of the multiplier including the sum frequency component and the difference frequency component using a bandpass filter. Note that a technique for converting the frequency of an input signal using a multiplier and a filter is also used in the wireless communication field, as described in Patent Documents 3 and 4, for example.

JP-A-10-123230 Japanese Patent Laid-Open No. 05-034095 Japanese Patent Laid-Open No. 06-291557 JP 05-083034 A

  The simulation apparatuses described in Patent Documents 1 and 2 described above are based on the assumption that the Doppler frequency is constant. That is, it is an apparatus that assumes a case where the detection device is on the moving line of a moving body that moves at a constant linear velocity.

  However, the detection device is not necessarily on the moving line of the moving body, and may detect the moving body at a position shifted from the moving line. In that case, even if the moving body is moving at a constant linear velocity, the Doppler frequency of the reflected wave from the moving body detected by the detection device changes every moment. Specifically, when the moving body approaches the detection device, the Doppler frequency gradually decreases on the plus (+) side, and when the moving body comes closest to the detection device, the Doppler frequency becomes zero (0) and moves. When the body leaves the detection device, the Doppler frequency gradually increases on the minus (−) side. The Doppler frequency plus (+) indicates a state in which the reflected wave frequency is higher than the outgoing wave frequency of the detection device, and the Doppler frequency minus (−) indicates the frequency of the outgoing wave of the detection device. The state where the frequency of the reflected wave is low is shown.

  As described above, since the simulation devices described in Patent Documents 1 and 2 are based on the assumption that the Doppler frequency is constant, it is possible to simulate a reflected wave from a moving body in which the Doppler frequency changes every moment. Not exclusively.

  For example, in Patent Document 2, an input signal and an output signal of an oscillator that generates a Doppler frequency are input to a multiplier, and any one of the output signals of the multiplier including the frequency components of the sum and difference is input using a bandpass filter. It is described that one of the frequency components is extracted. However, since these two frequency components are very close to each other, it is very difficult to realize a band-pass filter that extracts one of the frequency components.

  On the other hand, Patent Document 1 does not show any specific configuration of a frequency converter that generates a signal shifted in frequency from the outgoing wave of the detection device. The frequency converter is, for example, an A / D converter that performs A / D (Analog-to-digital) conversion of an input signal, a memory that records the waveform and level of the input signal, and an input signal by FFT (Fast Fourier Transform) analysis. A processing circuit equipped with a DSP (Digital Signal Processor), a CPU (Central Processing Unit), etc. that detects the frequency of the signal and generates a signal simulating the reflected wave of the moving object using the detection result and information recorded in the memory And a digital signal processing circuit including a D / A converter that performs D / A (Digital-to-Analog) conversion on a signal generated by the processing circuit.

  However, a simulation apparatus having such a digital signal processing circuit needs to include a high-performance DSP or CPU in order to execute the above-described complicated processing. For this reason, the cost of the simulation apparatus increases.

  The present invention has been made in order to solve the problems of the background art as described above. Even when the Doppler frequency of the reflected wave by the moving body changes from moment to moment, the Doppler frequency can be reduced with a simple configuration. An object of the present invention is to provide a frequency shift circuit capable of simulating a change and a simulation apparatus including the same.

In order to achieve the above object, a frequency shift circuit of the present invention has a configuration shown in the following first to sixth inventions.
(First invention)
A frequency shift circuit that outputs a signal obtained by shifting the frequency of the input signal from the input signal,
A first oscillator and a second oscillator having a variable oscillation frequency;
A first multiplier for multiplying the input signal by the first signal output from the first oscillator;
A high-pass filter that passes only the frequency component of the sum of the frequency of the input signal and the first frequency that is the frequency of the first signal from the output signal of the first multiplier;
A second multiplier that multiplies the output signal of the high-pass filter and the second signal output from the second oscillator;
A low-pass filter that passes only the frequency component of the difference between the frequency of the output signal of the high-pass filter and the second frequency that is the frequency of the second signal from the output signal of the second multiplier;
A frequency shift with respect to the frequency of the input signal by controlling the first oscillator and the second oscillator and changing either the first frequency or the second frequency, or changing the first frequency and the second frequency. A control unit for changing the amount;
I have a,
The frequency shift amount includes zero,
The controller is
The first frequency and the second frequency when the frequency shift amount is zero are set to 1.618 times the frequency of the input signal .
(Second invention)
A frequency shift circuit that outputs a signal obtained by shifting the frequency of the input signal from the input signal,
A first oscillator and a second oscillator having a variable oscillation frequency;
A first multiplier for multiplying the input signal by the first signal output from the first oscillator;
A low-pass filter that passes only the frequency component of the difference between the frequency of the input signal and the first frequency, which is the frequency of the first signal, from the output signal of the first multiplier;
A second multiplier that multiplies the output signal of the low-pass filter by the second signal output from the second oscillator;
A high-pass filter that passes only the frequency component of the sum of the frequency of the output signal of the low-pass filter and the second frequency that is the frequency of the second signal from the output signal of the second multiplier;
A frequency shift with respect to the frequency of the input signal by controlling the first oscillator and the second oscillator and changing either the first frequency or the second frequency, or changing the first frequency and the second frequency. A control unit for changing the amount;
Have
The first frequency and the second frequency are lower than the frequency of the input signal ;
The frequency shift amount includes zero,
The controller is
The first frequency and the second frequency when the frequency shift amount is zero are set to 0.618 times the frequency of the input signal .
(Third invention)
A frequency shift circuit that outputs a signal obtained by shifting the frequency of the input signal from the input signal,
A first oscillator and a second oscillator having a variable oscillation frequency;
A first multiplier for multiplying the input signal by the first signal output from the first oscillator;
A first low-pass filter that passes only the frequency component of the difference between the frequency of the input signal and the first frequency, which is the frequency of the first signal, from the output signal of the first multiplier;
A second multiplier that multiplies the output signal of the first low-pass filter by the second signal output from the second oscillator;
A second low-pass filter that passes only the frequency component of the difference between the frequency of the output signal of the first low-pass filter and the second frequency that is the frequency of the second signal from the output signal of the second multiplier. When,
A frequency shift with respect to the frequency of the input signal by controlling the first oscillator and the second oscillator and changing either the first frequency or the second frequency, or changing the first frequency and the second frequency. A control unit for changing the amount;
Have
The first frequency and the second frequency are higher than the frequency of the input signal ;
The frequency shift amount includes zero,
The controller is
The first frequency and the second frequency when the frequency shift amount is zero are set to twice the frequency of the input signal .
(Fourth invention)
A frequency shift circuit that outputs a signal obtained by shifting the frequency of the input signal from the input signal,
A plurality of oscillators each having a constant frequency and each outputting a signal of a different frequency;
A first multiplier that multiplies the output signal of any one of the plurality of oscillators by the input signal;
A high-pass filter that passes only a frequency component of the sum of the frequency of the oscillator and the frequency of the input signal from the output signal of the first multiplier;
A second multiplier for multiplying an output signal of any one of the plurality of oscillators by an output signal of the high-pass filter;
A low-pass filter that passes only the frequency component of the difference between the frequency of the oscillator and the frequency of the output signal of the high-pass filter from the output signal of the second multiplier;
A first switch that connects any one of the plurality of oscillators to the first multiplier;
A second switch that connects any one of the plurality of oscillators to the second multiplier;
A signal for controlling the first switch and the second switch to be supplied to the first multiplier or the second multiplier, or a signal supplied to the first multiplier and the second multiplier A control unit that changes the frequency shift amount with respect to the frequency of the input signal by changing the frequency of
I have a,
The frequency shift amount includes zero,
The controller is
A signal having a frequency of 1.618 times the frequency of the input signal is supplied to the first multiplier and the second multiplier when the frequency shift amount is zero .
(Fifth invention)
A frequency shift circuit that outputs a signal obtained by shifting the frequency of the input signal from the input signal,
A plurality of oscillators each having a constant frequency and each outputting a signal of a different frequency;
A first multiplier that multiplies the output signal of any one of the plurality of oscillators by the input signal;
A low-pass filter that passes only the frequency component of the difference between the frequency of the oscillator and the frequency of the input signal from the output signal of the first multiplier;
A second multiplier for multiplying an output signal of any one of the plurality of oscillators by an output signal of the low-pass filter;
A high-pass filter that passes only the frequency component of the sum of the frequency of the oscillator and the frequency of the output signal of the low-pass filter from the output signal of the second multiplier;
A first switch that connects any one of the plurality of oscillators to the first multiplier;
A second switch that connects any one of the plurality of oscillators to the second multiplier;
A signal for controlling the first switch and the second switch to be supplied to the first multiplier or the second multiplier, or a signal supplied to the first multiplier and the second multiplier A control unit that changes the frequency shift amount with respect to the frequency of the input signal by changing the frequency of
Have
The frequency of the output signal of the oscillator that is input to the first multiplier is lower than the frequency of the input signal ;
The frequency shift amount includes zero,
The controller is
A signal having a frequency 0.618 times the frequency of the input signal is supplied to the first multiplier and the second multiplier when the frequency shift amount is zero .
(Sixth invention)
A frequency shift circuit that outputs a signal obtained by shifting the frequency of the input signal from the input signal,
A plurality of oscillators each having a constant frequency and each outputting a signal of a different frequency;
A first multiplier that multiplies the output signal of any one of the plurality of oscillators by the input signal;
A first low-pass filter that passes only the frequency component of the difference between the frequency of the oscillator and the frequency of the input signal from the output signal of the first multiplier;
A second multiplier for multiplying an output signal of any one of the plurality of oscillators by an output signal of the first low-pass filter;
A second low-pass filter that passes only the frequency component of the difference between the frequency of the oscillator and the frequency of the output signal of the first low-pass filter from the output signal of the second multiplier;
A first switch that connects any one of the plurality of oscillators to the first multiplier;
A second switch that connects any one of the plurality of oscillators to the second multiplier;
A signal for controlling the first switch and the second switch to be supplied to the first multiplier or the second multiplier, or a signal supplied to the first multiplier and the second multiplier A control unit that changes the frequency shift amount with respect to the frequency of the input signal by changing the frequency of
Have
The frequency of the output signal of the oscillator input to the first multiplier is higher than the frequency of the input signal ;
The frequency shift amount includes zero,
The controller is
A signal having a frequency twice that of the input signal is supplied to the first multiplier and the second multiplier when the frequency shift amount is zero .

On the other hand, the simulation device of the present invention is a simulation device that simulates a reflected wave reflected by a moving body,
A wave receiving sensor that receives a wave emitted from a detection device that detects the moving body and converts the wave into an electric signal;
The frequency shift circuit of any one of the above, wherein the output signal of the receiving sensor is an input signal;
A power amplifier for amplifying an output signal of the frequency shift circuit;
A wave transmission unit that converts the signal amplified by the power amplifier into a wave corresponding to the output wave of the detection device and transmits the wave to the detection device;
Have

  According to the present invention, even when the Doppler frequency of the reflected wave from the moving body changes every moment, the change in the Doppler frequency can be simulated with a simple configuration.

It is a block diagram which shows the example of 1 structure of the simulation apparatus of 1st Embodiment. FIG. 2 is a block diagram illustrating a configuration example of a frequency shift circuit illustrated in FIG. 1. It is a wave form diagram which shows an example of the wave radiate | emitted from a detection apparatus. It is a schematic diagram which shows an example of the positional relationship of a moving body and a detection apparatus. It is a graph which shows the example of a change of the Doppler frequency of the reflected wave by the moving body shown in FIG. 6 is a graph showing an example of control of the oscillation frequency of the pre-stage synthesizer that realizes the change of the Doppler frequency shown in FIG. 5. In this case, the sum component of the frequency is extracted from the output signal of the pre-stage multiplier shown in FIG. 2, and the oscillation frequency of the pre-stage synthesizer and the post-stage synthesizer shown in FIG. It is a graph which shows the example of a relationship with two frequency components contained. FIG. 2 illustrates a case where a frequency difference component is extracted from the output signal of the pre-stage multiplier shown in FIG. 2, and the oscillation frequency of the pre-stage synthesizer and the post-stage synthesizer shown in FIG. It is a graph which shows the example of a relationship with two frequency components contained. FIG. 3 is a circuit diagram showing an example of a filter circuit that can be used in the high-pass filter and the low-pass filter shown in FIG. 2. It is a block diagram which shows one structural example of the frequency shift circuit with which the simulation apparatus of 2nd Embodiment is provided. It is a block diagram which shows one structural example of the frequency shift circuit with which the simulation apparatus of 3rd Embodiment is provided. It is a block diagram which shows the example of 1 structure of the test apparatus of this invention.

Next, the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a block diagram showing a configuration example of the simulation apparatus according to the first embodiment, and FIG. 2 is a block diagram showing a configuration example of the frequency shift circuit shown in FIG.

  As shown in FIG. 1, the simulation apparatus 1 according to the first embodiment includes a reception sensor 2, a band pass filter 3, a first stage amplifier 4, a frequency shift circuit 5, a power amplifier 6, and a transmission unit 7.

  The wave receiving sensor 2 receives a wave (sound wave, radio wave, etc.) emitted from a detection device (not shown) 20, converts it into an electric signal, and outputs it. The wave receiving sensor 2 can be realized by a microphone that receives sound waves, an antenna device that receives radio waves, or the like. For example, as shown in FIG. 3, the detector 20 emits a wave having an elliptical envelope and a constant frequency fi.

  The band pass filter 3 passes a signal in a band assumed in advance including the frequency of the outgoing wave of the detection device 20 among the output signals of the wave receiving sensor 2. The pass band of the band pass filter 3 is set in advance according to the frequency of the outgoing wave of the detection device 20. The band-pass filter 3 may be omitted as long as the noise level, dynamic range, and the like are within allowable ranges under the usage conditions of the simulation apparatus.

  The first stage amplifier 4 amplifies the output signal of the band pass filter 3 to an appropriate level. The first stage amplifier 4 may be omitted as long as a signal of an appropriate level can be supplied from the reception sensor 2 or the band pass filter 3 to the frequency shift circuit 5.

  The frequency shift circuit 5 generates and outputs a signal that simulates the reflected wave from the moving body 30 from the signal received by the wave receiving sensor 2 supplied from the first stage amplifier 4.

  The power amplifier 6 amplifies the output signal of the frequency shift circuit 5 to an appropriate transmission level.

  The wave transmission unit 7 converts the signal amplified by the power amplifier 6 into a wave (sound wave, radio wave, etc.) corresponding to the outgoing wave of the detection device 20 and transmits the wave to the detection device 20. The wave transmission unit 7 can be realized by a wave transmission sensor (for example, an ultrasonic sensor) that outputs sound waves, a speaker, or an antenna device that emits radio waves.

  As shown in FIG. 2, the frequency shift circuit 5 includes a pre-stage multiplier 51, a high-pass filter 52, a pre-stage amplifier 53, a post-stage multiplier 54, a low-pass filter 55, a post-stage amplifier 56, a control unit 57, and a pre-stage synthesizer 58. And a rear-stage synthesizer 59.

  The front-stage synthesizer 58 and the rear-stage synthesizer 59 oscillate and output a signal having a constant level and a variable frequency that is used to generate a signal shifted in frequency with respect to the frequency of the input signal. The front-stage synthesizer 58 and the rear-stage synthesizer 59 are realized by, for example, a known PLL (Phase Locked Loop) circuit.

  The control unit 57 controls the operations of the front-stage synthesizer 58 and the rear-stage synthesizer 59 and changes their oscillation frequencies. The oscillation frequencies of the front-stage synthesizer 58 and the rear-stage synthesizer 59 can be controlled, for example, by changing the frequency division number of the PLL circuit. The control unit 57 can be realized by a CPU or the like that executes processing according to a program.

  The pre-stage multiplier 51 multiplies the input signal of the frequency shift circuit 5 and the output signal of the pre-stage synthesizer 58 and outputs the result. When the frequency of the input signal of the frequency shift circuit 5 is fi and the oscillation frequency of the pre-stage synthesizer 58 is fl, the pre-multiplier 51 includes the sum frequency component fi + fla and the difference frequency component fi-fla. A signal is output.

  The high-pass filter 52 attenuates the frequency component fi−fla from the output signal of the pre-stage multiplier 51 and passes the frequency component fi + fla.

  The pre-stage amplifier 53 amplifies the output signal of the high-pass filter 52 to an appropriate level. When the output signal of the high-pass filter 52 is at a required level, the pre-stage amplifier 53 may not be provided.

  The post-stage multiplier 54 multiplies the output signal of the pre-stage amplifier 53 and the output signal of the post-stage synthesizer 59 and outputs the result. As described above, the frequency of the output signal of the pre-stage amplifier 53 is fi + fla, and if the oscillation frequency of the post-stage synthesizer 59 is flb, the post-stage multiplier 54 receives the difference between the frequency component fi + fla + flb and the difference frequency component fi + fla−flb. Are output.

  The low-pass filter 55 attenuates the frequency component fi + fla + flb from the output signal of the post-stage multiplier 54 and passes the frequency component fi + fla-flb.

  The post-stage amplifier 56 amplifies the output signal of the low-pass filter 55 to an appropriate level and outputs it to the power amplifier 6 shown in FIG. When the output signal of the low-pass filter 55 is at a required level, the post-stage amplifier 56 may not be provided.

  As described above, the frequency fout of the output signal of the frequency shift circuit 5 is fi + fla−flb, which is a signal shifted by (fla−flb) with respect to the frequency fi of the input signal. Here, if the oscillation frequency of the front-stage synthesizer 58 and the rear-stage synthesizer 59 or any one of the oscillation frequencies is swept, the frequency shift circuit 5 generates a frequency shift amount (Doppler frequency) with respect to the frequency fi of the input signal. A signal that changes from moment to moment is output. Since the frequency fout matches fi when fl = flb, a state where the Doppler frequency is zero (0) can also be reproduced.

  Further, if the oscillation frequency fla of the front-stage synthesizer 58 and the oscillation frequency flb of the rear-stage synthesizer 59 are set to frequencies that are somewhat separated from the frequency fi of the input signal, the frequency component fi + fla of the frequency components fi + fla and fi−fla. The low-pass filter 52 that passes only the frequency component fi + fla-flb among the frequency components fi + fla + flb and fi + fla-flb can be realized relatively easily.

  Further, by making the output signal levels of the front-stage synthesizer 58 and the rear-stage synthesizer 59 constant, the output signal of the frequency shift circuit 5 has the same envelope waveform as that of the input signal, and the level of the output signal is proportional to the level of the input signal. Become.

  Therefore, even when the Doppler frequency of the reflected wave by the moving body 30 changes every moment, the change in the Doppler frequency can be simulated with a simple configuration.

  The frequency shift circuit 5 shown in FIG. 2 first extracts the frequency component fi + fla using the pre-stage multiplier 51 and the high-pass filter 52, and then uses the post-stage multiplier 54 and the low-pass filter 55 to frequency. A configuration example for extracting the component fi + fla-flb has been shown. However, the frequency shift circuit 5 may be configured to extract the frequency component fi-fla using the pre-stage multiplier 51 and the low-pass filter 55 first. However, in the configuration in which the frequency component fi-fla is extracted first, it is necessary to change the filter provided on the output side of the post-stage multiplier 54 in accordance with the relationship between fi and fla. Specifically, when fi> fla, the high-pass filter 52 is used to extract the frequency component fi−fla + flb (sum frequency component) from the output signal of the post-stage multiplier 54. If fi <fla, the low-pass filter 55 is used to extract the frequency component fi-fla-flb (difference frequency component) from the output signal of the post-stage multiplier 54.

  For example, when fi = 50 kHz and fla = flb = 30 kHz (fi> fla), the frequency component extracted from the outputs of the pre-stage multiplier 51 and the low-pass filter 55 is fi−fla = 20 kHz. At this time, if the frequency component extracted from the output signal of the post-stage multiplier 54 is fi-fla-flb (difference frequency component), fi-fla-flb = -10 kHz, and fi = 50 kHz cannot be output. The minus (-) frequency indicates a state in which the rotation direction of the signal vector is clockwise. The plus (+) frequency is a state in which the rotation direction of the signal vector is counterclockwise, and the frequency is the same even if the rotation direction of the vector is different. That is, fi-fla-flb = 10 kHz.

  On the other hand, if the frequency component extracted from the output signal of the post-stage multiplier 54 is fi−fla + flb (sum frequency component), it is found that fi−fla + flb = 50 kHz, and fi = 50 kHz can be output.

  On the other hand, for example, when fi = 30 kHz and fla = flb = 50 kHz (fi <fla), the frequency component extracted from the outputs of the pre-stage multiplier 51 and the low-pass filter 55 is fi-fla = −20 kHz. At this time, if the frequency component extracted from the output signal of the post-stage multiplier 54 is fi−fla + flb (sum frequency component), fi−fla (= 20 kHz) + flb = 70 kHz, and fi = 30 kHz cannot be output.

  On the other hand, if the frequency component extracted from the output signal of the post-stage multiplier 54 is fi-fla-flb (difference frequency component), fi-fla (= 20 kHz) -flb = -30 kHz, and fi = 30 kHz is output. I understand that I can do it.

  Next, a specific example of this embodiment will be described with reference to the drawings.

  FIG. 4 is a schematic diagram illustrating an example of a positional relationship between the moving body and the detection device, and FIG. 5 is a graph illustrating an example of a change in Doppler frequency of a reflected wave by the moving body illustrated in FIG.

  FIG. 4 shows a state in which the detection device 20 detects the moving body 30 in water using sound waves, and is an example in which the detection device 20 is displaced from the movement line of the moving body 30 that moves at a constant linear velocity. The moving body 30 performs constant velocity linear motion, and the speed v is, for example, 20 knots. The closest approach distance d between the detection device 20 and the moving body 30 is 100 m. The frequency fi of the sound wave emitted from the detection device 20 is 20 kHz.

  In this case, the Doppler frequency of the reflected wave by the moving body 30 detected by the detection device 20 changes as shown in FIG. The vertical axis of the graph shown in FIG. 5 indicates frequency, and the horizontal axis indicates time. The horizontal axis in FIG. 5 represents zero (t = 0) when the detection device 20 and the moving body 30 are closest to each other, and minus (−) is a period during which the moving body 30 approaches the detection device 20. ) Is a period during which the moving body 30 moves away from the detection device 20. In this case, the simulation apparatus 1 can simulate the reflected wave by the moving body 30 by shifting the frequency of the sound wave transmitted from the detection apparatus 20 with the passage of time as shown in FIG.

  In the graph shown in FIG. 5, for example, the Doppler frequency is +145.1 Hz 0.1 minutes before the closest approach between the detection device 20 and the moving body 30. That is, the frequency of the reflected wave from the moving body 30 is 20145.1 Hz.

  In this case, for example, if the oscillation frequency flb of the post-stage synthesizer 59 is set to 30000 Hz and the oscillation frequency fa of the pre-stage synthesizer 58 is set to 30145.1 Hz, the frequency shift circuit 5 outputs a signal shifted in frequency (= 20145.1 Hz). The Further, for example, if the oscillation frequency flb of the post-stage synthesizer 59 is fixed and the oscillation frequency fl of the pre-stage synthesizer 58 is changed, the frequency shift circuit 5 outputs a signal whose Doppler frequency changes every moment.

  FIG. 6 shows a control example of the oscillation frequency fla of the pre-stage synthesizer 58 that realizes the change of the Doppler frequency shown in FIG. The oscillation frequency of the post-stage synthesizer 59 is constant at 30000 Hz.

  The simulator 1 can realize the change of the Doppler frequency shown in FIG. 5 by controlling the oscillation frequency fl of the pre-stage synthesizer 58 as shown in FIG. 6 by the frequency shift circuit 5. The reflected wave by the mobile body 30 shown can be simulated. FIG. 6 shows an example in which the Doppler frequency is controlled by fixing the oscillation frequency flb of the post-stage synthesizer 59 and changing the oscillation frequency fl of the pre-stage synthesizer 58. However, the frequency shift circuit 5 oscillates the pre-stage synthesizer 58. The Doppler frequency may be changed by fixing the frequency fl and changing the oscillation frequency flb of the post-stage synthesizer 59. Further, the frequency shift circuit 5 may change the Doppler frequency by changing the oscillation frequency flb of the front-stage synthesizer 58 and the oscillation frequency flb of the rear-stage synthesizer 59, respectively.

  In this specific example, a signal including a frequency component 50145.1 Hz (20000 Hz + 30145.1 Hz) and a frequency component 10145.1 Hz (30145.1 Hz−20000 Hz) is output from the pre-stage multiplier 51. The levels of these two frequency components are the same.

  In order to prevent the frequency component 10145.1 Hz from affecting the frequency component 50145.1 Hz, it is desirable to attenuate the frequency component 10145.1 Hz by 40 dB or more (in terms of voltage, 1/100 or less).

  From this relationship, the attenuation characteristic required for the high-pass filter 52 is calculated to be −25 dB / oct.

  On the other hand, the post-stage multiplier 54 outputs a signal including a frequency component 20145.1 Hz (50145.1 Hz-30000 Hz) and a frequency component 80145.1 Hz (50145.1 Hz + 30000 Hz). The levels of these two frequency components are the same.

  To prevent the frequency component 80145.1 Hz from affecting the frequency component 20145.1 Hz, it is desirable to attenuate the frequency component 80145.1 Hz by 40 dB or more (in terms of voltage, 1/100 or less).

  From this relationship, the attenuation characteristic required for the low-pass filter 55 is calculated to be −13.4 dB / oct. Note that oct (octave) indicates a double frequency, and -25 dB / oct indicates a characteristic that attenuates a signal having a double frequency by 25 dB. Further, −13.4 dB / oct refers to the characteristic of attenuating a signal having a double frequency by 13.4 dB.

  In this case, since the amount of attenuation required for the high-pass filter 52 is larger than the amount of attenuation required for the low-pass filter 55, the circuit scale of the high-pass filter 52 is larger than that of the low-pass filter 55. Therefore, the following will discuss the oscillation frequency flb of the front-stage synthesizer and the oscillation frequency flb of the rear-stage synthesizer in which both the low-pass filter 55 and the high-pass filter 52 can be configured most simply.

  As described above, in the frequency shift circuit 5 shown in FIG. 2, the signal including the frequency components fi + fla and fi−fla is output from the pre-stage multiplier 51, and only the frequency component fi + fla is extracted using the high-pass filter 52. . At this time, as the required frequency component fi + fla and the unnecessary frequency component fi-fla are more distant, the high-pass filter 52 can be configured with a smaller circuit.

  Similarly, in the frequency shift circuit 5 shown in FIG. 2, a signal including frequency components fi + fla + flb and fi + fla−flb is output from the post-stage multiplier 54, and only a required frequency component fi + fla−flb is obtained using the low-pass filter 55. Extract. At this time, as the required frequency component fi + fla-flb and the unnecessary frequency component fi + fla + flb are further away, the low-pass filter 55 can be configured with a smaller circuit.

If the ratio of the two frequency components output from the pre-stage multiplier 51 is x,
x = (fi + fla) / (fi−fla) (1)
It is represented by

Similarly, if the ratio of the two frequency components output from the post-stage multiplier 54 is y,
y = (fi + fla + flb) / (fi + fla−flb) (2)
It is represented by

  Hereinafter, the conditions under which each of the high-pass filter 52 and the low-pass filter 55 can be configured with a small circuit are obtained. In the following, in order to simplify the equation, a case where the Doppler frequency is 0 (that is, fla = flb) is considered.

At this time, the above equation (2) is
y = (fi + 2fla) / fi (3)
Can be transformed into

fi / fla = c (4)
When the above equation (1) is defined,
x = (c + 1) / (c-1) (5)
It becomes.

Also, the above equation (2) is
y = (c + 2) / c (6)
It becomes.

  FIG. 7A is a table showing the change of x and y with respect to the change of c based on the above equations (5) and (6), and FIG. 7 (b) is a graph. The vertical axis of the graph shown in FIG. 7B indicates x and y values, and the horizontal axis indicates the value of c.

  According to the above equation (5), when c is smaller than 1, x is a minus (−) value. However, even if x is a negative (−) value, the relationship between the ratios of the two frequency components is maintained, and it can be handled in the same manner as when x is positive (+). Therefore, in the graph of FIG.7 (b), x is shown with the absolute value.

  As shown in FIGS. 7A and 7B, x increases as the value of c approaches 1, and the difference between the frequency component fi + fla and the frequency component fi−fla increases. On the other hand, y increases as the value of c decreases, and the difference between the frequency component fi + fla + flb and the frequency component fi + fla−flb increases.

  Therefore, c is preferably a value smaller than 1 in order to increase the value of y, and is preferably a value close to 1 in order to increase the value of x. That is, if the value of c is set to the z point shown in FIG. 7B where x and y intersect, both x and y can be maximized.

The z point is -x = y. Therefore, using the above equations (5) and (6),
− (C + 1) / (c−1) = (c + 2) / c (7)
Is established.

When formula (7) is transformed,
c ² + c-1 = 0 (8)
Is obtained.

  If c is calculated from the equation (8) using the root formula,

  Therefore, c = 0.618 and -1.618.

  Here, since c does not become a negative (−) value, c = 0.618 is an optimal value.

Since c = fi / fla from equation (4),
fla = fi / c = fi / 0.618 = 1.618fi.

  Therefore, when setting c <1, that is, fi <fla, if the oscillation frequency flb of the front-stage synthesizer 58 and the oscillation frequency flb of the rear-stage synthesizer 59 are respectively set to 1.618 times the input signal, the front-stage multiplier 51, the difference between the two frequency components included in the output signal 51 and the difference between the two frequency components included in the output signal of the post-stage multiplier 54 can both be maximized. Both of the pass filters 55 can be configured most simply.

  When changing the Doppler frequency, the center frequency oscillated by the front-stage synthesizer 58 and the rear-stage synthesizer 59 is set to 1.618 fi, and either one or both of the oscillation frequencies of the front-stage synthesizer 58 and the rear-stage synthesizer 59 are set. Sweep it.

  When c> 1, that is, fi> fla, as shown in FIGS. 7A and 7B, the value of c is set to 1 as much as possible in order to increase the values of x and y. It is better to bring it closer. However, when the circuit sizes of the high-pass filter 52 and the low-pass filter 55 are approximately the same, it is desirable that the values of x and y be as close as possible. Therefore, from FIG. 7A and FIG. 7B, for example, c = 5 is set.

  In this case, fla = fi / c = fi / 5 = 0.2fi, and the oscillation frequency flb of the front-stage synthesizer 58 and the oscillation frequency flb of the rear-stage synthesizer 59 may be set to 0.2 times the input signal.

  Fla and flb do not need to be set strictly to be 1.618 fi or 0.2 fi when fl = flb. fla and flb may be any frequencies around 1.618 fi or 0.2 fi when fla = flb, and if the high-pass filter 52 and the low-pass filter 55 can sufficiently attenuate unnecessary frequency components. Any frequency may be set.

  As can be seen from FIGS. 7A and 7B, when fla = flb = 1.618fi, the values of x and y are 4.23. On the other hand, when fla = flb = 0.2fi, the values of x and y are 1.4 to 1.5. As x and y are larger values, the difference frequency and the sum frequency are more distant from each other. Therefore, the setting of fla = flb = 1.618 fi is more effective for the high-pass filter and the low-pass filter. Can be configured with a small circuit.

On the other hand, in the configuration in which the frequency component fi-fla is extracted from the output signal of the pre-stage multiplier 51 using a low-pass filter, the ratio x of the two frequency components output from the pre-stage multiplier 51 is expressed by the above equation (1). alike,
x = (fi + fla) / (fi−fla) (10)
It is represented by

Further, the ratio y of the two frequency components output from the post-stage multiplier 54 is similar to the above equation (2).
y = (fi−fla + flb) / (fi−fla−flb) (11)
It is represented by

  Hereinafter, the conditions under which the high-pass filter 52 and the low-pass filter 55 can be configured with a small circuit are obtained. In the following, in order to simplify the equation, a case where the Doppler frequency is 0 (that is, fla = flb) is considered.

At this time, the above equation (11) is
y = fi / (fi-2fla) (12)
Can be transformed into

fi / fla = c (13)
If defined, the above equation (10) is
x = (c + 1) / (c-1) (14)
It becomes.

Also, the above equation (12) is
y = c / (c-2) (15)
It becomes.

  FIG. 8A is a table showing the change in x and y with respect to the change in c based on the equations (14) and (15), and FIG. 8 (b) is a graph. The vertical axis of the graph shown in FIG. 8B shows the values of x and y, and the horizontal axis shows the value of c.

  According to the above equation (14), when c is smaller than 1, x is a minus (−) value. However, even if x is a negative (−) value, the relationship between the ratios of the two frequency components is maintained, and it can be handled in the same manner as when x is positive (+). Therefore, in the graph of FIG. 8B, x is shown as an absolute value.

  Further, according to the above equation (15), when c is smaller than 2, y is a minus (−) value. However, even if y is a minus (−) value, the relationship between the ratios of the two frequency components is maintained, and can be handled in the same manner as when y is plus (+). Therefore, y is shown as an absolute value in the graph of FIG.

  As shown in FIGS. 8A and 8B, x increases as the value of c approaches 1, and the difference between the frequency component fi + fla and the frequency component fi−fla increases. On the other hand, y increases as the value of c approaches 2, and the difference between the frequency component fi−fla + flb and the frequency component fi−fla−flb increases.

  Therefore, c is preferably a value close to 2 in order to increase the value of y, and is preferably close to 1 in order to increase the value of x. That is, if the value of c is set to the z1 point shown in FIG. 8B where x and y intersect, both x and y can be maximized.

The z1 point is x = −y. Therefore, using the above equations (14) and (15),
(C + 1) / (c-1) =-c / (c-2) (16)
Is established.

When the equation (17) is transformed,
c ² −c−1 = 0 (17)
Is obtained.

  If c is calculated from the equation (17) using the root formula,

  Therefore, c = −0.618 and 1.618.

  Here, since c does not become a negative (−) value, c = 1.618 is an optimal value.

Since c = fi / fla from equation (4),
fla = fi / c = fi / 1.618 = 0.618fi.

  Therefore, when setting c> 1, that is, fi> fla, if the oscillation frequency flb of the front-stage synthesizer 58 and the oscillation frequency flb of the rear-stage synthesizer 59 are respectively set to 0.618 times the input signal, the front-stage multiplier 51 It is possible to maximize the difference between the two frequency components included in the output signal and the difference between the two frequency components included in the output signal of the post-stage multiplier 54. The high-pass filter 52 and the low-pass filter Both filters 55 can be configured most simply.

  When c <1, i.e., fi <fla, as shown in FIGS. 8A and 8B, since x and y do not intersect, there is no value of c where x = y. . Therefore, the change in the reciprocal of y with respect to the change in c is obtained. x and y are the ratios of the two frequencies, and these two frequencies are in a relative relationship. For example, when the other frequency is doubled with respect to one frequency, one frequency is 0.5 times from the other frequency. Therefore, in order to obtain the value of c where x = y, the reciprocal of y can be used. In the graph of FIG. 8B, y is shown as an absolute value, and 1 / y is shown in the range of c <1.

  As shown in FIGS. 8A and 8B, x increases as the value of c approaches 1, and the difference between the frequency component fi + fla and the frequency component fi−fla increases. On the other hand, 1 / y increases as the value of c decreases, and the difference between the frequency component fi−fla + flb and the frequency component fi−fla−flb increases.

  Therefore, c is preferably as small as possible in order to increase 1 / y, and is preferably close to 1 in order to increase the value of x. That is, if the value of c is set to the z2 point shown in FIG. 8B where x and 1 / y intersect, both x and 1 / y can be maximized.

The z2 point is -x = -1 / y. Therefore, using the above equations (14) and (15),
-(C + 1) / (c-1) =-(c-2) / c (20)
Is established.

  Therefore, c = 0.5.

Since c = fi / fla from equation (4),
fla = fi / c = fi / 0.5 = 2fi.

  Therefore, when setting c <1, that is, fi <fla, if the oscillation frequency flb of the pre-stage synthesizer 58 and the oscillation frequency flb of the post-stage synthesizer 59 are set to twice the frequency of the input signal, the pre-stage multiplier 51 The difference between the two frequency components included in the output signal and the difference between the two frequency components included in the output signal of the post-stage multiplier 54 can both be maximized, and the low-pass filter can be configured most simply. .

  Next, the circuit scales of the high-pass filter 52 and the low-pass filter 55 when the oscillation frequencies of the front-stage synthesizer 58 and the rear-stage synthesizer 59 are set to 1.618 fi, for example, will be considered.

When c = 0.618, the ratio x of the two frequency components output from the preceding multiplier 51 from the above equation (5) is:
x = (1 + c) / (1-c) = (1 + 0.618) / (1-0.618)
= 4.236
It becomes.

Further, the ratio y of the two frequency components output from the post-stage multiplier 54 from the above equation (6) is:
y = (2 + c) / c = (2 + 0.618) /0.618
= 4.236.

  That is, the two frequency components included in the output signals of the pre-stage multiplier 51 and the post-stage multiplier 54 have a relationship of 1: 4.236.

  The high-pass filter 52 and the low-pass filter 55 can be realized by a filter circuit using an operational amplifier shown in FIGS. 9A and 9B, for example. FIG. 9A shows a circuit example of the low-pass filter 55 using an operational amplifier, and FIG. 9B shows a circuit example of the high-pass filter 52 using an operational amplifier.

  It is known that the filter circuit shown in FIGS. 9A and 9B has an attenuation characteristic of −12 dB / oct. Therefore, when a circuit in which two stages of the low-pass filter shown in FIG. 9A or the high-pass filter shown in FIG. 9B are connected in series is used, the frequency is 4.236 times (about 4 times). Of the two frequencies, an unnecessary frequency component can be attenuated by 1/100, that is, 40 dB. The reason is as follows.

  When one frequency is attenuated by 40 dB out of two frequencies having a relationship of about four times the frequency, one frequency may be attenuated by 20 dB when the two frequencies are in a double relationship. That is, an attenuation characteristic of 20 dB / oct or more is necessary. Since the filter circuit shown in FIG. 9 (a) or (b) has an attenuation characteristic of −12 dB / oct, when two stages are connected in series, −12 dB / oct × 2 = 24 dB / oct, which is −20 dB / oct or more. The attenuation characteristic can be realized.

  When it is desired to attenuate unnecessary frequency components by about 60 dB, three stages of low-pass filters shown in FIG. 9A and high-pass filters shown in FIG. 9B may be connected in series.

  If it is desired to attenuate unnecessary frequency components by about 80 dB, a low-pass filter shown in FIG. 9A or a high-pass filter shown in FIG. 9B may be connected in four stages in series.

As described above, the frequency shift circuit 5 of this embodiment can be configured using the high-pass filter 52 and the low-pass filter 55 that can be easily realized.
(Second Embodiment)
FIG. 10 is a block diagram illustrating a configuration example of a frequency shift circuit included in the simulation apparatus according to the second embodiment.

  As shown in FIG. 10, the frequency shift circuit 15 of the second embodiment is an oscillation circuit that replaces the front-stage synthesizer 58 and the rear-stage synthesizer 59 provided in the frequency shift circuit 5 of the first embodiment shown in FIG. In this configuration, a plurality of fixed oscillators 151 having a constant frequency and different oscillation frequencies are provided. An output signal of any one of the plurality of fixed oscillators 151 is supplied to the front-stage multiplier 51 via the switch 152, and any one of the plurality of fixed oscillators 151 is supplied to the rear-stage multiplier 54. The output signal of one fixed oscillator 151 is supplied via the switch 153.

  Since the other configuration of the frequency shift circuit 15 and the configuration of the simulation device are the same as those of the first embodiment, description thereof is omitted. Further, the principle of the frequency shift in the frequency shift circuit 15 is the same as that in the first embodiment, and the description thereof is omitted.

  FIG. 10 shows a configuration example in which the frequency shift circuit 15 includes four fixed oscillators (oscillation frequencies fl1 to fl4) 151. However, the number of the fixed oscillators 151 may be any number as long as it is two or more. It may be provided according to the number of Doppler frequencies to be set.

  Further, the frequency shift circuit 15 shown in FIG. 10 first extracts the frequency component fi + fla using the pre-stage multiplier 51 and the high-pass filter 52, and then uses the post-stage multiplier 54 and the low-pass filter 55 to frequency. Although a configuration example for extracting the component fi + fla-flb is shown, as in the first embodiment, the frequency shift circuit 15 first extracts the frequency component fi-fla using a pre-stage multiplier and a low-pass filter. A configuration of extracting and subsequently extracting the frequency component fi-fla + flb using a post-stage multiplier and a high-pass filter (when fi> fla), or using a post-stage multiplier and a low-pass filter, the frequency component fi-fla A configuration for extracting −flb (when fi <fla) may be used.

  The frequency shift circuit 15 of this embodiment can set the frequency shift amount (Doppler frequency) of the output signal by the combination of the frequency signals supplied to the pre-stage multiplier 51 and the post-stage multiplier. Therefore, for example, when the number of set Doppler frequencies is relatively small during the test of the detection device 20, or when the Doppler frequency is a fixed value, it may be used.

If the frequency shift circuit 15 of this embodiment is used, the Doppler frequency can be changed only by switching the switches 152 and 153 that connect the pre-stage multiplier 51 and the post-stage multiplier 54 and the fixed oscillator 151. Therefore, the control unit 57 can be configured more simply than the frequency shift circuit 5 shown in the first embodiment.
(Third embodiment)
FIG. 11 is a block diagram illustrating a configuration example of a frequency shift circuit included in the simulation apparatus according to the third embodiment.

  As shown in FIG. 11, the simulation apparatus according to the third embodiment has the frequency shift circuit 5 according to the first embodiment shown in FIG. 2 or the frequency shift according to the second embodiment shown in FIG. In this example, the circuit 15 is realized by digital signal processing.

  The frequency shift circuit 25 of the present embodiment includes, for example, an A / D converter 251 that performs A / D conversion of an input signal, a processing circuit 252 including a DSP, a CPU, an FPGA (Field Programmable Gate Array), a memory, and the like, and a processing circuit It can be realized by a digital signal processing circuit having a D / A converter 253 for D / A converting the signal generated at 252.

  The processing circuit 252 executes processing according to a program, for example, to thereby perform the pre-stage multiplier 51, the high-pass filter 52, the pre-stage amplifier 53, the post-stage multiplier 54, the low-pass filter 55, and the post-stage amplifier 56 illustrated in FIG. The functions of the control unit 57, the front-stage synthesizer 58, and the rear-stage synthesizer 59, the functions of the fixed oscillator 151 and the switches 152 and 153 shown in FIG. The processing circuit 252 uses, for example, a digital circuit (hardware) such as an FPGA, and the pre-stage multiplier 51, the high-pass filter 52, the pre-stage amplifier 53, the post-stage multiplier 54, and the low-pass filter shown in FIG. 55, the functions of the post-stage amplifier 56, the control unit 57, the pre-stage synthesizer 58, and the post-stage synthesizer 59, and the functions of the fixed oscillator 151 and the switches 152 and 153 shown in FIG.

  Since the configuration of the simulation apparatus including the frequency shift circuit 25 is the same as that of the first embodiment, the description thereof is omitted. Further, the principle of the frequency shift in the frequency shift circuit 25 is the same as that of the first embodiment, and the description thereof is omitted.

  In the frequency shift circuit 25 shown in FIG. 11, as in the first embodiment, the frequency component fi + fla is first extracted using the front-stage multiplier and the high-pass filter, and then the rear-stage multiplier and the low-pass The frequency component fi + fla-flb may be extracted using a pass filter, and the frequency component fi-fla is extracted first using a pre-stage multiplier and a low-pass filter, and then the post-stage multiplier and high-pass filter. Is used to extract the frequency component fi-fla + flb (if fi> fla), or is used to extract the frequency component fi-fla-flb using a post-stage multiplier and a low-pass filter (if fi <fla). But you can.

  Multipliers, amplifiers, high-pass filters, low-pass filters, synthesizers, fixed oscillators, switches, etc. included in the frequency shift circuits shown in the first and second embodiments can be simplified by digital signal processing. Can be realized. For this reason, for example, the frequency of the input signal is detected by FFT analysis, or a signal that simulates the reflected wave of the moving body 30 is generated from the detection result and the waveform information and level information of the input signal recorded in the memory. There is no need to execute any processing.

Therefore, since the frequency shift circuit 25 can be realized using a DSP, CPU, or the like that does not have high processing performance, the cost of the digital signal processing circuit that realizes the function of the frequency shift circuit 25 can be reduced.
(Fourth embodiment)
In the first to third embodiments described above, a simulation apparatus that simulates a reflected wave from the moving body 30 has been proposed. The fourth embodiment proposes a test apparatus 40 that is used in the test of the detection apparatus 20 and includes the frequency shift circuit shown in the first to third embodiments.

  The test apparatus 40 is an apparatus used in a test between a plurality of processes performed when the detection apparatus 20 is assembled and manufactured. For example, the test apparatus 40 receives a wave transmitted from the detection apparatus 20 as an electric signal, and simulates the moving body 30. In this configuration, a wave is generated and output to the detection device 20 as an electrical signal.

  FIG. 12 is a block diagram showing a configuration example of the test apparatus of the present invention.

  As shown in FIG. 12, the test apparatus 40 has a configuration in which the wave receiving sensor 2 and the wave transmission unit 7 are removed from the simulation apparatus 1 according to the first embodiment shown in FIG. Other configurations are the same as those of the simulated storage 1 of the first embodiment shown in FIG.

  FIG. 12 shows a configuration example in which the test apparatus 40 includes the frequency shift circuit 5 of the first embodiment shown in FIG. 1, but the test apparatus 40 includes the second shifter shown in FIG. The frequency shift circuit 15 of the embodiment or the frequency shift circuit 25 of the third embodiment shown in FIG. 11 may be provided.

  The present invention is not limited to simulating the Doppler frequency, but the approximate frequency range of the input signal is known, and it is desired to shift the frequency of the input signal dynamically or fixedly without changing the level or waveform of the input signal. Can be used for fields.

DESCRIPTION OF SYMBOLS 1 Simulation apparatus 2 Received sensor 3 Band pass filter 4 First stage amplifier 5 Frequency shift circuit 6 Power amplifier 7 Transmission part 20 Detection apparatus 30 Mobile body 40 Test apparatus 51 Pre-stage multiplier 52 High-pass filter 53 Pre-stage amplifier 54 Post-stage multiplier 55 Low-pass filter 56 Post-stage amplifier 57 Control unit 58 Pre-stage synthesizer 59 Post-stage synthesizer 151 Fixed oscillator 152, 153 Switch 251 A / D converter 252 Processing circuit 253 D / A converter

Claims (10)

A frequency shift circuit that outputs a signal obtained by shifting the frequency of the input signal from the input signal,
A first oscillator and a second oscillator having a variable oscillation frequency;
A first multiplier for multiplying the input signal by the first signal output from the first oscillator;
A high-pass filter that passes only the frequency component of the sum of the frequency of the input signal and the first frequency that is the frequency of the first signal from the output signal of the first multiplier;
A second multiplier that multiplies the output signal of the high-pass filter and the second signal output from the second oscillator;
A low-pass filter that passes only the frequency component of the difference between the frequency of the output signal of the high-pass filter and the second frequency that is the frequency of the second signal from the output signal of the second multiplier;
A frequency shift with respect to the frequency of the input signal by controlling the first oscillator and the second oscillator and changing either the first frequency or the second frequency, or changing the first frequency and the second frequency. A control unit for changing the amount;
I have a,
The frequency shift amount includes zero,
The controller is
A frequency shift circuit that sets the first frequency and the second frequency to 1.618 times the frequency of the input signal when the frequency shift amount is zero . A frequency shift circuit that outputs a signal obtained by shifting the frequency of the input signal from the input signal,
A first oscillator and a second oscillator having a variable oscillation frequency;
A first multiplier for multiplying the input signal by the first signal output from the first oscillator;
A low-pass filter that passes only the frequency component of the difference between the frequency of the input signal and the first frequency, which is the frequency of the first signal, from the output signal of the first multiplier;
A second multiplier that multiplies the output signal of the low-pass filter by the second signal output from the second oscillator;
A high-pass filter that passes only the frequency component of the sum of the frequency of the output signal of the low-pass filter and the second frequency that is the frequency of the second signal from the output signal of the second multiplier;
A frequency shift with respect to the frequency of the input signal by controlling the first oscillator and the second oscillator and changing either the first frequency or the second frequency, or changing the first frequency and the second frequency. A control unit for changing the amount;
Have
The first frequency and the second frequency are lower than the frequency of the input signal ;
The frequency shift amount includes zero,
The controller is
A frequency shift circuit that sets the first frequency and the second frequency to 0.618 times the frequency of the input signal when the frequency shift amount is zero . A frequency shift circuit that outputs a signal obtained by shifting the frequency of the input signal from the input signal,
A first oscillator and a second oscillator having a variable oscillation frequency;
A first multiplier for multiplying the input signal by the first signal output from the first oscillator;
A first low-pass filter that passes only the frequency component of the difference between the frequency of the input signal and the first frequency, which is the frequency of the first signal, from the output signal of the first multiplier;
A second multiplier that multiplies the output signal of the first low-pass filter by the second signal output from the second oscillator;
A second low-pass filter that passes only the frequency component of the difference between the frequency of the output signal of the first low-pass filter and the second frequency that is the frequency of the second signal from the output signal of the second multiplier. When,
A frequency shift with respect to the frequency of the input signal by controlling the first oscillator and the second oscillator and changing either the first frequency or the second frequency, or changing the first frequency and the second frequency. A control unit for changing the amount;
Have
The first frequency and the second frequency are higher than the frequency of the input signal ;
The frequency shift amount includes zero,
The controller is
A frequency shift circuit that sets the first frequency and the second frequency to be twice the frequency of the input signal when the frequency shift amount is zero . Wherein the first oscillator and the second oscillator, the frequency shift circuit according to any one of claims 1 to 3, the level of which outputs a constant signal. A frequency shift circuit that outputs a signal obtained by shifting the frequency of the input signal from the input signal,
A plurality of oscillators each having a constant frequency and each outputting a signal of a different frequency;
A first multiplier that multiplies the output signal of any one of the plurality of oscillators by the input signal;
A high-pass filter that passes only a frequency component of the sum of the frequency of the oscillator and the frequency of the input signal from the output signal of the first multiplier;
A second multiplier for multiplying an output signal of any one of the plurality of oscillators by an output signal of the high-pass filter;
A low-pass filter that passes only the frequency component of the difference between the frequency of the oscillator and the frequency of the output signal of the high-pass filter from the output signal of the second multiplier;
A first switch that connects any one of the plurality of oscillators to the first multiplier;
A second switch that connects any one of the plurality of oscillators to the second multiplier;
A signal for controlling the first switch and the second switch to be supplied to the first multiplier or the second multiplier, or a signal supplied to the first multiplier and the second multiplier A control unit that changes the frequency shift amount with respect to the frequency of the input signal by changing the frequency of
I have a,
The frequency shift amount includes zero,
The controller is
A frequency shift circuit for supplying a signal having a frequency of 1.618 times the frequency of the input signal to the first multiplier and the second multiplier when the frequency shift amount is zero . A frequency shift circuit that outputs a signal obtained by shifting the frequency of the input signal from the input signal,
A plurality of oscillators each having a constant frequency and each outputting a signal of a different frequency;
A first multiplier that multiplies the output signal of any one of the plurality of oscillators by the input signal;
A low-pass filter that passes only the frequency component of the difference between the frequency of the oscillator and the frequency of the input signal from the output signal of the first multiplier;
A second multiplier for multiplying an output signal of any one of the plurality of oscillators by an output signal of the low-pass filter;
A high-pass filter that passes only the frequency component of the sum of the frequency of the oscillator and the frequency of the output signal of the low-pass filter from the output signal of the second multiplier;
A first switch that connects any one of the plurality of oscillators to the first multiplier;
A second switch that connects any one of the plurality of oscillators to the second multiplier;
A signal for controlling the first switch and the second switch to be supplied to the first multiplier or the second multiplier, or a signal supplied to the first multiplier and the second multiplier A control unit that changes the frequency shift amount with respect to the frequency of the input signal by changing the frequency of
Have
The frequency of the output signal of the oscillator that is input to the first multiplier is lower than the frequency of the input signal ;
The frequency shift amount includes zero,
The controller is
A frequency shift circuit for supplying a signal having a frequency of 0.618 times the frequency of the input signal to the first multiplier and the second multiplier when the frequency shift amount is zero . A frequency shift circuit that outputs a signal obtained by shifting the frequency of the input signal from the input signal,
A plurality of oscillators each having a constant frequency and each outputting a signal of a different frequency;
A first multiplier that multiplies the output signal of any one of the plurality of oscillators by the input signal;
A first low-pass filter that passes only the frequency component of the difference between the frequency of the oscillator and the frequency of the input signal from the output signal of the first multiplier;
A second multiplier for multiplying an output signal of any one of the plurality of oscillators by an output signal of the first low-pass filter;
A second low-pass filter that passes only the frequency component of the difference between the frequency of the oscillator and the frequency of the output signal of the first low-pass filter from the output signal of the second multiplier;
A first switch that connects any one of the plurality of oscillators to the first multiplier;
A second switch that connects any one of the plurality of oscillators to the second multiplier;
A signal for controlling the first switch and the second switch to be supplied to the first multiplier or the second multiplier, or a signal supplied to the first multiplier and the second multiplier A control unit that changes the frequency shift amount with respect to the frequency of the input signal by changing the frequency of
Have
The frequency of the output signal of the oscillator input to the first multiplier is higher than the frequency of the input signal ;
The frequency shift amount includes zero,
The controller is
A frequency shift circuit for supplying a signal having a frequency twice the frequency of the input signal to the first multiplier and the second multiplier when the frequency shift amount is zero . Wherein the plurality of oscillators, the frequency shift circuit according to any one of claims 5 7, the level of which outputs a constant signal. A simulation device for simulating a reflected wave reflected by a moving body,
A wave receiving sensor that receives a wave emitted from a detection device that detects the moving body and converts the wave into an electric signal;
The frequency shift circuit according to any one of claims 1 to 8 , wherein an output signal of the reception sensor is an input signal;
A power amplifier for amplifying an output signal of the frequency shift circuit;
A wave transmission unit that converts the signal amplified by the power amplifier into a wave corresponding to the output wave of the detection device and transmits the wave to the detection device;
A simulation device. A test device for testing a detection device for detecting a moving object,
The frequency shift circuit according to any one of claims 1 to 8 , wherein an output signal of the detection device is used as an input signal;
A power amplifier that amplifies the output signal of the frequency shift circuit and outputs the amplified signal to the detection device;
Test equipment with

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