Noise phase measurement method and device based on homologous signals

Abstract

The invention belongs to the technical field of precision measurement, and discloses a noise phase measurement method based on homologous signals and a corresponding device. According to the method, the noise measurement precision of the phase meter is improved through the following steps that under the action of an external trigger clock, an original signal containing two different frequencies f1 and f2 is generated through the same channel of a signal source; the original signal is equally divided into two beams, one beam is subjected to low-pass filtering to obtain a to-be-measured signal with the frequency of f1, and the other beam is subjected to band-pass filtering to obtain a pilot signal with the frequency of f2; combining the two beams of signals to form a dual-frequency signal, and collecting the dual-frequency signal through a single port of a phase meter; the phase meter extracts phase fluctuations of the to-be-measured signal and the pilot signal respectively; and finally, correcting the phase fluctuation of the to-be-measured signal by using the phase fluctuation of the pilot signal so as to obtain the corrected phase fluctuation. Correspondingly, the invention further provides a noise phase measuring device based on the homologous signals, and the noise phase measuring device is used for achieving the method.

Description

Technical Field

[0001] The present invention belongs to the technical field of precision measurement, and more specifically, relates to a noise phase measurement method and device based on homologous signals. Background Art

[0002] High-precision phase measurement is of great significance in the fields of weak signal detection, laser ranging, gravitational wave detection, etc. With the development of precision measurement technology, the demand for phase measurement accuracy is getting higher and higher, and the background noise of the phase meter determines the limit of phase measurement.

[0003] The noise in the signal can be measured using a phase meter. In the prior art, the signal to be measured and the pilot signal are generally generated through two channels of the signal source, and the two signals are synthesized by an adder and then divided into two paths by a power divider. The signals are collected by two ports of the phase meter, and differential processing is performed to suppress the common-mode noise in the phase meter, thereby measuring the noise contained in the signal to be measured. The disadvantage is that two ports of the phase meter are required, and more importantly, the non-common-mode noise introduced by the two ports of the phase meter (different ADC aperture jitter noise of the two ports of the phase meter) will be coupled into the signal to be measured, affecting the accuracy of the phase meter noise measurement. Summary of the invention

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides a noise phase measurement method and device based on homologous signals, which aims to improve the accuracy of phase meter noise measurement.

[0005] To achieve the above object, according to a first aspect of the present invention, a noise phase measurement method based on homologous signals is provided, comprising:

[0006] Under the trigger of the external trigger clock, the original signal containing two different frequency components f1 and f2 is generated by the same channel of the signal source;

[0007] The original signal is divided into two beams of signals with equal power, one beam of signals is subjected to low-pass filtering, and a signal with a frequency of f1 is output, which is used as the signal to be measured; the other beam of signals is subjected to band-pass filtering, and a signal with a frequency of f2 is output, which is used as the pilot signal;

[0008] The signal to be measured and the pilot signal are combined to generate a dual-frequency signal; and after the dual-frequency signal is collected through a single port of a phase meter, the phase fluctuation Δp1 of the signal to be measured and the phase fluctuation Δp2 of the pilot signal are respectively extracted through different digital phase-locked loops of the phase meter;

[0009] The phase fluctuation Δp1 of the signal to be measured is corrected by using the phase fluctuation Δp2 of the pilot signal to obtain the phase fluctuation N after the pilot signal correction. re , The phase fluctuation N after the pilot correction is used to represent the residual noise phase in the signal to be measured.

[0010] re

[0011] Furthermore, the original signal is a square wave signal, the signal with a frequency of f1 is a sinusoidal signal with a frequency of f, and the signal with a frequency of f2 is a sinusoidal signal with a frequency of 3f.

[0012] Furthermore, when the phase meter collects the dual-frequency signal, the sampling clock used is the same as the external trigger clock that triggers the generation of the original signal.

[0013] Furthermore, the phase fluctuation Δp1 of the signal to be measured and the phase fluctuation Δp2 of the pilot signal are respectively:

[0014] Δp1=2πΔf1t+2πf1δt adc

[0015] Δp2=2πΔf2t+2πf2δt adc

[0016] Where 2πΔf1t is the noise caused by the frequency fluctuation of the measured signal, 2πf1δt adc is the ADC aperture jitter noise and the sampling clock jitter noise of the phase meter contained in the measured signal; 2πΔf2t is the noise caused by the frequency fluctuation of the pilot signal, 2πf2δt adc is the ADC aperture jitter noise and the sampling clock jitter noise of the phase meter contained in the pilot signal.

[0017] According to a second aspect of the present invention, there is provided a noise phase measurement device based on a homologous signal, comprising:

[0018] The signal generator is used to generate an original signal containing two different frequency components f1 and f2 from the same channel of the signal source under the triggering of an external trigger clock;

[0019] A first power divider, used to divide the original signal into two beams of signals with equal power;

[0020] A low-pass filter, used for performing low-pass filtering on a beam of signals after passing through the first power divider, and outputting a signal to be tested with a frequency of f1;

[0021] a bandpass filter, used for performing bandpass filtering on the other signal beam after passing through the first power divider, and outputting a pilot signal with a frequency of f2;

[0022] A second power divider is used to combine the signal to be measured and the pilot signal to generate a dual-frequency signal; wherein the dual-frequency signal is collected through a single port of a phase meter;

[0023] A phase meter, used for respectively extracting the phase fluctuation Δp1 of the signal to be measured and the phase fluctuation Δp2 of the pilot signal from the dual-frequency signal through different digital phase-locked loops;

[0024] The pilot correction module is used to correct the phase fluctuation Δp1 of the signal to be measured by using the phase fluctuation Δp2 of the pilot signal to obtain the phase fluctuation N after the pilot correction. re , The phase fluctuation N after the pilot correction is used to represent the residual noise phase in the signal to be measured.

[0025] re

[0026] Furthermore, the original signal is a square wave signal, the signal with a frequency of f1 is a sinusoidal signal with a frequency of f, and the signal with a frequency of f2 is a sinusoidal signal with a frequency of 3f.

[0027] Furthermore, when the phase meter collects the dual-frequency signal, the sampling clock used is the same as the external trigger clock that triggers the generation of the original signal.

[0028] Furthermore, the phase fluctuation Δp1 of the signal to be measured and the phase fluctuation Δp2 of the pilot signal are respectively:

[0029] Δp1=2πΔf1t+2πf1δt adc

[0030] Δp2=2πΔf2t+2πf2δt adc

[0031] Where 2πΔf1t is the noise caused by the frequency fluctuation of the measured signal, 2πf1δt adc is the ADC aperture jitter noise and the sampling clock jitter noise of the phase meter contained in the measured signal; 2πΔf2t is the noise caused by the frequency fluctuation of the pilot signal, 2πf2δt adc is the ADC aperture jitter noise and the sampling clock jitter noise of the phase meter contained in the pilot signal.

[0032] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0033] (1) In the noise phase measurement method or device based on homologous signals of the present invention, two signals with frequencies f1 and f2 are generated by the same external trigger clock at the same time, so the frequency and phase fluctuations of the two signals are consistent, that is, they are homologous; two signals with homologous sources and different frequency components (pilot signal and signal to be measured) are sampled by the same port of the phase meter, which is different from the independent and unrelated ADC aperture jitter noise generated by two channels in the prior art. At this time, the ADC aperture jitter noise contained in the pilot signal and the signal to be measured in the present invention is in a proportional relationship with their frequencies, that is, the ratio of the ADC aperture jitter noise contained in the pilot signal and the signal to be measured is consistent with the frequency ratio of the pilot signal and the signal to be measured, so the aperture jitter noise in the pilot signal and the signal to be measured is also consistent, that is, they still maintain the same source, so these consistent noises can be greatly suppressed by pilot correction corresponding to the frequency ratio, thereby lowering the background noise of the phase meter and improving the accuracy of the phase meter noise measurement.

[0034] (2) Preferably, the original signal is a square wave signal, whose different frequency components have high homology and is easy to generate.

[0035] In summary, in the noise phase measurement method or device based on homologous signals of the present invention, the signal to be measured and the pilot signal are generated at the same time, output from the same port, and collected from the same port, so the phase and frequency jitter contained in the different frequency signals extracted by the back end are the same, that is, homologous. Two homologous signals are measured through the same phase meter port, and then the phase fluctuation of the signal to be measured is corrected by the pilot correction algorithm, which can effectively suppress the background noise of the phase meter and achieve high-precision measurement of the residual noise in the signal to be measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The figure is a flow chart of a noise phase measurement method based on homologous signals in an embodiment of the present invention.

[0037] Figure 2 It is a structural block diagram of a noise phase measurement device based on homologous signals in an embodiment of the present invention.

[0038] Figure 3 1 is a diagram showing experimental results of noise measurement based on the measurement device in an embodiment of the present invention.

[0039] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0040] 1-Signal generator, 2-External trigger clock, 3-First power divider, 4-Low pass filter, 5-Band pass filter, 6-Second power divider, 7-Phase meter. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0042] In the present invention, the terms "first", "second", etc. in the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0043] Example 1

[0044] like Figure 1 As shown, an embodiment of the present invention provides a noise phase measurement method based on homologous signals, which mainly includes:

[0045] S1, under the triggering of external trigger clock 2, the same channel of the signal source generates an original signal containing two different frequency components f1 and f2;

[0046] S2. The original signal is divided into two beams of signals with equal power. After one beam of signals is low-pass filtered, a signal with a frequency of f1 is output, which is used as the signal to be measured; after the other beam of signals is band-pass filtered, a signal with a frequency of f2 is output, which is used as the pilot signal; wherein, the signal to be measured contains clock noise, noise introduced by temperature and humidity, electronic noise, etc., mainly the clock noise contained in the original signal.

[0047] S3, combining the signal to be measured and the pilot signal to generate a dual-frequency signal; collecting the dual-frequency signal through a single port of the phase meter 7, and extracting the phase fluctuation Δp1 of the signal to be measured and the phase fluctuation Δp2 of the pilot signal through different digital phase-locked loops of the phase meter;

[0048] Δp1=2πΔf1t+2πf1δt adc

[0049] Δp2=2πΔf2t+2πf2δt adc

[0050] Where 2πΔf1t is the noise introduced by the unstable frequency of the measured signal, 2πf1δt adc is the aperture jitter noise of the ADC and the sampling clock jitter noise of the phase meter contained in the measured signal; 2πΔf2t is the noise introduced by the unstable frequency of the pilot signal, 2πf2δt adc is the aperture jitter noise of the ADC and the sampling clock jitter noise of the phase meter contained in the pilot signal; Δf1 is the fluctuation of f1, Δf2 is the fluctuation of f2, t represents time, δtadc Sampling timing jitter, t adc is the sampling timing.

[0051] S4, using the phase fluctuation Δp2 of the pilot signal to correct the phase fluctuation Δp1 of the signal to be measured, to obtain the phase fluctuation N after the pilot correction, the phase fluctuation N after the pilot correction is used to represent the phase fluctuation of the signal to be measured

[0052] re re

[0053] The residual noise phase in the signal; where the pilot correction algorithm is:

[0054]

[0055] Where N re It is the phase fluctuation after pilot correction, which is used to indicate the residual noise phase in the signal to be measured.

[0056] In the noise phase measurement method based on homologous signals in the present invention, two signals with frequencies f1 and f2 are triggered and generated by the same external trigger clock at the same time, so the frequency and phase fluctuations of the two signals are consistent, that is, they are homologous; two signals (pilot signal and signal to be measured) with homologous sources and different frequency components are sampled by the same port of the phase meter, which is different from the independent and unrelated ADC aperture jitter noise generated by two channels in the prior art. At this time, the ADC aperture jitter noise contained in the pilot signal and the signal to be measured in the present invention is in a proportional relationship between their frequencies, that is, the ratio of the ADC aperture jitter noise contained in the pilot signal and the signal to be measured is consistent with the frequency ratio of the pilot signal and the signal to be measured, so the aperture jitter noise in the pilot signal and the signal to be measured is also consistent, that is, they still maintain the homologous source, so these consistent noises can be greatly suppressed by the pilot correction of the corresponding frequency ratio, thus lowering the background noise of the phase meter and improving the accuracy of the phase meter noise measurement.

[0057] As a preferred implementation, the original signals of the two different frequency components f1 and f2 generated in S1 are square wave signals, whose different frequency components have high homology and are easy to generate. Since the square wave is formed by combining a set frequency f with a sinusoidal signal of its odd multiple, the Fourier expansion form of the original square wave signal is:

[0058]

[0059] Wherein, A is the amplitude of the square wave signal, ω is the angular frequency of the square wave signal, ω=2πf; in the embodiment of the present invention, the signal to be measured is a sinusoidal signal with a frequency of f, and the pilot signal is a sinusoidal signal with a frequency of 3f, that is, f1=f, f2=3f; the signal to be measured and the pilot signal are generated at the same time, output from the same port, and collected at the same port, so the phase and frequency jitter contained in the different frequency signals extracted by the back end are the same, that is, they are of the same source. The two signals of the same source are measured by the same phase meter port and corrected by the corresponding pilot, which can effectively suppress the noise of the same source.

[0060] The noise caused by the frequency fluctuation in the phase fluctuation Δp1 of the signal to be measured and the phase fluctuation Δp2 of the pilot signal can be suppressed by the existing noise suppression method.

[0061] Example 2

[0062] like Figure 2 As shown, an embodiment of the present invention provides a noise phase measurement device based on homologous signals, which mainly includes:

[0063] The signal generator 1 is used for generating an original signal containing two different frequency components f1 and f2 from the same channel of the signal source under the triggering of the external trigger clock 2;

[0064] A first power divider 3, used for dividing the original signal into two signals with equal power;

[0065] A low-pass filter 4 is used to perform low-pass filtering on a beam of signals after passing through the first power divider 3, and output a signal to be tested with a frequency of f1;

[0066] The bandpass filter 5 is used to perform bandpass filtering on the other signal beam after passing through the first power divider 3, and output a pilot signal with a frequency of f2;

[0067] The second power divider 6 is used to combine the signal to be measured and the pilot signal to generate a dual-frequency signal; wherein the dual-frequency signal is collected by a single port of the phase meter 7;

[0068] A phase meter 7, used to extract the phase fluctuation Δp1 of the signal to be measured and the phase fluctuation Δp2 of the pilot signal in the dual-frequency signal;

[0069] The pilot correction module is used to correct the phase fluctuation Δp1 of the signal to be measured by using the phase fluctuation Δp2 of the pilot signal to obtain the phase fluctuation N after the pilot correction. re , the phase fluctuation after pilot correction N re It is used to represent the residual noise phase in the signal to be measured; wherein the pilot correction algorithm is:

[0070]

[0071] Where N re It is the phase fluctuation after pilot correction, which is used to indicate the residual noise phase in the signal to be measured.

[0072] As a preferred implementation, in the embodiment of the present invention, the signal generator 1 generates an original square wave signal having frequencies f and 3f.

[0073] The original square wave signal is divided into two beams after passing through the first power divider 3. After one beam of square wave signal passes through the low-pass filter 4, a sinusoidal signal f1(t) with a frequency of f is output:

[0074]

[0075] Among them, the sinusoidal signal f1(t) is the signal to be measured.

[0076] After another square wave signal passes through the bandpass filter 5, a sinusoidal signal f2(t) with a frequency of 3f is output:

[0077]

[0078] Among them, the sinusoidal signal f2(t) is the pilot signal.

[0079] The signal to be measured and the pilot signal are synthesized by the second power divider 6 to obtain a dual-frequency signal f co (t):

[0080]

[0081] The dual frequency signal f co (t) The phase fluctuations of the measured signal and the pilot signal are respectively extracted through the same channel of the phase meter 7, and then the phase fluctuations of the measured signal and the pilot signal are respectively extracted through different digital phase-locked loops of the phase meter, wherein the phase meter 7 and the signal generator 1 use the same external trigger clock 2; then, the phase fluctuations of the measured signal are corrected by the pilot correction algorithm to suppress the ADC aperture jitter noise and the phase meter sampling clock jitter noise, thereby achieving high-precision measurement of the residual noise in the measured signal.

[0082] The measurement device of the present invention can measure the clock noise in the measured signal to achieve the one-picometer noise accuracy requirement for gravitational wave detection. Figure 3 As shown in the figure, there are the noise of the pilot signal, the noise of the signal to be measured (measurement signal), the requirement of one picometer for space gravitational wave detection, and the residual noise curve after the noise in the signal to be measured is corrected with the noise of the pilot signal. It can be seen that by suppressing the background noise of the phase meter, the noise measurement requirement of one picometer accuracy is achieved, which has a high noise measurement accuracy.

[0083] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A noise phase measurement method based on homologous signals, characterized in that: include: Under the trigger of the external trigger clock, the original signal containing two different frequency components f1 and f2 is generated by the same channel of the signal source; The original signal is divided into two beams of signals with equal power, one beam of signals is subjected to low-pass filtering, and a signal with a frequency of f1 is output, which is used as the signal to be measured; the other beam of signals is subjected to band-pass filtering, and a signal with a frequency of f2 is output, which is used as the pilot signal; The signal to be measured and the pilot signal are combined to generate a dual-frequency signal; and after the dual-frequency signal is collected through a single port of a phase meter, the phase fluctuation Δp1 of the signal to be measured and the phase fluctuation Δp2 of the pilot signal are respectively extracted through different digital phase-locked loops of the phase meter; The phase fluctuation Δp1 of the signal to be measured is corrected by using the phase fluctuation Δp2 of the pilot signal to obtain the phase fluctuation N after the pilot signal correction. re , The pilot frequency corrected phase fluctuation N re Used to indicate the residual noise phase in the signal to be measured.

2. The noise phase measurement method based on homologous signals according to claim 1, characterized in that: The original signal is a square wave signal, the signal with a frequency of f1 is a sinusoidal signal with a frequency of f, and the signal with a frequency of f2 is a sinusoidal signal with a frequency of 3f.

3. The noise phase measurement method based on homologous signals according to claim 1 or 2, characterized in that: When the phase meter collects the dual-frequency signal, the sampling clock used is the same as the external trigger clock that triggers the generation of the original signal.

4. The noise phase measurement method based on homologous signals according to claim 3 is characterized in that: The phase fluctuation Δp1 of the signal to be measured and the phase fluctuation Δp2 of the pilot signal are respectively: Δp1=2πΔf1t+2πf1δt adc Δp2=2πΔf2t+2πf2δt adc Where 2πΔf1t is the noise caused by the frequency fluctuation of the measured signal, 2πf1δt adc is the ADC aperture jitter noise and the sampling clock jitter noise of the phase meter contained in the measured signal; 2πΔf2t is the noise caused by the frequency fluctuation of the pilot signal, 2πf2δt adc is the ADC aperture jitter noise and the sampling clock jitter noise of the phase meter contained in the pilot signal.

5. A noise phase measurement device based on homologous signals, characterized in that: include: The signal generator is used to generate an original signal containing two different frequency components f1 and f2 from the same channel of the signal source under the triggering of an external trigger clock; A first power divider, used to divide the original signal into two beams of signals with equal power; A low-pass filter, used for performing low-pass filtering on a beam of signals after passing through the first power divider, and outputting a signal to be tested with a frequency of f1; a bandpass filter, used for performing bandpass filtering on the other signal beam after passing through the first power divider, and outputting a pilot signal with a frequency of f2; A second power divider is used to combine the signal to be measured and the pilot signal to generate a dual-frequency signal; wherein the dual-frequency signal is collected through a single port of a phase meter; A phase meter, used for respectively extracting the phase fluctuation Δp1 of the signal to be measured and the phase fluctuation Δp2 of the pilot signal from the dual-frequency signal through different digital phase-locked loops; The pilot correction module is used to correct the phase fluctuation Δp1 of the signal to be measured by using the phase fluctuation Δp2 of the pilot signal to obtain the phase fluctuation N after the pilot correction. re , The pilot frequency corrected phase fluctuation N re Used to indicate the residual noise phase in the signal to be measured.

6. The noise phase measurement device based on homologous signals according to claim 5, characterized in that: The original signal is a square wave signal, the signal with a frequency of f1 is a sinusoidal signal with a frequency of f, and the signal with a frequency of f2 is a sinusoidal signal with a frequency of 3f.

7. The noise phase measurement device based on homologous signals according to claim 5 or 6, characterized in that: When the phase meter collects the dual-frequency signal, the sampling clock used is the same as the external trigger clock that triggers the generation of the original signal.

8. The noise phase measurement device based on homologous signals according to claim 7, characterized in that: The phase fluctuation Δp1 of the signal to be measured and the phase fluctuation Δp2 of the pilot signal are respectively: Δp1=2πΔf1t+2πf1δt adc Δp2=2πΔf2t+2πf2δt adc Where 2πΔf1t is the noise caused by the frequency fluctuation of the measured signal, 2πf1δt adc is the ADC aperture jitter noise and the sampling clock jitter noise of the phase meter contained in the measured signal; 2πΔf2t is the noise caused by the frequency fluctuation of the pilot signal, 2πf2δt adc is the ADC aperture jitter noise and the sampling clock jitter noise of the phase meter contained in the pilot signal.

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