A noise phase measurement method and apparatus based on homologous signals

Abstract

The present application belongs to the field of precision measurement, and discloses a noise phase measurement method based on homologous signals and a corresponding device. The method improves the precision of phase meter noise measurement through the following steps: under the action of an external trigger clock, a signal source is used to generate an original signal containing two different frequencies f1 and f2; the original signal is equally divided into two beams, one of which is low-pass filtered to obtain a to-be-measured signal with a frequency of f1, and the other is band-pass filtered to obtain a pilot signal with a frequency of f2; the two beams of signals are combined to form a dual-frequency signal, which is collected through a single port of a phase meter; the phase meter extracts the phase fluctuations of the to-be-measured signal and the pilot signal respectively; finally, the phase fluctuations of the to-be-measured signal are corrected using the phase fluctuations of the pilot signal, thereby obtaining the corrected phase fluctuations. Correspondingly, the present application also provides a noise phase measurement device based on homologous signals for implementing the above method.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of precision measurement, and more particularly, relates to a noise phase measurement method and device based on homologous signals. BACKGROUND

[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 noise floor of the phase meter determines the limit of phase measurement.

[0003] The phase meter can be used to measure the noise in the signal. In the prior art, two channels of a signal source are generally used to generate a to-be-measured signal and a pilot signal, respectively. The two signals are combined through an adder and then divided into two paths through a power divider, and are collected by two ports of the phase meter respectively, and are differentially processed to suppress common-mode noise in the phase meter, and then the noise contained in the to-be-measured signal is measured. The disadvantage is that two ports of the phase meter are needed, and more importantly, the non-common-mode noise (ADC aperture jitter noise of the two ports of the phase meter) introduced by the two ports of the phase meter will be coupled into the to-be-measured signal, affecting the accuracy of the phase meter noise measurement. SUMMARY

[0004] In view of the above defects or improvement needs of the prior art, the present application 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-mentioned purpose, according to the first aspect of the present application, a noise phase measurement method based on homologous signals is provided, comprising:

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

[0007] Divide the original signal into two signals with equal power, one of which is low-pass filtered to output a signal with a frequency of f1, which is used as a to-be-measured signal; the other is band-pass filtered to output a signal with a frequency of f2, which is used as a pilot signal;

[0008] Combine the to-be-measured signal and the pilot signal to generate a dual-frequency signal; and collect the dual-frequency signal through a single port of the phase meter, and extract the phase fluctuation Δp1 of the to-be-measured signal and the phase fluctuation Δp2 of the pilot signal through different digital phase-locked loops of the phase meter;

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

[0010] re

[0011] Further, the original signal is a square wave signal, the signal with frequency f1 is a sine signal with frequency f, and the signal with frequency f2 is a sine signal with frequency 3f.

[0012] Further, when the phase meter collects the dual-frequency signal, the sampling clock used is the same as the external trigger clock used to generate the original signal.

[0013] Further, the phase fluctuation Δp1 of the to-be-tested signal and the phase fluctuation Δp2 of the pilot signal are respectively:

[0014] Δp1 = 2πΔf1t + 2πf1δt adc

[0015] Δp2 = 2πΔf2t + 2πf2δt adc

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

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

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

[0019] a first power divider, configured to divide the original signal into two signals with equal power;

[0020] a low-pass filter, configured to perform low-pass filtering on one of the two signals after the first power divider, and output a to-be-tested signal with frequency f1;

[0021] a band-pass filter, configured to perform band-pass filtering on the other of the two signals after the first power divider, and output a pilot signal with frequency f2;

[0022] a second power divider, configured to combine the to-be-tested signal and the pilot signal to generate a dual-frequency signal; wherein the dual-frequency signal is collected by a single port of a phase meter;

[0023] a phase counter, configured to extract phase fluctuation Δp1 of the to-be-tested signal and phase fluctuation Δp2 of the pilot signal from the dual-frequency signal respectively through different digital phase-locked loops;

[0024] a pilot correction module, configured to correct the phase fluctuation Δp1 of the to-be-tested signal by the phase fluctuation Δp2 of the pilot signal, to obtain a pilot-corrected phase fluctuation N re , The pilot-corrected phase fluctuation N is used to represent residual noise phase in the to-be-tested signal.

[0025] re

[0026] Further, the original signal is a square wave signal, the signal with the frequency f1 is a sine signal with the frequency f, and the signal with the frequency f2 is a sine signal with the frequency 3f.

[0027] Further, when the phase counter collects the dual-frequency signal, a sampling clock used is the same as an external trigger clock for generating the original signal.

[0028] Further, the phase fluctuation Δp1 of the to-be-tested signal and the phase fluctuation Δp2 of the pilot signal are respectively:

[0029] Δp1=2πΔf1t+2πf1δt adc

[0030] Δp2=2πΔf2t+2πf2δt adc

[0031] In the formula, 2πΔf1t is noise caused by frequency fluctuation of the to-be-tested signal, 2πf1δt adc is ADC aperture jitter noise and sampling clock jitter noise of the phase counter contained in the to-be-tested signal; 2πΔf2t is noise caused by frequency fluctuation of the pilot signal, and 2πf2δt adc is ADC aperture jitter noise and sampling clock jitter noise of the phase counter contained in the pilot signal.

[0032] Overall, the above technical solutions conceived by the present application can achieve the following beneficial effects:

[0033] (1) The noise phase measurement method or device based on homologous signals in the application, the two signals with frequencies of f1 and f2 are triggered by the same external trigger clock at the same time, so the frequency and phase fluctuation of the two signals are consistent, that is, homologous; the two homologous signals with 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 irrelevant ADC aperture jitter noise generated by the two channels at present, at this time, the ADC aperture jitter noise contained in the pilot signal and the signal to be measured is in a proportional relationship with the frequency, 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 consistent, that is, still maintains homologous, so the consistent noise can be greatly suppressed by the pilot correction corresponding to the frequency ratio, in this way, the noise floor of the phase meter is reduced, and the accuracy of the phase meter noise measurement is improved.

[0034] (2) As a preferred, the original signal is a square wave signal, which has high homology of different frequency components and is easy to generate.

[0035] In summary, the noise phase measurement method or device based on homologous signals in the application, 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. The two homologous signals are measured through the same phase meter port, and then the phase fluctuation of the signal to be measured is corrected through the pilot correction algorithm, which can effectively suppress the noise floor of the phase meter and realize high-precision measurement of the residual noise in the signal to be measured. BRIEF DESCRIPTION OF DRAWINGS

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

[0037] Figure 2 The structure block diagram of the noise phase measurement device based on homologous signals in the embodiment of the application.

[0038] Figure 3 The experimental result diagram of the noise measurement based on the measurement device in the embodiment of the application.

[0039] In all the drawings, the same reference signs are used to represent 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 objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

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

[0043] Embodiment 1

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

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

[0046] S2, dividing the original signal into two signals with equal power, one signal is low-pass filtered, and the output signal with a frequency of f1 is taken as a to-be-measured signal; the other signal is band-pass filtered, and the output signal with a frequency of f2 is taken as a pilot signal; wherein the to-be-measured signal 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 to-be-measured signal and the pilot signal to generate a dual-frequency signal; and collecting the dual-frequency signal through a single port of a phase meter 7, and extracting the phase fluctuation Δp1 of the to-be-measured signal 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] In the formula, 2πΔf1t is the noise introduced due to the instability of the frequency of the to-be-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 to-be-measured signal; 2πΔf2t is the noise introduced due to the instability of the 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, and δtadc jitter of sampling timing, t adc is the sampling timing.

[0051] S4, the phase fluctuation N of the pilot signal is used to correct the phase fluctuation Δp1 of the to-be-measured signal, and the phase fluctuation N after pilot correction is obtained.

[0052] re re

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

[0054]

[0055] In the formula, N re is the phase fluctuation after pilot correction, used to represent the residual noise phase in the to-be-measured signal.

[0056] The noise phase measurement method based on homologous signals in the application, the two signals with frequencies f1 and f2 are triggered at the same time by the same external trigger clock, so the frequencies and phase fluctuations of the two signals are consistent, that is, homologous; the two homologous signals with different frequency components (pilot signal and to-be-measured signal) are sampled by the same port of the phase meter, which is different from the independent and irrelevant ADC aperture jitter noise generated by the two channels at present, at this time, the ADC aperture jitter noise contained in the pilot signal and the to-be-measured signal in the application is in the proportional relationship of its frequency, that is, the ratio of the ADC aperture jitter noise contained in the pilot signal and the to-be-measured signal is consistent with the frequency ratio of the pilot signal and the to-be-measured signal, so the aperture jitter noise in the pilot signal and the to-be-measured signal is consistent, that is, still maintains homology, so these consistent noises can greatly suppress the ADC aperture jitter noise through the corresponding frequency proportional pilot correction, in this way, the background noise of the phase meter is reduced, and the accuracy of the phase meter noise measurement is improved.

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

[0058]

[0059] Wherein, A is the amplitude of the square wave signal, and ω is the angular frequency of the square wave signal, ω=2πf;In the embodiment of the application, the to-be-measured signal 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 and f2=3f;The to-be-measured signal and the pilot signal are generated at the same time and output from the same port, and are collected from the same port, so that the phase and frequency jitter contained in the different frequency signals extracted by the back end are the same, that is, homologous, and the two homologous signals are measured by the same phase meter port and are corrected by the corresponding pilot, so that the homologous noise can be effectively suppressed.

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

[0061] Embodiment 2

[0062] As shown in Figure 2 , the embodiment of the application provides a noise phase measurement device based on homologous signals, which mainly comprises:

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

[0064] A first power divider 3 is used to divide the original signal into two signals with equal power;

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

[0066] A band-pass filter 5 is used to perform band-pass filtering on the other signal after the first power divider 3, and output a pilot signal with a frequency of f2;

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

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

[0069] A pilot correction module is used to correct the phase fluctuation Δp1 of the to-be-measured signal by the phase fluctuation Δp2 of the pilot signal, and obtain a pilot-corrected phase fluctuation N re , the pilot-corrected phase fluctuation N re is used to represent the residual noise phase in the to-be-measured signal;Wherein, the pilot correction algorithm is:

[0070]

[0071] In the formula, N re is the phase fluctuation of the pilot correction, used to represent the residual noise phase in the signal to be measured.

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

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

[0074]

[0075] The sinusoidal signal f1(t) is the signal to be measured.

[0076] The other beam of square wave signal passes through the band-pass filter 5, and a sinusoidal signal f2(t) with a frequency of 3f is output:

[0077]

[0078] The sinusoidal signal f2(t) is the pilot signal.

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

[0080]

[0081] The dual-frequency signal f co (t) is collected through the same channel of the phase meter 7, and then the phase fluctuation of the signal to be measured and the phase fluctuation of the pilot signal are 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 fluctuation of the signal to be measured is corrected through the pilot correction algorithm to suppress the ADC aperture jitter noise and the phase meter sampling clock jitter noise, and high-precision measurement of the residual noise in the signal to be measured is realized.

[0082] The measurement device based on the application can measure the clock noise in the signal to be measured, and can realize the requirement of one picometer precision noise for gravitational wave detection. Figure 3 As shown in the figure, the noise of the pilot signal, the noise of the signal to be measured (the measurement signal), the requirement of one picometer for spatial gravitational wave detection, and the residual noise curve after the noise in the signal to be measured is corrected by the noise of the pilot signal can be seen. After the phase meter background noise is suppressed, the requirement of one picometer precision noise measurement is realized, and the noise measurement precision is high.

[0083] Those skilled in the art can easily understand that the above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A noise phase measurement method based on homologous signals, characterized in that: include: Under the trigger of external trigger clock, the same channel of the signal source generates two different frequency components 、 The original signal; The original signal is divided into two signals with equal power. After low-pass filtering, the output frequency of one signal is The signal is used as the signal to be measured; after the other signal is band-pass filtered, the output frequency is signal, and use it as a pilot signal; The signal to be measured and the pilot signal are combined to generate a dual-frequency signal; the dual-frequency signal is collected through a single port of a phase meter, and the phase fluctuations of the signal to be measured are extracted respectively through different digital phase-locked loops of the phase meter. and the phase fluctuation of the pilot signal ; The phase fluctuation of the pilot signal Phase fluctuation of the signal to be measured Correction is performed to obtain the phase fluctuation after pilot correction , , the phase fluctuation after the pilot correction Used to represent the residual noise phase in the signal to be measured; 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; Phase fluctuation of the signal to be measured and the phase fluctuation of the pilot signal They are: Where, is the noise caused by the frequency fluctuation of the signal to be measured, is the ADC aperture jitter noise and the phase meter sampling clock jitter noise contained in the signal to be measured; is the noise caused by the frequency fluctuation of the pilot signal, is the ADC aperture jitter noise and the phase meter sampling clock jitter noise contained in the pilot signal.

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, and the frequency is The signal frequency is The sinusoidal signal, the frequency is The signal frequency is The sine signal.

3. A noise phase measurement device based on homologous signals, characterized in that: include: Signal generator, used to generate two different frequency components from the same channel of the signal source under the trigger of an external trigger clock 、 The original signal; A first power splitter, configured to split the original signal into two signals of equal power; A low-pass filter is used to perform low-pass filtering on a beam of signals after passing through the first power divider, and the output frequency is The signal to be tested; A bandpass filter is used to perform bandpass filtering on the other signal after passing through the first power divider, and the output frequency is pilot signal; A second power splitter is configured 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 a phase meter; Phase meter, used to extract the phase fluctuation of the signal to be measured through different digital phase-locked loops for the dual-frequency signal and the phase fluctuation of the pilot signal ; A pilot correction module is used to adjust the phase fluctuation of the pilot signal Phase fluctuation of the signal to be measured Correction is performed to obtain the phase fluctuation after pilot correction , , the phase fluctuation after the pilot correction Used to represent the residual noise phase in the signal to be measured; 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; Phase fluctuation of the signal to be measured and the phase fluctuation of the pilot signal They are: Where, is the noise caused by the frequency fluctuation of the signal to be measured, is the ADC aperture jitter noise and the phase meter sampling clock jitter noise contained in the signal to be measured; is the noise caused by the frequency fluctuation of the pilot signal, is the ADC aperture jitter noise and the phase meter sampling clock jitter noise contained in the pilot signal.

4. The noise phase measurement device based on homologous signals according to claim 3, characterized in that: The original signal is a square wave signal, and the frequency is The signal frequency is The sinusoidal signal, the frequency is The signal frequency is The sine signal.

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