Analog signal measurement method and device based on relative frequency control

Abstract

The invention discloses an analog signal measurement method and device based on relative frequency control, and belongs to the technical field of measurement. The method comprises the following steps: setting a frequency F0 of a signal to be measured and a period T0, determining a frequency difference delta f, and generating a sampling frequency F1; generating a sampling clock for measurement according to the sampling frequency F1 to obtain a voltage group V1 (k); by adjusting the delta f, different new sampling frequencies F1 are generated and measured, and voltage groups {V2 (k)} to {Vn (k)} are obtained respectively; and according to the data set {V1 (k), V2 (k),..., Vn (k)}, recovering a measurement waveform and calculating a related measurement value. According to the invention, equipment occupation, test difficulty and test cost can be reduced, and a stable and accurate analog signal parameter measurement result can be rapidly obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of measurement technology, and in particular to a method and device for measuring analog signals based on relative frequency control. Background Art

[0002] With the rapid development of semiconductor technology, signal chain products have shown the characteristics of high resolution and high conversion rate. In the fields of RF, radar, audio, etc., the frequency of analog signals will reach above GHz. Measurement will directly affect the effectiveness, safety and reliability of digital-analog hybrid systems. Therefore, the signal test end shows the characteristics of high complexity, high indicators and high cost.

[0003] At present, the testing of such signal chain products is generally carried out through automated test equipment in conjunction with high-performance oscilloscopes and spectrum analyzers to achieve data sampling and analysis, and the testing cost is very high. It has become a common demand in the domestic integrated circuit field to achieve low-cost testing through test method design and to achieve testing of high-speed signal parameters.

[0004] Traditional equivalent sampling testing requires obtaining accurate input waveform cycles and a stable trigger clock to ensure sampling intervals, which results in hardware problems such as complex processing procedures, high system resource usage, and difficulty in meeting clock accuracy requirements. Analog signals are highly dependent on the indicators of test hardware, and dedicated test systems or devices have problems such as high hardware design complexity and difficulty in noise calibration. These hardware design requirements make equivalent sampling testing methods very difficult to implement on test platforms that are mainly based on inherent equipment or instruments. Summary of the invention

[0005] The object of the present invention is to provide a method and device for measuring an analog signal based on relative frequency control to solve the problems in the background technology.

[0006] In order to solve the above technical problems, the present invention provides an analog signal measurement method and device based on relative frequency control, comprising: Step S1: Set a frequency F0 of a signal to be measured, whose period is T0, determine the frequency difference Δf, and generate a sampling frequency F1; Step S2: Generate a sampling clock according to the sampling frequency F1 to perform measurement and obtain a voltage group V1(k); Step S3: By adjusting Δf, different new sampling frequencies F1 are generated and measured to obtain voltage groups {V2(k)} to {V n (k)}; Step S4: Based on the data set {V1(k), V2(k), . . . , V n (k)}, recover the measured waveform and calculate the relevant measurement values; The calculation formula of AC voltage U is: , each group {V n (k)} corresponds to a U n ; Phase φ positioning formula: ; Based on the relationship between the phase and voltage of the entire waveform cycle after the arrangement, the signal-to-noise ratio, spurious-free dynamic range and power parameters are obtained.

[0007] In one embodiment, the step S1 comprises: initially setting a frequency difference Δf according to the frequency F0 of the signal to be measured, , by controlling the frequency difference, the sampling frequency F1 is determined, and its period is T1, and the number of samples N required for each period of the measured signal is determined.

[0008] In one embodiment, the relationship for determining the sampling frequency F1 is: or .

[0009] In one embodiment, step S2 includes: determining the number of sampling points in a single equivalent sampling period to be N according to the actual needs of the measurement, wherein k represents the number of samplings, and the value range of k is 0 to N-1; in this case, the voltage V(k) of a single measurement point is expressed by the amplitude of the signal to be measured V FS , the frequency F1 of the signal to be measured and the position k are expressed as:

[0010] When the number of measurements k=N-1, the measurement is stopped, which is recorded as {V1(k)}.

[0011] In one implementation, the signal to be measured is a periodic voltage signal or a periodic current signal.

[0012] The present invention also provides an analog signal measurement device based on relative frequency control, comprising a cycle counter, a frequency controller, an ADC and a parameter calculation module; The frequency controller determines the frequency difference Δf and generates a sampling frequency F1; The ADC generates a sampling clock according to the sampling frequency F1, and measures the signal to be measured through the sampling ADC; The cyclic counter measures the count of position k in a single measurement and the count of group V in multiple measurements. n (k) the count of n; The parameter calculation module is based on the data set {V1(k), V2(k), . . . , V n (k)}, recover the measured waveform and calculate the related measurement values.

[0013] In one embodiment, the frequency controller initially sets a frequency difference Δf according to the input frequency F0 of the signal to be measured, determines the sampling frequency F1 and its period T1 by controlling the frequency difference, and determines the number of samples N required for each period of the signal to be measured.

[0014] In one embodiment, the cyclic counter counts the measurement group as n, the measurement position as k, and stops measuring when the measurement number k=N-1. After completing a set of tests, modify Δf, and generate a new F1 according to the principle, repeat the steps to obtain the second set of measurement values ​​{V2(k)}, and complete {V2(k)} according to the required number of measurement points. n (k)} measurement.

[0015] The present invention provides an analog signal measurement method and device based on relative frequency control, which reduces hardware requirements by forming a frequency difference transformation with a signal to be tested through sampling frequency control. Under the premise that it can be implemented by a wider range of equipment and instruments, a method and device for measuring analog signals based on relative frequency control are provided, which reduces equipment occupancy, reduces test difficulty, reduces test costs, and quickly obtains stable and accurate analog signal parameter measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a flow chart of a specific implementation method of the measurement method of the present invention.

[0017] Figure 2 It is a flow chart of a specific implementation of the measuring device of the present invention.

[0018] Figure 3 It is a schematic diagram of a positioning method of the measurement method of the present invention. DETAILED DESCRIPTION

[0019] The following is a further detailed description of an analog signal measurement method and device based on relative frequency control proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer according to the following description. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0020] The present invention provides an analog signal measurement method based on relative frequency control, the process of which is as follows: Figure 1 As shown, the following steps are included: In this embodiment, the signal to be measured is a periodic voltage signal or a periodic current signal. Step S1: Determine the frequency difference Δf and generate the sampling frequency F1.

[0021] According to the input F0, a frequency difference Δf is initially set, and the frequency control relationship is: ; or

[0022] Determine the sampling frequency F1 with a period of T1, and determine the number of samples N required for each period of the measured signal. Since the frequency F and the period T of the same signal have an inverse correlation, the frequency representation is used uniformly in the following text; F0 control principle: , m and n are any different natural numbers; it can be considered that F1 is not equal to m·F0 / n, and if it is not divisible, it can ensure that the sampling is not repeated; Δf control principle: .

[0023] Step S2: Generate a sampling clock according to the sampling frequency F1 to perform measurement and obtain a voltage group V1(k).

[0024] According to the sampling frequency F1, a sampling clock is generated, and the signal to be measured is measured through the sampling ADC. The group is recorded as 1, the measurement position is k, and the measured voltage is recorded as V1(k). When the measurement number k=N-1, the measurement is stopped; according to the actual needs of the measurement, the sampling points in a single equivalent sampling cycle are determined to be N, and k is used to represent the sampling number, and the value range of k is 0 to N-1. In this case, the voltage V(k) of a single measurement point can be measured by the amplitude V of the signal to be measured. FS , the frequency F1 of the signal to be measured and the position k are expressed as: .

[0025] Step S3: By adjusting Δf, different new sampling frequencies F1 are generated and measured to obtain voltage groups {V2(k)} to {V n (k)}, different test groups obtain different phase point information of the same signal.

[0026] Modify Δf in step S1, and generate a new sampling frequency F1 according to the principle, repeat step S2 to obtain the second set of measurement values ​​{V2(k)}, and so on, until {V n (k)}. Figure 3 The figure shows a positioning method provided by the present invention.

[0027] Step S4: Based on the data set {V1(k), V2(k), . . . , V n (k)}, recover the measured waveform and calculate the related measurement values.

[0028] The calculation formula of AC voltage U is: , each group {V n (k)} corresponds to a U n ; Phase φ positioning formula:

[0029] Based on the relationship between the phase and voltage of the entire waveform cycle after arrangement, parameters such as signal-to-noise ratio, spurious-free dynamic range, and power can be obtained.

[0030] In this embodiment, the present invention also provides an analog signal measurement device based on relative frequency control, such as Figure 2 As shown, it includes a cycle counter, an adder, a frequency controller, an ADC and a parameter calculation module.

[0031] The frequency controller determines the frequency difference Δf and generates the sampling frequency F1. Based on the input F0, a frequency difference Δf is initially set. By controlling the frequency difference, the sampling frequency F1 and its period T1 are determined, and the number of samples N required for each period of the measured signal is determined. Based on F1, a sampling clock is generated for measurement to obtain the voltage group V n (k).

[0032] The ADC generates a sampling clock according to the sampling frequency F1, and measures the signal to be measured through the sampling ADC.

[0033] The loop counter is used to count the measurement group as n and the measurement position as k. When the measurement number k=N-1, the measurement is stopped. After completing a set of tests, Δf is modified and a new F1 is generated according to the principle. The steps are repeated to obtain the second set of measurement values ​​{V2(k)}. The number of measurement points required is completed to {V n (k)} measurement.

[0034] The parameter calculation module is based on the data set {V1(k), V2(k), ···, V n (k)}, recover the measured waveform and calculate the related measurement values.

[0035] The calculation formula of AC voltage U is: , each group {V n (k)} corresponds to a U n ; Phase φ positioning formula: .

[0036] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A method for measuring an analog signal based on relative frequency control, characterized in that: include: Step S1: Set a frequency F0 of a signal to be measured, whose period is T0, determine the frequency difference Δf, and generate a sampling frequency F1; Step S2: Generate a sampling clock according to the sampling frequency F1 to perform measurement and obtain a voltage group V1(k); Step S3: By adjusting Δf, different new sampling frequencies F1 are generated and measured to obtain voltage groups {V2(k)} to {V n (k)}; Step S4: Based on the data set {V1(k), V2(k), . . . , V n (k)}, recover the measured waveform and calculate the relevant measurement values; The calculation formula of AC voltage U is: , each group {V n (k)} corresponds to a U n ; Phase φ positioning formula: ； Based on the relationship between the phase and voltage of the entire waveform cycle after the arrangement, the signal-to-noise ratio, spurious-free dynamic range and power parameters are obtained.

2. The analog signal measurement method based on relative frequency control according to claim 1, characterized in that: The step S1 comprises: initially setting a frequency difference Δf according to the frequency F0 of the signal to be measured, , by controlling the frequency difference, the sampling frequency F1 is determined, and its period is T1, and the number of samples N required for each period of the measured signal is determined.

3. The analog signal measurement method based on relative frequency control according to claim 2, characterized in that: The relationship for determining the sampling frequency F1 is: or .

4. The analog signal measurement method based on relative frequency control according to claim 1, characterized in that: The step S2 includes: determining the number of sampling points in a single equivalent sampling period to be N according to the actual needs of the measurement, wherein k represents the sampling number, and the value range of k is 0 to N-1; in this case, the voltage V(k) of a single measurement point is expressed by the amplitude V of the signal to be measured. FS , the frequency F1 of the signal to be measured and the position k are expressed as: When the number of measurements k=N-1, the measurement is stopped, which is recorded as {V1(k)}.

5. The analog signal measurement method based on relative frequency control according to claim 1, characterized in that: The signal to be measured is a periodic voltage signal or a periodic current signal.

6. A measuring device based on the method according to any one of claims 1 to 5, characterized in that: It includes a cycle counter, a frequency controller, an ADC and a parameter calculation module; The frequency controller determines the frequency difference Δf and generates a sampling frequency F1; The ADC generates a sampling clock according to the sampling frequency F1, and measures the signal to be measured through the sampling ADC; The cyclic counter measures the count of position k in a single measurement and the count of group V in multiple measurements. n (k) the count of n; The parameter calculation module is based on the data set {V1(k), V2(k), . . . , V n (k)}, recover the measured waveform and calculate the related measurement values.

7. The measuring device according to claim 6, characterized in that The frequency controller initially sets a frequency difference Δf according to the input frequency F0 of the signal to be measured, determines the sampling frequency F1 and its period T1 by controlling the frequency difference, and determines the number of samples N required for each period of the signal to be measured.

8. The measuring device according to claim 6, characterized in that The loop counter counts the measurement group as n, and the measurement position as k. When the measurement number k=N-1, the measurement is stopped. After completing a set of tests, Δf is modified, and a new F1 is generated according to the principle. The steps are repeated to obtain the second set of measurement values ​​{V2(k)}. The number of measurement points required is completed to {V n (k)} measurement.

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