Clock frequency source punctuality compensation method

Abstract

The invention discloses a clock frequency source punctuality compensation method, and belongs to the technical field of clock frequency, and the method comprises the steps: S1, first tested equipment is placed in an incubator, the temperature of the incubator is set to be 25 DEG C, the incubator is started to work, aging characteristic separation is carried out, and the first tested equipment internally comprises a crystal oscillator or a rubidium clock; s2, after the aging characteristic curve is obtained, temperature characteristics are extracted, the first tested equipment is placed in an incubator, the temperature of the incubator changes within a preset range along with time, and the incubator is started to work; s3, comprehensive compensation of the first tested equipment is calculated; and S4, performing sectional compensation on the second tested equipment. The punctuality index of the medium crystal oscillator or the rubidium clock can be compensated through the punctuality compensation method, so that the cost is reduced. The timekeeping indexes of crystal oscillators or rubidium clocks with good timekeeping performance can be improved again through the method. The method can be used for various crystal oscillators or rubidium clocks and cannot be changed due to different hardware types.

Description

Technical Field

[0001] The present invention relates to the technical field of clock frequencies, and particularly to a method for compensating the timekeeping of a clock frequency source. Background Art

[0002] The main factors affecting the timekeeping performance of crystal oscillators or rubidium clocks include two aspects. The first aspect is the aging characteristic of the clock source itself, that is, as time goes by, the deviation of the frequency of the clock source from the standard frequency will become larger and larger; the second aspect is that the frequency of the clock source will change with the change of the ambient temperature. Traditional compensation methods take the combined influence result of the two as the target parameter and use the least squares method or other algorithms for comprehensive compensation, without accurately compensating after separating the aging characteristic and the temperature characteristic. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for compensating the timekeeping of a clock frequency source.

[0004] The purpose of the present invention is achieved by the following technical solutions:

[0005] The present invention discloses a method for compensating the timekeeping of a clock frequency source, including the following steps:

[0006] S1. Place the first device under test in an incubator, set the temperature of the incubator to a constant 25°C, turn on the incubator to work, and separate the aging characteristic. The first device under test includes a crystal oscillator or a rubidium clock inside;

[0007] S2. After obtaining the aging characteristic curve, extract the temperature characteristic. Place the first device under test in the incubator, and the temperature of the incubator changes within a preset range over time. Turn on the incubator to work;

[0008] S3. Calculate the comprehensive compensation of the first device under test;

[0009] S4. Perform segmented compensation on the second device under test.

[0010] Preferably, step S1 specifically includes: after the first device under test is normally powered on, obtain the first Ori signal and the first Ref signal output by the first device under test per second, where the frequencies of both the first Ori signal and the first Ref signal are 10 MHz. Continuously obtain the first Ori signal and the first Ref signal for three days, calculate the first frequency difference Δf between all the first Ori signals and the first Ref signals, and record it as the first data group Time-Freq; the first data group Time-Freq is where Δf i(i = 1, 2, 3…n) represents the first frequency difference at the i-th second. The first data set Time-Freq is solved by a polynomial equation to obtain the aging characteristic function f(x). time = a time + b time x + c time x 2 , where x represents time, and its unit is seconds. a time represents the first constant term, b time represents the first first-order term coefficient, and c time represents the first second-order term coefficient.

[0011] Preferably, step S2 specifically includes: after the first device under test is powered on normally, obtain the second Ori signal and the second Ref signal output by the first device under test per second. The frequencies of the second Ori signal and the second Ref signal are both 10 MHz. Continuously obtain the second Ori signal and the second Ref signal for thirty hours, calculate the second frequency difference Δf’ between all the second Ori signals and the second Ref signals, and record it as the second data set Syn-Freq: where △t i (i = 1, 2, 3…n) represents the temperature deviation at the i-th second, and △f i ’(i = 1, 2, 3…n) represents the second frequency difference at the i-th second; according to the aging characteristic function set the value range of time x to [0, 108000] to obtain the third data set Time-Freq’: By taking the difference between the second data set Syn-Freq and the third data set Time-Freq’, obtain the frequency deviation caused by temperature changes: where △f ti (i = 1, 2, 3…n) represents the frequency deviation corresponding to the temperature change at the i-th second. Perform a multivariate equation solution on it to obtain the temperature characteristic function f(Δt) temp = a temp + b temp Δt + c temp Δt 2 , where Δt is the temperature change amount, a temp represents the second constant term, b temp represents the second first-order term coefficient, and c temp represents the second second-order term coefficient.

[0012] Preferably, step S3 specifically includes: based on the aging characteristic function f(x) obtained in step S1 time = a time + b time x + c time x 2and the temperature characteristic function f(Δt) is obtained in step S2 temp = a temp + b temp Δt + c temp Δt 2 , and the timekeeping compensation of the crystal oscillator or rubidium clock inside the first device under test is expressed as f(x) comp = f(x) time + f(Δt) temp , where the time x is used to calculate the aging frequency compensation data, and the temperature change Δt is used to calculate the frequency compensation data caused by the temperature change.

[0013] Preferably, step S4 specifically includes: the second device under test includes a crystal oscillator or a rubidium clock inside. Based on the power-on time, the temperature and aging characteristic deviation of the crystal oscillator or rubidium clock inside the second device under test is greater than a preset threshold, and the second device under test is segmented and compensated through steps S1 - S3.

[0014] The beneficial effects of the present invention are as follows:

[0015] 1) Cost reduction. The crystal oscillator or rubidium clock with better timekeeping indicators is relatively more expensive. The timekeeping compensation method of the present invention can make up for the timekeeping indicators of medium crystal oscillators or rubidium clocks, thereby reducing costs.

[0016] 2) Improvement of timekeeping indicators. With the current development of technology, the requirements for timekeeping indicators are getting higher and higher. For crystal oscillators or rubidium clocks with better timekeeping performance, the timekeeping indicators can be further improved through the present invention.

[0017] 3) Versatility. The method of the present invention can be used for various crystal oscillators or rubidium clocks and will not change due to different hardware types. Description of the Drawings

[0018] Figure 1 is a schematic diagram of the steps of a timekeeping compensation method for a clock frequency source according to an embodiment of the present invention;

[0019] Figure 2 is a temperature change curve graph of the temperature chamber of a timekeeping compensation method for a clock frequency source according to an embodiment of the present invention;

[0020] Figure 3 is an aging characteristic curve graph of a certain crystal oscillator of a timekeeping compensation method for a clock frequency source according to an embodiment of the present invention. Detailed Embodiment

[0021] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0022] The present invention discloses a timekeeping compensation method for a clock frequency source, and describes the calculation method for frequency compensation during the timekeeping of a crystal oscillator and a rubidium clock. Specifically, it can be divided into four steps: aging characteristic calculation, temperature characteristic calculation, comprehensive compensation, and regression test. The schematic diagram of the steps is as Figure 1 shown, and includes the following steps:

[0023] S1. Place the first device under test in an incubator, set the temperature of the incubator to a constant 25°C, turn on the incubator to work, and perform aging characteristic separation. The first device under test includes a crystal oscillator or a rubidium clock inside;

[0024] S2. After obtaining the aging characteristic curve, perform temperature characteristic extraction. Place the first device under test in an incubator, and the temperature of the incubator changes within a preset range over time. Turn on the incubator to work. The preset range is not specifically a certain numerical range, but a range set according to the actual working conditions;

[0025] S3. Calculate the comprehensive compensation of the first device under test;

[0026] S4. Perform segmented compensation on the second device under test.

[0027] Specifically, step S1 specifically includes: after the first device under test is normally powered on, obtain the first Ori signal and the first Ref signal output by the first device under test per second. The frequencies of the first Ori signal and the first Ref signal are both 10 MHz. Continuously obtain the first Ori signal and the first Ref signal for three days. Calculate the first frequency difference Δf between all the first Ori signals and the first Ref signals, and record it as the first data group Time-Freq; the first data group Time-Freq is where Δf i (i = 1, 2, 3…n) represents the first frequency difference at the i-th second. Since the ambient temperature is constant, the frequency deviation value of the first data group Time-Freq is only related to the aging characteristic. Therefore, the aging characteristic of the frequency source can be calculated according to the first data group Time-Freq. Perform polynomial equation solution on the first data group Time-Freq to obtain the aging characteristic function f(x) time = a time + b time x + c time x 2, where x represents time, with the unit of seconds, a time represents the first constant term, b time represents the first linear term coefficient, c time represents the first quadratic term coefficient.

[0028] Exemplarily, step S2 specifically includes: In this embodiment, the temperature change curve of the incubator is as Figure 2 shown. After the first DUT is normally powered on, the second Ori signal and the second Ref signal output by the first DUT per second are acquired, where the frequencies of the second Ori signal and the second Ref signal are both 10 MHz. The second Ori signal and the second Ref signal are continuously acquired for thirty hours, and the second frequency difference Δf’ between all the second Ori signals and the second Ref signals is calculated and recorded as the second data set Syn-Freq: where △t i (i = 1, 2, 3…n) represents the temperature deviation at the i-th second, △f i ’(i = 1, 2, 3…n) represents the second frequency difference at the i-th second; according to the aging characteristic function f(x) time = a time + b time x + c time x 2 , the value range of time x is set to [0, 108000], and the third data set Time-Freq’ is obtained: In step S1, the aging characteristic curve is obtained. The frequency variation caused by the aging characteristic can be deducted from the comprehensive frequency difference data, and the relationship between temperature and frequency can be obtained; that is, by subtracting the third data set Time-Freq’ from the second data set Syn-Freq, and subtracting the frequency deviation of the second data set Syn-Freq from the frequency deviation of the third data set Time-Freq’, the frequency deviation caused by temperature change per second can be obtained; obtaining the frequency deviation caused by temperature change: where △f ti (i = 1, 2, 3…n) represents the frequency deviation corresponding to the temperature change at the i-th second. By performing multivariate equation solving on it, the temperature characteristic function f(Δt) temp = a temp + b temp Δt + c temp Δt 2 is obtained, where Δt is the temperature change amount, a temp represents the second constant term, b temp represents the second linear term coefficient, c temp represents the second quadratic term coefficient.

[0029] Specifically, step S3 specifically includes: Based on the aging characteristic function f(x) obtained in step S1time = a time + b time x + c time x 2 and obtain the temperature characteristic function f(Δt) in step S2 temp = a temp + b temp Δt + c temp Δt 2 , and express the timekeeping compensation of the crystal oscillator or rubidium clock inside the first device under test as f(x) comp = f(x) time + f(Δt) temp , where the time x is used to calculate the aging frequency compensation data, and the temperature change amount Δt is used to calculate the frequency compensation data caused by the temperature change.

[0030] Specifically, step S4 specifically includes: the second device under test includes a crystal oscillator or a rubidium clock inside. The crystal oscillator or rubidium clock inside the second device under test is based on the power-on time, so that the temperature and aging characteristic deviation is greater than the preset threshold, and the second device under test is segmented and compensated through steps S1 - S3. That is, some frequency sources enter the timekeeping stage when the power-on time is short. The aging characteristic curve of a certain crystal oscillator is as Figure 3 shown. This stage can be split into multiple stages for compensation, and the calculation method of the segmented compensation function is the same as that of steps S1 - S3.

[0031] Exemplarily, the existing crystal oscillators or rubidium clocks with better timekeeping indicators are relatively higher in price. The timekeeping compensation method described in the present invention can be used to make up for the timekeeping indicators of medium crystal oscillators or rubidium clocks, thereby reducing costs. To improve the timekeeping indicators, the current scientific and technological development has higher and higher requirements for timekeeping indicators. For crystal oscillators or rubidium clocks with better timekeeping performance, the timekeeping indicators can be further improved through the present invention to meet the requirements of scientific and technological development for timekeeping indicators; the method described in the present invention can be used for various crystal oscillators or rubidium clocks and will not change due to different hardware types.

[0032] The above is only the preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be changed within the scope of the concept described herein through the above teachings or the technology or knowledge in related fields. And the changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention should all be within the protection scope of the appended claims of the present invention.

Claims

1. A timekeeping compensation method for a clock frequency source, characterized in that, It includes the following steps: S1. Place the first device under test in an incubator, set the temperature of the incubator to a constant 25°C, turn on the incubator to work, and perform aging characteristic separation. The first device under test includes a crystal oscillator or a rubidium clock inside; S2. After obtaining the aging characteristic curve, extract the temperature characteristics. Place the first device under test in an incubator, and the temperature of the incubator changes within a preset range over time. Turn on the incubator to work; S3. Calculate the comprehensive compensation of the first device under test; S4. Perform segmented compensation on the second device under test.

2. The method for compensating timekeeping of a clock frequency source according to claim 1, wherein Step S1 specifically includes: After the first DUT is powered on normally, obtain the first Ori signal and the first Ref signal output by the first DUT per second. The frequencies of the first Ori signal and the first Ref signal are both 10 MHz. Continuously obtain the first Ori signal and the first Ref signal for three days. Calculate the first frequency difference Δf between all the first Ori signals and the first Ref signals, and record it as the first data set Time-Freq; the first data set Time-Freq is where Δf i (i = 1, 2, 3…n) represents the first frequency difference at the i-th second. Perform polynomial equation solution on the first data set Time-Freq to obtain the aging characteristic function f(x) time = a time + b time x + c time x 2 , where x represents time, and its unit is seconds. a time represents the first constant term, b time represents the first linear term coefficient, and c time represents the first quadratic term coefficient.

3. A clock frequency source timekeeping compensation method according to claim 2, characterized in that, Step S2 specifically includes: After the first device under test is powered on normally, obtain the second Ori signal and the second Ref signal output by the first device under test per second. The frequencies of the second Ori signal and the second Ref signal are both 10 MHz. Continuously obtain the second Ori signal and the second Ref signal for 30 hours, calculate the second frequency difference Δf’ between all the second Ori signals and the second Ref signals, and record it as the second data set Syn-Freq: where △t i (i = 1, 2, 3…n) represents the temperature deviation at the i-th second, and △f i ’(i = 1, 2, 3…n) represents the second frequency difference at the i-th second; According to the aging characteristic function f(x) time = a time + b time x + c time x 2 , set the value range of time x to [0, 108000] to obtain the third data set Time-Freq’: By taking the difference between the second data set Syn-Freq and the third data set Time-Freq’, obtain the frequency deviation caused by temperature change: where △f ti (i = 1, 2, 3…n) represents the frequency deviation corresponding to the temperature change at the i-th second, perform multivariate equation solution on it, and obtain the temperature characteristic function f(Δt) temp = a temp + b temp Δt + c temp Δt 2 , where Δt is the temperature change amount, a temp represents the second constant term, b temp represents the second first-order term coefficient, and c temp represents the second second-order term coefficient.

4. A method for compensating the timekeeping of a clock frequency source according to claim 3, characterized in that, Step S3 specifically includes: Based on the aging characteristic function f(x) obtained in Step S1 time = a time + b time x + c time x 2 and the temperature characteristic function f(Δt) obtained in Step S2 temp = a temp + b temp Δt + c temp Δt 2 , express the timekeeping compensation of the crystal oscillator or rubidium clock inside the first device under test as f(x) comp = f(x) time + f(Δt) temp , where the time x is used to calculate the aging frequency compensation data, and the temperature change amount Δt is used to calculate the frequency compensation data brought about by the temperature change.

5. A clock frequency source timekeeping compensation method according to claim 4, characterized in that Step S4 specifically includes: The second device under test includes a crystal oscillator or a rubidium clock inside. The crystal oscillator or rubidium clock inside the second device under test is based on the power-on time, so that the temperature and aging characteristic deviation is greater than a preset threshold, and segmented compensation is performed on the second device under test through steps S1 - S3.

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