CN104485956A - Method for debugging high-stability crystal oscillator - Google Patents
Method for debugging high-stability crystal oscillator Download PDFInfo
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- CN104485956A CN104485956A CN201410815303.9A CN201410815303A CN104485956A CN 104485956 A CN104485956 A CN 104485956A CN 201410815303 A CN201410815303 A CN 201410815303A CN 104485956 A CN104485956 A CN 104485956A
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Abstract
The invention relates to a method for debugging a high-stability crystal oscillator. The method is characterized in that a high-accuracy frequency measuring device formed by connecting a Beidou satellite receiver, a rubydium atomic clock, a frequency counter and a control computer is used for debugging a crystal oscillator; high-accuracy 1PPS signals demodulated by the Beidou satellite receiver are output to a 1PPS IN port of the rubydium atomic clock by virtue of a 1PPS signal port and are used for taming the rubydium atomic clock; 10 MHZ signals output by the 10 MHZ output end of the rubydium atomic clock are transmitted to an external reference signal input port REF IN of the frequency counter; the control computer is connected to a GPIB interface of the frequency counter by virtue of a USB (Universal Serial Bus) GPIB (General Purpose Interface Bus) forwarding wire; the signal output end of the tested oscillator is connected to the frequency counter. By utilizing high-stability frequency reference, the frequency measuring precision is greatly improved; almost an hour of preheating and stabilizing during starting the frequency counter for each time is omitted; the error and data omission caused by artificially estimating and recording data when operators read frequently-flashed digital tubes can be reduced; all the data are recorded in a file for saving.
Description
Technical field
The present invention relates to electronic product production test field, in particular to the adjustment method of high stability crystal oscillator, crystal oscillator in communication equipment is accurately debugged, be applicable to communication equipment accurately measure and calibration frequency error, and record adjustment process data, the application of analytical error trend.
Technical background
In the scientific research of digital communication product and in producing, the precision of transmitting and receiving frequency is an important indicator of communication equipment, the precision of reception, tranmitting frequency is determined by the high stability crystal oscillator in product, oscillator frequency is adjusted to specification error scope and ensures that long-term stability is an important process in communication equipment research and production.
Existing problems: the way in the past adjusting oscillator frequency is: the input interface rate-adaptive pacemaker of tested crystal oscillator being terminated to frequency counter, according to the reading of frequency counter, operating personnel judge whether frequency of oscillation meets technical specification, then adjust tested crystal oscillator make it to meet the requirements as exceeded error range, when adjusting within the scope of specification error, observed frequency stability need be continued, must ensure that the range of readings of frequency counter can not exceed technical requirement within the continuous time of regulation.This method has following shortcoming: 1. frequency counter itself can not be determined when stable operation personnel test, and needs the stabilization time of 1 hour after frequency counter start.2. operating personnel's frequency counter screen of wanting long-term observation constantly to flash when measuring, easily because of visual fatigue generation error, too fastly hand-writtenly cannot catch up with data jump because flashing, can only with estimated record.3. the observation of frequency stability can only observe display data whether within the scope of technical indicator for a long time by operating personnel.Trend can only be moved towards according to reading evaluated error, there is no data record, be not easy to quality of production management and follow-uply carry out data analysis.
How to address this problem the problem just becoming those skilled in the art and will study and solve.
Summary of the invention
Object of the present invention is exactly for overcoming the deficiencies in the prior art, reading for existing frequency counter judges the accurate problem of frequency of oscillation, a kind of method utilizing High Precision Frequency equipment to carry out crystal oscillator debugging is provided, adopt big-dipper satellite time signal Tame Rubidium Clock, the high accuracy 10MHZ signal supply frequency counter exported by rubidium clock, by computer installation frequency counter breaking inner crystal oscillator, adopt the external reference signal that rubidium clock provides.By the characteristic utilizing the time signal of big-dipper satellite synchronous with the high accuracy atomic clock of Big Dipper ground station, realize the long-time stability of frequency counter, thus make the frequency accurate adjustment of tested crystal oscillator within the scope of specification error, greatly improve Measurement sensibility degree.
The present invention is realized by such technical scheme: the adjustment method of high stability crystal oscillator, it is characterized in that, utilize a kind of High Precision Frequency equipment to carry out the debugging of crystal oscillator, described High Precision Frequency equipment is connected and composed by Beidou satellite navigation receiver, rubidium atomic clock, frequency counter and computer for controlling;
Satellite earth antenna is connected to the ANT interface of Beidou satellite receiver, and the high accuracy 1PPS signal demodulated through Beidou satellite navigation receiver outputs to the 1PPS IN port of rubidium atomic clock by 1PPS signal port, for taming rubidium atomic clock; The external reference signal input port REF IN of frequency counter is sent to from the 10MHZ signal of rubidium atomic clock 10MHZ output output, computer for controlling is connected to the gpib interface of frequency counter through USB GPIB patchcord, the test frequency input IN of the signal output part OUTPUT rate of connections counter of tested oscillator, outputs to frequency counter by the signal of tested oscillator;
The step of the adjustment method of crystal oscillator comprises:
Step 1. Beidou satellite navigation receiver, antenna, rubidium atomic clock power up operation for a long time, obtain with the synchronous high stability of Big Dipper ground station with reference to 10MHZ signal, precision can reach 10E-12 magnitude, is sent to the external reference signal input port REF IN of frequency counter through stube cable;
The USB port of step 2. computer for controlling turns GPIB connecting line through USB and is connected with the GPIB mouth of frequency counter, complete metering system by computer for controlling control frequency counter by setting instruction to set, the measurement frequency sets, input port setting operation, and operating process is as follows:
1) computer for controlling confirms the connection with frequency counter;
2) computer for controlling give an order setpoint frequency counter switching frequency reference data from internal oscillator be converted to outside REF port send into high stable 10MHZ reference frequency signal, the precision of such frequency counter just reaches 10E-12; High 2 ~ 3 orders of magnitude of the standard of the tested frequency accuracy≤10E-9 of my unit communication products relatively, the stability error of frequency counter self is negligible;
3) send and gather thresholding, gather frequency, input channel such as to arrange at the order; By computer Lookup protocol before each test of these orders, avoid operating personnel owing to arranging mistake, leaking item, ensure the accurate of image data;
4) in the time interval set by operating personnel by column corresponding in interface by computer for controlling, times of collection starts to read data; In the initial data write EXCEL electrical form of each collection, be marked on frequency error tendency chart through calculating, each mark point simultaneously, multiple point is a composition Trendline just, be designated as curve 1, the transverse axis of tendency chart is times of collection, and the longitudinal axis is frequency error;
5) curve 2 is provided with in tendency chart, curve 2 is the technical parameter that operator is arranged on Plays frequency hurdle, interface, this parameter specifies in the technical specification of product, the frequency of tested oscillator is adjusted to prescribed limit according to the different trend trends of curve 1, curve 2 two lines by operating personnel, and the unstable oscillation crystal that Timeliness coverage is potential in debug process, to reject in time;
6), when data acquisition arrives set point number, computer for controlling stops data in reading frequency counter, data in EXCEL is preserved stored in specified file; Data can be called by analysis software, carry out statistical analysis calculating.
The adjustment method of described high stability crystal oscillator, is characterized in that, the operating process 5 of the step 2 of the adjustment method of crystal oscillator) detailed process comprise:
A. under normal circumstances, tested oscillator frequency curve 1 can be progressively close to standard frequency curve 2, through stablizing after a period of time, curve 1 is substantially parallel with curve 2, illustrates that tested oscillator frequency is basicly stable but has certain error with the parameter that specifies in technical specification;
B. oscillator now can be regulated to make curve 1 continue, near curve 2, namely to be continued close to hope frequency by measured frequency;
C. curve 1 is adjusted to curve 2 and substantially overlaps by repetitive process a, process b, and through running within the Product Specifications stipulated time, two lines still overlap, then judge that frequency error is in prescribed limit, calibration completes;
D. through operation curve 1 in the Product Specifications stipulated time cannot convergence curve 2 to parastate or curve 2 intersect with curve 1 after leave away gradually, oscillator poor stability is in time described, can not use in the product, this debug process was carried out in one to three hours, when needing aging examination, this debug process is more than 1 day.
Beneficial effect of the present invention: actual use in production process, this scheme will have employed high stable frequency reference, substantially increase frequency measurement accuracy, the error brought by frequency counter has dropped to negligible degree, eliminate the nearly one hour pre-heat-stable time that frequency counter is started shooting at every turn, accomplish that start can use.Adopt computer recording data, decrease operating personnel and read the charactron frequently flashed and manually to estimate and the error brought of record data and data are omitted, all data record are preserved hereof.Adopt the design philosophy of visual production, long-time for operating personnel observed frequency timer number shown and the process reading, estimate, judge, be reduced to and the trend tendency of red green two curves is judged, need not personnel on duty for a long time.Long-term stability for examination frequency stability provides a new thinking.Data basis is provided for improving product total quality control.
Accompanying drawing explanation
Fig. 1, High Precision Frequency device connection diagram;
Fig. 2, measurement procedure figure;
Fig. 3, frequency debugging curve interface.
Embodiment
For a more clear understanding of the present invention, the present invention is described in detail in conjunction with the accompanying drawings and embodiments:
As shown in Figure 1-Figure 3, the adjustment method of crystal oscillator, utilize a kind of High Precision Frequency equipment to carry out the debugging of crystal oscillator, described High Precision Frequency equipment is connected and composed by Beidou satellite navigation receiver, rubidium atomic clock, frequency counter and computer for controlling;
Satellite earth antenna is connected to the ANT interface of Beidou satellite receiver, and the high accuracy 1PPS signal demodulated through Beidou satellite navigation receiver outputs to the 1PPS IN port of rubidium atomic clock by 1PPS signal port, for taming rubidium atomic clock; The external reference signal input port REF IN of frequency counter is sent to from the 10MHZ signal of rubidium atomic clock 10MHZ output output, computer for controlling is connected to the gpib interface of frequency counter through USB GPIB patchcord, the test frequency input IN of the signal output part OUTPUT rate of connections counter of tested oscillator, outputs to frequency counter by the signal of tested oscillator.
Adopt big-dipper satellite time signal Tame Rubidium Clock, the high accuracy 10MHZ signal exported by rubidium clock supply frequency counter, the external reference signal adopting rubidium clock to provide by computer installation frequency counter breaking inner crystal oscillator.
Due to the time signal of big-dipper satellite and the high accuracy atomic clock of Big Dipper ground station synchronous, there are excellent long-time stability.Taming this scheme of the excellent rubidium atomic clock of short-term stability by satellite-signal can provide precision to reach the frequency stability of 10E-12, is better than more than measured signal 2 orders of magnitude.
Rubidium atomic clock and satellite receiver long-time running, external reference signal with connect with, eliminate the start warm-up time of frequency counter, make the certainty of measurement of frequency counter meet the requirement of research and production completely.
Be connected with frequency counter through USB GPIB connecting line by computer for controlling, read all frequency data measuring tested oscillator and send, and with EXCEL form, the data at every turn measured are recorded in specified file, thoroughly avoid the human error that operating personnel bring.The data file of preserving can be used for scientific research personnel and quality department for analytic product quality problems.
The measurement data that computer for controlling reads from frequency counter, is labeled on frequency stability tendency chart in real time.Operating personnel need not observe ground measurement data estimated frequency error change trend of frequently beating as before for a long time.Only need namely can determination frequency variation tendency according to the curvilinear motion on tendency chart, there is an objective evaluation to the quality of oscillator.
Specific implementation:
Step 1. Beidou satellite navigation receiver, antenna, rubidium atomic clock power up operation for a long time, obtain with the synchronous high stability of Big Dipper ground station with reference to 10MHZ signal, precision can reach 10E-12 magnitude, is sent to the external reference signal input port REF IN of frequency counter through stube cable;
The USB port of step 2. computer for controlling, turns GPIB connecting line through USB and is connected with the GPIB mouth of frequency counter, and complete metering system by computer for controlling control frequency counter by setting instruction and set, measure frequency setting operation, operating process is as follows:
1). computer for controlling confirms the connection with frequency counter;
2). computer for controlling give an order setpoint frequency counter switching frequency reference data from internal oscillator be converted to outside REF port send into high stable 10MHZ reference frequency signal.The precision of such frequency counter just reaches 10E-12; High 2 ~ 3 orders of magnitude of the tested frequency accuracy of my unit communication products (ordinary circumstance≤10E-9) relatively, the stability error of frequency counter self is negligible.
3). send and gather thresholding, gather frequency, input channel such as to arrange at the order; By computer Lookup protocol before each test of these orders, avoid operating personnel owing to arranging mistake, leaking item, ensure the accurate of image data.
4). in the time interval set by operating personnel by column corresponding in interface by computer for controlling, times of collection starts to read data; See Fig. 3, in each initial data write EXCEL electrical form gathered, be marked on frequency error tendency chart through calculating, each mark point, multiple point is a composition Trendline just, and the transverse axis of tendency chart is times of collection, and the longitudinal axis is frequency error simultaneously;
5). the curve 2 in tendency chart is the technical parameter that operator is arranged on Plays frequency hurdle, interface, and this parameter specifies in the technical specification of product.The frequency of tested oscillator just can be adjusted to prescribed limit according to the different trend trend of red green two lines by operating personnel, and can the potential unstable oscillation crystal of Timeliness coverage in debug process, rejects in time;
Detailed process is as follows:
A. under normal circumstances, tested oscillator frequency (curve 1 in Fig. 3) can be progressively close to standard frequency (curve 2 in Fig. 3), and through stablizing after a period of time, curve 1 is substantially parallel with curve 2.Illustrate that tested oscillator frequency is basicly stable but have certain error with the parameter that specifies in technical specification.B. oscillator now can be regulated to make curve 1 continue, near curve 2, namely to be continued close to hope frequency by measured frequency.C. repeat a, b step curve 1 is adjusted to curve 2 substantially overlaps, and still overlap through long-play (the concrete time is specified by Product Specifications) two lines.Frequency error is in prescribed limit, and calibration completes.D. through long-play, curve 1 cannot convergence curve 2 to parastate or leave away gradually after intersecting with curve 2.Oscillator poor stability is in time described, can not uses in the product.This debug process is generally at one to three hours.During aging examination more than 1 day;
6). when data acquisition arrives set point number, computer for controlling stops data in reading frequency counter, data in EXCEL is preserved stored in specified file.Data can be called by analysis software, carry out statistical analysis calculating.
According to the above description, the solution of the present invention can be realized in conjunction with art technology.
Claims (2)
1. the adjustment method of high stability crystal oscillator, it is characterized in that, utilize a kind of High Precision Frequency equipment to carry out the debugging of crystal oscillator, described High Precision Frequency equipment is connected and composed by Beidou satellite navigation receiver, rubidium atomic clock, frequency counter and computer for controlling;
Satellite earth antenna is connected to the ANT interface of Beidou satellite receiver, and the high accuracy 1PPS signal demodulated through Beidou satellite navigation receiver outputs to the 1PPS IN port of rubidium atomic clock by 1PPS signal port, for taming rubidium atomic clock; The external reference signal input port REF IN of frequency counter is sent to from the 10MHZ signal of rubidium atomic clock 10MHZ output output, computer for controlling is connected to the gpib interface of frequency counter through USB GPIB patchcord, the test frequency input IN of the signal output part OUTPUT rate of connections counter of tested oscillator, outputs to frequency counter by the signal of tested oscillator;
The step of the adjustment method of crystal oscillator comprises:
Step 1. Beidou satellite navigation receiver, antenna, rubidium atomic clock power up operation for a long time, obtain with the synchronous high stability of Big Dipper ground station with reference to 10MHZ signal, precision can reach 10E-12 magnitude, is sent to the external reference signal input port REF IN of frequency counter through stube cable;
The USB port of step 2. computer for controlling turns GPIB connecting line through USB and is connected with the GPIB mouth of frequency counter, complete metering system by computer for controlling control frequency counter by setting instruction to set, the measurement frequency sets, input port setting operation, and operating process is as follows:
1) computer for controlling confirms the connection with frequency counter;
2) computer for controlling give an order setpoint frequency counter switching frequency reference data from internal oscillator be converted to outside REF port send into high stable 10MHZ reference frequency signal, the precision of such frequency counter just reaches 10E-12; High 2 ~ 3 orders of magnitude of the standard of the tested frequency accuracy≤10E-9 of my unit communication products relatively, the stability error of frequency counter self is negligible;
3) send and gather thresholding, gather frequency, input channel such as to arrange at the order; By computer Lookup protocol before each test of these orders, avoid operating personnel owing to arranging mistake, leaking item, ensure the accurate of image data;
4) in the time interval set by operating personnel by column corresponding in interface by computer for controlling, times of collection starts to read data; In the initial data write EXCEL electrical form of each collection, be marked on frequency error tendency chart through calculating, each mark point simultaneously, multiple point is a composition Trendline just, be designated as curve 1, the transverse axis of tendency chart is times of collection, and the longitudinal axis is frequency error;
5) curve 2 is provided with in tendency chart, curve 2 is the technical parameter that operator is arranged on Plays frequency hurdle, interface, this parameter specifies in the technical specification of product, the frequency of tested oscillator is adjusted to prescribed limit according to the different trend trends of curve 1, curve 2 two lines by operating personnel, and the unstable oscillation crystal that Timeliness coverage is potential in debug process, to reject in time;
6), when data acquisition arrives set point number, computer for controlling stops data in reading frequency counter, data in EXCEL is preserved stored in specified file; Data can be called by analysis software, carry out statistical analysis calculating.
2. the adjustment method of high stability crystal oscillator as claimed in claim 1, is characterized in that, the operating process 5 of the step 2 of the adjustment method of crystal oscillator) detailed process comprise:
A. under normal circumstances, tested oscillator frequency curve 1 can be progressively close to standard frequency curve 2, through stablizing after a period of time, curve 1 is substantially parallel with curve 2, illustrates that tested oscillator frequency is basicly stable but has certain error with the parameter that specifies in technical specification;
B. oscillator now can be regulated to make curve 1 continue, near curve 2, namely to be continued close to hope frequency by measured frequency;
C. curve 1 is adjusted to curve 2 and substantially overlaps by repetitive process a, process b, and passes through
?run in the Product Specifications stipulated time, two lines still overlap, then judge that frequency error is in prescribed limit, calibration completes;
D. pass through
?in the Product Specifications stipulated time operation curve 1 cannot convergence curve 2 to parastate or curve 2 intersect with curve 1 after leave away gradually, oscillator poor stability is in time described, can not use in the product, this debug process was carried out in one to three hours, when needing aging examination, this debug process is more than 1 day.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106814249A (en) * | 2017-02-28 | 2017-06-09 | 中国科学院国家空间科学中心 | A kind of frequency measurement method for optical pumped magnetometer frequency meter |
| CN108039886A (en) * | 2017-12-12 | 2018-05-15 | 晶晨半导体(上海)股份有限公司 | A kind of method that crystal frequency deviation is calibrated by central processing unit internal loop |
| CN111257633A (en) * | 2018-11-30 | 2020-06-09 | 上海海拉电子有限公司 | Test system and test method for nominal frequency of crystal oscillator |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106814249A (en) * | 2017-02-28 | 2017-06-09 | 中国科学院国家空间科学中心 | A kind of frequency measurement method for optical pumped magnetometer frequency meter |
| CN108039886A (en) * | 2017-12-12 | 2018-05-15 | 晶晨半导体(上海)股份有限公司 | A kind of method that crystal frequency deviation is calibrated by central processing unit internal loop |
| CN111257633A (en) * | 2018-11-30 | 2020-06-09 | 上海海拉电子有限公司 | Test system and test method for nominal frequency of crystal oscillator |
| CN111257633B (en) * | 2018-11-30 | 2022-09-02 | 上海海拉电子有限公司 | Test system and test method for nominal frequency of crystal oscillator |
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