CN112098731A - Electromagnetic field probe with autonomous calibration function and calibration method thereof - Google Patents
Electromagnetic field probe with autonomous calibration function and calibration method thereof Download PDFInfo
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- 230000005672 electromagnetic field Effects 0.000 title claims abstract description 38
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- 238000003199 nucleic acid amplification method Methods 0.000 claims abstract description 10
- 238000005259 measurement Methods 0.000 claims abstract description 8
- 238000012360 testing method Methods 0.000 claims description 36
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- 238000002955 isolation Methods 0.000 claims description 3
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- 238000007689 inspection Methods 0.000 abstract description 2
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/08—Measuring electromagnetic field characteristics
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
- G01R1/02—General constructional details
- G01R1/06—Measuring leads; Measuring probes
- G01R1/067—Measuring probes
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R35/00—Testing or calibrating of apparatus covered by the other groups of this subclass
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Abstract
The invention relates to an electromagnetic field probe with an autonomous calibration function, comprising: a frequency synthesizer for generating various frequency signals; the gain control circuit is used for carrying out gain amplification or attenuation on the output signal of the frequency synthesizer; the signal switching circuit is used for switching between the output signal of the gain control circuit and the output signal of the electromagnetic field antenna and is connected with the probe signal processing circuit; and the control unit is used for controlling the frequency synthesizer to generate a frequency signal, controlling the gain control circuit to perform gain amplification or attenuation on the output signal of the frequency synthesizer, controlling the signal switching of the signal switching circuit, and reading and processing data in the probe. The invention can realize self calibration, prolong the inspection period of the probe and ensure the accuracy and reliability of the measurement result.
Description
Technical Field
The invention belongs to the technical field of electromagnetic field measurement, and particularly relates to an electromagnetic field probe with an autonomous calibration function and a calibration method thereof.
Background
After any electronic product works for a long time, the performance of the electronic product is reduced to a certain degree, and particularly, in the aspect of test data of a measuring instrument, along with the increase of the service time of the instrument and the change of the external environment, the test data can generate errors, so that the test accuracy is influenced. Generally, after an instrument is used for a period of time, the instrument needs to be sent to an instrument detection mechanism for evaluation and calibration, and a latest calibration factor of the instrument is given for correcting a test error caused by long-time service performance reduction of the instrument. The disadvantages of the conventional instrument calibration method include: first, performance changes of an instrument during two calibration cycles cannot be evaluated, and generally, an empirical detection value is used to determine whether the instrument is normal, and good or bad judgment cannot be made on accurate changes and small data deviations. Secondly, during the period of sending the instrument for inspection, the test cannot be carried out, the period of stopping the instrument is long, the test continuity can be influenced to a certain extent, and especially, the influence degree is larger for the equipment needing to be continuously monitored for 7 × 24 hours. And, even if monitoring is performed using a replacement device, the consistency of data cannot be guaranteed.
After the electromagnetic field probe is used as one instrument, the accuracy of the test data can be changed due to the influence of the electromagnetic field probe and external factors after the electromagnetic field probe is used for a period of time, the change not only influences the accuracy of the test, there are also side effects (calibration factor variation and uncertainty) on the calibration metric, which, when too large or too small, can result in the metric failing to pass, and, there is also a slight deviation in the test data between the two calibration periods, which is caused by the influence of the test environment and its uncertainty, except in the case of large data deviation (generally referred to as data abnormality caused by instrument damage), the small data deviation can be judged artificially, and generally considered to be caused by the instability of the measured data, and the specific reason (the change of the measured data or the change of an instrument and a meter) cannot be judged well.
The electromagnetic field probe is generally composed of an electromagnetic field sensor (such as an antenna), a signal processing circuit (including an operational amplification circuit and an AD sampling processing circuit), the antenna is a passive circuit, the working performance of the antenna is determined during design and basically does not change along with time, and the operational amplification circuit and the AD sampling processing circuit in the signal processing circuit may age along with time, and the performance degradation or the working point drift is a main factor causing the change of the measurement performance. The equipment manufacturer calibrates the electromagnetic field measuring instrument, mainly performs zero setting calibration on the signal processing circuit.
Disclosure of Invention
Aiming at the problems pointed out in the background technology, the invention provides an electromagnetic field probe with an autonomous calibration function and a calibration method thereof, which can ensure that the measurement data of the electromagnetic field probe is more accurate.
The technical scheme adopted by the invention is as follows:
an electromagnetic field probe with autonomous calibration function, comprising:
a frequency synthesizer for generating various frequency signals;
the gain control circuit is used for carrying out gain amplification or attenuation on the output signal of the frequency synthesizer;
the signal switching circuit is used for switching between the output signal of the gain control circuit and the output signal of the electromagnetic field antenna and is connected with the probe signal processing circuit;
and the control unit is used for controlling the frequency synthesizer to generate a frequency signal, controlling the gain control circuit to perform gain amplification or attenuation on the output signal of the frequency synthesizer, controlling the signal switching of the signal switching circuit, and reading and processing data in the probe.
Furthermore, the signal isolation degree of the signal switching circuit module is more than or equal to 60dB, and the insertion loss is less than 0.3 dB.
A calibration method of an electromagnetic field probe with an autonomous calibration function,
when the probe is calibrated, the control unit firstly reads a preset standard level value in the probe, and simultaneously, the control signal switching circuit changes the input of the probe signal processing circuit from an electromagnetic field antenna to the output of the gain control circuit; then, the control unit controls the frequency synthesizer to generate signals of each frequency point one by one so as to test one by one, and after the gain control circuit performs gain control on the signals of each frequency point, the signals of each frequency point are output to the probe signal processing circuit through the signal switching circuit to process the signals until all the frequency points needing to be calibrated are calibrated;
after the calibration of each frequency point is completed, the control circuit compares the test level value of each frequency point with the preset standard level value, calculates the calibration coefficient and uses the calibration coefficient as a new calibration coefficient for the normal measurement of the probe.
Further, Ii＝Vm/Va，IiRepresent each oneCalibration factor of frequency points, VmIndicating a preset standard level value, VaRepresenting a test level value.
Furthermore, the error of the gain control accuracy of the gain control circuit is less than 0.8 dB.
The invention has the beneficial effects that:
1) the whole signal receiving link of the electromagnetic field measuring probe is calibrated and evaluated through a stable and controllable test signal generated by a signal source in the probe, real-time data calibration can be carried out according to actual test conditions, so that the stability and consistency of data of the probe in daily use are better guaranteed, errors in daily tests are reduced, and when the signal changes slightly, the change of the measured signal can be judged through self calibration of the probe instead of the test error generated by the probe.
2) The calibration period of the probe sending detection mechanism can be properly prolonged, when the detection mechanism is calibrated, the calibration factor tested by the detection mechanism is good due to the self-calibration function of the probe head, the difference of the calibration factor mainly expressed in the calibration period is small, the consistency of the probe used for a long time is high, and the phenomenon that metering cannot be passed due to the fact that the calibration factor is too poor (except for a result caused by damage of the probe) hardly exists.
3) And the working condition of the electromagnetic field measuring probe is mastered, and the working condition of the electromagnetic field measuring probe is confirmed to be in a normal state, so that the accuracy and the reliability of the measuring result are ensured.
Drawings
FIG. 1 is a block circuit diagram of an electromagnetic field probe with autonomous calibration capability of the present invention;
FIG. 2 is a block flow diagram of a method of calibrating an electromagnetic field probe.
Detailed Description
The electromagnetic field probe with autonomous calibration function and the calibration method thereof according to the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
As shown in fig. 1, an electromagnetic field probe having an autonomous calibration function includes:
a frequency synthesizer (or called a signal generator) for generating various frequency signals;
the gain control circuit is used for carrying out gain amplification or attenuation on the output signal of the frequency synthesizer;
the signal switching circuit is used for switching between the output signal of the gain control circuit and the output signal of the electromagnetic field antenna and is connected with the probe signal processing circuit;
and the control unit is used for controlling the frequency synthesizer to generate a frequency signal, controlling the gain control circuit to perform gain amplification or attenuation on the output signal of the frequency synthesizer, controlling the signal switching of the signal switching circuit, and reading and processing data in the probe.
The number of frequency points generated by the frequency synthesizer is required to meet the signal detection of each frequency band of the probe (for example, one test frequency point is selected for each frequency band). The gain control circuit can ensure that the amplitude of each output frequency point signal is relatively fixed, the module can feed back internal gain according to the monitored output level to control, and the stability of the signal output amplitude under each condition is ensured. Without an automatic gain control circuit, frequency synthesized output amplitude can generally be used, but stability is relatively poor.
The signal switching circuit controls the electromagnetic field antenna to output to the probe signal processing circuit for normal electromagnetic field measurement when the probe is normally tested, and controls the gain control circuit to output to the probe signal processing circuit for calibration when the probe is automatically calibrated so as to meet the self-calibration and normal test of the probe. The signal switching circuit (module) needs to have a relatively good signal isolation (greater than or equal to 60dB) and a relatively small insertion loss (less than 0.3dB) so as not to interfere with each other (the test is not affected by the calibration circuit (the test is performed with the calibration circuit closed), the self-calibration is not affected by the output signal of the electromagnetic field antenna) and not to generate too much loss on the input signal during the probe calibration and the normal test, thereby ensuring the accuracy of the probe test and the self-calibration.
As shown in fig. 2, a calibration method of an electromagnetic field probe having an autonomous calibration function,
when the probe is calibrated, the control unit firstly reads a preset standard level value in the probe, and simultaneously, the control signal switching circuit changes the input of the probe signal processing circuit from an electromagnetic field antenna to the output of the gain control circuit; then, the control unit controls the frequency synthesizer to generate signals of each frequency point one by one so as to test one by one, and after the gain control circuit performs gain control on the signals of each frequency point, the signals of each frequency point are output to the probe signal processing circuit through the signal switching circuit to process the signals until all the frequency points needing to be calibrated are calibrated;
after the calibration of each frequency point is completed, the control circuit compares the test level value of each frequency point with the preset standard level value, calculates the calibration coefficient and uses the calibration coefficient as a new calibration coefficient for the normal measurement of the probe. In particular, Ii＝Vm/Va，IiCalibration coefficients, V, representing individual frequency pointsmIndicating a preset standard level value, VaRepresenting a test level value.
In this embodiment, the error of the gain control accuracy of the gain control circuit should be less than 0.8 dB.
After the calibration is completed, two results are obtained
1. After the self-calibration test is successful, the test functions of the probe except the antenna can be proved to be normal.
2. The probe automatically takes the test result as a standard (for example, after the self-calibration system tests the signal of 50Hz and 20dBm, the probe automatically takes the signal of 20dBm as a standard to record, and when the probe completes the self-calibration and carries out the normal test, the tested amplitude value is compared with the signal so as to accurately display the current test value and ensure the test accuracy).
Whether the probe calibration is successful or not is detected through a calibration state evaluation module arranged in the probe, and when the probe calibration is successful, the calibration state evaluation module obtains a value (such as a high level signal) to indicate that the calibration is successful and a calibration part and a receiving part of the probe are not abnormal. When the calibration state evaluation module cannot obtain the value, the module performs self-check on the probe (the state monitoring points are arranged at each link of the probe), can judge which link of the probe is abnormal through the self-check, and sends corresponding data and warning signals to a data analysis unit such as an external monitoring host computer after judging the abnormality.
The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any alternative or alternative method that can be easily conceived by those skilled in the art within the technical scope of the present invention should be covered by the scope of the present invention.
Claims (5)
1. An electromagnetic field probe having an autonomous calibration function, comprising:
a frequency synthesizer for generating various frequency signals;
the gain control circuit is used for carrying out gain amplification or attenuation on the output signal of the frequency synthesizer;
the signal switching circuit is used for switching between the output signal of the gain control circuit and the output signal of the electromagnetic field antenna and is connected with the probe signal processing circuit;
and the control unit is used for controlling the frequency synthesizer to generate a frequency signal, controlling the gain control circuit to perform gain amplification or attenuation on the output signal of the frequency synthesizer, controlling the signal switching of the signal switching circuit, and reading and processing data in the probe.
2. The electromagnetic field probe with the autonomous calibration function as recited in claim 1, wherein the signal isolation of the signal switching circuit module is greater than or equal to 60dB, and the insertion loss is less than 0.3 dB.
3. A calibration method of an electromagnetic field probe with an autonomous calibration function is characterized in that,
when the probe is calibrated, the control unit firstly reads a preset standard level value in the probe, and simultaneously, the control signal switching circuit changes the input of the probe signal processing circuit from an electromagnetic field antenna to the output of the gain control circuit; then, the control unit controls the frequency synthesizer to generate signals of each frequency point one by one so as to test one by one, and after the gain control circuit performs gain control on the signals of each frequency point, the signals of each frequency point are output to the probe signal processing circuit through the signal switching circuit to process the signals until all the frequency points needing to be calibrated are calibrated;
after the calibration of each frequency point is completed, the control circuit compares the test level value of each frequency point with the preset standard level value, calculates the calibration coefficient and uses the calibration coefficient as a new calibration coefficient for the normal measurement of the probe.
4. Method for calibrating an electromagnetic field probe with autonomous calibration function according to claim 3, characterized in that Ii＝Vm/Va，IiCalibration coefficients, V, representing individual frequency pointsmIndicating a preset standard level value, VaRepresenting a test level value.
5. The method of calibrating an electromagnetic field probe having an autonomous calibration function of claim 3, wherein the gain control accuracy error of the gain control circuit is < 0.8 dB.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114280521A (en) * | 2021-12-23 | 2022-04-05 | 北京森馥科技股份有限公司 | Calibration method and device of electromagnetic field probe, electronic equipment and storage medium |
Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0563676B1 (en) * | 1992-03-31 | 2000-05-17 | Siemens Aktiengesellschaft | Calibrating method for the transmitting and measuring circuit of a test appliance |
| CN1553582A (en) * | 2003-06-05 | 2004-12-08 | 中兴通讯股份有限公司 | Calibrating apparatus and method for automatic gain control circuit of array receiver |
| CN101304542A (en) * | 2007-05-10 | 2008-11-12 | 联发科技股份有限公司 | Device and method for calibrating data processing apparatus |
| CN101447813A (en) * | 2008-12-29 | 2009-06-03 | 芯通科技（成都）有限公司 | An antenna self calibration method and circuit of TD-SCDMA radio remote unit |
| CN101561481A (en) * | 2009-01-24 | 2009-10-21 | 国网电力科学研究院 | Method for calibrating high-frequency electric field probe |
| CN101655544A (en) * | 2008-08-20 | 2010-02-24 | 武汉华瑞测控科技有限公司 | Device for measuring and checking errors of digital mutual inductor |
| CN101915902A (en) * | 2010-09-06 | 2010-12-15 | 株洲南车时代电气股份有限公司 | Calibration method and calibration system for field test equipment |
| CN102164010A (en) * | 2010-02-03 | 2011-08-24 | 特里奎恩特半导体公司 | Automatic calibration circuit |
| CN102662163A (en) * | 2012-05-28 | 2012-09-12 | 中国电子科技集团公司第二十二研究所 | Digital control device based on microprocessor ARM (Advanced RISC Machines) and radar active calibrator |
| CN102680768A (en) * | 2012-06-26 | 2012-09-19 | 重庆朗普科技有限公司 | Mono-polar type voltage measurement sensor with self-correction and self-construct electric filed and measurement method |
| CN103048538A (en) * | 2012-11-29 | 2013-04-17 | 焦作市神盾科技有限公司 | Method for testing collective frequency of radio frequency card and tester for realizing method |
| CN104198976A (en) * | 2014-09-19 | 2014-12-10 | 西安电子科技大学 | Correction method for Hall voltage sensor measuring voltage |
| CN104635047A (en) * | 2013-11-08 | 2015-05-20 | 苏州普源精电科技有限公司 | Spectrum analyzer with calibration function |
| CN105911460A (en) * | 2016-06-21 | 2016-08-31 | 电子科技大学 | Multichannel logic analyzer with synchronous signal self-calibration function |
| CN108982978A (en) * | 2018-08-02 | 2018-12-11 | 卢小丽 | Impulse electric field detector and application method with sensitivity coefficient self calibration and power management function |
| CN109975731A (en) * | 2018-12-28 | 2019-07-05 | 北京航天测控技术有限公司 | A kind of measuring system based on real time calibration |
-
2020
- 2020-09-16 CN CN202010972791.XA patent/CN112098731A/en active Pending
Patent Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0563676B1 (en) * | 1992-03-31 | 2000-05-17 | Siemens Aktiengesellschaft | Calibrating method for the transmitting and measuring circuit of a test appliance |
| CN1553582A (en) * | 2003-06-05 | 2004-12-08 | 中兴通讯股份有限公司 | Calibrating apparatus and method for automatic gain control circuit of array receiver |
| CN101304542A (en) * | 2007-05-10 | 2008-11-12 | 联发科技股份有限公司 | Device and method for calibrating data processing apparatus |
| CN101655544A (en) * | 2008-08-20 | 2010-02-24 | 武汉华瑞测控科技有限公司 | Device for measuring and checking errors of digital mutual inductor |
| CN101447813A (en) * | 2008-12-29 | 2009-06-03 | 芯通科技（成都）有限公司 | An antenna self calibration method and circuit of TD-SCDMA radio remote unit |
| CN101561481A (en) * | 2009-01-24 | 2009-10-21 | 国网电力科学研究院 | Method for calibrating high-frequency electric field probe |
| CN102164010A (en) * | 2010-02-03 | 2011-08-24 | 特里奎恩特半导体公司 | Automatic calibration circuit |
| CN101915902A (en) * | 2010-09-06 | 2010-12-15 | 株洲南车时代电气股份有限公司 | Calibration method and calibration system for field test equipment |
| CN102662163A (en) * | 2012-05-28 | 2012-09-12 | 中国电子科技集团公司第二十二研究所 | Digital control device based on microprocessor ARM (Advanced RISC Machines) and radar active calibrator |
| CN102680768A (en) * | 2012-06-26 | 2012-09-19 | 重庆朗普科技有限公司 | Mono-polar type voltage measurement sensor with self-correction and self-construct electric filed and measurement method |
| CN103048538A (en) * | 2012-11-29 | 2013-04-17 | 焦作市神盾科技有限公司 | Method for testing collective frequency of radio frequency card and tester for realizing method |
| CN104635047A (en) * | 2013-11-08 | 2015-05-20 | 苏州普源精电科技有限公司 | Spectrum analyzer with calibration function |
| CN104198976A (en) * | 2014-09-19 | 2014-12-10 | 西安电子科技大学 | Correction method for Hall voltage sensor measuring voltage |
| CN105911460A (en) * | 2016-06-21 | 2016-08-31 | 电子科技大学 | Multichannel logic analyzer with synchronous signal self-calibration function |
| CN108982978A (en) * | 2018-08-02 | 2018-12-11 | 卢小丽 | Impulse electric field detector and application method with sensitivity coefficient self calibration and power management function |
| CN109975731A (en) * | 2018-12-28 | 2019-07-05 | 北京航天测控技术有限公司 | A kind of measuring system based on real time calibration |
Non-Patent Citations (1)
| Title |
|---|
| 王翠娟;: "基于多路复用开关的信号发生器自动校准技术应用", no. 03 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114280521A (en) * | 2021-12-23 | 2022-04-05 | 北京森馥科技股份有限公司 | Calibration method and device of electromagnetic field probe, electronic equipment and storage medium |
| CN114280521B (en) * | 2021-12-23 | 2023-10-31 | 北京森馥科技股份有限公司 | Calibration method and device of electromagnetic field probe, electronic equipment and storage medium |
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