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CN-121995290-A - Current probe calibration device and calibration method

CN121995290ACN 121995290 ACN121995290 ACN 121995290ACN-121995290-A

Abstract

The invention relates to a current probe calibration device and a calibration method, wherein the device comprises a network analyzer, a calibration fixture, a non-conductive bracket and an adapter; the non-conductive support is used for fixing the calibration clamp, the input end of the calibration clamp is connected with a PORT PORT1 of the network analyzer, the output end of the calibration clamp is connected with a load, the current probe to be calibrated is clamped on a central wire of the calibration clamp, and the adapter is used for connecting the output end of the current probe to be calibrated with a PORT PORT2 of the network analyzer. The calibration method comprises the steps of setting and calibrating a network analyzer, assembling a calibration fixture, installing a current probe to be calibrated, starting the network analyzer to scan, recording the amplitude data of parameters S 21 , calculating the transmission impedance of the current probe to be calibrated according to a formula Z t =S 21 +34, and completing the calibration. The invention solves the problems of complex calibration method and larger error of the existing current probe.

Inventors

  • ZHAO MAN
  • LI ZENGLIN
  • ZHANG WEI
  • WANG TAOLIN
  • FAN FENGJUN

Assignees

  • 上海航天技术基础研究所

Dates

Publication Date
20260508
Application Date
20260203

Claims (9)

  1. 1. The current probe calibration device is characterized by comprising a network analyzer, a calibration fixture, a non-conductive bracket and an adapter, wherein the calibration fixture is used for simulating a cable in actual interference test, the non-conductive bracket is used for fixing the calibration fixture, the input end of the calibration fixture is connected with a PORT PORT1 of the network analyzer, the output end of the calibration fixture is connected with a load, a current probe to be calibrated is clamped on a central wire of the calibration fixture, and the adapter is used for connecting the output end of the current probe to be calibrated with a PORT PORT2 of the network analyzer.
  2. 2. The current probe calibration device of claim 1, wherein the network analyzer is E5071C type, supports 10 kHz-8.5 GHz frequency band, the non-conductive support is height-adjustable, and the adapter is BNC-N type adapter.
  3. 3. The current probe calibration device of claim 1, wherein the calibration fixture is an air coaxial line with a 50Ω characteristic impedance, and the input and output ends of the calibration fixture are both N-type interfaces.
  4. 4. A current probe calibration method, characterized in that a current probe calibration device according to any one of claims 1 to 3 is employed, the method comprising the steps of: 1) Setting and calibrating a network analyzer; setting the frequency range and the power level of a network analyzer according to the frequency band to be measured of the current probe to be calibrated, and carrying out full two-port calibration on the network analyzer to eliminate system errors; 2) Assembling a calibration fixture; 3) Installing a current probe to be calibrated; 4) Starting a network analyzer to scan, and recording amplitude data of the parameters S 21 ; 5) And calculating the transmission impedance of the current probe to be calibrated according to a formula Z t =S 21 +34, and completing calibration.
  5. 5. The method for calibrating a current probe according to claim 4, wherein in the step 1), the network analyzer is subjected to open-circuit, short-circuit and load calibration, so that impedance matching of ports of the network analyzer is ensured, and system errors are eliminated.
  6. 6. The method of calibrating a current probe according to claim 4, wherein the step 2) includes horizontally fixing a calibration jig on a non-conductive support, and connecting an input end of the calibration jig to a PORT1 of a network analyzer and an output end of the calibration jig to a load.
  7. 7. The method for calibrating a current probe according to claim 4, wherein the step 3) comprises clamping the current probe to be calibrated on a central wire of a calibration fixture, closing a lock catch to ensure that the current probe to be calibrated is tightly closed, an air gap is smaller than 0.1mm, a magnetic core axis of the current probe to be calibrated is perpendicular to the central wire of the calibration fixture, and an output end of the current probe to be calibrated is connected with a PORT PORT2 of a network analyzer through an adapter.
  8. 8. The method for calibrating a current probe according to claim 4, wherein in the step 1), a frequency range of the network analyzer is set to 10 kHz-500 MHz, a power level is set to-10 dBm, and in the step 3), a scanning frequency range of the network analyzer is set to 0.3 MHz-100 MHz.
  9. 9. The method of calibrating a current probe according to claim 4, wherein the average value obtained by 10 continuous measurements in the step 5) is a calibration result.

Description

Current probe calibration device and calibration method Technical Field The invention relates to the technical field of electromagnetic compatibility testing, in particular to a current probe calibration device and a current probe calibration method. Background The current probe is used as a core tool in electromagnetic compatibility (EMC) transmission interference test, and radio frequency current on a cable is measured in a non-contact mode, so that the accuracy of performance parameters directly influences the reliability of a test result. In the prior art, the calibration of the current probe is mainly based on CISPR 16-2-1 standard and JJF (military) 27.6-2020 standard, but the traditional calibration method has the problems of complex equipment, complex operation, multiple error sources and the like. For example, the spectrum analyzer method needs to use a plurality of devices such as a signal generator, a power divider, two spectrum analyzers and the like, is easily influenced by factors such as cable loss, device matching and the like in the calibration process, and the total uncertainty can reach 1.2 dB-2.5 dB, while the existing network analyzer method has few devices but is greatly influenced by parasitic parameters in a high frequency band, and the calibration precision needs to be improved. Therefore, a current probe calibration scheme that is simple to operate, has small errors and is widely used is needed. Patent CN107765204a discloses a current probe calibration fixture, which solves the problem that the conventional calibration fixture structure cannot meet the calibration requirement of an annular closed current probe, is suitable for current probes with different sizes, and has good universality. Patent CN104749544a discloses a temperature error correction method for transmission impedance of electromagnetic compatibility current probe, which calculates the relative error between the transmission impedance of the current probe under different temperature conditions and the standard temperature conditions, and corrects the transmission impedance of the electromagnetic probe by using the error. Disclosure of Invention The invention aims to provide a current probe calibration device and a current probe calibration method, which solve the problems of complex and larger error of the existing current probe calibration method. In order to achieve the aim, the invention provides a current probe calibration device which comprises a network analyzer, a calibration clamp, a non-conductive support and an adapter, wherein the calibration clamp is used for simulating a cable in an actual interference test, the non-conductive support is used for fixing the calibration clamp, the input end of the calibration clamp is connected with a PORT PORT1 of the network analyzer, the output end of the calibration clamp is connected with a load, a current probe to be calibrated is clamped on a central wire of the calibration clamp, and the adapter is used for connecting the output end of the current probe to be calibrated with a PORT PORT2 of the network analyzer. The current probe calibrating device comprises a network analyzer, a non-conductive support, an adapter, a calibration fixture, an N-type interface and an N-type interface, wherein the network analyzer is E5071C type and supports 10 kHz-8.5 GHz frequency bands, the non-conductive support is adjustable in height, the adapter is BNC-N type adapter, the calibration fixture is an air coaxial line with 50 omega characteristic impedance, and the input end and the output end of the calibration fixture are both N-type interfaces. The invention also provides a current probe calibration method by adopting the current probe calibration device, which comprises the following steps of 1) setting and calibrating a network analyzer, setting the frequency range and the power level of the network analyzer according to the frequency band to be measured of the current probe to be calibrated, and carrying out full-two-port calibration on the network analyzer to eliminate system errors, 2) assembling a calibration fixture, 3) installing the current probe to be calibrated, 4) starting scanning of the network analyzer, recording amplitude data of parameters of S 21), and 5) calculating the transmission impedance of the current probe to be calibrated according to a formula Z t（dBΩ）=S21 +34 to finish calibration. According to the current probe calibration method, in the step 1), the network analyzer is subjected to open-circuit, short-circuit and load calibration, so that the impedance matching of the ports of the network analyzer is ensured, and the system error is eliminated. The current probe calibration method comprises the following steps that step 2) a calibration fixture is horizontally fixed on a non-conductive support, the input end of the calibration fixture is connected with a PORT (PORT 1) of a network analyzer, and the output end of the calibration fixture is connected