The Design Of Portable Electric Field Probe Calibrator

The electric field probe is one of the important core components for measuring the electric field strength in the EMR.Real-time calibration of the electric field probe is an important step to ensure the accuracy.Therefore,the electric field probe calibrator is an indispensable test device for the electric field probe during the application process.At present,the commonly used electric field probe calibrator can be accurately calibrated,but it is large in size and is not convenient to carry,and is not suitable for off-site real-time calibration.In response to this problem,this paper aims to study the design of an electric field probe calibrator that is compact,portable and meets calibration requirements.Based on the requirements of real-time calibration of 1MHz~18GHz wide-band electric field probes,according to the international standard of electric field probe calibration of IEEE1309-2013,the three frequency points of low,medium and high are given,and the miniaturized calibrator signal generator circuit and calibration field generating device are designed.Set up the calibrator system to complete the performance test of the calibrator.The main work of the thesis is as follows:(1)According to the international standard of electric field probe calibration,the design requirements of the electric field probe calibrator are given.The basic composition of the electric field probe calibration system and the calibration method of the electric field probe are introduced.The realization idea of the portable electric field probe calibration instrument is proposed.(2)In order to realize the wide-band calibration of the electric field probe,based on the RF circuit theory,three calibration frequency points of 200 MHz,2.5GHz and 5.9GHz are selected to select the signal generation module of the corresponding frequency;a small-sized control switch and power supply circuit are designed.And give the calibrator signal generator system circuit design schematic diagram,and analyze the circuit performance indicators.(3)Based on electromagnetic field theory and microwave antenna technology,using HFSS simulation software,three field generating device models of parallel two-wire,parallel plate transmission line and horn antenna were established for three calibration frequency points;simulation and design of small size,the portable field generating device provides a uniform field region that satisfies the calibration requirements of the electric field probe by analyzing the uniform characteristics of the electric field formed by the field generating devices at each frequency point.(4)Based on the designed signal generator circuit and field generating device,build a portable calibration system and make physical objects;separately verify the designed circuit performance;measure the electric field of three field generating devices,analyze the uniform field characteristics;and the signal generator is coupled with the field generating device to perform system verification of the portable calibrator.The experimental results show that the portable calibrator designed in this paper can be used for real-time calibration of the field electric field probe,which realizes the miniaturization of the calibrator.