Research And Design Of RF Circuit Board Electromagnetic Radiation Measuring Probe

With the increasing miniaturization and integration of electronic circuits and the increase in the operating frequency of circuit boards,the electromagnetic radiation interference between integrated chips and the traces of radio frequency circuits cannot be ignored.Whether the electromagnetic probe can accurately detect the electromagnetic radiation leakage determines the performance of the near-field scanner,so it is of great practical 'significance and market value to do research on the probe.The thesis mainly studies the probes used to' measure the magnetic field,and the main work completed is as follows:Firstly,the magnetic field probe based on the IEC-61967 standard has been studied.The probe uses the stripline structure for measuring electromagnetic radiation signals among the frequency range between 150kHz and 1 GHz.On the one hand,a lot of simulation studies have been carried out on the structural parameters of the probe using three-dimensional electromagnetic field analysis software.These studies summarize the important factors that affect the performance index of the standard probe,and provide guidance for the subsequent probe design.What's more,a strip-line magnetic field probe has been processed in size,which is used for the experimental measurement of the standard probe and the experimental comparison with the probe designed subsequently.Secondly,a low-cost magnetic field probe with a microstrip line structure has been designed and processed.Compared with the IEC-61967 standard probe,the using frequency range of the microstrip magnetic field probe is extended to 3GHz,and the frequency response curve in the frequency band is good,reducing the difficulty of probe calibration.The microstrip magnetic field probe is processed and measured.The measured results and the simulation results are in good agreement.The measured spatial resolution at the 3 GHz frequency is 1.4mm.The magnetic field probe is suitable for occasions where the electric field suppression is not required.Finally,a magnetic field probe with a coplanar waveguide transmission line structure has been designed,and an improved half-loop coplanar waveguide magnetic field probe has been proposed based on it.The proposed improved magnetic probe extends the frequency range of use to 5 GHz.While improving the flatness of the frequency response curve at high frequencies,it also improves the degree of electric field isolation in the frequency range of the magnetic field probe.The improved half-loop coplanar waveguide magnetic field probe has been processed and tested.Its processing cost is much lower than the IEC-61967 standard magnetic field probe with strip line structure.The test results show that the probe has good frequency characteristics and its space resolution at 5GHz is up to 1.2mm.