Design And Calibration Of Near-field Probe For Measuring Normal Component Of Electric Field

With the decrease of electronic device and the increase system integration, the problem of electromagnetic interference in the system and any electronic devices has become more and more bulgy. EMI can not only degrade the system, but also pollute the environment. In order to determine the position and amplitude of electromagnetic radiation source, near-field mapping system is used to determine electromagnetic field radiated by electronic systems. The probe is the main element of this measurement tool. The exactness and accuracy for imaging depended on the performances of the probe.Firstly, the related knowledge on EMC and electromagnetic near-field imaging system have been briefly introduced. Types of near field probe and their applications are also summarized. According to the engineering application of electromagnetic mapping system, the parameters of near-field probe were extracted. Secondly, the operation principle of the probe is explained from the viewpoint of coupling. Meanwhile, all simulations were made to validate the operation principle by Ansoft HFSS, which is a commercial3D electromagnetic simulator based on Finite Element Method (FEM). Finally, by simulation and experiment, we analyze all performances of the normal field probe, such as the isolation, spatial resolution, frequency bandwidth and sensitivity. And the effect of the probe geometry on the probe parameters is obtained.In this thesis, the normal field probe can be calibrated by TEM cell and microstrip line where electromagnetic field is known. By analyzing and comparing the theoretical and simulation data with measured data, it can be found that the normal field probe has better performance in isolation, spatial resolution, frequency bandwidth and sensitivity. And measurement error analysis is carried out. The fabrication of the normal field probe is simple, the cost is low, in addition it can be used in application.