Design Of Antennas For Wideband Electric-field Measurement Based On Distributed Impedance

With the advancement of science and technology,human society has become more and more informatized and digitized,and more and more electronic devices have entered human life.While electronic devices bring convenience to people,the problem of EMR in the environment is becoming more and more serious.EMR not only affects human health,but also causes interference and even damage to the surrounding electronic equipment.Therefore,in order to protect human health and the surrounding environment from harm,it is necessary to have simple and accurate measuring instruments to monitor EMR to determine whether the current area complies with relevant standards.The core component of EMR measurement equipment is the electric-field probe.So the in-depth study of electric-field probes is of great theoretical significance and application value.Aiming at the design requirements of UWB electric-field probes,based on the reference of relevant research at home and abroad,this article uses the lumped loading antenna technology to design a miniaturized UWB electric-field probe that can monitor the electric field strength in the frequency band of 1-40GHz.The main work of this thesis is as follows:(1)Aiming at the design requirements of 1-40GHz UWB electric-field probes,based on the basic structure of electric-field probes and based on the principle of loading antennas,the HFSS simulation software was used to establish distributed impedance loading and lumped impedance loading antenna models in UWB electric-field probes respectively.And the influence of different parameters on the broadband performance of the electric-field probe is analyzed.(2)According to the simulation results and the structural model of the existing electric-field probe,a number of physical electric field probes based on lumped resistance loading are fabricated and tested experimentally.By comparing the simulation and experimental results,the actual effects of lumped resistance and detector diode parameters on the performance of the electric-field probe are analyzed.Combining the conclusions obtained by simulation and actual measurement,the structure and loading parameters of the electric-field probe are optimized.(3)Based on the optimization results,the comprehensive design of lumped resistance loaded UWB electric-field probes is carried out.The influence of the feed point position on the probe performance is analyzed by simulation,and a better feed structure is obtained.And through simulation,the resistance distribution at the best performance is obtained.According to the simulation results,the real object of electric-field probe is made,and the standard probe method is used to calibrate it.The test result shows that the flatness of the UWB electric-field probe based on lumped resistance is ±3dB,which meets the design requirements.The lumped resistance loading electric-field probe designed in this thesis is simple in structure,easy to manufacture and low in cost.The flatness of the frequency response in the frequency range of 1-40GHz is ±3dB.And a chip resistor with a wide operating temperature range is used in the loading part.Therefore,compared with the distributed loading electric field probe,the probe designed in this thesis can be used in a wider temperature range.