Investigation Of Coupling Character For Complex Shielding Body

Electromagnetic interferer is a critical factor in electromagnetic compatibility(EMC). The electronic device or system is located in the situation, where radiativefield from other devices is very complex. In order to analyze these EMC issues, thecharacteristic of electromagnetic coupling is needed to be known. It is necessary tomodel the real environment and calculate the field. While the situation is very socomplex that traditional analyse method can not deal with, numerical methodbecomes the most important tool to calculate the field.In the design of EMC, shielding is one of the important technologies. It canprevent the device from interfering from other devices. But inevitable slots inshielding body may degrade greatly shielding effectiveness. In order to analyzedifferent shielding body, this paper utilizes different algorithms to calculate shieldingeffectiveness of the shielding body. It contains the following aspects:1,To utilize equivalent transmission line theory to analyze multilayer shieldingbodies. Based on the consistency between plane wave transmission characteristic inisotropy media and that of transmission line, it is simple and clear to utilizetransmission line theory to analyze multilayer shielding bodies.2,The interest in the development of lightweight transparent electromagneticshields for RF range has been growing up in the recent years. A complete study isperformed, from material characterization and design, to fabrication and experimentaltest of a prototype sample consisting of several alternating zinc oxide and silver (Ag)layers. The transparent metal is designed to obtain high shielding effectiveness but asexperimentally measured.3,The FDTD is effective to analyze the shielding body having wide slots. Whilethe algorithm Yee put forward is lower order, its precision is very poor. Based on theTaylor series, the high order FDTD is developed in this paper, which can savememory size and computating time. The total field FDTD formulations of the fourthorder scheme are derived in detail in a three dimensional space of lossy and losslessmedia. 4,A simple transmission line model is given to approximately represent anarrow slot having depth when the conductivity of the conducting plane is large butnot necessarily infinite. Usually, there is conductor in the coupling zone, so thissituation is analyzed when one slim lead is located in the coupling zone. Thedepicting equations of slot and slim lead are obtained, and MoM is used to calculatethe coupling feature. The most difficult is to analyze cavity with narrow slot. Basedon the former results, the different field is introduced to deal with this situation.