印制电路板电磁辐射等效偶极子建模与预测

Equivalent dipole modeling and predicting of electromagnetic emissions of printed circuit boards

提出了一种计算由印刷电路板产生的电磁辐射的新方法。这种方法是从近场扫描推导出的等效偶极子模型,建立了一系列可以产生相同辐射场的无穷小偶极子来代替PCB板。等效偶极子的参数直接由被测近场磁场决定,在封闭环境下仿真,等效的方法被推广应用到电介质平面偶极子模型,通过等效PCB基本物理特征来解决在PCB板和外壳之间的相互作用。通过用数学法求解等效模型来预测电磁辐射,极大的减少了仿真时间,提高了仿真效率。最后,以一块印制电路板为对象,通过对其进行电磁辐射仿真与试验测试,证明了利用本文方法建模与预测的正确性和高效性。

In this paper, a new method for calculating the electromagnetic emissions generated from printed circuit board （PCB） is proposed. This method uses the equivalent dipole model deduced from near-field scanning. A series of infinitesimal dipoles that generate the same radiation fields are established and used to replace the PCB. The pa- rameters of the equivalent dipoles are determined by directly fitting the magnetic near fields to be measured. In closed-environment simulations, the equivalent method is extended to the dipole dielectric conducting plane model; and the basic physical features of the equivalent PCB are used to solve the interactions between the PCB and enclo- sure. Then the electromagnetic emissions can be predicted by solving the equivalent model with numerical method; thereby, the simulation time is significantly reduced and the simulation efficiency is improved. A printed circuit board was modelled in different configurations ,and used as the object to carry out electromagnetic emission simulation and experiment test, and the result proves the validity and efficiency of the method.