组装印刷电路板中涂覆磁性材料电源板上的电磁辐射研究

Investigation of radiated emissions from magnetic material coating on power planes in populated printed circuit board

基于对谐振腔模型的分析研究,得出了一个计算矩形电源总线结构中电磁辐射场强度的表达式,电路板上的组装元件、铜制电源板和地板的内层表面上增加的磁性涂覆层对辐射场所产生的影响可以由修正过的电源总线结构内部的波的传播常数所模拟,辐射场的强度可以用电源总线结构边缘的等效磁流和修正的传播常数计算出来。由改良的谐振腔模型得到的仿真结果表明在谐振频率处辐射场大幅度减少。

An expression for the intensity of radiated emissions from a rectangular power bus structure can be given on the basis of an analytical cavity resonator model. The effect of components mounted on the board and the adding thin layer of magnetic material coating to the inside facing surfaces of copper power and ground plates are modeled by modifying the propagation constant of the waves within the power bus structure. The radiated field intensity is calculated using the equivalent magnetic current around the edges of the power bus structure together with the modi lied propagation constant. The simulation results obtained from a modified cavity resonator model show that the ra diation emissions can dramatically reduce at board resonant frequencies.