An accurate method of calculating the radiated emission from multilayer printed circuit board edge structures

An accurate method for evaluating the radiated emission from power distribution system in multilayer printed circuit boards was investigated.Firstly，the impedance caused by signal current returning through power and ground（P/G)planes was calculated using high efficient 2D boundary element method（BEM)，then the equivalent physics circuit model of via transition was connected with exterior circuit to form integral circuit，so the precise excitation current can be obtained through circuit simulation method.The field distribution on the peripheral surfaces of P/G planes induced by the excitation current was also calculated by BEM， finally the far field radiation was obtained through equivalent magnetic current of edge field.The radiation excitation current and maximum radiated emissions were provided for different frequencies. Research results show that the radiation reaches its anti-resonance frequencies.The obtained results agree very well with those from electromagnetic simulation based on full-wave finite-element method.