This paper formulates two different boundary-element＋Born series schemes for wave propagation simulation in multilayered media by incorporating a Born series and boundary integral equations. The first scheme directly...This paper formulates two different boundary-element＋Born series schemes for wave propagation simulation in multilayered media by incorporating a Born series and boundary integral equations. The first scheme directly decomposes the resulting boundary integral equation matrix into the self-interaction operators associated with each boundary itself and the extrapolation operators expressing cross-interactions between different boundaries in a subregion. For the second scheme, the matrix dimension is firstly reduced to a half by the elimination of the traction field in the equations. The resulting new matrix can also be split into the self-interaction matrices associated each subregion itself and the extrapolation matrices interpreting cross-interactions between different subregions in a whole model. Both the numerical schemes avoid the inversion of the relatively much larger boundary integral equation matrix of a full-waveform BE method and hence save computing time and memory greatly. The two schemes are validated by calculating synthetic seismograms for a homogeneous layered model, compared with the full-waveform BE numerical solution. Numerical experiments indicate that both the BEM＋Born series modeling schemes are valid and effective. The tests also confirm that the second modeling scheme has a faster convergence in comparison with the first one.展开更多
The radiation emission （RE） of multilayer primed circuit board （PCB） will cause electromagnetic compatibility problem. An efficient numerical method for evaluating the effectiveness of decoupling capacitors in red...The radiation emission （RE） of multilayer primed circuit board （PCB） will cause electromagnetic compatibility problem. An efficient numerical method for evaluating the effectiveness of decoupling capacitors in reducing RE from power ground （P/G） planes in PCB was presented. A two-dimensional boundary-element method （BEM） was used to establish the radiation model. Then, the RE was calculated by equivalent magnetic current of edge field around P/G planes. Furthermore, the radiation and input impedance of P/G planes mounted decoupling capacitors were calculated for frequency up to 5 GHz The results were compared to those of the case without decoupling capacitors. It shows that the decoupling capacitors can effectively decrease RE except for anti-resonant frequency. At higher frequencies, the decoupling effectiveness mainly depends on the parasitic inductance of capacitor pin rather than the value.展开更多
基金supported by National Natural Science Foundation of China (No.40830423)National Basic Research Program of China(973 Program,2009CB219403)
文摘This paper formulates two different boundary-element＋Born series schemes for wave propagation simulation in multilayered media by incorporating a Born series and boundary integral equations. The first scheme directly decomposes the resulting boundary integral equation matrix into the self-interaction operators associated with each boundary itself and the extrapolation operators expressing cross-interactions between different boundaries in a subregion. For the second scheme, the matrix dimension is firstly reduced to a half by the elimination of the traction field in the equations. The resulting new matrix can also be split into the self-interaction matrices associated each subregion itself and the extrapolation matrices interpreting cross-interactions between different subregions in a whole model. Both the numerical schemes avoid the inversion of the relatively much larger boundary integral equation matrix of a full-waveform BE method and hence save computing time and memory greatly. The two schemes are validated by calculating synthetic seismograms for a homogeneous layered model, compared with the full-waveform BE numerical solution. Numerical experiments indicate that both the BEM＋Born series modeling schemes are valid and effective. The tests also confirm that the second modeling scheme has a faster convergence in comparison with the first one.
基金supported by the National Natural Science Foundation of China (61171051)
文摘The radiation emission （RE） of multilayer primed circuit board （PCB） will cause electromagnetic compatibility problem. An efficient numerical method for evaluating the effectiveness of decoupling capacitors in reducing RE from power ground （P/G） planes in PCB was presented. A two-dimensional boundary-element method （BEM） was used to establish the radiation model. Then, the RE was calculated by equivalent magnetic current of edge field around P/G planes. Furthermore, the radiation and input impedance of P/G planes mounted decoupling capacitors were calculated for frequency up to 5 GHz The results were compared to those of the case without decoupling capacitors. It shows that the decoupling capacitors can effectively decrease RE except for anti-resonant frequency. At higher frequencies, the decoupling effectiveness mainly depends on the parasitic inductance of capacitor pin rather than the value.
