||Electromagnetic interference problems have become serious gradually because many devices are getting more sophisticated and sensitive in modern life. Designers often need to consider a variety of situations complex problems so their demand for software also enhanced. Computation time of the frequency domain algorithm grows with the complexity of the problem, but the time domain algorithm is linear growth. Therefore, the efficiency of time domain algorithm will be greater than the frequency domain algorithm at highly complex issue. It’s quite suitable to analyze electromagnetic interference of missiles using time domain algorithm.|
Subgridding FDTD method can enhance the efficiency of simulation by using different precision grid to describe any structure in the whole computational domain. Therefore, the stability and accuracy of the subgrid method are both popular topics for studies around the world. In this thesis, we proposed the adaptive time step method combined with non-uniform grid method to link boundary between main grid and local grid. One-time’s surface coupling process doesn’t need to lower time step, therefore, the stability and the computing speed can be improved effectively.
In the second part, we analyze electromagnetic interference of missile’s model using the method described above. The PCB structure is built by local grid, the remaining structures are built by main grid, two types of grid are defined by a scale of one to five. To simulate electromagnetic pulse, a Gaussian plane wave was passed through the missile model in different angle. To explain the feasibility of our approach, the result will be compared with HFSS at last.