A Software Design For High Power Microwave Device And Thermal Effects Analysis

With the rapid development of electromagnetic theory and computer technology, numerical techniques have made much progress. The finite-difference time-domain (FDTD) method is a time domain method, which is good at solving inhomogeneous materials and complicated structures. So it becomes very popular and has been given more and more attentions. High power microwave theory has been rapidly improved due to the needs of national defence, scientific research, and civil fields. The failure of semiconductor due to high power microwave has been puzzling people for a long time. The goal to design high power devices is to get high output power and some extend applications. Numerical techniques provide a feasible method for analyzing high power microwave devices and the failure of semiconductor devices.In this paper, the electromagnetic fields distribution and thermal effects are computed by the software. FDTD is employed in the software, which is written in Visual C++, to get electromagnetic fields distribution and genetic algorithm is employed to get the optimum structure. If the medium's parameters don't depend on temperature and time, there needn't any modification in the calculation. On the contrary, the long reaction time is divided into some equal parts. In each part, the parameters and the temperature of the solution are set to be constant, then electromagnetic fields are gotten by FDTD in each period. With the electromagnetic fields, power and temperature distribution in every grid can be computed. The parameters of the medium are modified in the last step. In fact, the whole process is that Maxwell's equations combined with heat transport equation have been solved by FDTD method with the leapfrog technique.