Numerical Modeling for High-Power Microwave Propagation in Soil

A theoretical investigation is presented for the physical phenomena of high-power microwave (HPM) propagation in soil. The soil resistivity will decrease due to the breakdown process caused by strong electric field of the HPM, and this process will in turn lead to dramatic attenuation of the HPM. The soil resistivity changes with time, which can be described by time-varying partial differential equations. Combined with the Maxwell equations, a model of HPM propagation in soil has been established, and numerical simulation has been made by using the finite-difference time-domain (FDTD) method. Finally, the physical processes of the HPM propagation in soil have been revealed by the numerical results.