Theoretical and numerical studies on cage antenna of EMP radiating-wave simulator based on parallel computing

Large electromagnetic pulse (EMP) simulation equipment are needed in order to study the EMP effect produced by nuclear blast and reinforce measure of electron system. Considering the target is electrically large, a parallelized finite difference time domain (FDTD) algorithm based on MPI platform, combined with antenna theory, is presented for analysis of the radiation characteristics of the biconical-cylindrical cage antenna fed through the coaxial transmission line and excited by a double-exponential pulse, which can not be done on a personal computer due to over long time and prohibitive computation resources. The number of total cells for parallelized FDTD computing is about 2 billion. Numerical results show that cage antenna radius do not have a significant effect on the rise time and the peak value of the radiated electric field when the cage antenna radius is more than 3.5 m. In addition, the reflection and the loss from the ground have a great effect on the rise time, the peak value and pulse width of the radiated E-field in the horizontal plan above the ground up to 0.5 m and have little effect on the rise time and the peak value of the radiated E-field in the horizontal plan above the ground up to 6 m except the pulse width of the radiated E-field at the same point. It is found that nearer to the ground, faster the decrease of the peak value. (authors)