To study electromagnetic scattering by vehicle above ground,a half-space multilevel fast multipole algorithm (MLFMA) is proposed.Near terms in the MLFMA are evaluated by rigorous half-space dyadic Green functions.Far MLFMA interactions employ an approximate dyadic Green function via a direct-radiation term plus a single real image.The real image method leads to fast and convenient computation compared with the discrete complex image method (DCIM).It also results in less memory requirement and CPU time.Finally,bistatic radar cross sections are shown for a realistic 3D car model over lossy ground.

In order to solve EMC problems for multiple antennas mounted on airborne platforms with limited computer resources, a multilevel fast multipole algorithm (MLFMA) with adaptive number of levels is implemented based on Electric Field Integral Equation(EFIE). For the analysis of coupling between antennas, more reasonable arbitrary isolation is adopted instead of traditional isolation. BiCGStab(l) combined with near-field preconditioner is employed which improves efficiency of the MLFMA. Radiation pattern and isolation of ultra-shortwave antennas on a full-scale Boeing 747 aircraft model are obtained and discussed.

Based on nonlinear Schrodinger equation, the properties of two-source-coupled-inputed soliton and the interaction between such soli tons and the first order solitons are numerically investigated by the split-step Fourier transformation method. A tentative idea of triply optical soliton communication system is proposed and disscussed, which made the relay distance further extended with the information increased by 1.6 factor. Besides, the high power input of the light source is not necessary by using such solitons.

Based on the nonlinear schodinger equation, the interaction between a couple of second order or quasi-second order optical solitons is numerically investigated by the split-step Fourier transformation method. This let us have a good understanding of the properties in the interactions, which is referential for the utilization of second solitions to communication.