Analysis of Doppler effect of moving conducting surfaces with Lorentz-FDTD method

To analyze scattering fields from moving conducting bodies, a novel Lorentz finite-difference time-domain (FDTD) method is proposed in this paper. The transformation formulas of electromagnetic field parts, space parts, and time variable are gained by using Lorentz transformation between the rest and the moving reference frame. To calculate the scattering fields from moving conducting bodies, the total-field-scattered-field boundary condition is set up to introduce an incident plane wave in the moving reference frame. Using the interpolation method, the relation between electromagnetic fields in the moving reference frame and that of the related grids in the rest is estimated. Using the proposed Lorentz-FDTD method analyze the scattering fields from one-dimensional moving conducting surface. Thus, variations of the amplitude and frequency of scattering fields with the moving conducting surface speed are considered. Caused by the moving conducting surface, the amplitude and frequency of incident plane wave suffer a modulation shift. Numerical results are in a good agreement with analytical results for the discussed case.