论文部分内容阅读
用时域有限差分法计算目标的雷达散射截面时,一般用连接边界来引入平面入射波.理想情况下,当总场区没有散射目标时,该区域仅有入射波,散射场区电磁波为0.但在实际计算过程中,散射场区的电磁波一般不会严格等于0,这是因为在连接边界引入入射波时产生了电磁泄漏.一维情形下,用散射场区电场的平方和来衡量电磁泄漏程度.二维情形下,用等效原理将散射场区的电磁场进行远场外推,得到雷达散射截面,以此衡量电磁泄漏的大小.研究表明:时间步长、入射角度都能影响电磁泄漏大小.为使电磁泄漏较小,时间步长应接近于稳定性要求的最小步长,入射方向应避免垂直于计算区域边界.
When calculating the radar cross section of a target by finite difference time domain method, the incident plane wave is usually introduced by the connection boundary. Ideally, when there is no scattering target in the total field region, there is only incident wave in the region, and the electromagnetic wave in the scattering field is zero. However, during the actual calculation, the electromagnetic field in the scattering field is not strictly equal to zero, because electromagnetic leakage occurs when the incident wave is introduced into the connection boundary. In one-dimensional case, the square sum of the electric field in the scattering field is used to measure the electromagnetic Leakage degree.In the two-dimensional case, the electromagnetic fields in the scattering field are extrapolated by using the principle of equivalence to obtain the radar cross section, so as to measure the size of the electromagnetic leakage.Research shows that time step and angle of incidence all affect the electromagnetic To minimize electromagnetic leakage, the time step should be close to the minimum step required for stability, and the incident direction should be avoided perpendicular to the boundary of the calculation area.