基于基尔霍夫积分的近远场变换的改进

Improved near-to far-field transformation based on Kirchhoff integral in FDTD simulation

改进了 FDTD中基于 Kirchhoff积分的近远场变换。它的优点在于实现简单 ,计算某一远场分量只用到与之相同的近场分量 ,既能计算远场又能计算近场 ,可以大大缩减 FDTD计算空间。同时将每一时间步的近场对远区的贡献分别计算 ,避免了存储积分面上上一时间步近场值的内存开销 ,近远场变换得到了进一步简化。计算结果表明 ,这种变换方法非常准确。

improves near to far field transformation based on Kirchhoff Integral in Finite Difference Time Domain simulation. Its distinct advantages are simple implement and that the calculation of any far field component depends only on the value of the same near field component over a closed surface. The contributions of near field on each time step to far field on different time step are calculated separately, which avoids saving near field value of the former time step on the surface, resulting in simpler transformation. The provided examples indicate that the algorithm is highly accurate.