利用频谱信息改善时域电磁散射算法MOO的后时振荡现象

Treating the Instabilities of MOO in Transient Scattering by Using a Little of Frequency Data

分析了MOO算法在后时低能区产生振荡的原因,提出了一种改善MOO算法计算时域电磁散射稳定性的方法。根据时、频域响应之间存在的傅立叶变换关系,及Laguerre多项式的时频域振荡特性,通过计算少量准确的频域数据替换掉时域数据经傅立叶变换后由于级数截断而产生的振荡频谱,并利用希尔伯特变换的内插技术进行数据平滑,对修正之后的频域数据进行逆傅立叶变换得到稳定的时域数据。通过对实际目标的仿真验证了方法的有效性。

In this paper,the reason of oscillations appeared in late time low energy region of time domain electric filed integral equation using laguerre polynomials were analyzed, and then,we proposed an approach to reduce the oscillations by combining frequency time domain. According to the Fourier transforms relation between frequency responses and time responses, and oscillation character of laguerre polynomial in time and frequency domain, respectively. Replace the spectrum of oscillation parts of time domain data with accurate frequency data by MOM. The stable time domain data can be obtained by performing a IFFT to the revised frequency data. Numerical results are presented to illustrate the efficacy of this approach.