对频域推进法的改进

IMPROVEMENT ON MARCHING-ON-IN-FREQUENCY METHOD

频域推进法的基本技术是在递进的取样频率上用迭代法解离散化积分方程,并用基于误差最小化的外推法为迭代法产生初始解。把对比源截断法中的迭代公式修改后,可明显加速在低频的收敛。在复频域求解是加速迭代法收敛的有效途径,因为方程的性态在复频域得到改善。而且,解随频率的变化比在实频域平缓,用外推法能产生较精确的初始解。

The basic idea of marching-on-in-frequency method is that the discretized integral equation is solved by using one of the iterative approaches, and the initial estimates are produced by using an extrapolation scheme based on error minimization. The iteration formula in the CST is corrected, which increases the convergence rate considerably at lower frequencies. It is important for convergence that the iteration is carried out in complex-frequency domain, because the matrix condition is improved and more accurate initial estimate can be obtained from the smoothly varying solutions in complex-frequency domain.