一种计算屏蔽箱体外部辐射场的混合算法

提出一种新的混合算法用以计算屏蔽箱体开口外侧的辐射场。利用时域有限差分法得到箱体开口处电场的切向分量以便确定开口处的等效磁流源,箱体外的辐射场则通过等效磁流源的积分方程获得。通过对箱体外辐射场的验证表明,该混合算法与时域有限差分法和传统混合算法具有相同的计算精度,但需要的计算机内存和计算时间则远小于后两种方法,数学上的处理也比传统混合算法简单。与近场计算量相比,远场的计算量没有明显增加,因此该方法对远场辐射问题尤其有效,具有实际的工程应用价值。

A Hybrid Method for the Calculation of Radiation Field From Aperture in the Shielding Enclosure

The paper presents a new hybrid method for the calculation of the radiation field outside the shielding enclosure. The method computes the tangential component of the electric field on the aperture by finite difference time domain (FDTD) method to determine the equivalent magnetic current source. This magnetic current, once determined, can be used to ascertain the radiate field anywhere external to the aperture in a shielding enclosure. Advantages of the proposed method include low computational loads and simple implementation. The accuracy of the proposed method is verified by comparing the exterior radiation fields with those calculated by full FDTD and the traditional hybrid method. Simulation results show that the new hybrid method significantly reduces the computational effort and time, but still maintains satisfactory results. It also shows that the proposed method is very effective for the far field in that the computational effort, as compared with that of the near field, does not increase remarkably. Therefore, the method has practical application value to evaluate the shielding efficiency of metallic rectangular enclosures.