介质覆盖无限长理想导体圆柱上线源的辐射

介质覆盖无限长理想导体圆柱上线源的辐射 RADIATION FROM MAGNETIC LINE-SOURCE ON INFINITELY LONG PERFECTLY CONDUCTING CIRCULAR CYLINDER WITH DIELECTRIC COATING 李永俊 Li Yongjun first-author 导弹、空间飞行体表面的介质覆盖层（如防热瓦）对装于其上孔经天线的辐射有何影响已成为当前必须研究的课题。本文通过求解一个典型问题,揭示出:1.覆盖层很薄时,不影响覆射方向图;2.覆盖层的ε值很大。且层厚为λ/2的整数倍时,不改变辐射方向图;3.ε值很大,且层厚为λ/4的奇数倍时,电极化波的辐射方向图变成了磁极化波的方向图。对于本问题,辐射波瓣展宽,暗区场变亮。4.e值很大。但层厚不是上述特殊值时,辐射场由复合福克函数描绘。 It is of interest to study how the dielectric coating plated on the surface of spacecrafts influence the radiation from the source on the same surface. In this paper, a canonical problem is investigated, The main results are as follows: If e is much larger than δ 0 and 1. The coating is very thin or the thickness of the coating is equivalent to nλ/2,the influece may be neglected. The radiation pattern doesn’t alter. the creeping waves creep on the dielectric coatng surface. 2. The thickness of coating is equivalent to （21+1）λ/4, there will be a variation of radiation pattern. In this canonical problem the radiation pattern to the electric polarisation becomes the radiation pattern to the magnetic polarisation, and it broadens. 3. In other cases the fields are described by compound Fock function. 电磁波辐射 共形天线 几何绕射理论 介质覆盖 复合福克函数 electromagnetic radiation conformal antenna geometrical theory of diffraction diectrical coating compound Fock function. 国家教委重点科研课题 1989-01-01 2021-04-01 1