电流元近场照射下球体目标散射的解析解

Scattering Property of a Spheric Target Irradiated by Near Field of a Current Element

得到了目标坐标系中电流元辐射近场的表达式,验证了该函数的正确性。在目标坐标系中将电流元的辐射近场、散射场等用球矢量波函数展开,利用球矢量波函数的正交性得到了展开系数并给出了其数值结果及物理分析。在天线近场照射下,得到了目标散射场的解析解,对所得结果进行了数值仿真,利用矩量法验证了结果的正确性。结果表明,天线近场照射目标时,目标上的电磁波为TE波和纵波,纵波是目标散射的主要因素,测量角θ对散射的影响较大。该方法可用于其他天线如相控阵天线等照射下目标散射以及目标电磁相互作用等领域的研究。

The expression of near field of a current element in the target coordinate system is obtained and its validity is tested. Then we expand the near field and the scattering field with the spherical vector wave functions. The expanding coefficients are acquired by using the orthogonality among those functions. Their simulations and the physical analysis are presented. When the target in this near filed, its scattering field is obtained. Simulations of the obtained results are given. The correctness of the results is demonstrated by the method of moment. It is concluded that when the target exists in the near field, there are respectively the TE wave and the longitudinal wave, and the longitudinal wave is the major one in scattering. The measuring angle θ has a great effect on hte scattering field. This method can be used to research scattering by other antennas such as phase array one as well as the electromagnetic interactions among targets, etc.