金属骨架结构对天线罩散射特性的影响*

在轮廓尺寸确定的情况下,天线罩金属骨架的结构划分对其电磁性能起着至关重要的作用。从骨架 拓扑结构的角度出发,研究了不同结构对骨架散射特性的影响。通过构建物理参数一致的规则和非规则金属骨架, 采用感应电流率理论得出骨架不同位置的感应电流分布,最后确定骨架的扩散场影响。结果表明,非规则划分的金 属骨架,由于桁杆在球面上近似为随机分布,远区散射能量被分配到了偏离主辐射方向的旁瓣区域,主辐射方向相 对于规则骨架的影响要小很多。应用非规则划分方法设计的骨架,可以有效提高天线罩的性能。

The Effect of Metal Frame Structure on EM Scattering Characteristics of Radomes

The structure of metal space frame (MSF) has a significance influence on the electromagnetic properties of radomes when the overall size is determined. In this paper, the effects of different frame structures on scattering characteris tics are studied based on the topological structure. On the basement of regular and irregular MSFs with the same mechanical parameters, the method of induced current ratio is employed to calculate the induced current distribution on the different posi tions of frame, and the scattered field of frame is obtained. The result proves that the scattering energy in far-field is dispers ed to the side-lobe area far from the radiation direction because of the quasi-random arrangement of struts in irregular MSF. This dispersion leads to a smaller influence on the radiation field near the radiation direction. The performance of radomes can be improved with the employment of metal frame which is designed by the irregular division method.