中文摘要：

飞行器翼身接合部构成的二面角反射器是很强的电磁散射源。但是传统的计算方法仅仅适用于理想二面角反射器。该文采用几何光学法和物理光学法分析矩形二面角反射器的多次反射，在照明宽度概念的基础上，提出了等效照明面积的概念。通过对等效照明面积的分析，给出了能计算任意平面形状、有遮挡效应的二面角反射器后向雷达散射截面的工程方法。通过对某高超声速飞行器翼身结合段雷达散射截面的计算，验证了该方法的正确性。

英文摘要：

The dihedral corner reflector with wing and fuselage joint of aircraft is a very strong electromagnetic source in a wide angular range. But traditional RCS computation method is only suit for the ideal dihedral corner reflector. This paper adopts Geometrical Optics （GO） and Physical Optics （PO） methods to compute double and thrice bounce contributions of a rectangle dihedral corner reflector. And on the base of illumination width, a concept of Equivalent Illumination Area （EIA） is presented. Through the analysis of EIA, a modified computational method is given, which can analyze a dihedral corner reflector with arbitrary shape of planes and with shadow objects. To valid this method, RCS of wing and fuselage joints of a certain hypersonic vehicle is computed, and the result validates its correctness.