Abstract: In order to investigate the effects of the inlet shape on the electromagnetic characteristic of the S-shaped inlets lips and cavities, the radar cross-section(RCS) of S-shaped inlet of W-shaped, circular, ellipse, rectangle and diamond with the same eccentric distance, variation pattern of the inlet cross-section and variation pattern of the center line was studied through Iteration Physical Optics(IPO) and Equivalent Edge Current(EEC) method. The results show that the inlet shapes obviously affect the RCS characteristic of S-shaped inlet. The RCS of the S-shaped inlet with W-shaped inlet is lower than others in a large detecting angle range. The RCS of the S-shaped inlet with diamond inlet is the lowest among the inlets without lip modification. W-shaped lip modification can effectively lower the RCS of the diffraction field. As for negative detecting angle, beveled lip modification can reduce the RCS of the total scattering field.

Key words: Iteration physical optics; Equivalent edge current; Radar cross section; S-shaped inlet;Lip modification

摘要： 为了研究进口形状对S形进气道唇口边缘绕射场与其腔体内部散射场电磁特性的影响,在S形进气道偏心距、面积变化规律、中心线变化规律不变的条件下,采用迭代物理光学法(IPO)与等效边缘电流法(EEC)方法,对圆形、椭圆形、矩形、菱形、W形等5种不同进口形状的S形进气道进行了雷达散射截面(RCS)的数值分析。结果表明,进口形状对进气道的RCS特性影响较大；在较大的探测角范围内,W形进口S形进气道的RCS值明显低于其它进口形状的S进气道；菱形进口进气道的RCS在唇口未做修型S形进气道中最低。W形唇口修型可有效降低唇口边缘绕射场的RCS；而在负探测角时,斜切唇口修型可大大降低S形进气道总散射场的RCS。 

关键词: 迭代物理光学法;等效边缘电流法;雷达散射截面;S-形进气道;唇口修型 