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台阶板在斜入射时的散射主要来自平板后向散射和台阶绕射回波的贡献,在一定条件下还有表面波的贡献。试验表明入射角大于5°时台阶的绕射回波是散射回波的主要组成部分。对于3台阶板,当台阶沿入射方向的距离为半波长的整数倍时,其散射回波相位相同,产生相干叠加使雷达散射截面(RCS)较大,在RCS曲线上反映为波峰。这些波峰的特点是台阶间距越大,波峰越多,且较高波峰与较低波峰交替出现。一种根据台阶散射的叠加估算多台阶板RCS的方法是用单台阶板和平板散射的试验结果按相位相减得到纯台阶的散射,再将平板的散射与多条纯台阶的散射按相位叠加。对3台阶板的预估结果与测试结果符合较好,预估结果的平均误差在3dB以内。
The scattering of the step plate at oblique incidence mainly comes from the contribution of backscattering and step diffraction echoes of the slab, as well as the contribution of surface waves under certain conditions. Experiments show that when the incident angle is greater than 5 °, the diffraction echo of the stage is the main component of the diffuse echo. For a 3-step plate, when the step distance is an integer multiple of half wavelength along the incident direction, the scattering echoes have the same phase and generate coherent superposition to make the radar cross section (RCS) larger and reflect it as a peak on the RCS curve. The characteristics of these peaks are the larger the step spacing, the more peaks, and the higher peaks alternate with the lower peaks. A method for estimating the RCS of a multi-step plate based on the superposition of step scattering is to obtain the scattering of a pure step by subtracting the phase from the test result of the single plate and the plate scattering, and then the scattering of the plate and the scattering of multiple pure steps are phase-superimposed . The estimated results of 3 plates agree well with the test results. The average error of the estimated results is within 3 dB.