尖劈吸波体的研究和微波暗室的模拟

对尖劈形状吸波体的吸波性能进行了研究,并对导弹导引仿真实验用的微波暗室的性能进行分析和仿真.首先对尖劈体的二维反射性能进行了研究,从单条波线反射的原理出发,得到波束平面反射的统计模型.单条波线的反射通过数值模拟得到;波束反射模型则通过对数值模拟的结果进行统计和拟合得到,最终用多项式表示.对于一些简单或特殊的情况,也给出了解析解.通过分析发现,三维反射和二维反射之间有明确的关系.这种关系可以由三维入射角和反射次数决定,而反射次数可以通过二维模型得到.据此将平面反射模型扩展为三维反射模型,从而得到尖劈形状吸波体的三维反射模型.无回波暗室用于模拟没有背景微波辐射的环境,其关键在于选择合适的吸波材料.基于微波反射通量平衡原理,建立了考虑暗室墙面各点之间的相互影响的耦合模型,从而可以求解出在指定的发射源照射之下墙面各点的辐射强度分布.对模型的求解精度和收敛性进行了验证.基于此模型,对一个导弹引导试验进行了数值模拟,推算出了使用两种不同吸波材料时静区接收到的微波信号的信噪比.

Research on Wedge-shaped Microwave Absorber and Simulation of Microwave Anechoic Chamber

In this paper,the microwave absorbing property of a wedge-shaped absorber is studied,and the performance of the microwave anechoic chamber used for simulation experiments of missile guidance is analyzed and simulated.Firstly,the 2D reflection performance of wedge-shaped microwave absorber is studied.Based on the reflection principle of a single wave ray,a statistical model of wave beam planar reflection is established.The reflection model of a single wave ray is obtained by numerical simulation while the wave beam reflection model is established by using results of the simulation with statistic and fitting methods.The wave beam reflection model is finally expressed by polynomials.For some simple or special situation,this paper also gives analytical solutions.Analysies showed a clear relationship between 3D reflection mode,and the 3D reflection model of the wedge-shaped microwave absorber is established.Microwave anechoic chambers are used to simulate environments with no background microwave.Based on the principle of microwave reflection flux balance,a coupled model is established.The model can consider influences among each point on the chamber walls.In this way,giving a specified emission source,the radiation intensities of all points on the walls can be determined.The accuracy and convergence rate of the model are verified.Based on this model,a numerical simulation of missile guidance test is carried out. SNR(Signal to Noise Ratio) of the microwave signal received in the quiet zone,are calculated, b using two different absorbing materials.