射频/红外波束复合器边齿设计与分析方法

Edge Serration Design and Analysis Method of RF/IR Beam Combiners

为了抑制射频/光学波束复合器的边缘绕射效应对工作区场均匀性的影响,在几何绕射理论、口径场积分理论基础上提出了一种射频/光学波束复合器的边齿设计与分析方法。首先,为了区分直达波和绕射波,将空间域及频域的场分布通过傅里叶逆变换,转换为角频域和时域分布;然后,给出了典型的边齿设计案例,通过分析比较场在空域、时域及角频域内边齿处理前后的场均匀性,发现场的幅度和相位起伏从边齿处理前的2.87 dB、18.76°下降到1 dB、8.41°。分析结果表明,通过边齿处理,场的均匀性可获得较大的改善。

To reduce the influence on the field uniformity in the working zone caused by edge diffraction effect from the RF(radio frequency)/IR(infrared)beam combiner,the edge serration design method for beam combiners is proposed by using geometrical theory of diffraction and aperture field integral.In order to separate the direct wave and diffracted wave,the spatial and frequency domain field computed by aperture field integral is transformed into the angular and time domain spectrum by inverse Fourier transform.An edge serration design example is also proposed and analysed.By comparing the field uniformity in spatial,time and angular domains before and after serrating the edges,the amplitude and phase ripples decrease from 2.87 dB and 18.76°to 1.00 dB and 8.41°respectively.The results show that the field uniformity is significantly improved by serrated edge.