Abstract：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.
