Abstract: Ka band compact antenna test range (CATR) antenna is designed in the paper. The power level of pyramid horndecreases quickly at the edge of the reflector. And corrugated horn has a greater beam width. Combining these two features, feedresource is designed. Irradiation of the reflector is achieved by adding choke to pyramid horn. Serration edge is employed toreduce the edge diffraction. Moreover, for the areas where serration is impossible, triangle wave absorbing materials are attachedto reduce the influence of diffraction on quiet zone performance. The planar measurement result shows that the quiet zone featureof ka band