电尺寸小(70λ以下)的卡塞格伦天线,只要对副面进行修正,主面保持为拋物面,天线的效率便可提高到70％左右。困难在于要实验确定整形副面的等效相位中心。本文导出一组公式,可用以计算确定整形副面的等效相位中心,无需进行困难的副面散射场测量。 The Cassegrain antenna, which has a small electrical dimension (less than 70λ), can improve the efficiency of the antenna to about 70% as long as the main surface is a paraboloid, as long as the secondary surface is corrected. The difficulty is to experimentally determine the equivalent phase center of the shaping face. This article derives a set of equations that can be used to calculate the equivalent phase center of the shaping facets without having to make difficult side scatter field measurements.