Abstract: A Design method of an Archimedes' planar spiral antenna and equiangular planar spiral antenna developed for active radar echo enhancer is presented, and the testing results of some electric parameters, Such as radiation pattern, voltage standing wave ratio, circular polarization, etc. from S band to X band, are shown in this paper.The design is proceeded by useing DJ-052 microcomputer and plotter with SKG language. Thus, the various precise shapes of antennas are automatically yielded. The program of design is quite concise and efficient.