Abstract: Antenna and EM Scatterng, Xidian Univ., Xi′an 710071， China; 3. P.O.B.2863, Beijing 100085， China)
Two novel spherical helical antennas are designed by projecting the planar equiangular spiral antenna onto the surfaces of hemisphere and partial sphere. Their radiation properties are analyzed by the moment method with the curved basic and testing function, and the curves of the VSWR, gain, polarization and pattern vs. frequency are also given, respectively. It can be seen that the circular polarization band of the novel hemispherical helical antenna is broader.The gain curve of the partial spherical helical antenna is flatter and the structure is simpler.

Key words: spherical helical antenna, moment method, curved basic function