A new spiral antenna is proposed in this paper. The developed antenna has im- proved axial ratio (AR) and shorted arm length. The developed spiral antenna combines the low frequency characteristic of power spiral antenna and high frequency characteristic of Archimedean spiral antenna. The results reveal that the developed spiral antenna has noticeable improved ax- ial ratio at low frequencies compared with Archimedean spiral antenna, and the problem of axial ratio degradation of power spiral antenna is also solved. The arm length is shorted by 46.4% than conventional Archimedean spiral antenna, and 63.5% than power spiral antenna.