The polarization match between the antennae operated in the circular polarization mode can be maintained well without the use of complex tracking systems,many modern satellite and terrestrial point-to-point communications systems use circular polarization(CP) wave propagation in order to maximize the polarization component of the link budget.The effective design method of circular polarized crossed dipole feeds is presented analyzing the self-impedance of linear antennas and the useful design curves also is given here,the crossed dipoles is excited by a single hard coaxial-cable with a slot.The gain and circular polarized axial-ratio of the crossed dipoles is calculated with the electromagnetic simulation software HFSS,the results indicate that the design is reasonable and practical.