With the rapid development of modern science and technology, various radio systems require more and more performance of antennas in complex environments, and traditional antennas are more and more difficult to meet the needs of modern radio systems. In this paper, the basic principle of finite element-boundary element hybrid algorithm to analyze the cavity is deduced by taking the three-dimensional open cavity on the infinite conductive surface as an example. And the SSPP circularly polarized dipole array antenna structure is designed, and the finite element-boundary element hybrid algorithm is used to analyze the radiation characteristics of the SSPP circularly polarized antenna, and the case of the SSPP circularly polarized antenna radiating beam is divided into the symmetric and asymmetric cases, and the radiation characteristics of the antenna are analyzed by simulation experiments. By changing the parameters in the impedance modulation method, the antenna is able to achieve dual beam radiation with dual circular polarization in any direction with circular polarization purity of more than 97.5%, and secondly, the antenna can achieve an impedance bandwidth of 66% (1.3 GHz-2.4 GHz) as well as an axial ratio bandwidth of 34% (1.22 GHz-1.85 GHz).
