Abstract:With the application development of satellite communication and satellite positioning systems, higher application requirements are put forward for the performance of terminal antennas. In order to realize the design of a wideband and wide-beam circularly polarized antenna, an orthogonal phase-shifted feed network is adopted to feed the cross-dipole antenna with a cavity-backed，achieving broadband circularly polarized unidirectional radiation characteristics, meanwhile using the cross dipole loaded with magnetic dipole to broadens the beam width of the antenna. A relative bandwidth of 50.7%( S11<-10dB) and axial ratio less than 3-dB in the frequency of 1.3~1.75GHz is achieved , while the circularly polarized beam width can reach 180° and the gain is not less than 6.6dB. It has been verified through the actual measurement that the designed antenna has wide band and wide beam characteristics, at the same time, it has the advantages of compact structure and stable performance, which is suitable for satellite communication and navigation terminal systems.