Abstract:The stability of antenna phase center is important for navigating and locating precisely in navigation system. To meet the technical requirements, a circularly polarized navigation antenna which is used in two frequency bands with high stability of phase center is designed. By using the structure of double air-box coupling antenna and feeding by two feed points，a wide frequency band and high phase center stability can be obtained. Both of the simulated results and the measured results show that the stability of phase center is less than 1.72 mm. The antenna is applicable and feasible.