Double-frequency cavity filter compatible to working frequencies of GPS and Beidou

The invention discloses a structure of a double-frequency cavity filter compatible to working frequencies of GPS and Beidou. The double-frequency cavity filter is provided with a cavity (1), resonators (2), coupling blocks (3), tuning threaded rods (4), cross coupling windows (5) among the resonators, a covering plate (6) and a radio-frequency connector (7), and is characterized in that passages among the resonators (2) are of an all-pass structure, meanwhile, the coupling blocks (3) are arranged to reinforce coupling among the resonators, and therefore a broadband filtering performance is achieved. The double-frequency cavity filter is applied to a GPS and Beidou double-mode navigation receiving system, is used for receiving the front segment of system radio frequency in the process of navigation, receives GPS and Beidou signals, restrains useless signals out of band, and has the advantages of being small in insertion loss and high in out-of-band rejection.