Tunable filter and adjustable duplexer

The invention discloses a tunable filter and an adjustable duplexer, and relates to the technical field of communication. The tunable filter comprises: a filter cavity, wherein a plurality of resonantcavities are formed in the filter cavity; a tuning structure, wherein the tuning structure comprises a plurality of conductor columns which are fixed on lifting plates through insulating connecting pieces, the conductor columns can be inserted into the resonant cavities, and the depths of the conductor columns inserted into the resonant cavities are the same; and a driving structure for driving the lifting plates to move so as to enable the conductor columns to be inserted into the resonant cavities, and adjusting the insertion depths. According to the invention, the frequency can be tuned byadjusting the depth of the conductor column inserted into the resonant cavity; the surface conductivity of the conductor column is extremely high, so that the tunable filter can maintain good insertion loss performance in a w