摘要 |
The present invention comprises: a conductive chassis having a cavity resonator; a conductive cover to cover the cavity resonator; a resonant element arranged in the cavity resonator, one end of the resonant element being connected with the chassis and the other end being open end; and a movable conductor arranged in a space between the open end of the resonant element and the conductive cover. As a result, a tunable band-pass filter which is inexpensive and of a simple structure and which can change a resonance frequency of a cavity resonator and the coupling amount between cavity resonators easily is realized. |