Dielectric filter

摘要

A dielectric filter is provided which permits one to obtain desired external coupling easily without lowering Qo of resonators. The filter comprises a dielectric block having an open end surface and a shorted end surface and provided with resonator holes. Excitation holes are formed in the block outside the resonator holes, respectively. Input/output electrodes are formed on the open end-surface. The electrodes are electrically connected with conductors formed inside the excitation holes but isolated from an outer conductor. The conductors inside the excitation holes are electrically connected with the outer conductor on the shorted end surface. The excitation holes are electromagnetically coupled to the respective adjacent resonator holes, thus providing external coupling.