US Patent 7283022 Dual mode ceramic filter

A dual mode ceramic filter has an enclosure with two cavities separated by a wall, and two TM dual-mode resonators, each TM dual-mode resonator positioned in a corresponding cavity. Each TM dual-mode resonator has first and second modes, and a body having a central portion with a plurality of arms extending outwardly from the central portion. The filter also has two input conductive members, each input conductive members positioned in a corresponding cavity. Each input conductive member is disposed proximate a corresponding TM dual-mode resonator for coupling between the input conductive member and the TM dual-mode resonator.