Additive-Manufactured TM01δ Mode Dielectric Resonators for Compact On-Board Wideband Filters

The design and first RF experimental results of a compact wideband 6th order elliptic Ku-band filter are presented in this paper. The proposed filter is based on dielectric resonators with custom geometry that uses a quasi TM_01δ resonant mode. The ceramic resonator is fabricated in additive manufacturing technology (Lithography-based Ceramic Manufacturing) that allows for custom and exotic shapes. In the proposed filter concept, each dielectric resonator and its supporting elements are fully fabricated in a single piece of ceramic. The use of a single piece minimizes the risk of misalignments that generally occur between the resonator and the typical supports used in conventional TM_01δ mode dielectric resonators. The effect of the supports on the resonator performance is also reduced. These features potentially make the filter more robust to the manufacturing tolerances. To validate the proposed concept, the design and the experimental results of a wideband 6th order filter at Ku-band with 2 transmission zeros are presented.