Compact Ku band filter based on BMT dielectric resonators made in a single part using 3D ceramic stereolithography process

A Ku band 6 pole quasi-elliptic filter based on dielectric resonators is presented. To the best of our knowledge, this is the first time that temperature stable BMT ceramic material (εr = 24.4 and tan δ = 0.95.10⁻⁴ ± 0.29.10⁻⁵ at 11.1 GHz) is associated with stereolithography process for the manufacturing of 3D parts. The proposed filter is composed of 6 dielectric resonators, their support and a dielectric negative coupling element all connected into one single ceramic part. This configuration is optimized to achieve a 1.7% pass band at 11.7 GHz which does not require any glue or advanced positioning technique for its assembly into silver cylindrical cavities. A 41% volume reduction compared to standard 6 pole TE113 cavity filter is proposed while keeping a Qu of 8500 and insertion loss close to −0.3 dB.