A Ku-band low-loss stripline low-pass filter for LTCC modules with low-impedance lines to obtain plural transmission zeros

A Ku-band low temperature co-fired ceramic (LTCC) multi-layered stripline low-pass filter (LPF) is presented. By employing a low-impedance line as an inductive element in the resonator, plural transmission zeros can be obtained near passband. Therefore, the presented LPF realizes excellent attenuation characteristics despite a small number of resonators. The LPF has extremely low insertion loss and compact dimensions, an especially thin profile, and is suitable for RF-modules. An LPF with dimensions of 0.9 mm/spl times/0.9 mm/spl times/0.4 mm has been fabricated, and measured results show the validity of the proposed structure.