Alignment and conductor-with tolerant multi-layered stripline LPF with elliptic-function response and their design method

摘要

A stripline low-pass filter (LPF) with elliptic-function response for embedding into multi-layered substrates, such as LTCC, is presented. Novel vertically inter-digital capacitors tolerant to misalignment in multi-layered substrates are proposed and applied to those of parallel resonators in LPF to obtain transmission zeros near cut-off frequency fc. In addition, design conditions of the resonators are derived to reduce degradation and variation of its characteristics due to error in fabrication of conductor width. A Ku-band LTCC LPF has been fabricated, which has transmission zeros at 1.1 fc. Measured results demonstrate agreement with theory.