Simplified analysis technique for the initial design of LTCC filters with all-capacitive coupling

Abstract

The paper proposes a new low-temperature co-fired ceramic (LTCC) filter configuration, which improves the stopband behavior of previous designs by using all-capacitive couplings. Moreover, a simplified analysis technique is presented to aid filter engineers in the initial design of capacitively coupled LTCC resonators. Relationships from well-known conformal mapping expressions are used to model individual parts of the filter, which are combined by standard two-port parameters. This technique is shown to agree well with measurements of previously published filters. The proposed filter configuration is then verified by results obtained with different commercially available field solvers.