Small size cross-coupled trisection filter

摘要

The present invention relates to a three-order filtering structure. Each resonator includes an inductive portion and a capacitive portion. The inductive portion of the second resonator is folded that the inductive portion of the first resonator is coupled to the inductive portion of the third resonator forming a trisection filtering structure. The cross-couple between resonator 1 and 3 adds additional finite transmission zero below the passband.