Abstract: A ladder-type ceramic filter is formed of a plurality of series and parallel resonators arranged in series and in parallel between the input and output terminals. In this filter, a series resonator on the side of the input terminal has a resonant frequency lower than those of other series resonators and an antiresonant frequency higher than those of other series resonators. Further, a parallel resonator on the side of the output terminal has a resonant frequency lower than those of other parallel resonators and an antiresonant frequency higher than those of other parallel resonators.

Abstract: A ladder-type ceramic filter formed of a plurality of series and parallel resonators arranged in series and in parallel between the input and output terminals. In this filter, resonators are arranged in a manner that a resonator (or resonators) in which each difference between resonant and antiresonant frequencies thereof is minimum is (or are) positioned in the center of the resonator arrangement, and that resonators in which respective differences between resonant and antiresonant frequencies thereof are a larger value or values are positioned on the sides of the input and output terminals, respectively.