Bandpass filter, high-frequency module, and wireless communications equipment

Abstract

There is included: N (N≧2) resonators formed by laminating a plurality of conductor patterns and dielectric layers alternately and arranged in an at least partially overlapped manner when viewed in the laminating direction to be coupled electromagnetically to each other; and input and output linesandcoupled, respectively, to two resonatorsandselected among the N resonators, in which one end of each of the N resonators is grounded, and the length of each of the N resonators in the signal propagation direction is basically λ/4, where λ represents a propagation wavelength inside the dielectric layers at approximately the center frequency of the pass band. A wider pass bandwidth, size and loss reduction, and a large amount of attenuation within a narrow band can be achieved.