Bandpass filter and radio communication module and radio communication device using the same

A bandpass filter comprising:

• a laminated body comprising a plurality of laminated dielectric layers;
• a ground electrode disposed on a bottom surface of said laminated body;
• a plurality of strip-shaped single resonance electrodes that are disposed side by side so as to be electromagnetically coupled to each other on a first interlayer of said laminated body, and each one end thereof is operable to be connected to a standard potential to function as a resonator that resonates at a first frequency;
• a plurality of complex resonance electrodes each comprising a first end portion and a second end portion which is divided into divided portions arranged side by side, each divided portion having a strip shape, wherein each of the plurality of complex resonance electrodes is operable to be connected to a standard potential at its first end and resonate at a second frequency higher than said first frequency while said plurality of divided portions are operable to resonate at a third frequency higher than said second frequency, and said plurality of complex resonance electrodes are disposed side by side so as to be electromagnetically coupled to each other on a second interlayer different from said first interlayer of said laminated body;
• a strip-shaped first input coupling electrode that is disposed on a third interlayer located between said first interlayer and said second interlayer of said laminated body, facing a first region over more than half a length, in a longitudinal direction, of a single resonance electrode on an input stage of said plurality of single resonance electrodes and electromagnetically coupled to the first region, and has an electrical signal input point into which electrical signals are input;
• a strip-shaped first output coupling electrode that is disposed on said third interlayer of said laminated body, facing a second region over more than half a length, in a longitudinal direction, of a single resonance electrode on an output stage of said plurality of single resonance electrodes and electromagnetically coupled to the second region, and has an electrical signal output point from which said electrical signals are output;
• a second input coupling electrode that is disposed on said third interlayer of said laminated body, and facing a divided portion on an input stage of said divided portions on a complex resonance electrode on an input stage of said plurality of complex resonance electrodes and electromagnetically coupled to the divided portion of the input stage;
• and
• a second output coupling electrode that is disposed on said third interlayer of said laminated body, and facing a divided portion on an output stage of said divided portions on a complex resonance electrode on an output stage of said plurality of complex resonance electrodes and electromagnetically coupled to the divided portion of the output stage;
• wherein said plurality of single resonance electrodes and said divided portions on said plurality of complex resonance electrodes are disposed orthogonally to each other in a direction of lamination of said laminated body, said first input coupling electrode faces the single resonance electrode on the input stage of said plurality of single resonance electrodes in a first portion, said second input coupling electrode is connected to a side farther from said electrical signal input point relative to a center of said first portion of said first input coupling electrode in the longitudinal direction, and said electrical signals are input into the second input coupling electrode via said first input coupling electrode, and said first output coupling electrode faces the single resonance electrode on the output stage of said plurality of single resonance electrodes in a second portion, said second output coupling electrode is connected to a side farther from said electrical signal output point relative to a center of said second portion of said first output coupling electrode in the longitudinal direction, and said electrical signals are output from the second output coupling electrode via said first output coupling electrode.