| 摘要 |
PROBLEM TO BE SOLVED: To provide a bandpass filter having an extremely wide passband with a required width, and to provide a radio communication module and radio communication equipment using the bandpass filter. SOLUTION: The bandpass filter includes: first and second ground electrodes 21, 22 arranged on the upper and lower surface of a laminate constituted by laminating a plurality of dielectric layers 11; a composite resonance electrode 26 that is arranged in a first interlayer, that is composed of a base part 27 of which the one end is grounded and a plurality of band-like projection parts 28a, 28b of which the one-ends are each connected to the other end of the base part 27 and which are arranged in parallel with each other, and that is allowed to be resonated by two frequencies; and an input coupling electrode 40a opposed to the input-stage projection part 28a in the composite resonance electrode 26 and electromagnetic-resonant-coupled with the projection part 28a and an output coupling electrode 40d opposed to the output-stage projection part 28b and electromagnetic-resonant-coupled with the projection part 28b, which are arranged in an interlayer different from the first interlayer. Accordingly, the bandpass filter having flat, low-loss and excellent passage characteristics over the whole passband can be easily obtained. COPYRIGHT: (C)2009,JPO&INPIT
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