| 摘要 |
PROBLEM TO BE SOLVED: To provide a small bandpass-type filter circuit capable of providing a wide bandpass characteristic, and to provide a filter circuit device and a multilayered circuit board, and a circuit module each which includes the filter circuit. SOLUTION: This filter circuit includes: a first impedance element 111 disposed in an input side; a second impedance element 112 disposed in an output side, having an input end connected to an output end of the first impedance element 111, and made of the same element as that of the first impedance element 111; a distributed constant resonance circuit 113, having one end connected to a connection point between the output end of the first impedance element 111 and the input end of the second impedance element 112; and a third impedance element 114, having one end connected to the input end of the first impedance element 111 and the other end connected to the output end of the second impedance element 112. The first and second impedance elements 111 and 112 and the distributed constant resonance circuit 113 are each constituted by a transmission line, having a predetermined distributed constant, and the third impedance element 114 is constituted by a capacitor. having a predetermined concentrated constant. COPYRIGHT: (C)2009,JPO&INPIT
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