Bandpass filter, high-frequency device and communications apparatus

摘要

A bandpass filter comprising two or more resonators arranged between two input/output terminals in a laminate substrate comprising pluralities of dielectric layers; each resonator being constituted by a resonance line and a resonance capacitance connected to one end of the resonance line; capacitance electrodes forming said resonance capacitances and said resonance lines being arranged on different dielectric layers, via a planar ground electrode covering the entire structural portion of the bandpass filter when viewed in a lamination direction; and in each of the resonators connected to said two input/output terminals, the junctions of said input/output terminals to said paths between said resonance lines and said resonance capacitances being closer to said resonance capacitances than said resonance lines in a lamination direction.

主权项

1. A bandpass filter comprising:
three resonators arranged between two input/output terminals in a laminate substrate comprising a plurality of dielectric layers; each of the three resonators being constituted by a resonance line and a resonance capacitance connected in series to one end of said resonance line, and both ends of said each of the three resonators being grounded; wherein capacitance electrodes forming said resonance capacitances and said resonance lines are arranged on different dielectric layers among the plurality of dielectric layers, wherein the resonance lines and the capacitance electrodes are separated by a planar ground electrode covering the resonance lines and the capacitance electrodes when viewed in a lamination direction; and wherein each of said input/output terminals is connected to respective a via-conductor path between the resonance line and the capacitance electrode of each of two of the three resonators via a corresponding connecting line, and a junction of each of said input/output terminals connecting to said respective via-conductor path is formed in said laminate substrate so that each of said junctions is positioned closer to said respective capacitance electrode than said respective resonance line in the lamination direction.