US 8,284,000 B2Granted

Resonator and filter

AssigneeTDK Corporation

InventorTatsuya Fukunaga

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Abstract

A resonator includes: a dielectric block; first and second ground electrodes provided on or in the dielectric block, and disposed to oppose each other; a first via conductor provided in the dielectric block orthogonally to the first and second ground electrodes, and having a short-circuit end connected to the first ground electrode and an open end extending toward the second ground electrode; a second via conductor interdigitally-coupled with the first via conductor, and provided in the dielectric block orthogonally to the first and second ground electrodes, and having a short-circuit end connected to the second ground electrode and an open end extending toward the first ground electrode; a first capacitor electrode provided in the dielectric block, and connected to the first via conductor; and a second capacitor electrode provided in the dielectric block, and connected to the second via conductor.

Claims8

Dependent claims

A resonator for a bandpass filter, comprising:

a dielectric block;
a first ground electrode and a second ground electrode provided on or in the dielectric block so as to oppose each other;
a first via conductor provided in the dielectric block so as to extend in a direction orthogonal to faces of the first and second ground electrodes, and having a short-circuit end and an open end, the short-circuit end being connected to the first ground electrode, and the open end extending toward the second ground electrode;
a second via conductor provided in the dielectric block so as to extend in the direction orthogonal to faces of the first and second ground electrodes, and having a short-circuit end and an open end, the short-circuit end being connected to the second ground electrode, and the open end extending toward the first ground electrode;
a third via conductor provided in the dielectric block so as to extend in the direction orthogonal to faces of the first and second ground electrodes, and having a short-circuit end and an open end, the short-circuit end being connected to the first ground electrode, and the open end extending toward the second ground electrode;
a fourth via conductor provided in the dielectric block so as to extend in the direction orthogonal to faces of the first and second ground electrodes, and having a short-circuit end and an open end, the short-circuit end being connected to the second ground electrode, and the open end extending toward the first ground electrode,
a first capacitor electrode provided in the dielectric block, and connected to the first via conductor and the third via conductor;
and
a second capacitor electrode provided in the dielectric block, and connected to the second via conductor and the fourth via conductor, wherein
every couple of via conductors immediately neighboring one another, selected from the first to fourth via conductors, are interdigitally coupled with each other,
the interdigitally coupled via conductors have a first resonant mode resonating at a first resonance frequency f1 which is higher than a resonance frequency f0 determined by a physical length of each via conductors, and a second resonant mode resonating at a second resonance frequency f2 which is lower than the resonance frequency fo and
an operating frequency is set at the resonance frequency f2.

9 more elements

A bandpass filter, comprising:

a dielectric block;
and
a first resonator and a second resonator provided in the dielectric block, in parallel to each other, so as to be electromagnetically coupled to each other,
each of the first and second resonators including:
a first ground electrode and a second ground electrode provided on or in the dielectric block so as to oppose each other;
a first via conductor provided in the dielectric block so as to extend in a direction orthogonal to faces of the first and second ground electrodes, and having a short-circuit end and an open end, the short-circuit end being connected to the first ground electrode, and the open end extending toward the second ground electrode;
a second via conductor provided in the dielectric block so as to extend in the direction orthogonal to faces of the first and second ground electrodes, and having a short-circuit end and an open end, the short-circuit end being connected to the second ground electrode, and the open end extending toward the first ground electrode;
a third via conductor provided in the dielectric block so as to extend in the direction orthogonal to faces of the first and second ground electrodes, and having a short-circuit end and an open end, the short-circuit end being connected to the first ground electrode, and the open end extending toward the second ground electrode;
a fourth via conductor provided in the dielectric block so as to extend in the direction orthogonal to faces of the first and second ground electrodes, and having a short-circuit end and an open end, the short-circuit end being connected to the second ground electrode, and the open end extending toward the first ground electrode;
a first capacitor electrode provided in the dielectric block, and connected to the first via conductor and the third via conductor;
and
a second capacitor electrode provided in the dielectric block, and connected to the second via conductor and the fourth via conductor, wherein
every couple of via conductors immediately neighboring one another, selected from the first to fourth via conductors, are interdigitally coupled with each other,
the interdigitally coupled via conductors have a first resonant mode resonating at a first resonance frequency f1 which is higher than a resonance frequency f0 determined by a physical length of each via conductors, and a second resonant mode resonating at a second resonance frequency f2 which is lower than the resonance frequency fo and
an operating frequency is set at the resonance frequency f2.

12 more elements

Dependencies are inferred from the claim text.