US 7,548,141 B2Granted

High frequency filter

AssigneeTDK Corporation

InventorsHideya Matsubara, Shigemitsu Tomaki, Shinichiro Toda, Atsunori Okada

Life of this patent

Estimating the term…

Loading patent…

Abstract

A high frequency filter incorporates: an unbalanced input/output terminal; two balanced input/output terminals; two resonators respectively provided between the unbalanced input/output terminal and the two balanced input/output terminals; and a layered substrate for integrating components of the high frequency filter. The two resonators are inductively coupled to each other, and are also capacitively coupled to each other through two capacitors. Each of the two capacitors is formed using a pair of first and second electrodes and a dielectric layer. The first electrode is connected to one of the resonators via a through hole. The second electrode is connected to the other of the resonators and opposed to the first electrode forming the pair with the second electrode, the dielectric layer being disposed between the second electrode and the first electrode.

Claims4

Dependent claims

A high frequency filter comprising:

a layered substrate including dielectric layers and conductor layers that are alternately stacked;
a first resonator and a second resonator that are formed of part of the conductor layers inside the layered substrate and that are inductively coupled to each other;
at least one pair of first and second electrodes that are formed of part of the conductor layers inside the layered substrate and that capacitively couple the first and second resonators to each other;
at least one first through hole provided inside the layered substrate and connecting the first electrode to one of the first and second resonators;
and
at least one second through hole provided inside the layered substrate and connecting the second electrode to the other of the first and second resonators,
wherein the first and second electrodes are opposed to each other, one of the dielectric layer inside the layered substrate being disposed between the first and second electrodes.

4 more elements

Dependencies are inferred from the claim text.