US 6,556,109 B2 · Dual mode band pass filter

Abstract

A dual mode band pass filter is constructed to be very compact and such that the coupling strength and bandwidth can be easily and widely adjusted while maintaining sufficient freedom of design. A metal film for forming a resonator is arranged on a first main surface of a dielectric body or at a certain height in the dielectric body. At least one ground electrode is arranged such that the ground electrode is opposed to the metal film via the dielectric body. The metal film is connected to input/output coupling circuits. In the region where the metal film is opposed to the ground electrode, two portions are partially provided. Each of these two portions has a relative permittivity that is different from the relative permittivity of the remaining portion, in order to couple two resonance modes.

Claims19

Dependent claims

A dual mode band pass filter comprising:

a dielectric body having a first main surface and a second main surface;
a metal film partially disposed on one of the first main surface and in the interior of the dielectric body;
a ground electrode disposed on one of the second main surface and the interior of the dielectric body in such a manner that the metal film is opposed to the ground electrode via a portion of the dielectric body;
and
a pair of input/output coupling circuits coupled to different portions of the metal film;
wherein, in the region where the metal film is opposed to the ground electrode via the portion of the dielectric body, some portions of the dielectric body have relative permittivities that are different from a relative permittivity of the remaining portion of the dielectric body so that two resonance modes generated at the metal film are mutually coupled at a certain resonance frequency.

3 more elements

Dependencies are inferred from the claim text.

Dual mode band pass filter

Life of this patent

Dual mode band pass filter

Life of this patent

Abstract

Claims19