Murata Manufacturing Co., Ltd.

Murata Mfg. Co., Ltd.

Murana Mfg. Co. Ltd.

Seiji Kanba

Teruhisa Tsuru

Harufumi Mandai

Kenji Asakura

Hisatake Okamura

Naoki Mizoguchi

Tsuyoshi Suesada

Koji Shiroki

Hiroshi Takagi

Yujiro Dakeya

Kazuya Kawabata

Harunobu Sano

Yasutaka Sugimoto

Osamu Chikagawa

Nobuyuki Wada

Naoya Mori

Toshifumi Oida

Kunihiro Watanabe

Yujiro Dakeyo

A dual mode band-pass filter includes a metallic film for defining a resonator, disposed on the first main surface of a dielectric substrate having first and second main surfaces, or inside of the dielectric substrate. An opening is formed in the metallic film. At least one ground electrode is provided on the second main surface of the dielectric substrate or inside of the dielectric substrate, so as to be opposed to the metallic film through a dielectric layer. A pair of input-output coupling circuits is connected to the metallic film.

Dual mode band-pass filter

A dual mode band-pass filter includes a metallic film for defining a resonator, disposed on the first main surface of a dielectric substrate having first and second main surfaces, or inside of the dielectric substrate. An opening is formed in the metallic film. At least one ground electrode is provided on the second main surface of the dielectric substrate or inside of the dielectric substrate, so as to be opposed to the metallic film through a dielectric layer. A pair of input-output coupling circuits is connected to the metallic film

A bandpass filter includes a dielectric substrate, a resonator electrode that is provided on a portion of a plane at an intermediate height in the thickness direction of the dielectric substrate so as to oppose the top face of the dielectric substrate and includes an aperture, first and second ground electrodes provided over and under the resonator electrode, respectively, so as to oppose the resonator electrode with dielectric layers disposed therebetween and so as to sandwich the resonator electrode, input-output coupling electrodes coupled to the resonator electrode, input-output terminal electrodes that are provided on the outside surface of the dielectric substrate and are electrically connected to the input-output coupling electrodes, and a via-hole electrode that penetrates through the aperture in the thickness direction of the dielectric substrate so as not to be electrically connected to the resonator electrode and is electrically connected to the first and second ground electrodes.

Bandpass filter

A method for easily adjusting the frequency of an attenuation pole in a dual-mode band pass filter which is very compact and greatly increases coupling strength while maintaining a great deal of freedom of design. The dual-mode band pass filter includes a metal film partially disposed on a main surface of a dielectric substrate or disposed inside of the dielectric resonator so as to define a resonator. An opening is formed in the metal film to couple two resonance modes. Input/output coupling circuits are coupled to the metal film. At least one of coupling portions of the input/output coupling circuits or input/output portions thereof are moved in a direction along a perimeter of the metal film.

Method for adjusting frequency of attenuation pole of dual-mode band pass filter

A method of producing a band-pass filter includes selecting the shape of a metallic film and the connection points of input-output coupling circuits such that first and second resonance modes are generated in a metallic film provided on a dielectric substrate. At least a portion of the resonance current or the resonance electric field in at least one of the resonance modes is made discontinuous such that the first and second resonance modes are coupled.

Method of producing band-pass filter and band-pass filter

Dual mode band-pass filter having coupled modes

A band-pass filter includes a metal film provided on a dielectric body. The shape and size of the metal film and the coupling points of input-output coupling circuits are selected such that first and second resonance modes are generated. The metal film has protruding portions or concavities provided thereon such that resonance electric field strength in the first or second resonance mode is controlled to couple the first and second resonance modes to each other.

Band-pass filter

A dual mode band-pass filter includes a dielectric body having first and second main surfaces, a metal film partially disposed on the first main surface of the dielectric body or at a predetermined level in the dielectric body, the metal film having any one of an opening, a protrusion, and a cut-out arranged to combine two resonant modes, at least one ground electrode disposed on the second main surface or in the interior of the dielectric body so as to be opposed to the metal film with a portion of the dielectric body being disposed therebetween, and a pair of input-output coupling circuits that are coupled with different portions of the metal film. The dielectric body includes a dielectric ceramic containing a ceramic and a glass as main constituents, capable of being fired simultaneously with Cu, Ag, or Au, and having a Q value of more than approximately 300 at about 10 GHz.

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.

Dual mode band pass filter

A portable telephone includes a portable telephone body made from plastic having a receiver, a transmitter, and dial keys, and a chip antenna which is mounted on a circuit board secured at the inside of the portable telephone body and which is electrically connected to an RF section provided on the circuit board in the portable telephone. The chip antenna is disposed near the transmitter at a location where a transmitted electromagnetic signal is unlikely to be affected by the body of a person who is holding the portable telephone.

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Kusatsu, Japan

Seiji Kanba