Murata Manufacturing Co., Ltd.

Murata Mfg. Co., Ltd.

Tadahiro Yorita

Haruo Matsumoto

Yasuo Yamada

Hideyuki Kato

Yukihiro Kitaichi

Tatsuya Tsujiguchi

Hisashi Mori

Hitoshi Tada

Toshio Nishikawa

Youhei Ishikawa

Hirohumi Miyamoto

Sadao Yamashita

Motoharu Hiroshima

Takashi Maruyama

Hirofumi Miyamoto

Koji Saito

Hiroshi Okawa

Itsuo Nakatsuji

A method of adjusting characteristics of a dielectric filter including the following steps: forming a dielectric filter having a dielectric body, the dielectric body having an outer surface; forming an external conductor on the outer surface of the dielectric body; and forming at least one hole extending through the dielectric body, the at least one hole having a respective inner surface, and a respective internal conductor and a respective non-conductive portion at the inner surface; the outer surface of the dielectric body comprising first and second end surfaces and a side surface extending between the first and second end surfaces; the at least one hole extending through the dielectric body between the first and second end surfaces; the respective inner conductor being formed as a respective pair of internal conductors conductively connected to the external conductor at respective ends of the at least one hole, the respective non-conductive portion at the inner surface of the at least one hole being spaced from both end surfaces, thereby separating the corresponding pair of internal conductors and defining a respective capacitance between the corresponding pair of internal conductors; and a predetermined portion of the outer surface of the dielectric body being formed with a shape such that a first portion of the external conductor at the predetermined portion of the outer surface is closer to at least one of the internal conductors in the at least one hole as compared with a second portion of the external conductor at a portion of the outer surface of the dielectric body other than the predetermined portion; the method further comprising the steps of: initially forming the respective inner conductor over an entire length of the inner surface of the corresponding hole; and thereafter grinding off a portion of the respective inner conductor with a grinding tool in order to form the non-conductive portion.

Method of adjusting characteristics of dielectric filter

A dielectric filter having a dielectric body made of dielectric material and having an outer surface including first and second end faces; an external conductor disposed on the outer surface of the dielectric body; at least one hole extending through the dielectric body between the two end faces, the at least one hole having a respective inner surface; the at least one hole having a pair of internal conductors respectively provided in the corresponding hole and conductively connected to the external conductor at respective ends of the corresponding hole, a respective non-conductive portion at the inner surface of the corresponding hole being spaced from both ends of the respective hole and thereby separating the corresponding pair of internal conductors and defining a capacitance between the corresponding pair of internal conductors; the first end face of said dielectric body being closer to the non-conductive portion at the inner surface of the corresponding hole than the second end face; the first end face having a non-conductive portion free of a portion of the external conductor, the non-conductive portion being disposed at a location for adjusting either a resonance frequency or a coupling degree of the filter, or both. At the first end face of the dielectric body, the non-conductive portion may in addition be free of a portion of the dielectric material.

Dielectric filter having non-conductive adjusting regions

Grooves are formed on the connection faces of the dielectric basic plates as a dielectric resonator, and also, an internal conductor is provided on the inside face, and coupling electrodes are formed on the other dielectric basic plate. These three dielectric basic plates are connected so that the coupling electrode effects capacity connection between internal conductors and the coupling electrode effects capacity connection between the internal conductors, whereby an earth electrode (external conductor) can be formed on almost full face on the reverse face side of the dielectric basic plate and the reduction of Qo of the resonator and the electromagnetic field leakage can be prevented.

Manufacturing method of dielectric filter having a pattern electrode disposed within a dielectric body

A dielectric filter, having a dielectric block with an outer surface including first and second end surfaces and a side surface extending between the first and second end surfaces; an external conductor disposed on the outer surface of the dielectric block, the external conductor substantially completely covering the outer surface; at least one hole extending through the dielectric body between the first and second end surfaces, the at least one hole having an inner surface; the at least one hole having a respective pair of internal conductors disposed on the corresponding inner surface thereof and conductively connected to the external conductor respectively at the first and second end surfaces, a respective non-conductive portion at the corresponding inner surface being spaced from both of the end surfaces and thereby separating the corresponding pair of internal conductors and defining a respective capacitance between the corresponding pair of internal conductors; a predetermined portion of the side surface of the dielectric block having a shape such that a first portion of the external conductor at the predetermined portion is closer to at least one of the internal conductors of the at least one hole, as compared with a second portion of the external conductor at a portion of the dielectric block other than the predetermined portion.

Dielectric filter having side surface indentation

A dielectric filter, having a dielectric block with an outer surface including first and second end surfaces and a side surface extending between the first and second end surfaces; an external conductor disposed on the outer surface of the dielectric block, the external conductor substantially completely covering the outer surface; at least one hole extending through the dielectric body between the first and second end surfaces, the at least one hole having an inner surface; the at least one hole having a respective pair of internal conductors disposed on its corresponding inner surface and conductively connected to the external conductor respectively at the first and second end surfaces, a respective non-conductive portion at the corresponding inner surface being spaced from both of the end surfaces and thereby separating the corresponding pair of internal conductors and defining a respective capacitance between the corresponding pair of internal conductors; a predetermined portion of one of the first and second end surfaces of the dielectric block having a shape such that a first portion of the external conductor at the predetermined portion is closer to at least one of the internal conductors of the at least one hole, as compared with a second portion of the external conductor at a portion of the dielectric block other than the predetermined portion.

Dielectric filter with recessed end surface

A dielectric filter in which both the resonant frequency of each resonator and the degree of coupling between resonators can be adjusted independently. The dielectric filter includes at least first and second dielectric blocks, each having a through bore extending between first and second end faces thereof and a plurality of side surfaces extending between those end faces. Substantially all of the faces of the dielectric blocks, including the bore, are covered with a conductive film to define a first dielectric resonator whose electric energy component varies in the direction of an axis of the through bore. A first coupling electrode is formed, isolated from the conductive film, on at least one and preferably bridging between two of the side surfaces of the first dielectric block for coupling an input signal applied thereto to the first dielectric resonator. A second coupling electrode is formed, isolated from the conductive film, on a second one of the side surfaces of the first dielectric block in a location wherein the electric energy component in the first dielectric block is at a relatively high level so that electric energy in the first dielectric block exits the first dielectric block via the second coupling electrode. The second dielectric block has a first side surface which abuts the second side surface of the first dielectric block. A third coupling electrode is formed on the first side surface of the second dielectric block at a location corresponding to the second coupling electrode such that electric energy leaving the first dielectric block via the second coupling electrode enters the second dielectric block via the third coupling electrode and sets up an electromagnetic field in the second dielectric block whose electric energy component varies in the direction of the through bore of the second dielectric block. A fourth coupling electrode is formed on at least one and preferably bridging between two of the surfaces of the second dielectric block at a location where the resonant electric energy component in the second dielectric block is relatively high such that electric energy in the second dielectric block leaves the dielectric block via the fourth coupling electrode.

Dielectric filter having coupling windows between resonators, and transceiver using the dielectric filter

A dielectric filter includes a first dielectric block having a through bore, substantially all of the surface area of the first dielectric block being covered with a conductive film to define a first dielectric resonator whose magnetic energy varies in the direction of an axis of the through bore. A first coupling window is formed in the conductive film on a first side surface for coupling an input signal applied thereto to the first dielectric resonator. A second coupling window is formed on a second side surface in a location wherein the magnetic energy in the first dielectric block is relatively high so that magnetic energy exits the first dielectric block via the second coupling window. A second dielectric block has a through bore and substantially all of the surface area of the second dielectric block is covered with a conductive film to define a second dielectric resonator. A third coupling window is formed on a first side surface of the second dielectric block at a location corresponding to the second coupling window such that magnetic energy leaving the first dielectric block via the second coupling window enters the second dielectric block via the third coupling window and sets up a magnetic field in the second dielectric block whose magnetic energy varies in the direction of the through bore of the second dielectric block. A fourth coupling window is formed on a second surface of the second dielectric block at a location where the resonant magnetic energy in the second dielectric block is relatively high such that magnetic energy leaves the second dielectric block via the fourth coupling window.

Dielectric filter having inductive coupling windows between resonators, and transceiver using the dielectric filter

A dielectric filter in which the resonant frequency of each resonator and the degree of coupling between resonators can be adjusted independently. The dielectric filter includes first and second dielectric blocks, each having a through bore. The dielectric blocks, including the bores, are covered with a conductive film to define respective dielectric resonators whose electric energy component varies in the direction of an axis of the through bore. A first isolated coupling electrode is formed on the first dielectric block for coupling an input signal to the first dielectric resonator. A second isolated coupling electrode is formed on the first dielectric block in a location with a relatively high electric energy component so that electric energy exits the first dielectric block via the second coupling electrode. The second dielectric block has a third isolated coupling electrode at a location corresponding to the second coupling electrode such that electric energy leaving enters the second dielectric block via the third coupling electrode and sets up an electromagnetic field in the second dielectric block whose electric energy component varies in the direction of the through bore of the second dielectric block. A fourth isolated coupling electrode is formed on the second dielectric block at a location with a relatively high resonant electric energy component such that electric energy leaves the dielectric block via the fourth coupling electrode.

Dielectric filter having capacitive coupling windows between resonators,

Dielectric resonator wherein an internal conductor non-formed portion is provided near one open face of the internal conductor formed holes, and signal input, output electrodes are provided on one portion of the external conductor, whereby electromagnetic field leakage is restrained, because the open face is not formed, and individual parts such as signal input, output pins and so on are not required.

Dielectric filter having stepped resonators with non-conductive gap

A method of adjusting characteristics of a dielectric filter having integral electromagnetic shielding, the dielectric filter comprises a dielectric body having an outer surface including first and second end surfaces and side surfaces extending between the first and second end surfaces; an external conductor disposed on the outer surface of the dielectric body and providing integral electromagnetic shielding of the dielectric filter; at least one hole extending through the dielectric body between the first and second end surfaces; a respective pair of internal conductors provided in the at least one hole and conductively connected to the external conductor at respective ends of the hole, a respective non-conductive portion in the hole being spaced from both ends and thereby separating the pair of internal conductors and defining a respective capacitance between the pair of internal conductors; and signal input and output electrodes provided on the outer surface of the dielectric body and electrically isolated from the external conductor. According to the method, a portion of the dielectric material is removed, for example by grinding, to form the respective non-conductive portion in the hole. The hole may have a changing diameter along its length, due to a hollow formed in one end surface, the non-conductive portion being adjacent to the hollow; or due to a narrowed throttle portion formed at or near the end surface, the non-conductive portion being formed on the throttle portion. Alternatively, the hole may have a substantially constant cross-section, and the non-conductive portion may be substantially flush with the inner surface of the hole. The dielectric body may be regular in shape or may have a side surface with portions spaced from the resonator hole by different respective distances.

Characteristic adjusting method for dielectric filter using a grinding

A dielectric filter includes a plurality of dielectric blocks, each having a resonator therein, in which both the resonant frequency of each resonator and the degree of coupling between adjacent resonators are independently adjustable. The outer and inner surfaces of each dielectric block are coated with a thin film of a conductive material. Input and output electrodes are formed on the dielectric blocks by disposing a conductive film area on exposed areas of the blocks which are not coated with conductive film. Adjacent dielectric blocks are integrally bonded to one another via a conductive adhesive material and output coupling electrodes on the side surfaces of the dielectric blocks are bonded to input coupling electrodes on the side surfaces of adjacent dielectric blocks.

Dielectric filter having pairs of capacitive coupling windows between

Grooves are formed on the connection faces of the dielectric basic plates as a dielectric resonator, and also, an internal conductor is provided on the inside face, and coupling electrodes are formed on the other dielectric basic plate. These three dielectric basic plates are connected so that the coupling electrode effects capacity connection between internal conductors and the coupling electrode effects capacity connection between the internal conductors whereby an earth electrode (external conductor) can be formed on almost full face on the reverse face side of the dielectric basic plate and the reduction of Qo of the resonator and the electromagnetic field leakage can be prevented.

Dielectric filter having resonator electrodes, shield electrodes, and

A dielectric filter in which both the resonant frequency of each resonator and the degree of coupling between resonators can be adjusted independently. The dielectric filter includes first and second dielectric blocks, each having a through bore which defines a dielectric resonator whose electric energy component varies along the through bore. An isolated first coupling electrode is formed on a first side surface of the first dielectric block for coupling an input signal to the first dielectric resonator. An isolated second coupling electrode is formed on a second side surface of the first dielectric block where the electric energy component is relatively high so that electric energy in the first dielectric block exits the first dielectric block via the second coupling electrode. A third coupling electrode is formed on the first side surface of the second dielectric block corresponding to the second coupling electrode such that electric energy leaving the first dielectric block enters the second dielectric block via the third coupling electrode and sets up an electromagnetic field in the second dielectric block whose electric energy component varies along the through bore. A fourth coupling electrode is formed on a second side surface of the second dielectric block where the resonant electric energy component in the second dielectric block is relatively high such that electric energy leaves the second dielectric block via the fourth coupling electrode.

Dielectric filter having coupling windows between resonators, and

Dielectric resonator filter having a portion of the outer surface closer

A dielectric filter with integral electromagnetic shielding comprises a dielectric block having an outer surface including first and second end surfaces and a side surface extending between the first and second end surfaces; an external conductor disposed on the outer surface of the dielectric block and providing integral electromagnetic shielding of the dielectric filter; at least one hole extending through the dielectric body between the first and second end surfaces, having a respective inner surface with a substantially constant cross-sectional shape; a respective pair of internal conductors provided in the at least one hole and conductively connected to the external conductor at respective ends of the hole, a respective non-conductive portion in the hole being spaced from both ends and thereby separating the pair of internal conductors and defining a respective capacitance between the pair of internal conductors, a surface of the respective non-conductive portion being substantially flush with the rest of the inner surface of the hole; and signal input and output electrodes provided on the outer surface of the dielectric body and electrically isolated from the external conductor. Conductive and possibly dielectric material is removed from an end surface of the dielectric block to adjust the resonance frequency and/or the coupling degree of the dielectric filter.

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Nagaokakyo, Japan

Tadahiro Yorita