Murata Manufacturing Co., Ltd.

Hisashi Mori

Hideyuki Kato

Haruo Matsumoto

Tadahiro Yorita

Yukihiro Kitaichi

Tatsuya Tsujiguchi

Yasuo Yamada

Hitoshi Tada

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

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

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

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.

Grooves are formed on the connection faces of two dielectric base plates in a dielectric resonator. Internal conductors are provided on the inside faces. Coupling electrodes are formed on another dielectric base plate. These three dielectric base plates are connected so that the coupling electrode effects a capacity connection between the internal conductors. This arrangement permits an earth electrode (e.g., an external conductor) to be formed on almost the full exterior of the dielectric resonator, thereby preventing the reduction of the Qo of the resonator and electromagnetic field leakage.

Dielectric filter having a pattern electrode disposed within a

Dielectric filter

A dielectric resonator including a dielectric block through which an inner conductor formation hole passes; an inner conductor partially formed on an inner surface of the inner conductor formation hole; and an outer conductor formed on an outer surface of the dielectric block. A portion where the inner conductor is not formed is provided on the inner surface of the inner conductor formation hole in the vicinity of one open end portion of the inner conductor formation hole. A stepped portion is provided at a predetermined position on one of the inner surface of the inner conductor formation hole and the outer surface of the dielectric block. Two portions with corresponding resonant characteristics and respective line impedances different from each other are provided with a boundary defined by the stepped portion between the two portions.

Dielectric resonator and dielectric resonant component having stepped

A dielectric block having an external conductor on the outer surface and a plurality of holes with internal conductors formed therein; no internal conductors are provided near one end of each of the plurality of holes. Portions of the dielectric block and the external conductor are removed so as to obtain a dielectric resonator having desired resonator characteristics. In another embodiment, portions of the dielectric block are removed so as to bring the external conductor closer to the internal conductors thereby obtaining a dielectric resonator resonant with a desired frequency. The dielectric resonators limit leakage of electromagnetic field and do not require additional parts such as terminals and case.

Dielectric filter having respective capacitance gaps flushed with the

A compact dielectric resonator apparatus is comprised of a dielectric block having a plurality of mutually parallel throughholes formed therethrough with inner surfaces covered with a conductive film so as to provide coaxial resonators. The degree of coupling between a mutually adjacent pair of such dielectric resonators can be adjusted by forming grooves, a bottomed hole or a slit or burying a conductive plate therebetween in the dielectric block, and varying physical characteristics of such grooves, bottomed hole, slit and/or conductive plate, without changing the separations between the throughholes or the external dimensions of the dielectric block.

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Nagaokakyo, Japan

Hisashi Mori