Murata Manufacturing Co., Ltd.

Motoharu Hiroshima

Hideyuki Kato

Shohachi Nishijima

Jun Toda

Hirotsugu Mori

Haruo Matsumoto

Yasunori Takei

Hitoshi Tada

Soichi Nakamura

Katsuhito Kuroda

Tatsuya Tsujiguchi

Tadahiro Yorita

Jinsei Ishihara

Kikuo Tsunoda

Yuichi Kushihi

Junichi Kurita

A stripline filter having a substrate, a grounding electrode, principal-surface lines, side-surface lines, and common electrodes, and is mounted on a set substrate by soldering. The side-surface lines are disposed on a side surface of the substrate, and are wetted by solder during soldering. Each of the common electrodes is connected to a corresponding one of the principal-surface lines. The common electrodes are also connected to the grounding electrode via the side-surface lines.

Stripline filter

A microstripline filter that includes principal-surface lines, a ground electrode, and input/output electrodes. A first principal-surface line is capacitively coupled to a second principal-surface line. The second principal-surface line is inductively coupled to a third principal-surface line. The third principal-surface line is capacitively coupled to a fourth principal-surface line. The first through fourth principal-surface lines include open-end-side electrodes, short-circuit-end-side electrodes, and end-opened electrodes. A first pair of the end-opened electrodes are adjacent to each other, whereas a first pair of the short-circuit-end-side electrodes are separate from each other. A second pair of end-opened electrodes are adjacent to each other, whereas a second pair of short-circuit-end-side electrodes are separate from each other.

Microstripline filter

A stripline filter with wide-band filter characteristics having an attenuation pole on a high frequency side of frequency characteristics. The stripline filter includes at least three resonant lines, and two of the resonant lines include parallel line parts and bent parts. The third resonant line has a U shape in which both ends thereof are open and interdigitally coupled to the two resonant lines located on both sides thereof. The parallel line parts extend from base ends connected to a ground electrode via side surface lines that are parallel to respective line parts of the third resonant line. The bent parts extend so as to be bent from ends of the parallel line parts, and face each other at an interval.

A microstripline filter in which characteristics of a plurality of resonators which are connected to one another in a manner of inductive coupling are precisely set. The microstripline filter includes a ground electrode, main-surface lines, common electrodes, short-circuit electrodes, and input/output electrodes. The ground electrode is arranged on a lower surface of a dielectric substrate having a rectangular plate shape. The plurality of main-surface lines are arranged on an upper surface of the dielectric substrate and form respective resonators. The common electrodes connect some of the main-surface lines to one another in conduction states. The plurality of short-circuit electrodes connect a group of the main-surface lines which are brought to conduction states by the common electrodes to the ground electrode through an identical side surface of the dielectric substrate. The input-and-output electrodes are connected to corresponding ones of the resonators including the main-surface lines.

Microstripline filter and method for manufacturing the same

A balance-unbalance conversion element that easily adjusts the phase balance between two balance signals. The balance-unbalance conversion element includes a dielectric substrate and an electrode pattern on a surface of the dielectric substrate. The electrode pattern includes a first &#xbc;-wavelength resonance line coupled to a first balance terminal; a second &#xbc;-wavelength resonance line coupled to a second balance terminal; a &#xbd;-wavelength resonance line having a first open end coupled to an unbalance terminal and the first &#xbc;-wavelength resonator and a second open end coupled to the second &#xbc;-wavelength resonator; and a balance characteristic adjustment electrode having a tip end opposed to a side of the &#xbd;-wavelength resonance line and a base end electrically coupled to a ground electrode. A center line of the electrode pattern on the surface of the dielectric substrate and the center of the tip end of the balance characteristic adjustment electrode are separated from each other.

Balance-unbalance conversion element

A balanced-unbalanced conversion element for realizing easy adjustment of a phase balance of two balanced signals is provided. The balanced-unbalanced conversion element includes a first &#xbc;-wavelength resonant line coupled to a first balanced terminal, a second &#xbc;-wavelength resonant line coupled to a second balanced terminal, and a &#xbd;-wavelength resonant line. The &#xbd;-wavelength resonant line includes a first open-end-side line coupled to an unbalanced terminal and the first &#xbc;-wavelength resonator and a second open-end-side line coupled to the second &#xbc;-wavelength resonator. In addition, a width of the first open-end-side line differs from a width of the second open-end-side line.

Balanced-unbalanced conversion element

A resonant element is manufactured through a process including a setting step and a forming step. A substrate of the resonant element is made of a dielectric material. A ground electrode is formed on a rear principal surface side of the substrate. Principal-surface electrodes that define resonators together with the ground electrode and the dielectric material are formed on a front principal surface side of the substrate. An electrode protecting layer is formed on substantially entire surfaces on a front principal surface side of the principal-surface electrodes and the substrate. A coupling adjusting electrode with both ends facing a plurality of the principal-surface electrodes is formed on a front principal surface side of the electrode protecting layer. In the setting step, the shape of the coupling adjusting electrode is set in each manufactured lot. In the forming step, the coupling adjusting electrode having the shape set in the setting step in each manufactured lot is formed on the front principal surface side of the substrate and the electrode protecting layer that are sintered in advance, and the coupling adjusting electrode is baked to the electrode protecting layer.

Method for manufacturing resonant element

A chip device having a ground electrode and a plurality of top-surface electrodes on a plate-like dielectric substrate. Two of the top-surface electrodes are connected to the ground electrode via respective short-circuit side-surface electrodes to form quarter wavelength resonant lines. A third top-surface electrode is provided between the two top-surface electrodes and both ends thereof are opened to form a half wavelength resonant line. The two top-surface electrodes each have a parallel portion arranged near and in parallel to the third top-surface electrode and a flexion that curves from the parallel portion, extends toward the remaining of the two top-surface electrodes, and is jump-coupled to the remaining of the two top-surface electrodes. The short-circuit side-surface electrodes are jump-coupled to each other, like the flexions.

Dielectric filter having electrodes jump-coupled to a flexion, a chip device having the dielectric filter and method of manufacturing the chip device

A balanced-unbalanced transformation device includes a plate-like dielectric substrate having a ground electrode and a plurality of major surface electrodes formed thereon. Two of the major surface electrodes are connected to the ground electrode via short-circuit side surface electrodes so as to form &#xbc; wavelength resonator transmission lines. A third major surface electrode is disposed between the two major surface electrodes and has either end open so as to form a &#xbd; wavelength resonator transmission line. A balancing characteristic adjustment side surface electrode is provided on a side surface of the dielectric substrate. By adjusting a capacitance formed between the balancing characteristic adjustment side surface electrode and the third major surface electrode, a phase balance between two balanced signals is set to a desired value.

Balanced-unbalanced transformation device and method for manufacturing balanced-unbalanced transformation device

A &#x3bb;/2 resonator comprises an inner conductor formed hole having an inner conductor with both open-ends, formed therein, and &#x3bb;/4 resonators comprise inner conductor formed holes having inner conductors with one short-circuited ends and the other open ends, respectively. The resonators are coupled, whereby a terminal electrode connected to the vicinity of the one open end of one of the &#x3bb;/4 resonators functions as an unbalanced terminal, and terminal electrodes connected to both open ends of the &#x3bb;/2 resonator function as balanced terminals.

Dielectric filter, dielectric duplexer, and communication apparatus

The present invention provides a dielectric resonator, a dielectric filter, a dielectric duplexer capable of reducing leakage of electromagnetic waves and capable of being miniaturized, and a communication apparatus incorporating the same. In each of the dielectric resonator and filter, inside a dielectric block, there is formed a L-shaped inner-conductor-formed hole having a bend at some point of the hole in a manner extending from an outer surface of the dielectric block to a surface perpendicular to the outer surface. An inner conductor is formed on the inner surface of the inner-conductor-formed hole. On the substantially entire outer surfaces of the dielectric block, there is disposed an outer conductor, with one end of the inner-conductor-formed hole open-circuited and the remaining end of the hole short-circuited. Around the edge of the open-circuited end there is formed an outer coupling electrode. This structure enables formation of the dielectric resonator and the dielectric filter having the L-shaped inner-conductor-formed holes.

Dielectric resonator, dielectric filter, dielectric duplexer, and communication apparatus incorporating the same

A dielectric filter including: a &lgr;/2 resonator for generating resonance of &frac12;-wavelength at a predetermined frequency, having both ends open-circuited or short-circuited; and a pair &lgr;/4 resonators respectively for generating resonance of &frac14;-wavelength at a frequency substantially equal to the predetermined frequency, each having one end open-circuited and the other end short-circuited; wherein the pair of &lgr;/4 resonators are disposed in proximity to each of both ends from the vicinity of the center of the &lgr;/2 resonator; a terminal coupling to the &lgr;/2 resonator is provided as an unbalanced terminal; and terminals coupling to the pair of &lgr;/4 resonators is used as a balanced terminal. In the above filter, the balanced-type input/output of signals can be performed without using a balun.

A dielectric filter includes a dielectric block having inner-conductor-formed holes extending from a first face of the dielectric block to a second face opposed to the first face. Inner conductors are formed inside the inner-conductor-formed holes such that both ends of the inner-conductor-formed holes are open-circuited. On the exterior surface of the dielectric block, balanced input/output terminals are capacitively coupled to the open ends of the inner-conductor-formed holes. A metal cover is provided so as to cover one of the first or second face of the dielectric block. The metal cover functions as a short-circuit conductor in a spurious mode such as a TE mode other than a TEM mode, and hence the influence of the spurious mode is avoided.

In a dielectric block, an array of three excitation holes, in each of which one opening is a short-circuited end and the other opening is an open-circuited end, are disposed so as to be interdigitally coupled and balanced input-output terminals are provided at the opening of the excitation holes at both ends of the array. A resonator hole is provided so as to be coupled to one excitation hole of the excitation holes at either end of the array. Thus, a compact dielectric filter with balanced input-output terminals is constructed.

Dielectric filter, dielectric duplexer, and communication device

A dielectric filter and a dielectric duplexer, which obviate the need to change the design of a circuit board when the dielectric filter or the dielectric duplexer are to be changed and in which the degree of freedom of design is improved, and a communication apparatus using them are constructed. Resonator holes having internal conductor formed on the respective inner surfaces thereof, and excitation holes are provided in a dielectric block, and electrodes and an external conductor are formed on the outer surface of the dielectric block. The positions of input/output coupling electrodes on the mounting surface with respect to the circuit board are aligned with the positions of the input/output coupling electrodes on the circuit board. At least one of the electrodes provided on the opening surfaces of the resonator holes is disposed in a direction which is not perpendicular to the mounting surface.

Growing community of inventors

Ishikawa-ken, Japan

Motoharu Hiroshima