Ngk Spark Plug Company, Limited

Eiji Ozeki

Toshiharu Ito

Kenji Kawakami

Kazuhiro Hayashi

Tatsuo Ogawa

Kozo Okada

Kanji Oya

A piezoelectric filter which is adapted to reduce its height and to electrically and mechanically protect the resonators thereof, and is easy to manufacture and assemble, wherein a plurality of resonators S,through S,and P,through P,are surrounded by respective frame-like spacers,and laid one on the other with intermediary printed circuit boards,interposed therebetween, a top printed circuit board,are placed on the top, a bottom printed circuit board,provided on the lower surface thereof with a plurality of connection electrodes,are placed on the bottom, the frame-like spacers, the top printed circuit board and the bottom printed circuit board are bonded together along the peripheral edges thereof, and the electrodes of the resonators are electrically connected to respective connection electrodes by way of conduction patterns,through,through,formed on the respective printed circuit boards to produce an intended filter circuit.

Multilayer type piezoelectric filter with intermediary printed circuit board elements

A multielement-type piezoelectric filter capable of facilitating assembly and having a reduced size. The base substrate carries a conduction circuit. An input terminal portion, an output terminal portion and a ground terminal portion are formed on a bottom surface of the base substrate and connected to corresponding connection end portions of the conduction circuit. Furthermore, series resonators and parallel resonators are arranged side by side on the base substrate. The lower electrodes of the resonators are connected to the corresponding connection end portions of the conduction circuit via through-holes. In one embodiment, conductive sheets are attached onto exposed upper electrodes of some of the resonators so as to establish a required connection between the upper electrodes. In another embodiment, a common path layer is formed on the upper surface of the base substrate. The upper electrodes of some of the resonators are connected to the common path layer via bonding wires. A cap is attached to the base substrate which covers the resonators.

Multielement-type piezoelectric filter with through-hole connection of

A ladder-type electric filter device having rubber plates each provided on one or both sides of each of the piezoelectric resonators so as to be brought into resilient contact with the surface of the associated piezoelectric resonator. The rubber plates are shaped so as to not be brought into contact with the respective corner edges of the respective piezoelectric resonators which generate extensive contour vibrations. Thus, the contour vibrations are not suppressed, the insertion loss can be reduced, and a mechanical quality factor Q can be substantially decreased, thereby improving group delay frequency characteristics.

Ladder type piezoelectric filter including conductive rubber plates

A ladder-type electric filter apparatus having at least one electric filter unit wherein each electric filter unit includes a casing into which piezoelectric resonator elements and an input, output and earth terminal plates are mounted, one or two of said terminal plates are integrally formed together with the casing, the connecting leg(s) of said terminal plate(s) integrally formed together with the casing are protruded through the wall portion opposite to the opening of the casing, and the remaining terminal plate(s) have a connecting leg(s) protruded from the opening side, all of the connecting legs being connected to a printed circuit board.

Ladder-type electric filter apparatus and housing therefor

A piezoelectric transducer in which a casing is mounted in a sealing manner on a base member for supporting two rod-shaped terminals, a piezoelectric element is bonded to the inner surface of said casing, and electrodes on the front and back surfaces of said piezoelectric element are electrically connected to said terminals. The transducer is supported at the position of a node of the free oscillation mode or the forced oscillation mode. The interior of the casing in the transducer is filled with nitrogen gas.

Piezoelectric transducer for transmitting or receiving ultrasonic waves

An improved ultrasonic transducer including an oscillation housing composed of a cylindrical side plate and a wave transmitting and receiving top plate provided at one end of the side plate, a piezoelectric element integrally bonded to the inside of the top plate for oscillation therewith, and electrodes arranged on the piezoelectric element so that ultrasonic waves may be generated from the top plate when an electric field is applied to the electrodes and/or an electric output is delivered from the electrodes when the top plate receives ultrasonic waves. The improvement includes the oscillation housing which is formed, at least in its top plate, of a porous plastic material.

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Nagoya, Japan

Eiji Ozeki