Japan Radio Co., Ltd.

Nihon Musen Kabushiki Kaisha

Hiromi Yatsuda

Yoshihiko Takeuchi

Takashi Kogai

Naoyuki Yoshimura

Hiroaki Iijima

Nobuhiro Mineshima

Shokichiro Yoshikawa

Toichi Kohda

A surface acoustic wave sensor of the invention includes: a piezo element that propagates a surface acoustic wave; an electrode that carries out conversion of an electrical signal and a surface acoustic wave; and a porous base member into which liquid infiltrates and which comes into contact with the piezo element.

Surface acoustic wave sensor

An object characteristics measurement apparatus of the invention includes a surface acoustic wave device. The surface acoustic wave device includes: an interdigitated electrode that is formed on a first surface on a piezoelectric substrate, excites an elastic wave, and receives reflection based on the elastic wave; a reflector that has a third surface and a fourth surface between the interdigitated electrode and a second surface orthogonal to the first surface in a propagation direction of the elastic wave; a reaction field that is formed between the interdigitated electrode and the reflector, in which the measured object is to be loaded; and a propagator that is formed between the reflector and the second surface.

Object characteristics measurement apparatus

A surface acoustic wave device having electrodes disposed on a piezoelectric substrate, comprising a sealing member having a peripheral wall disposed on the piezoelectric substrate in surrounding relation to the electrodes, and a top plate covering the peripheral wall; and a sealing stiffener disposed on the piezoelectric substrate in facing relation to a liquid material imposed on the piezoelectric substrate and which extends parallel to a portion of the peripheral wall.

Surface acoustic wave element and equipment for measuring characteristics of liquid material

A first substrate has a plurality of bumps and a second substrate has a plurality of openings at positions in registration with the plurality of bumps when the first and second substrates are placed one on top of the other in a confronting manner. The first and second substrates are put together by fusing a sealing wall formed on the second substrate, to hermetically seal an electronic device lying on the first substrate therein. Gas that may be generated upon fusing of the sealing wall can be effectively removed through the openings in the second substrate.

Electronic component to be mounted on a circuit board having electronic circuit device sealed therein and method of manufacturing the same

Electronic compoment to be mounted on a circuit board having electronic circuit device sealed therein and method of manufacturing the same

In a surface-acoustic-wave (SAW) device and method of fabricating the same, a SAW chip is flip-chip mounted in a package. The package has a window facing an electrode formed surface of the SAW chip. After the SAW chip is mounted, the in-process item is inserted into reactive ion etching equipment, with the window open. The substrate or electrodes of the SAW chip is etched by an etching gas introduced into the ion etching equipment. Films may be formed on the electrode formation surface, in place of etching. Thus, variation in characteristics stemming from variations in manufacturing processes can be suppressed.

Method of making surface acoustic wave device

A surface acoustic wave device has a package and a surface acoustic wave element mounted therein face down. The package includes a side wall comprising linear inner side surfaces close to respective outer side surfaces of the surface acoustic wave element and recesses defined where the inner side surfaces of the side wall intersect at respective inner corners. When the surface acoustic wave element is inserted into the side wall along the inner side surfaces thereof, the corners of the surface acoustic wave element do not engage the side wall because of the recesses. Therefore, the outer side surfaces of the surface acoustic wave element may be positioned very closely to the inner side surfaces of the side wall. The surface acoustic wave device may be reduced in size, and the surface acoustic wave element may have input and output electrode pads and ground pads positioned highly accurately with respect to electrode pads on the bottom plate of the package.

Surface acoustic wave device

A composite surface acoustic wave filter includes an interdigitated interdigital surface acoustic wave filter having input and output terminals. Two one-port surface acoustic wave resonators are electrically connected in series to the interdigitated interdigital surface acoustic wave filter respectively at the input and output terminals, the one-port surface acoustic wave resonators having antiresonant frequencies in a stop band that is close to and higher than the passband of the interdigitated interdigital surface acoustic wave filter. Two other one-port surface acoustic wave resonators are electrically connected parallel to the interdigitated interdigital surface acoustic wave filter, the one-port surface acoustic wave resonators having resonant frequencies in a stop band that is close to and lower than the passband of the interdigitated interdigital surface acoustic wave filter.

Surface acoustic wave filter and mobile communication system using same

A surface acoustic wave device and its manufacturing method. A surface acoustic wave device is used as filters for VHF and UHF range signals, or resonators for VHF and UHF range, by driving the surface of a surface acoustic wave element with applied signal to electrodes, transmitting a surface acoustic wave, and receiving the surface acoustic wave with other electrodes. In a configuration of a surface mount type surface acoustic wave device where a surface acoustic wave element is stored inside a package consisting of a base and a cover, pads are attached on a surface of the base and the surface acoustic wave element is fixed to the base by face down bonding.

Method of manufacturing a surface acoustic wave

Surface acoustic wave device and its manufacturing method

A surface elastic wave filter includes a plurality of input interdigital transducers for receiving a high-frequency input signal, and a plurality of output inter-digital transducers for producing an output signal derived from the input signal and having predetermined frequency characteristics. Each of the input and output interdigital transducers having a pair of confronting connectors for receiving the input signal and extracting the output signal, respectively, and a pair of groups of interdigitating electrode fingers extending from the connectors. The input and/or output interdigital transducers include finger-withdrawn interdigital transducers with electrode fingers selectively withdrawn in different positions. With such withdrawal weighting, the interdigital transducers have different sidelobe characteristics, i.e., frequency blocking characteristics, so that the surface elastic wave filter operates with a greater sidelobe suppression.

Surface elastic wave filter having finger omitted transducers to

A surface elastic wave filter for processing a supplied signal into a signal with nonlinear-phase frequency characteristics has a piezoelectric substrate for propagating a surface elastic wave through a surface layer thereof and spaced input and output electrodes disposed on the surface layer for sending and receiving the surface elastic wave. Each of the input and output electrodes has a pair of common electrodes having comb-shaped interdigitating electrode fingers extending therebetween. The central electrode fingers of the input and output electrodes have central axes across the direction of propagation of the surface elastic wave. The distance along the direction of propagation between the central axes is varied in the direction substantially normal to the direction of propagation. The surface elastic wave filter may include an electric conductor disposed on the piezoelectric substrate between the input and output electrodes and having a dimension in the direction of propagation, the dimension being varied in the direction substantially normal to the direction of propagation. A medium for varying the speed of propagation of the surface elastic wave may be positioned in place of the electric conductor.

Surface elastic wave device

A surface elastic wave filter has a pair of electrodes on a surface of a piezoelectric body, and at least one of the electrodes is constructed as electrode fingers in the form of comb teeth which are progressively spread away from each other along a direction normal to the direction in which a surface elastic wave is propagated on the surface of the piezoelectric body. A grating or dot structure as a scattering reflector for scattering and reflecting a portion of the surface elastic wave is disposed in a desired position between the electrodes. Alternatively, some of electrode fingers of a surface elastic wave filter are dropped or removed, or divided voltages are applied to electrode fingers, or a scattering reflector is added to a filter with some of its electrode fingers removed or with divided voltages applied to electrode fingers. With such an arrangement, a filter having good selectivity and desired frequency characteristics can be achieved.

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Tokyo, Japan

Hiromi Yatsuda