Abstract: A surface acoustic wave device for implementing an attenuation characteristic outside of the pass band and the narrow band characteristics, preferably for use as a filter. The surface acoustic wave device includes a piezoelectric substrate, interdigital transducers formed on the piezoelectric substrate, and first and second reflectors disposed on the sides of the interdigital transducers. Each of the first and second reflectors includes an open electrode block with a plurality of electrically independent electrode fingers, and a short electrode block with a plurality of electrode fingers of which both ends are electrically shorted.

Abstract: Efficient transverse energy confinement, and provision of a surface acoustic wave filter having preferable characteristics of both insertion loss and shape factor are obtained. In the surface acoustic wave filter, electrode fingers of one comb electrode are laid in a state of being inserted to the electrode fingers of the other comb electrode, and a thick film thicker than each plurality of electrode fingers is produced in a partial area of the bus bar, and a tip gap is provided between the top of each plurality of electrode fingers and the end face of the opposed bus bar, with a distance therebetween set not greater than 0.2&lgr; (where, &lgr; is one period of the comb electrode).

Abstract: A surface acoustic wave device includes: interdigital transducers; first electrode pads that are connected to the interdigital transducers through wire patterns; and a piezoelectric substrate on which the interdigital transducers, the first electrode pads, and the wire patterns, are formed. In this surface acoustic wave device, at least one of the first electrode pads is not connected to a ground pattern, and the piezoelectric substrate has a conductivity in the range of 10−12/&OHgr;·cm to 10−6/&OHgr;·cm.

Abstract: A package for an electronic device includes a cavity that houses an electronic element, and grooves or holes formed on or in sidewalls that define the cavity. The grooves or holes extend from an open side of the cavity so as not to reach a bottom side of the package.

Abstract: A surface acoustic wave filter capable of obtaining a low insertion loss and wide bandwidth characteristic is provided. The surface acoustic wave filter includes a piezoelectric substrate; a pair of reflective electrodes formed on the piezoelectric substrate; and a plurality of comb electrodes formed between the pair of reflective electrodes on the piezoelectric substrate, wherein, in regard to the neighboring two comb electrodes among the plurality of comb electrodes, an electrode pitch of one comb electrode is set so that continuously varying phases of surface acoustic waves respectively generated by the two comb electrodes are obtained in a gap opposite to an outermost finger electrode of the other neighboring comb electrode.

Abstract: A surface acoustic wave device includes, a first substrate, a surface acoustic wave chip attached to the first substrate, and a second substrate that hermetically seals the surface acoustic wave chip. At least one of the first and second substrates includes. The first and second substrates have respective joining surfaces. An electric circuit is formed on a surface area of the first substrate other than the joining surfaces.

Abstract: A surface acoustic wave device includes a piezoelectric substrate having a first surface on which comb-like electrodes, first pads connected thereto, and a first film are provided. The first film is located so as to surround the comb-like electrodes. A base substrate has a second surface on which second pads joined to the first pads and a second film joined to the first film are provided. The first and second films joined by a surface activation process define a cavity in which the comb-like electrodes and the first and second pads are hermetically sealed.

Abstract: A method of fabricating a surface acoustic wave device includes the steps of: joining a supporting substrate to a second surface of a piezoelectric substrate opposite to a first surface thereof; grinding and polishing the first surface of the piezoelectric substrate; grinding and polishing a third surface of the supporting substrate opposite to another surface thereof to which the second surface of the piezoelectric substrate is joined; and forming, on the first surface of the piezoelectric substrate, an on-chip pattern including comb-like electrodes and electrode pads.

Abstract: A surface acoustic wave device includes an input interdigital transducer and an output interdigital transducer, disposed on a surface acoustic wave propagation path of a piezoelectric substrate, wherein when an aperture length of an electrode finger of the input or output interdigital transducer is denoted by X, the output or input interdigital transducer has two divided interdigital transducers having the electrode finger in which each aperture length is denoted by substantially X/2, wherein the two divided interdigital transducers are serial-connected, and the electrodes of the respective electrode fingers are led from the two divided interdigital transducers, and are disposed so that two output and input signals connected to a balance terminal pair have a different phase at 180°.

Abstract: A surface acoustic wave filter is free from any loss arising from the impedance mismatching by finding out optimum values achieving a widened band and lowered loss for the electrode width of the interdigital transducer and reflector electrodes. The surface acoustic wave filter includes interdigital transducers and reflectors arranged on both sides of the transducer. The piezoelectric substrate has a ratio h/&lgr; of an electrode thickness h to a surface acoustic wave wavelength &lgr; lying within the range of 0.05≦h/&lgr;0.15 and has an electrode width ratio wr/pr of a reflector electrode width wr to an electrode pitch pr lying within the range of 0.5≦wr/pr≦0.6 and has an electrode width ratio wi/pi of an interdigital transducer interdigital electrode width wi to a pitch pi lying within the range of 0.6≦wi/pi≦0.9.

Abstract: The present invention provides a surface acoustic wave filter having an unbalance-to-balance conversion function and an impedance conversion function. This surface acoustic wave filter includes a piezoelectric substrate, a first surface acoustic wave filter that is made up of input and output interdigital transducers (IDTs), and a second surface acoustic wave filter that is also made up of input and output IDTs. The phase difference between the first surface acoustic wave filter and the second surface acoustic wave filter is approximately 180°. The input IDT of the first surface acoustic wave filter is connected to the input IDT of the second surface acoustic wave filter by a connecting wire, and a terminal extending from this connecting wire serves as an unbalanced terminal.

Abstract: A SAW device includes a piezoelectric substrate and a package body holding the piezoelectric substrate, wherein the package body includes a bottom part carrying the piezoelectric substrate in a face-down state and a side wall part laterally surrounding the piezoelectric substrate, the bottom part carrying a wiring pattern for electrical connection with an electrode pattern on the piezoelectric substrate, the wiring pattern including a first ground pattern and a second ground pattern in a mutually separated relationship, the first ground pattern and the second ground pattern being connected electrically with each other.

Abstract: A surface acoustic wave device includes an input interdigital transducer and an output interdigital transducer, disposed on a surface acoustic wave propagation path of a piezoelectric substrate, wherein when an aperture length of an electrode finger of the input or output interdigital transducer is denoted by X, the output or input interdigital transducer has two divided interdigital transducers having the electrode finger in which each aperture length is denoted by substantially X/2, wherein the two divided interdigital transducers are serial-connected, and the electrodes of the respective electrode fingers are led from the two divided interdigital transducers, and are disposed so that two output and input signals connected to a balance terminal pair have a different phase at 180°.

Abstract: A surface acoustic wave filter is free from any loss arising from the impedance mismatching by finding out optimum values achieving a widened band and lowered loss for the electrode width of the interdigital transducer and reflector electrodes. The surface acoustic wave filter includes interdigital transducers and reflectors arranged on both sides of the transducer. The piezoelectric substrate has a ratio h/&lgr; of an electrode thickness h to a surface acoustic wave wavelength &lgr; lying within the range of 0.05≦h/&lgr;≦0.15 and has an electrode width ratio wr/pr of a reflector electrode width wr to an electrode pitch pr lying within the range of 0.5≦wr/pr≦0.6 and has an electrode width ratio wi/pi of an interdigital transducer interdigital electrode width wi to a pitch pi lying within the range of 0.6≦wi/pi≦0.9.

Abstract: A SAW-filter device includes a piezoelectric substrate carrying thereon a first interdigital electrode pair connected to an input terminal and a second interdigital electrode pair connected to an output terminal. The first interdigital electrode pair is grounded to a first ground pad, while the second interdigital electrode pair is grounded to a second ground pad different from the first ground pad. The piezoelectric substrate is accommodated into a space formed in a package body, wherein the space is covered by a metal cap member connected to one of the first and second ground pads.

Abstract: A SAW-filter device includes a piezoelectric substrate carrying thereon a first interdigital electrode pair connected to an input terminal and a second interdigital electrode pair connected to an output terminal. The first interdigital electrode pair is grounded to a first ground pad, while the second interdigital electrode pair is grounded to a second ground pad different from the first ground pad. The piezoelectric substrate is accommodated into a space formed in a package body, wherein the space is covered by a metal cap member connected to one of the first and second ground pads.

Abstract: A surface acoustic wave device includes a piezoelectric substrate of a single crystal LiTaO3 and an electrode pattern provided on the piezoelectric substrate. The electrode pattern contains Al as a primary component and has a thickness in a range of 0.03-0.15 times a wavelength of a surface acoustic wave excited on the piezoelectric substrate. The piezoelectric substrate has an orientation rotated about an X-axis thereof from a Y-axis thereof toward a Z-axis thereof, with a rotational angle of 38-46°.

Abstract: The present invention provides a surface acoustic wave filter having an unbalance-to-balance conversion function and an impedance conversion function. This surface acoustic wave filter includes a piezoelectric substrate, a first surface acoustic wave filter that is made up of input and output interdigital transducers (IDTs), and a second surface acoustic wave filter that is also made up of input and output IDTs. The phase difference between the first. surface acoustic wave filter and the second surface acoustic wave filter is approximately 180°. The input IDT of the first surface acoustic wave filter is connected to the input IDT of the second surface acoustic wave filter by a connecting wire, and a terminal extending from this connecting wire serves as an unbalanced terminal.

Abstract: A surface acoustic wave device supported by a package body. At least one surface acoustic wave element having interdigital electrodes disposed on a propagation path of a surface acoustic wave on the piezoelectric substrate. These interdigital electrodes include an input-side interdigital electrode connected to a ground pad on the package body and an output-side interdigital electrode connected to another ground pad on the package body.

Abstract: A piezoelectric substrate having two reflectors along a propagation path of a surface acoustic wave and three interdigital electrodes provided on said piezoelectric substrate consecutively between the reflectors. A primary side electrode is connected to an input/output terminal and a secondary side electrode is connected to a second input/output terminal. Each interdigital electrode includes include pairs of electrode fingers, where the pair of electrodes for one interdigital electrode is different than a pair of electrodes for another interdigital electrode.