Abstract: A 1-port type surface acoustic wave device can be produced by using the same tools as used for the production of a 2-port type surface acoustic wave device and achieves a substantial improvement in terms of impact resistance. A 1-port surface acoustic wave resonator includes a surface acoustic wave substrate, two dummy bump electrodes and two input/output bump electrodes disposed on the surface acoustic wave substrate adjacent to a plurality of input/output extraction electrodes.

Abstract: A method and an apparatus for analyzing a structure, for example, a fingerprint or a hand print, in which the finger or hand is placed upon a plate which forms an ultrasonic wave waveguide and ultrasonic radiation, launched into the waveguide parallel to the surface against which the object is placed. The reflected and backscattered waves are analyzed utilizing horizontally polarized ultrasonic shear waves propagated in the body from at least one transducer at a side of the body. The pickup transducer can also be provided on the side of the body.

Abstract: The surface-acoustic-wave device has surface-acoustic-wave element 1 provided with interdigital electrodes 2, shut-off member 32 and ground patterns 35-1, 35-2. Interdigital electrodes 2 are formed on a first surface of surface-acoustic-wave element 1 and covered with protective film 33. Surface-acoustic-wave element 1 is mechanically supported above mounting substrate 36. Shut-off member 32 serves to shut off surface-acoustic-wave element 1 electrically and airtightly from an ambience. The ground patterns 35-1, 35-2, grounded electrically, serve to discharge an electric charge. Ground patterns 35-1, 35-2 contact a surface of mounting substrate 36. Shut-off member 32 covers surface-acoustic-wave element 1 and also is connected with ground patterns 35-1, 35-2 that are in contact with the surface of mounting substrate 36.

Abstract: A method of producing a SAW (Surface Acoustic Wave) device, including the steps of implanting ions in an entire surface of a piezoelectric member of the SAW device, so that an ion implantation layer is formed therein; performing a heat treatment of the piezoelectric member, so that a heat-treated ion implantation layer is formed in the entire surface of the piezoelectric member; and providing an electrode of a comb type resonator on the heat-treated ion implantation layer.

Abstract: The SAW device comprises a diamond or quartz substrate as a wave propagation layer, a piezoelectric layer on the wave propagation layer and at least one interdigitated electrode on the piezoelectric layer.

Abstract: A real time nonvolatile residue (NVR) monitor operates to efficiently detect molecular contamination in a given environment. The present NVR monitor utilizes surface acoustic wave (SAW) resonators in a controlled environment which efficiently promotes deposition of NVR on the sensor surface. The SAW resonators preferably operate at a resonant frequency of approximately 200 MHz-2,000 MHz which enables the NVR monitor to detect molecular contamination on the order of 10.sup.-11 g-cm.sup.-2 to 10.sup.-13 g-cm.sup.-2. The NVR monitor utilizes active temperature control of (SAW) resonators to achieve a stable resonant frequency and to thermally separate NVR from a sample fluid contacting the SAW. The temperature control system of the NVR monitor is able to directly heat and cool the SAW resonators utilizing a thermoelectric element to maintain the resonators at a preset temperature in accordance with optimal environmental conditions for separating NVR from the sample fluid.

Abstract: A surface acoustic wave filter is formed by arranging electrode portions, each obtained by interdigitally forming a pair of comb electrodes on a piezoelectric substrate to oppose each other at a predetermined distance, on input and output sides, respectively. Each electrode portion includes an impedance matching circuit.

Abstract: An ultrasound detector comprises an array of electrically isolated electrodes (2) embedded in a non-conducting matrix (4) of acoustically engineered material to form a composite body (5). A piezoelectric film (8) is bonded to the body (5) by an insulating adhesive (12), providing an ohmic/capacitive coupling between the electrodes (2) and respective areas of the film (8). The signal generated between the individual electrodes (2) and an electrode layer (18) overlaying the film (8) is processed to provide information on the sound pressure distribution of an ultrasound wave. The use of a non-conductive connection between the film (8) and electrodes (2) greatly facilitates manufacture but provides good performance.

Abstract: A surface acoustic wave device includes a quartz rotated Y-cut plate and at least one interdigital transducer disposed on the quartz rotated Y-cut plate. The quartz rotated Y-cut plate has a Euler angle represented by (0, .theta., .phi.). The angle .theta. is within a range of about 125.degree.<.theta.<130.degree. or equivalents thereto, and the angle .phi. is approximately 90 degrees. The interdigital transducer is made of tungsten.

Abstract: Radio-interrogated surface-wave technology sensor, in which the sensitive element (12) is an impedance which is electrically connected as termination to a surface-wave structure (26) of the sensor.

Abstract: A spread spectrum communication apparatus employs a surface acoustic wave matched filter and surface acoustic wave delay lines which enables the demodulation in accordance with the QPSK scheme. A SS demodulator has a correlated signal acquisition circuit for demodulating a received SS signal to acquire a correlated signal, first and second delay circuits for delaying an output signal from the correlated signal acquisition circuit, and first and second adder circuits for adding the output signal of the correlated signal acquisition circuit and respective outputs of the first and second delay circuits. The first delay circuit delays the input signal by T+(.+-.n+5.times.a/8)/fc, while the second delay circuit delays the input signal by T+(.+-.m-5.times.a/8)/fc. Thereby, a spread spectrum communication apparatus which enables the demodulation in accordance with the QPSK scheme by a simple configuration using a surface acoustic wave matched filter and surface acoustic wave delay lines is provided.

Abstract: A structure for mounting a SAW (Surface Acoustic Wave) device includes photosensitive resin filling a gap between the SAW device and a mounting substrate in the peripheral portion of the SAW device. The entire structure is substantially as small in size as the SAW device and light weight. The photosensitive resin is formed in a region including pads for connection in order to absorb thermal stresses and extraneous forces apt to act on the pads. Second resin may surround the photosensitive resin or may be provided in a laminate structure together with the photosensitive resin so as to enhance a sealing ability. A method of mounting a SAW device is also disclosed.

Abstract: It is an object on the invention to provide a SAW device sealed by resin, which is low priced and suited for decreasing its thickness and weight and requires no particular course for processing a substrate, and a method for fabricating the same. A functional surface of a piezoelectric substrate provided with interdigtal transducers and a mounting surface of a circuit substrate are opposed to each other to form vibration cavities for surface wave propagation areas therebetween. Electrical power is supplied to the piezoelectric substrate from the circuit substrate via electrode pads formed on respective inner surface of both the substrate and bumps inserted therebetween. A resin film adheres to the respective inner surfaces of both the substrates except the surface wave propagation areas to shield the vibration cavity from the environmental space. Apertures are previously formed at predetermined parts of the resin film by means of a laser.

Abstract: A surface acoustic wave system having a mounting receptacle on which there are mounted a plurality of surface acoustic wave elements being bonded together by sides of their surface acoustic wave substrates so as to form a single element assembly. With this structure, a plurality of surface acoustic wave elements can be treated as one surface acoustic wave element in the mounting process, and so less problem is taken in the mounting process. For there is no need for saving a space between two neighboring surface acoustic wave elements for the mounting process, the mounting density can be increased. Further, it is possible to bond together the surface acoustic wave elements having different surface acoustic wave substrates and treat the bonded elements as one element, which provides more flexibility to the system design.

Abstract: A surface acoustic wave position-sensing device comprising a piezoelectric substrate, a nonpiezoelectric plate and an interdigital transducer formed on one end surface of the piezoelectric substrate. The piezoelectric substrate is mounted on an upper end surface of the nonpiezoelectric plate through the interdigital transducer. When using the surface acoustic wave transducing device as an input device, an electric signal is applied to the interdigital transducer. In this time, a surface acoustic wave is excited in the piezoelectric substrate, and then transmitted to the upper end surface of the nonpiezoelectric plate. When using the surface acoustic wave transducing device as an output device, a surface acoustic wave transmitted from the upper end surface of the nonpiezoelectric plate to the piezoelectric substrate is transduced to an electric signal at the interdigital transducer.

Abstract: An ultrasonic touch-position sensing device comprising a piezoelectric substrate, an input interdigital transducer T formed at the middle of a lower end surface of the piezoelectric substrate, four output interdigital transducers R.sub.1, R.sub.2, R.sub.3 and R.sub.4, a nonpiezoelectric plate, and a signal controller connected with output terminals of the output interdigital transducers. The interdigital transducers R.sub.1 and R.sub.2, are formed at one edge of the lower end surface of the piezoelectric substrate, and the interdigital transducers R.sub.3 and R.sub.4, are formed at the other edge thereof. Each output interdigital transducer is placed such that the finger direction thereof is slanting to that of the interdigital transducer T. A lower end surface of the nonpiezoelectric plate is cemented on an upper end surface of the piezoelectric substrate, causing a bilayer assembly. An upper end surface of the nonpiezoelectric plate consists of four areas S.sub.1, S.sub.2, S.sub.3 and S.sub.4.

Abstract: In accordance with the invention, the piezoelectric layer of a SAW device is mechanically coupled to a substrate of temperature-sensitive material having a large coefficient of thermal expansion or contraction. In a preferred embodiment, the temperature-sensitive material is a nickel/titanium alloy having high negative coefficient of thermal expansion of about -200.times.10.sup.-6. The frequency of the device can be tuned by changing the temperature of operation.

Abstract: An improved surface acoustic wave device includes a film of a magnetostrictive material disposed on a substrate and spaced apart input and output transducer elements disposed on the film. The input element causes horizontally polarized shear waves to propagate along the film via the magnetostriction of the film. The shear waves propagating along the film are received by the output transducer element. The SAW device can be integrated on a microelectronic circuit useable in single chip radio frequency applications.

Abstract: A boundary wave device and a fabrication method thereof that allow the conversion efficiency of a boundary wave excited by electrodes to be improved and prevents the device from being affected by parasitical resistance between the electrodes are provided. interdigital transducers 3 are formed on a main surface of a piezoelectric first substrate 2. A dielectric film 5 is formed on a main surface of the first substrate 2 so that the dielectric film 5 coats the interdigital transducers 3 and has a smooth surface 4. A Si second substrate 6 is layered on the dielectric film 5.

Abstract: A surface acoustic wave signal processing apparatus for processing first and second high-frequency signals having frequencies f.sub.1 and f.sub.2 respectively, which comprises: first and second surface acoustic wave delay elements for receiving the first and second high-frequency signals respectively and independently of each other, the delay elements being formed as surface acoustic wave excitation and reception transducers on a piezoelectric substrate so that a phase delay .phi..sub.1 with respect to the frequency f.sub.1 is substantially equal to a phase delay .phi..sub.2 with respect to the frequency f.sub.2 (that is, .phi..sub.1 .apprxeq..phi..sub.2); and a mixer for mixing first and second high-frequency output signals of the first and second surface acoustic wave delay elements so that a signal having a frequency .vertline.f.sub.1 -f.sub.2 .vertline. which is a difference between the two frequencies f.sub.1 and f.sub.2 is taken out as an output signal of the mixer.

Abstract: A surface acoustic wave functional element is provided that includes a piezoelectric substrate or a multilayer piezoelectric substrate having a large electromechanical coupling coefficient. Semiconductor layers are formed on the piezoelectric substrate. The semiconductor layers include an active layer and a buffer layer. The buffer layer is formed of a structure that has a lattice constant that is the same as or similar to that of the active layer. In addition, input and output electrodes are formed on both sides of the semiconductor layers. The surface acoustic wave functional clement attains a large amplification gain at low voltage, and can be used as part of a transmitting/receiving circuit in a high frequency portion of a mobile communication device.

Abstract: A surface acoustic wave filter provided on a substrate, in which input "hot" and ground busbars and output "hot" and ground busbars are disposed substantially symmetrically with respect to an axis lying between the input and the output of the filter.

Abstract: A surface acoustic wave device includes a piezoelectric substrate, an input first interdigital electrode, and an output second interdigital electrode. The input first interdigital electrode is formed on the piezoelectric substrate. The output second interdigital electrode is formed on the piezoelectric substrate to be adjacent to the first interdigital electrode. A ratio of an overlap width to an aperture width of the first interdigital electrode and a ratio of an overlap width to an aperture width of the second interdigital electrode are set to different values, so that a transverse secondary mode is suppressed with one of the first and second interdigital electrodes while a transverse quaternary mode is suppressed with the other of the first and second interdigital electrodes.

Abstract: This invention relates to an acoustic surface wave device suitably used in a high-frequency circuit, in which high attenuation characteristics are provided.The present invention includes an acoustic surface wave element, a ceramic package having a ceramic substrate of a multi-layer structure, the ceramic substrate having a die-attach portion on which the acoustic surface wave element is mounted, the ceramic package having an input terminal and an output terminal connected to the acoustic surface wave element, the ceramic package having an opening located above the ceramic substrate, each of the input terminal and the output terminal having a ground terminal, and a metallic cap sealing the opening of the ceramic package. The metallic cap is electrically connected to one of the ground terminal of the input terminal and the ground terminal of the output terminal.

Abstract: A piezoelectric sensor and assembly for measuring chemical, biochemical and physical measurands is disclosed. The piezoelectric sensor comprises a piezoelectric material, preferably a crystal, a common metal layer attached to the top surface of the piezoelectric crystal, and a pair of independent resonators placed in close proximity on the piezoelectric crystal such that an efficacious portion of acoustic energy couples between the resonators. The first independent resonator serves as an input port through which an input signal is converted into mechanical energy within the sensor and the second independent resonator serves an output port through which a filtered replica of the input signal is detected as an electrical signal. Both a time delay and an attenuation at a given frequency between the input signal and the filtered replica may be measured as a sensor output.

Abstract: A quartz single crystal substrate (12), includes a prescribed range of Euler angles for substrate and crystal orientation which improves signal processing for surface acoustic wave (SAW) devices (10). When a voltage is applied to an input inter digital transducer (IDT) (16) of the SAW device (10), a surface acoustic wave is generated in the quartz substrate (12). The surface acoustic wave propagates in a direction generally perpendicular to electrodes (20) of the IDT (16). The quartz crystal cut and wave propagation directions are defined to reduce the adverse effects of diffraction on SAW devices (10). As a result, frequency response distortions and insertion loss increases due to diffraction are reduced while maintaining good temperature stability and a low power flow angle.

Abstract: A hydrogen sensor including a piezoelectric device with a hydrogen-interactive metal film that reversibly interacts with hydrogen to provide a correspondingly altered frequency response characteristic, relative to the frequency response in the absence of hydrogen. The piezoelectric device may be for example a quartz microbalance or a surface acoustic wave device, having a thin film (e.g., 10-100,000 Angstroms thickness) coating thereon of a hydrogen-interactive metal such as palladium, platinum, nickel or the like.

Abstract: A surface acoustic wave converter for converting an electric signal into a surface acoustic wave includes an interdigital transducer provided on a piezoelectric substrate. The interdigital transducer has first and second electrode groups each having one or more electrode fingers to which a first signal is almost simultaneously inputted. The surface acoustic wave converters includes first input unit for inputting the first signal to the one or more electrode fingers of the first electrode group, and second input unit for inputting the first signal to the one or more electrode fingers of the second electrode group when at least one of surface acoustic waves excited by the first signal in the one or more electrode fingers of the first electrode group reaches one of the one or more electrode fingers of the second electrode group.

Abstract: A surface acoustic wave device is manufactured by directly or indirectly bonding a lid to a substrate having a surface acoustic wave element to seal the element under the lid. The lid is made of at least one material selected from the group comprising lithium niobate, lithium tantalete, lithium borate, glass and quartz. The substrate is made of at least one material selected from the group comprising quartz, lithium niobate, lithium tantalete and lithium borate.

Abstract: To realizing a filter which is capable of properly controlling the passband, and the attenuation pole of a surface acoustic wave filter, a surface acoustic wave filter connected in a ladder type with the surface acoustic wave resonators 104, 105 has an element 106 which changes in capacity by voltage to be impressed and is connected in series with a resonator 105 connected in parallel to the signal line 100.

Abstract: The transducer according to the invention, driven in differential mode, consists of at least a first transducer (5) and a second transducer (6) which are connected in parallel so as to obtain the symmetry of the differential inputs, respectively forming a first and a second acoustic channel; the two transducers (5, 6) exhibiting a specified longitudinal offset with respect to one another. Applications: mobile radio filters.

Abstract: A surface mounting stress relief system for mounting a surface mount package such as a leadless ceramic chip carrier on a printed circuit board includes a printed circuit board having a top layer attached to a bottom layer. The top layer includes cavities for exposing top surface portion of the bottom layer which carry a plurality of solder pads. The surface mount package is positioned on the printed circuit board for placing the package bottom surface on a top surface of the printed circuit board between the cavities while positioning package contact pads in spaced relation above corresponding preselected solder pads. A solder column extends between each of the plurality of corresponding solder pads and the selected contact pads for providing an electrical connection.

Abstract: An ultrasonic touch-position sensing device comprises a nonpiezoelectric plate, two ultrasonic transducing units mounted on an upper- or a lower end surface of the nonpiezoelectric plate, and a signal controller connected with the ultrasonic transducing units. Each ultrasonic transducing unit consists of a first- and a second piezoelectric substrates, at least an input interdigital transducer and at least an output interdigital transducer. The output interdigital transducer has at least a finger-overlap zone R.sub.i (i=1). The finger-overlap zone R.sub.i comprises zones R.sub.ia, R.sub.ib and R.sub.im. The finger direction of the zones R.sub.ia and R.sub.ib runs parallel with that of the input interdigital transducer. The finger direction of the zone R.sub.im is slanting to that of the input interdigital transducer. When an electric signal is applied to the input interdigital transducer, an ultrasound is excited in the bilayer zone B.sub.

Abstract: A surface acoustic module is stable, and its operation frequencies can be varied with high precision. A method of manufacturing the surface acoustic module prevents the module's electrodes from being broken during separation of a sheet of modules into individual components. The surface acoustic module includes electrodes for transmitting and receiving a surface acoustic wave, a surface acoustic wave transmitting substrate, a high resistance thin film, and a thin film for differentiating the transmission velocity of a surface acoustic wave at the high resistance thin film from that at the substrate. The method includes the steps of forming a metallic film on a sheet of the surface acoustic wave transmitting substrate, of forming the electrodes on the metallic film, and of irradiating light or the like to the metallic film so as to increase the film's resistivity.

Abstract: A surface acoustic wave device has a main substrate; a comb-like electrode formed on one of the main surfaces of said main substrate; and a supplementary substrate joined with the other main surface of said main substrate, wherein said supplementary substrate has a smaller thermal expansion coefficient and a larger thickness than said main substrate.

Abstract: An ultrasonic touch-position sensing device comprises a piezoelectric substrate, two ultrasonic transducing units formed on an upper end surface of the piezoelectric substrate, and a signal controller connected with the ultrasonic transducing units. Each ultrasonic transducing unit consists of at least an input interdigital transducer and at least an output interdigital transducer. The output interdigital transducer has at least a finger-overlap zone R.sub.i (i=1). The finger-overlap zone R.sub.i comprises zones R.sub.ia, R.sub.ib and R.sub.im. The finger direction of the zones R.sub.ia and R.sub.ib runs parallel with that of the input interdigital transducer. The finger direction of the zone R.sub.im is slanting to that of the input interdigital transducer. When an electric signal is applied to the input interdigital transducer, an ultrasound is excited in the piezoelectric substrate, and transduced to electric signals E.sub.ia and E.sub.ib (i=1, 2, . . . , N) at the zones R.sub.ia and R.sub.

Abstract: A surface acoustic wave (SAW) sensor system and associated method for accurately measuring mercury gas concentrations. The sensor includes a SAW device that may be a SAW delay-line oscillator or a SAW resonator. The surface of the piezoelectric substrate of the SAW device includes a material suitable for amalgamation with mercury. Mercury in the gaseous environment is captured with the amalgamating material so as to cause a change in the mechanical and electrical properties on the surface of the device, thereby causing a change in the frequency output of the device. The piezoelectric substrate of the SAW device is preferably coupled to a heater to permit control of the temperature at the surface of the device. The piezoelectric substrate temperature may be regulated to produce a substantial equilibrium of mercury amalgamation/desorption kinetics. Under the conditions provided by the invention, the mercury concentration in the gaseous environment can be determined.

Abstract: An elastic surface acoustic wave filter device provides balanced operation with a neutral terminal kept at a ground potential and is adaptable for any system of unbalanced input-to-balanced output or balanced input-to-unbalanced output even with an input and an output having a different characteristic impedance. A first elastic surface acoustic wave filter having a first predetermined phase is connected in a cascade arrangement to a second elastic surface acoustic wave filter having a phase that is different by about 180 degrees from the first predetermined phase to form a first set of cascaded elastic surface acoustic wave filters. A third elastic surface acoustic wave filter having the first predetermined phase is connected in a cascade arrangement to a fourth elastic surface acoustic wave filter having the predetermined phase to form a second set of cascaded elastic surface acoustic wave filters.

Abstract: A compact, low height, low cost, and high reliability surface acoustic wave device, and its method of manufacture. The surface acoustic wave device consists of a substrate, a comb-electrode disposed on the main surface of the substrate, plural electrode pads disposed around the comb-electrode, protecting means covering the comb-electrode through a closed space produced by combining the comb-electrode and the electrode pads with the substrate by using substantially covalent bonding force acting between conductive bumps formed on the electrode bumps, a conductive adhesive layer disposed at least on the top of the conductive bumps, and a package adhered on the conductive bumps by means of the conductive adhesive, and insulation adhesive filled into the package contacting the conductive adhesive, the conductive bumps, and the protective means.

Abstract: An acoustic wave identification transponder device, having a substrate, an electroacoustic transducer generating an acoustic wave in said substrate and a set of encoding elements disposed in a path of the acoustic wave for modifying the acoustic wave, having at least two reflective elements disposed in the acoustic path of the acoustic wave such that an acoustic path length of the acoustic wave on the substrate is longer than twice a largest linear dimension of the substrate. The device preferably includes an angled elongated conductor formed on said substrate, having angle magnitudes whose sum exceeds .pi. radians, said angled elongated conductor defining at least a portion of the acoustic path.

Abstract: An ultrasonic switching device comprising a piezoelectric substrate, an input- and an output interdigital transducers formed on an upper end surface of the piezoelectric substrate, and a nonpiezoelectric plate, a lower end surface of the nonpiezoelectric plate being cemented on the upper end surface of the piezoelectric substrate. The output interdigital transducer has a finger-overlap zone R.sub.i (i=1), or has N finger-overlap zones R.sub.i (i=1, 2, . . . , N) and N-1 finger-overlap zones Q.sub.i {i=1, 2, . . . , (N-1)} between two finger-overlap zones R.sub.i and R.sub.(i+1). Each finger-overlap zone R.sub.i comprises three zones R.sub.ia, R.sub.ib and R.sub.im. The finger direction of the zones R.sub.ia and R.sub.ib runs parallel with that of the input interdigital transducer. The finger direction of the zone R.sub.im is slanting to that of the input interdigital transducer by an angle .alpha.. The finger direction of the finger-overlap zone Q.sub.

Abstract: A method for packaging an acoustic wave device (10) without contaminating an active area (12) disposed on a face (14) thereof, including steps of: providing a substrate with a top (30) having conductive pads (18), bonding stud bumps (20) to a periphery (22) of the face (14) of the acoustic wave device, disposing a dam (26) onto the top (30) of the substrate and inside of the location of the conductive pads (18), aligning and connecting the stud bumps (20) to the conductive pads (18) on the top of the substrate to form electrically conductive interconnections between the acoustic wave device (10) and the substrate (16), flowing an underfill material (28) at the periphery (22) of the acoustic wave device and around the interconnections such that the underfill material (28) stops at a boundary (32) defined by the dam (26), and curing the underfill material (28) to mechanically reinforce and protectively encapsulate the interconnections.

Abstract: A surface acoustic wave device includes a quartz substrate and generates surface acoustic waves having a high sonic speed. A surface acoustic wave device includes a surface wave substrate comprising a quartz substrate on which an ZnO thin film functioning as a piezoelectric thin film is disposed. IDTs comprising respective pairs of comb electrodes are disposed in contact with the ZnO thin film. A thickness and arrangement of the piezoelectric thin film relative to the quartz substrate and comb electrodes is such that a novel higher order mode of leakage elastic surface acoustic waves are generated and effectively used enable operation at higher sonic velocity and higher frequency.

Abstract: In a surface acoustic wave apparatus, a surface acoustic wave element for obtaining a convolution signal is housed in a recess of a substrate. Since the surface acoustic wave element is housed in the recess of the substrate in this surface acoustic wave apparatus, the apparatus can be compactified. This effect of compactification is remarkable, because the surface acoustic wave element has an output electrode for obtaining the convolution signal and thus originally has a big element size. When a laminate substrate is used as the substrate, a configuration for effectively using surfaces of respective layers may be arranged in such a manner that output wiring of the convolution signal is separately formed in the layers. This further enhances the effect of compactification. There are further disclosed a spread spectrum signal receiver using the above surface acoustic wave apparatus for receiving a spread spectrum signal, and a spread spectrum communication system using the spread spectrum signal receiver.

Abstract: In accordance with the invention, the operating frequency of a SAW device is magnetically tuned. In a first embodiment, the SAW device comprises a piezoelectric layer mechanically coupled to a substrate or body of magnetostrictive material. Strains magnetically induced in the magnetostrictive substrate is coupled to the piezoelectric layer, altering the velocity at which it can transmit acoustic waves. In an alternative embodiment, surface waves are directly generated in a magnetostrictive material and the velocity is directly altered by an applied magnetic field.

Abstract: A first surface acoustic wave device for 2nd mode surface acoustic wave of a wavelength .lambda. (.mu.m) according to the present invention is a SAW device of "type A" device shown in FIG. 6A, wherein a parameter kh3=2.pi.(t.sub.A /.lambda.) is: 0.033.ltoreq.kh3.ltoreq.0.099, and wherein a parameter kh1=2.pi.(t.sub.Z /.lambda.) and a parameter kh2=2.pi.(t.sub.S /.lambda.) are given within a region ABCDEFGHIJKLA in a two-dimensional Cartesin coordinate graph of FIG. 1.

Abstract: A transponder antenna is carried by a substrate and is sandwiched between the substrate and a cover sheet. A rectangular opening extends through the cover sheet and receives a signal processing chip adhesively carried in a recess below a cap which covers the opening. The chip is spaced with respect to the antenna so as to facilitate direct or inductive coupling between the chip and antenna. The cap has a protective portion which extends through the cover opening substantially all the way to the substrate so as to prevent accidental contact between the chip, on one hand, and the substrate and/or antenna on tee other.

Abstract: A surface acoustic wave device includes a quartz rotated Y-cut plate and at least one interdigital transducer disposed on the quartz rotated Y-cut plate. The quartz rotated Y-cut plate has a Euler angle represented by (0, .theta., .o slashed.). The angle .theta. is within a range of about 125.degree.<.theta.<130.degree. or equivalents thereto, and the angle .o slashed. is approximately 90 degrees. The interdigital transducer is made of tungsten.

Abstract: A surface acoustic wave element 11 having an inter digital electrode 12 formed on one surface of a piezo-electric substrate is arranged in a recess of a package 13 with the one surface being faced to a bottom surface of the recess of the package 13. An elastic conductive pad 35 having pads electrically connected to the electrode of the surface acoustic wave element 11 and electrodes of the package 13 is provided between the one surface of the surface acoustic wave element 11 and the package 13. The conductive pad 35 includes wiring means 35a, with which it is possible to connect the surface acoustic wave element 11 to the package 13 even when the position of the surface acoustic wave element in which the interdigital electrode is formed is deviated from the position of the electrodes of the package 13. The package 13 includes a cap 30 for pressing down the surface acoustic wave element 11.

Abstract: A sapphire single crystal wafer 11 having a diameter not less than two inches and having an off-angled surface which is obtained by rotating an R (1-102) surface about a ?11-20! axis by a given off-angle is introduced in a CVD apparatus, and a double-layer structure of first and second aluminum single crystal layers 12 and 13 is deposited on the off-angled surface of the sapphire single crystal wafer by MOCVD. The thus deposited aluminum single crystal layer 13 has (1-210) surface. The first aluminum nitride single crystal layer 12 serves as a buffer layer and has a thickness of 5-50 nm, and the second aluminum nitride single crystal layer 13 has a thickness not less than 1 .mu.m. The off-angle is preferably set to a value not less than .+-.1.degree., much preferably a value .+-.2.degree., more preferably a value not less than -3.degree., and particularly preferable to a value within a range from -2.degree.-+10.degree..