Abstract: A surface acoustic wave device having a novel structure capable of restricting TTE and ripple noise on a frequency characteristics and group delay time characteristics thereof is provided under a condition by which acoustic reflection is suppressed when there is internal dissipation in the device and/or a peripheral circuit thereof. When the device includes a unidirectional interdigital transducer, it is possible to restrict ripple of the frequency characteristics and the group delay time characteristics and to reduce loss without using a phase shifter. By using the surface acoustic wave device according to the present invention, a communication apparatus can be improved in performance.

Abstract: A method for packaging an acoustic wave filter (102). The method includes a step of providing a first wafer (100). The first wafer (100) supports acoustic wave transduction and propagation. The method also includes steps of processing the wafer (100) to provide transducer patterns (18, 18') thereon and disposing a seal ring (25) on the wafer (100). The seal ring (25) completely encloses active areas allowing portions of each bond pad to extend outside of the seal ring. The method further includes steps of disposing a second wafer (40) atop the seal ring (25) and the first wafer (100), sealing the second wafer (40) to the first wafer (100), dicing the second wafer (40) with a saw that provides a first kerf width, whereby portions of the second wafer (40) overlying bonding pads (20) of the transducer patterns (18, 18') are removed and dicing the first wafer (100) with a saw that provides a second kerf width narrower than the first kerf width to provide a packaged SAW die.

Abstract: A full duplex radio (10) having improved properties is obtained by using asymmetric surface acoustic wave (SAW) filters (70, 92, 100, 100', 112). The filters (70, 92, 100, 100', 112) are composed of series (50.sub.1, 50.sub.1 ') and parallel (50.sub.2, 50.sub.2 ') coupled SAW resonators. Asymmetry is obtained by covering either of the series (50.sub.1, 50.sub.1 ') or parallel (50.sub.2, 50.sub.2 ') resonators of each filter (70, 92, 100, 100', 112) with a dielectric layer (96) to increase the SAW coupling coefficient (Cs, Cp) of the covered resonators (50.sub.1 ', 50.sub.2 ') relative to the uncovered resonators (50.sub.1, 50.sub.2). The filters (70, 92, 100, 100', 112) are desirably in pairs arranged with mirror image frequency asymmetry such that the steeper skirts (87, 79) of the frequency response (91', 91") are adjacent. Greater pass-band bandwidths (77, 77', 77") can be obtained without adverse affect on transmitter and receiver isolation.

Abstract: A surface acoustic wave position-sensing device comprising a piezoelectric substrate, a nonpiezoelectric plate, at least two surface acoustic wave transducing units X and Y having N propagation lanes U.sub.Xi (i=1, 2, ...... , N) and U.sub.Yi (i=1, 2, ...... , N), respectively, and a controlling system connected with the units X and Y. Each unit includes input and output interdigital transducers formed on the upper end surface of the piezoelectric substrate. One end surface of the nonpiezoelectric plate is mounted on the upper end surface of the piezoelectric substrate through the interdigital transducers. When an electric signal E.sub.T is applied to the input interdigital transducer, a surface acoustic wave is excited on an area, in contact with the input interdigital transducer, of the upper end surface of the piezoelectric substrate.

Abstract: The present invention provides surface acoustic wave devices which do not require a balanced-to-unbalanced transformer circuit regardless of the type of the peripheral circuits of the balanced type surface acoustic wave filter, i.e. a balanced type device or an unbalanced type. A transmitting interdigital transducer and a receiving interdigital transducer are formed on a substrate comprising 41.degree. Y cut-X propagation lithium niobate. A balanced type surface acoustic wave filter is formed on a substrate comprising 36.degree. Y cut-X propagation lithium tantalate. The balanced type surface acoustic wave filter comprises two series-arm surface acoustic wave resonators and two crossed-arm surface acoustic wave resonators connected in a lattice. The substrate on which the transmitting interdigital transducer and the receiving interdigital transducer are formed and the substrate on which the balanced type surface acoustic wave filter is formed are located in a ceramic package.

Abstract: In a resonator-type surface acoustic wave filter comprising a lithium tantalate substrate, lithium niobate substrate or lithium tetraborate substrate having a cut plane of high velocity, the direction of propagation of surface acoustic waves is set within the range of (40 deg to 90 deg, 40 deg to 90 deg, 0 deg to 60 deg) as expressed in Eulerian angles, and the frequency difference .increment.f between the resonance frequency frs of series resonators and the resonance frequency frp of parallel resonators is set within a predetermined range formulated with the center frequency, the capacitance Cos of the series resonators and the capacitance Cop of the parallel resonators taken as parameters. Optimum ranges of the required design parameters are thus clarified to assure the resonator-type surface acoustic wave filter of higher performance.

Abstract: In a resonator-type surface acoustic wave filter comprising a lithium tantalate substrate, lithium niobate substrate or lithium tetraborate substrate having a cut plane of high velocity, the direction of propagation of surface acoustic waves is set within the range of (40 deg to 90 deg, 40 deg to 90 deg, 0 deg to 60 deg) as expressed in Eulerian angles, and the capacitance Cos of the series resonators and the capacitance Cop of the parallel resonators are set within a predetermined range formulated with the center frequency taken as a parameter. Optimum ranges of the required design parameters are thus clarified to assure the resonator-type surface acoustic wave filter of higher performance.

Abstract: A surface acoustic wave device includes a piezoelectric substrate, a wave guide path provided on the piezoelectric substrate and an interdigital transducer for exciting a surface acoustic wave. The interdigital transducer is provided with plural portions of mutually different pitches of the electrode finger, respectively corresponding to different frequencies. The portions are parallelly arranged along a direction perpendicular to the propagation direction of the surface acoustic wave. The surface acoustic wave generated by the interdigital transducer is entered in concentrated manner into the wave guide path.

Abstract: A SAW device (11) includes a SAW element (13) which is bonded onto a support substrate (12) in a face down mode through solder (19, 20), and a metal cap (21) enclosing the SAW element (13). Assuming that and .alpha..sub.1, .alpha..sub.2 and .alpha..sub.3 represent the thermal expansion coefficients of the SAW element (13), the support substrate (12) and the conductive cap (21) along the surface wave propagation direction respectively, .alpha..sub.3 .ltoreq..alpha..sub.1 when .alpha..sub.1 >.alpha..sub.2, and .alpha..sub.3 .ltoreq..alpha..sub.1 when .alpha..sub.1 <.alpha..sub.2.

Abstract: A surface acoustic wave filter device includes a piezoelectric substrate having mirror-polished surfaces on both sides, so that it is essentially free from warping. One surface of the substrate is provided with two filter stages which are cascade connected with each other thereby to sufficiently attenuate bulk wave spurious noise below a practically negligible extent. The filter device can be manufactured with an improved yield.

Abstract: A surface acoustic wave device includes a substrate having piezoelectricity, at least two input electrodes, provided on the substrate, for exciting first and second surface acoustic waves, and an output electrode for taking a convolution signal of the two surface acoustic waves out. The substrate has a roughness configuration on a back face thereof and a maximum depth of the roughness configuration is not less than a wavelength of bulk waves of convolution output taken out of the output electrode.

Abstract: A touch position sensor or "touchscreen" utilizes acoustic waves within a sensor substrate to determine the position of touch. The substrate is made of a transparent material, such as borosilicate glass or a barium glass, which exhibits substantially less acoustic absorption than soda-lime glass.

Abstract: To obtain a surface acoustic wave device which can be produced with ease at a low cost and can be reduced in size without causing deterioration of characteristics, a surface acoustic wave device having input and output transducers arranged alternately on the surface of a substrate for propagating a surface acoustic wave includes metal patterns provided outside the transducers along the extension line of the propagation path of the surface acoustic wave and having at least one surface inclined at an angle .theta. (5.degree.<.theta.<85.degree. or -85.degree.<.theta.<-5.degree.) with respect to the propagation direction of the surface acoustic wave.

Abstract: A chemical sensor for measuring a change in the sensor mass relating to the interaction of a surface of the sensor with a solution comprises a crystal detector oscillator capable of providing a measurement signal based upon the resonant frequency of the crystal detector oscillator. The crystal detector oscillator has a first crystal side for directly contacting the solution, and a second crystal side isolated from contacting the solution. A first electrode is integral to the first crystal side, with the first electrode having an inner and outer perimeter defining an outer portion of the first crystal side which is exterior to the outer perimeter of the first electrode and an inner portion of the first crystal side which is interior to the inner perimeter of the first electrode. A second electrode is integral to the second crystal side.

Abstract: Methods and compositions are described for the preparation of piezoelectric ceramic-polymer composites having improved properties for application in piezoelectric devices. These composites consist of piezoelectric particles embedded in a polymer matrix. The improvements of this invention result from discoveries of the effects of particle size, particle size dispersity, volumetric loading levels, ceramic dielectric constant, and polymer dielectric constant on performance. Various improved devices based on these compositions are also described.

Abstract: A surface acoustic-wave resonator filter having improved group delay time characteristics. The filter comprises three energy-confined acoustic-wave resonator filter sections formed on a piezoelectric substrate. The second resonator filter section is positioned between the first and third resonator filter sections. One frequency in a vertical higher-order mode of the second filter section is placed on the lower-frequency side of one frequency in a vertical higher-order mode of the first and third filter sections. Or, one frequency in a vertical lower-order mode of the second filter section is placed on the higher-frequency side of one frequency in a vertical lower-order mode of the first and third filter sections.

Abstract: A surface acoustic wave device including a dielectric substrate having an input electrode and an output electrode and a grounding electrode on a first surface of the dielectric substrate, and an outer electrode on a second surface of the dielectric substrate; and a surface acoustic wave element having an electrode pad and a comb-shaped electrode disposed on a first surface of the surface acoustic wave element. The surface acoustic wave element is bonded to the dielectric substrate via a metal bump and a conductive resin formed on the electrode pad. The surface acoustic wave device further includes an insulating resin deposited on the periphery of the metal bump, and a guard layer shorter in height than the surface acoustic wave element formed adjacent the surface acoustic wave element on the first surface of the dielectric substrate.

Abstract: An interdigital converter of a surface acoustic wave filter is internally protected against electrostatic discharges. The protection is provided by a resistor which is connected in parallel to the interdigital converter.

Abstract: A surface acoustic wave (SAW) resonance device includes a SAW resonator formed on a piezoelectric substrate and including driving electrodes formed in a comb-like shape and reflectors arranged in both sides of the driving electrodes, and at least one capacitor formed on the piezoelectric substrate and electrically connected to the driving electrodes. A capacitance of the capacitor is set to be a specific value in accordance with a manner of connection of the capacitor to the SAW resonator. By the constitution, it is possible to simply and precisely carry out a frequency adjustment of the SAW resonance device. It is also possible to suppress occurrence of undesirable ripples or spurious signals to thereby obtain electric characteristics equivalent to those obtained in the case where the number of pairs of driving electrodes is increased.

Abstract: An identification and/or sensor system includes an identification and/or sensor configuration having resonators for determining at least one parameter to be interrogated. The resonators have a quality being good enough to effect a storage of energy in the resonators. A transmitting and receiving apparatus transmits interrogation signals by radio to the identification and/or sensor configuration and receives and evaluates reply signals transmitted back from the identification and/or sensor configuration. The transmitting and receiving apparatus is a broadband device.

Abstract: An end face reflection type surface wave resonator utilizing a surface wave of an SH type is constructed by forming comb electrodes on one major surface of a piezoelectric substrate, which constitute an IDT, and forming grooves extending from one major surface to the other major surface to form a pair of end faces on which a surface wave is to be reflected the resonator having piezoelectric plate portions outside the grooves.

Abstract: A first interdigitated transducer and a second interdigitated transducer are disposed such that an acoustic port of the first interdigitated transducer confronts an acoustic port of the second interdigitated transducer. A first electric terminal of respective interdigitated transducers are electrically coupled together. The first and second interdigitated transducers have different resonance frequencies and may be acoustically coupled.

Abstract: An elastic wave position-sensing device comprising at least two elastic wave transducing units X and Y having N propagation lanes U.sub.Xi, (i=1, 2, . . . , N) and U.sub.Yi (i=1, 2, . . . , N), respectively, a nonpiezoelectric plate, a display panel mounted on one end surface of the nonpiezoelectric plate, and a controlling system connected with the units X and Y. Each unit includes a piezoelectric substrate P.sub.T, a piezoelectric substrate P.sub.R, at least an input interdigital transducer formed on one end surface of the piezoelectric substrate P.sub.T, and at least an output interdigital transducer formed on one end surface of the piezoelectric substrate P.sub.R. Each piezoelectric substrates mounted on one or the other end surface of the nonpiezoelectric plate and the nonpiezoelectric plate form N bilayer zones L.sub.Ti (i=1, 2, . . . , N), a bilayer zone L.sub.R, and a monolayer zone between the bilayer zones L.sub.Ti and the bilayer zone L.sub.R. When an electric signal E.sub.

Abstract: To obtain a surface acoustic wave device which can be produced with ease at a low cost and can be reduced in size without causing deterioration of characteristics, a surface acoustic wave device having input and output transducers arranged alternately on the surface of a substrate for propagating a surface acoustic wave includes metal patterns provided outside the transducers along the extension line of the propagation path of the surface acoustic wave and having at least one surface inclined at an angle .theta. (5.degree.<.theta.<85.degree. or -85.degree.<.theta.<-5.degree.) with respect to the propagation direction of the surface acoustic wave.

Abstract: A surface wave device, for use in differential coherent detection in a commutation signaling communications system using N predetermined M-bit codewords, propagates surface waves for each codeword to a first coded output IDT (inter-digital transducer) comprising M parallel taps with a pitch t=T/M, the taps having phases representing bits of the respective codeword, and to a second output IDT which is at a distance from an input IDT greater by T than the first coded output IDT, to provide an additional delay of one information symbol. The input IDT, or each tap of each coded output IDT, has a length equal to t. The second output IDT can comprise a coded IDT, or a delay tap responsive to the surface wave propagated via the first coded output IDT.

Abstract: Without increasing propagation loss or diffraction loss, (unlike conventional surface acoustic wave, SAW, filters which need many electrode finger pairs for constructing interdigital transducers, IDTs, to realize a steep cutoff frequency characteristic by conventional weighting or apodization that involves a high propagation loss and a high diffraction loss), there is provided a SAW filter with a very steep cutoff frequency characteristic on the low frequency side which uses three IDTs having N1, N2 and N3 electrode finger pairs, respectively. The filter is particularly applicable to a mobile radio communication device, such as a cellular radio. The relation between all the number of pairs N1+N2+N3 of the IDTs and the electromechanical coupling coefficient k.sup.2 of the piezoelectric substrate is N2<(N1+N3)<3.times.N2, and 2/k.sup.2 .gtoreq.(N1+N2+N3).gtoreq.0.8/k.sup.2.

Abstract: A demodulation apparatus and a communication system using the same are disclosed. The apparatus comprises code generation means for generating a reference spread code corresponding to a first signal modulated by a spread code, and an elastic surface wave element for receiving the first signal and a second signal output from the code generation means, and outputting a demodulated information signal.

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 inductive coupling between the chip and antenna.

Abstract: A SAW filter having an even number of tracks, each track comprising reflective input and output IDTs having a partially reflecting grating disposed between them. One of the IDTs of each pair of tracks has its electrodes connected in opposite polarity to those of the other IDTs of the pair of tracks and the separation of the input and output IDTs of respective tracks of each pair of tracks is substantially the same. The relative dispositions of the partially reflecting gratings are such that waves launched into respective tracks of a pair of tracks undergo at least one reflection from the partially reflecting grating prior to being coherently incident on the output IDTs. By virtue of the oppositely connected electrodes of one of the IDTs, direct coupling through the tracks is inhibited at substantially all frequencies.

Abstract: The present invention directed to a SAW device comprising a diamond layer and an LiTaO.sub.3 layer, which can be operated at the frequency of 3 GHz or higher, with superior durability and less energy loss. The SAW device for 1st mode surface acoustic wave of a wavelength .lambda. (.mu.m) according to the present invention comprises: a diamond layer, an interdigital transducer formed onto the diamond layer, and a polycrystalline C-axis-oriented LiTaO.sub.3 layer formed over the interdigital transducer; wherein the SAW device satisfies a relationship of 0.4.ltoreq.kh.sub.1 .ltoreq.1.2, where a parameter kh.sub.1 is defined as kh.sub.1 =2.pi.(t.sub.1 /.lambda.), and t.sub.1 (.mu.m) is the thickness of the LiTaO.sub.3 layer.

Abstract: An acoustic wave filter (200, 300) having a substrate for supporting propagation of acoustic waves, and first (220, 315), second (235, 330) and third (210, 310) acoustic wave transducers disposed on the substrate. The first acoustic wave transducer (220, 315) includes at least one bus bar (221, 316) electrically coupled to a first electrical port (205, 305) of the acoustic wave filter (200, 300). The second acoustic wave transducer (235, 330) is disposed on the substrate in line with the first acoustic wave transducer (220, 315) and is acoustically coupled thereto. The second acoustic wave transducer (235, 330) includes at least one bus bar (236', 331) electrically coupled to a second electrical port (240, 345) of the acoustic wave filter (200, 300). The third acoustic wave transducer (210, 310) includes at least one bus bar (211, 311') electrically coupled to the first electrical port (205, 305).

Abstract: A SAW filter includes a first SAW resonator having a pair of terminals and a predetermined resonance frequency (f.sub.rp), the first SAW resonator being provided in a parallel arm of the SAW filter. A second SAW resonator has a pair of terminals and a predetermined resonance frequency (f.sub.rs) approximately equal to a predetermined antiresonance frequency of the first SAW resonator (f.sub.ap). The second SAW resonator is provided in a series arm of the SAW filter. An inductance element is connected in series to the first SAW resonator.

Abstract: This invention relates to an electronic device having a frequency dependent signal transfer characteristic which is electrically coupled to at least one SAW transducer. The SAW transducer acts as a SAW impedance element since it exhibits frequency dependent electrical characteristics. Such characteristics are utilised so that the transmission loss of the SAW impedance element is high in a relatively low signal transfer region of the signal transfer characteristic of the electronic device, and low in a relatively high signal transfer region of the signal transfer characteristic of the electronic device. This has the advantage that signals outside of the passband of the electronic device can be attenuated without increasing the transmission loss of the electronic device in its passband.

Abstract: A surface acoustic wave (SAW) device includes a plurality of SAW filters connected in cascade. An impedance matching element in the form of a SAW resonator is interposed between two adjoining SAW filters. Each filter includes a first piezoelectric substrate having a first electromechanical coupling factor and the resonator includes a second piezoelectric substrate having a second electromechanical coupling factor. The second electromechanical coupling factor is greater than the first factor so that the inductive band of the SAW resonator is wider than the pass band of the SAW filter. The device affords improved filter properties including an increased fractional bandwidth and an increased out-of-band attenuation.

Abstract: An opening is formed in a region of a circuit board opposite a vibration region E of a piezoelectric element. The piezoelectric element is mounted to the circuit board, and electrical connections extend between and support the piezoelectric element from the circuit board by a solder. The soldered connection portions are surrounded by a bonding agent. An opening in the circuit board prevents any excess bonding agent from invading the vibration region E of the piezoelectric element, and the bonding agent assists in dispersing stresses exerted on the circuit board thereby minimizing the stresses transferred to the piezoelectric element.

Abstract: A SAW filter is configured so that a resonator-type filter portion, in which a plurality of SAW resonators are connected in series and in parallel, and a 3-electrode type serially coupled filter portion, in which three IDTs for inputting and outputting signals are interposed between reflectors, are serially connected on one and the same substrate. The design parameters of the respective SAW resonators are adjusted so that the impedances of respective sides of the filter portions, when viewed from the node of the resonator-type SAW filter portion and the 3-electrode type serially coupled SAW filter portion, substantially have a complex conjugate relationship with each other in the pass frequency band.

Abstract: A surface acoustic wave resonator filter includes an interdigital electrode on a piezoelectric substrate and has a two-dimensional mode coupling structure coupling a longitudinal resonation in the longitudinal direction consistent with a propagating direction of a surface acoustic wave and a transversal mode resonation in a transverse direction perpendicular to the propagating direction.

Abstract: A surface acoustic wave filter having a configuration in which a plurality of series surface acoustic wave resonators and parallel surface acoustic wave resonators are connected is used as a receiving filter included in a receiving circuit of a communication apparatus capable of simultaneously transmitting and receiving signals. When the transmitting frequency is higher than the receiving frequency, one of the parallel surface acoustic wave resonator, connected between the signal line and the ground, is disposed most closely to the input terminal of the filter. When the transmitting frequency is lower than the receiving frequency, one of the series surface acoustic wave resonator, connected in series to the signal line, is disposed most closely to the input terminal of the filter. Accordingly, the singular point of the filter is prevented from coinciding with the transmitting frequency, so that the deterioration of the resonator is prevented.

Abstract: An integrated varactor and piezoelectric device for an acoustic ink jet ejector includes a substrate having a first surface, the silicon substrate forming a first electrode, an epitaxial layer formed over the first surface of the silicon substrate, a silicon dioxide layer formed over the epitaxial layer, a second electrode formed over the silicon dioxide, a piezoelectric layer formed over the second electrode, a third electrode formed over the piezoelectric layer and an acoustic lens formed over a second surface of the silicon substrate. The acoustic lens is aligned with the center of the piezoelectric layer generally along an axis perpendicular to the first and second surfaces of the silicon substrate.

Abstract: A three-terminal resonator device (200) resonant at a resonant frequency has a first terminal (201), a second terminal (202), and a common terminal (203). The resonator includes a surface acoustic wave transducer (290) disposed on a piezoelectric substrate (201). The SAW transducer (290) is comprised of a first sub-transducer (210) and a second sub-transducer (220) which respectively include a first set of electrodes (211,213) and a second set of electrodes (221,223). One of the electrodes of each of the first set and the second set of electrodes respectively provide the first terminal (201) and the second terminal (203). The other terminals of the first and second set of electrodes are connected at the common terminal (203) to provide a serial connection between the first sub-transducer (210), and the second sub-transducer (220).

Abstract: A high frequency Surface Acoustic Wave (SAW) device includes a highly oriented diamond layer adjacent a piezoelectric layer. In one embodiment, laterally spaced apart piezoelectric layers or portions confine propagation of the wave within the diamond layer. Interdigitated electrodes may be provided by electrically conductive metal lines and/or by heavily doped surface portions of the diamond layer. Undesirable reflections may be reduced by providing the piezoelectric layer with opposing ends canted at an angle from orthogonal to the axis of surface acoustic wave propagation. The surface acoustic wave device may be used as a filter, amplifier, convolver, and phase shifter. Methods for making the surface acoustic wave device are also disclosed.

Abstract: Moisture corrosive gas stream is measured as a function of the difference in resonant frequencies between two acoustic wave (AW) devices, each with a film which accepts at least one of the components of the gas stream. One AW is located in the gas stream while the other is located outside the gas stream but in the same thermal environment. In one embodiment, the film is a hydrophilic material such as SiO.sub.2. In another embodiment, the SiO.sub.2 is covered with another film which is impermeable to the corrosive gas, such that the AW device in the gas stream measures only the water vapor. In yet another embodiment, the film comprises polyethylene oxide which is hydrophobic and measures only the partial pressure of the corrosive gas. Other embodiments allow for compensation of drift in the system.

Abstract: A surface acoustic wave device (100), includes a piezoelectric substrate (105) having a surface acoustic wave structure with an acoustic region (130). An acoustic element (115) disposed in a portion (110) of the acoustic region (130), has a different mass loading than an acoustic element (122) disposed in another portion (120) of the acoustic region (130).

Abstract: A surface acoustic wave device for propagating a surface acoustic wave having input and output transducers and a multistrip coupler formed on the surface of a substrate. The input and output transducers each have two opposite electrodes having a plurality of electrode fingers extending toward their opposites and meshing with the electrode fingers of their opposites. The multistrip coupler has strip lines of a configuration wherein portions of at least some of the coupler strip lines are more widely spaced from adjacent patterns than other portions of the coupler strip lines. The width of these more widely spaced portions of at least one of the coupler strip lines which are more widely spaced from adjacent patterns is made larger than the width of the other portions of the at least one coupler strip line to compensate for the thinning effect of the lithography process.

Abstract: A SAW device which includes at least, diamond, an LiNbO.sub.3 layer disposed on the diamond, and an IDT provided so as to contact the LiNbO.sub.3 layer; and utilizes SAW of an "n-th" mode (n=0, 1 or 2) having a wavelength of .lambda..sub.n (.mu.m), wherein a parameter of kh.sub.1 =2.pi.(t.sub.1 /.lambda..sub.n) is in a specific range provided that the thickness of the LiNbO.sub.3 layer is denoted by t.sub.1 (.mu.m).

Abstract: An orientational material including: diamond, and a ZnO film disposed on a surface of (111) orientational diamond provided by the diamond. Such an orientational material may suitably be used as a component for fabricating a surface acoustic wave device utilizing diamond.

Abstract: A SAW filter includes a first SAW resonator having a pair of terminals and a predetermined resonance frequency (f.sub.rp), the first SAW resonator being provided in a parallel arm of the SAW filter. A second SAW resonator has a pair of terminals and a predetermined resonance frequency (f.sub.rs) approximately equal to a predetermined antiresonance frequency of the first SAW resonator (f.sub.ap). The second SAW resonator is provided in a series arm of the SAW filter. An inductance element is connected in series to the first SAW resonator.

Abstract: In a SAW filter, first and second geometrically parallel two-port SAW resonators, each operable in triple longitudinal modes having first through third resonance peaks in a descending frequency order, are electrically parallel connected on a piezoelectric substrate to have lower and higher frequency passbands with the first and the second resonance peaks of the lower frequency passband brought into substantial coincidence in frequency with the second and the third resonance peaks of the higher frequency passband.

Abstract: The invention concerns unidirectional ground-wave transducers using an alternating series of emitter cells (E) and reflector cells (R).The invention consists in using, in the emitter cells (E), fingers having a width of .lambda./3 spaced apart by a distance of 2 .lambda./3; and, in the reflector cells (R), fingers having a width of .lambda./4 spaced apart by a distance of .lambda./2.Using identical engraving precision, the invention makes it possible to increase by 50% the frequency at which the unidirectional transducer thus produced can be used.

Abstract: A SAW substrate is disclosed which can be adapted to a particular signal in multitude of signal possibilities. Each signal adaptation is made by connecting alternate electrodes of sequential tap transducers to either a positive bus or a negative bus, through auxiliary buses. A pair of the auxiliary buses is dedicated to each tap transducer, with one auxiliary bus in each pair being disposed adjacent to the positive bus and the other auxiliary bus in each pair being disposed adjacent to the negative bus. A pad is associated with each auxiliary bus for locating it adjacent to the positive bus or the negative bus which is not otherwise adjacent thereto. When a large number of signal possibilities are necessary, an unreasonably lengthy substrate is avoided by aligning the tap transducers in parallel channels across the substrate.