Abstract: A surface acoustic wave device makes it possible to increase the electrode width without generating mass-electrical-loading and is capable of operating in a high-frequency band higher than or equal to the UHF band, and this surface acoustic way device may be used in a communication device to eliminate need for any down-converter which is indispensable to the conventional high-frequency communication device, and which is therefore capable of being manufactured at a reduced cost. The surface acoustic wave device is provided with an electrode structure meeting conditions represented by: s+m=(2n+1)L/(4k), where L is electrode period, not taking into consideration the polarity of an interdigital transducer, m is electrode line width, s is minimum electrode gap width, and n and k are natural numbers. The surface acoustic wave device is used as the demodulator of the communication device.

Abstract: A piezoelectric substrate (120) and a method for preparing same. The method includes steps of (i) providing a boule of piezoelectric material, (ii) orienting the boule to Euler angles chosen to provide a boundary condition matched to a partially-metallized surface and (iii) sawing the boule into at least a first slice (120) having first and second surfaces, at least one of the first and second surfaces comprising a planar surface. The method desirably but not essentially further includes steps of (iv) polishing at least one of the first and second surfaces to provide a substantially planar polished surface, (v) disposing a layer of metal on the at least one of the first and second surfaces and (vi) patterning the layer of metal to provide at least one interdigitated pattern (105, 110) comprising an acoustic wave transducer (105, 110), the acoustic wave transducer (105, 110) providing the boundary condition matched to a partially-metallized surface.

Abstract: A surface wave device comprises first and second SPUDT (single phase unidirectional transducer) resonator filters each comprising first and second transducers, which are preferably RSPUDTs (resonant SPUDTs), the resonator filters being the same except that one transducer of the second resonator filter is a mirror image of the corresponding transducer of the first resonator filter to provide a phase difference of 180.degree.. The surface wave device serves as a balun by having an unbalanced signal connection to the first transducers, and a balanced signal connection comprising signal connections to the second transducer of each of the first and second resonator filters. The resonator filters can be arranged side by side on a common piezoelectric substrate.

Abstract: 36.degree. -rotated Y-cut X-propagation lithium niobate substrate (LiNbO.sub.3) was used as a piezoelectric substrate to compose a surface acoustic wave filter and is connected with a dielectric filter in series. The dielectric filter having a sign of the frequency temperature characteristic which is opposite to that of the surface acoustic wave filter was used. Accordingly, a high frequency filter, comprising a surface acoustic filter and a dielectric filter connected in series, which can secure sufficient attenuation without an increase in the insertion loss within the band can be provided.

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: A surface acoustic wave device includes a piezoelectric substrate, an interdigital electrode pattern, and a resistor thin film. The piezoelectric substrate has a piezoelectric effect. The interdigital electrode pattern is made of a conductive thin film and formed on the piezoelectric substrate to perform conversion between an electrical signal and a surface acoustic wave. The resistor thin film is formed on the piezoelectric substrate to electrically connect the piezoelectric substrate to the interdigital electrode pattern. The resistor thin film serves to remove charges from a surface of the piezoelectric substrate due to a pyroelectric effect to the interdigital electrode pattern.

Abstract: A surface acoustic wave filter comprises a first electrode structure array which is formed on the piezoelectric substrate, and includes an input/output IDT, two receipt IDTs formed outside the input/output IDT and two reflectors formed outside the two receipt IDTs, and a second electrode structure array which is formed on the piezoelectric substrate and includes an input/output IDT, two receipt IDTs formed outside the input/output IDT and two reflectors formed outside the two receipt IDTs, which are concatenated with each other. In a case that the surface acoustic wave filter is represented by a symmetrical lattice-type circuit which is expressed by a serial arm impedance and a parallel arm impedance and is electrically equivalent to the same, at least two resonances of the serial arm impedance and at least three resonances of the parallel arm impedance are used to form a passband. The surface acoustic wave filter can have wide bands and low spurious signal.

Abstract: A longitudinal coupling type SAW resonator filter achieves improved selectivity without increasing the insertion loss and is constructed so as to be more easily mass-produced. The longitudinal coupling type SAW resonator filter has a piezoelectric substrate and first, second and third sets of interdigital electrodes each including a pair of comb electrodes disposed on the piezoelectric substrate. A pair of reflectors are located on the opposite sides in the surface wave propagation direction of the area in which the first to third sets of interdigital electrodes are disposed. The distance between the centers of adjacent electrode fingers of the first and second sets of interdigital electrode and the distance between the centers of adjacent electrode fingers of the first and third sets of interdigital electrode are set to different values.

Abstract: A dual-function converter, particularly for a dual filter, suitable as a channel filter for double-standard input signals in television sets. Only a single input converter is disposed on the substrate chip, and it has two inputs. The filter configuration of the converter includes interdigital adaptation regions, which are connected in terms of potential to suit whichever of the input signals is selected.

Abstract: A surface acoustic wave device which not only is low-loss in a pass band and has high attenuation in an attenuation region but also has superior power-resistance and has a large reflection coefficient in a blocking region comprises a first one-port SAW resonator filter connected in parallel with a three-electrode vertically connected double mode SAW resonator filter. The first one-port SAW resonator filter is so constructed that its resonance frequency is outside the pass band of the vertically connected double mode SAW resonator filter on the low-frequency side thereof and a connection point between the double mode SAW resonator filter and the first one-port SAW resonator filter is provided to an input terminal.

Abstract: In a resonator type surface acoustic wave filter, a fundamental mode of a mode to distribute in a direction perpendicular to propagating direction of a surface acoustic wave (hereinafter referred to as transverse mode) becomes a primary response, whereas a transverse secondary mode becomes spurious. In case of the surface acoustic wave device formed on a piezoelectric substrate having smaller electromechanical coupling factor of a quartz substrate or so forth, it is impossible to obtain sufficient restriction of the second mode spurious. This problem is solved by canceling electrical potential of transverse secondary mode and whereby restricting excitation with a resonator type surface acoustic device formed on a quartz substrate, in which a configuration of an interdigital electrode is selected to establish a ratio of an overlap width of an electrode finger versus an aperture width in a range greater than or equal to 0.75 to smaller than or equal to 0.85.

Abstract: An acoustic wave resonator filter (10) provides series and shunt resonator elements (22, 24) in a ladder network. The series elements (22) are configured in a lowpass configuration. The shunt elements (24) act as impedance inverters in a passband of the filter and they series resonate at an antiresonant frequency of the series elements (22) in a stopband which provides additional isolation. The electrodes (14) of the elements (22, 24) are of a metal thickness which improve the losses of a series resonant frequency in a passband which improves insertion loss. However, any increase in loss near the antiresonant frequency is compensated by the reduced loss near the resonant frequency of the shunt elements (24).

Abstract: An ultrasonic touch-position sensing device comprising a piezoelectric substrate, two surface acoustic wave transducing units X and Y, and a controlling system connected with the units X and Y. The unit X includes interdigital transducers T.sub.X and R.sub.X, and the unit Y includes interdigital transducers T.sub.Y and R.sub.Y on the upper end surface of the substrate. When an electric signal is applied to each of the interdigital transducers T.sub.X and T.sub.Y, a surface acoustic wave is excited on the upper end surface of the substrate. The surface acoustic wave excited by the interdigital transducer T.sub.X and that excited by the interdigital transducer T.sub.Y are transduced to electric signals E.sub.Xi (i=x, . . . , 2, 1, 0, -1, -2, . . . , -x) and E.sub.Yj (j=y, . . . , 2, 1, 0, -1, -2, . . . , -y), respectively. If touching a crossing point made from the position F.sub.Xx and F.sub.Yy, the electric signals E.sub.X-x and E.sub.Y-y are delivered from the interdigital transducers R.sub.X and R.sub.

Abstract: A first electrode structure row formed on a piezoelectric substrate, and including N1 pairs of an input/output IDT, N2 pairs of a connection IDT, and reflectors is cascade-connected to a second electrode structure row formed on the piezoelectric substrate, and including N1 pairs of an input/output IDT, N2 pairs of a connection IDT, and reflectors, the connection IDT of the first electrode structure row, and the connection IDT of the second electrode structure row being arranged electrically symmetric with respect to the cascade-connected plane. The pair number N1 of the input/output IDT is different from the pair number N2 of the connection IDT. When a normalized electrode film thickness of the input/output IDT and the connection IDT is represented by h/L, the pair number N1 of the input/output IDT satisfies the following formula43-11(h/L).ltoreq.N1.ltoreq.61-11(h/L).

Abstract: A surface acoustic wave filter according to the present invention has one or a plurality of filter functional units each comprising a series arm resonator and a parallel arm resonator. Each of the series arm resonator and the parallel arm resonator is constituted by a interdigital transducer and grating reflectors formed on a piezoelectric substrate composed of 64.degree.-rotated Y-cut X-propagating LiNbO.sub.3. The series arm resonator is constructed by electrically connecting a one-port resonator in series with a signal line, and the parallel arm resonator is constructed by electrically connecting a one-port resonator in parallel with the signal line. In the interdigital transducer in the series arm resonator and/or the parallel arm resonator, one or more sets of electrode fingers continuously adjacent to each other are formed.

Abstract: A surface acoustic wave position-sensing device comprising two surface acoustic wave transducing units, a nonpiezoelectric plate and a controlling system connected with the units. Each unit consists of two piezoelectric substrates, a first group of interdigital transducers (IDTs) and a second group of interdigital transducers (IDTs). The second group of the IDTs is placed such that the finger direction thereof is slanting to that of the first group of the IDTs by an angle .alpha.. The thickness of each piezoelectric substrate is smaller than an interdigital periodicity of the IDTs. The thickness of the nonpiezoelectric plate is larger than three times the interdigital periodicity. When an electric signal is applied to the first group of the IDTs, a SAW is excited in one of the piezoelectric substrates and transmitted to the other of the piezoelectric substrates through the upper end surface of the nonpiezoelectric plate.

Abstract: A surface acoustic wave device achieving improved insertion loss and fraction defective without lowering the TTE level includes an IDT electrode located on a piezoelectric substrate. The IDT electrode includes a solid electrode portion and a split electrode portion continuously formed at an end of the solid electrode portion in the propagating direction of a surface acoustic wave and having an electrode finger width of about .lambda./8 wherein .lambda. is the wavelength of the surface acoustic wave.

Abstract: A method and apparatus for preparing thin films, a device, an electronic and magnetic apparatus, an information recording and reproducing apparatus, an information processing apparatus and a crystal preparing method from the molten state. A thin film is prepared as the substrate or the surface of the substrate is being excited and characterized by a device having at least a substrate and a thin film with at least one layer prepared thereon and an electronic and magnetic apparatus having integration of the devices, wherein at least one layer of the thin film is prepared as the surface of the substrate is being excited. The recording and reproducing apparatus for recording and reproducing information is composed of an information memory medium device having a recording layer of the thin film prepared as the surface of the substrate is being excited and a recording head whose core is prepared as the surface of the substrate is being excited.

Abstract: A double-mode SAW filter of a longitudinally coupling type utilizing an SH-type surface wave, which is structured with first and second IDTs formed on said piezoelectric substrate to cause reflection of an SH-type surface wave between opposite two end faces, thereby creating a standing wave.

Abstract: A longitudinally coupled double mode surface wave resonator comprises two reflectors, two lateral IDTs (inter-digital transducers), and a centre IDT arranged on a surface of a piezoelectric substrate, for coupling surface waves longitudinally between the IDTs. The two lateral IDTs operate with opposite signal phases by virtue of opposite connections, opposite polarities, or oppositely phased spacings from the centre IDT. Alternatively, or in addition, the centre IDT is divided into two oppositely phased halves. A filter comprising one or more resonators can replace both a filter and a balun in a radio frequency circuit.

Abstract: A dual track, low signal loss surface acoustic wave filter includes tapered transducers and tapered reflectors within an axis of propagation for each track to achieve an improved pass band response associated with tapered transducers. The bandwidth of the filter is achieved by adjusting the taper of periodicity normal to the propagation axis. Each track includes reflector gratings mounted on the filter substrate for reflecting a surface acoustic wave propagating from a transducer mounted within each track back to the transducer. Input and output transducers are positioned between the reflectors within each track for providing a direct surface acoustic wave propagation path within the track between the transducers. Alternate parallel tracks have the reflector with an input transducer, and a reflector with an output transducers mounted in an offset alignment with a corresponding adjacent track reflector and transducer for constructively adding surface acoustic wave signals detected within the adjacent track.

Abstract: Selected transducer geometries including unbalanced split electrode and three electrode per wavelength structures are employed for use in wide band tapered SAW devices. Combining geometries useful in narrow bandwidth SAW filters for canceling reflected waves leading to triple transit interference, and electrode tapering useful in wide bandwidth SAW filters for permitting transduction of a wide range of surface acoustic wavelengths has the unexpected result of significantly reducing insertion loss and improving triple transit suppression over wider bandwidths than can be achieved with SPUDT designs on non-tapered devices. The interdigitized electrode fingers of opposing bus bars in the transducer have a tapered alignment wherein a period of electrode finger portions along an acoustic wave propagation axis decreases along a transducer dimension.

Abstract: A surface wave device filter comprises two 2-pole waveguide coupled double mode resonators (WCRs) electrically connected together in cascade. To permit narrowing of the filter passband for improved out-of-band rejection, e.g. for use of the filter as an intermediate frequency channel filter in a wireless communications system, while maintaining good matching for low ripple in the passband, a shunt capacitance is connected in parallel with the static capacitances of the two WCRs. The shunt capacitance is constituted by interdigital fingers provided on the same piezoelectric substrate as one or both of the WCRs, perpendicularly to the WCR fingers to avoid surface wave interference, conveniently in space otherwise used by rails of the WCRs, optionally with oppositely phased fingers to cancel surface waves generated by these fingers. A capacitance can be similarly provided on the same substrate as any other type of surface wave device.

Abstract: A SAW resonator filter apparatus includes attenuation characteristics which are steep in a frequency region from a pass band to a higher-frequency stop band without experiencing an increase in insertion losses and enlargement of the apparatus. First, second and third SAW resonator filters are disposed on a piezoelectric substrate and are connected in a cascade arrangement to each other. The first and third SAW resonator filters have interdigital electrodes formed of solid electrode fingers, while the second SAW resonator filter disposed between the first and third filters has interdigital electrodes formed of split electrode fingers. With this construction, the steep attenuation characteristics of the response in a higher frequency range appearing in the frequency characteristics of the second SAW resonator filter can be combined with the attenuation characteristics from the pass band to a higher-frequency stop band of the first and third SAW resonator filters.

Abstract: Surface acoustic wave (SAW) filter performance is enhanced using series-block weighting and line-width weighting combined for providing a transducer having a finely adjusted uniform weighting across the beam profile. Such a transducer permits practical transducer pairing within a surface acoustic wave filter, as well as use with transducers requiring uniform weighting, such as transducers employing apodized weighting. A three electrode per wavelength transducer electrode finger geometry includes line-width weighting for providing a fine weighting control to complement the inherently coarse weighting control of the series-block weighted transducer. Selected transducer geometries including three electrode per wavelength structures are employed for use in wide band tapered electrode finger SAW devices.

Abstract: Aluminum is used for the interdigital transducer mounted on a piezoelectric substrate to realize a surface acoustic wave transducer having a small capacity ratio, no spurious resonance, and a low loss. A .theta. rotated Y cut lithium niobate single crystal piezoelectric substrate is used for the piezoelectric material, a metal film of which principal ingredient is aluminum is used for the interdigital transducer, the direction of the interdigital transducer is made parallel to the X-axis of the lithium niobate single crystal, and thick h and electrode pitch P of the interdigital transducer have the following relationship:(.theta.+5).sup.2 /300+11/12.ltoreq.h/P.times.100-8.ltoreq.-0.0001.times.(.theta.+5).sup.3 +0.1625.times.(.theta.+5)+5.5and-30.ltoreq..theta..ltoreq.20.

Abstract: A matched filter has an input IDT and an output IDT, and also has a device for preventing propagating surface acoustic waves from diverging. By preventing the divergence of surface acoustic waves, signals obtained in units of electrode finger pairs of the output IDT are uniformed. Furthermore, this application also discloses the following arrangement. That is, an arrangement for converging surface acoustic waves is adopted, and the width of surface acoustic waves input to the output IDT is set to be larger than at least the crossing width of electrode fingers, nearest to the input IDT, of those of the output IDT, so that some surface acoustic waves propagate along non-crossing portions of the electrode fingers, on the input IDT side, of those of the output IDT. With this arrangement, the influence of the crossing portions of the electrode fingers, closer to the input IDT, on the surface acoustic waves input to the crossing portions of the electrode fingers, farther from the input IDT, can be relaxed.

Abstract: A method of manufacturing a surface wave device of an end-face reflection type comprising forming an IDT 12 on a piezoelectric plate 11, and cutting the piezoelectric plate 11 in a direction which is parallel to the outermost electrode fingers of the IDT within a target area which extends from the out edges of the outermost electrodes to a position .lambda./8 outwardly therefrom, .lambda. being the wavelength of the surface wave generated by the IDT, so as to form opposite end faces of the surface wave device.

Abstract: A surface acoustic wave position-sensing device comprising a piezoelectric substrate, a nonpiezoelectric plate, two surface acoustic wave transducing units and a controlling system connected with the units. Each unit consists of interdigital transducers (IDTs). The thickness of the piezoelectric substrate is larger than three time an interdigital periodicity of the IDTs. The thickness of the nonpiezoelectric plate is smaller than the interdigital periodicity. Each of the IDTs is placed such that the finger direction thereof is slanting to that of the IDTs by an angle .alpha.. When an electric signal is applied to each of the IDTs a SAW is excited on an area, and transmitted to an area, in contact with the IDTs of the upper end surface of the piezoelectric substrate through the nonpiezoelectric plate. The controlling system senses a touch with a finger by the generation of the electric signal at one of the interdigital transducers.

Abstract: An improved surface acoustic wave device that utilizes M electrodes per each N transduction length(s) of a transducer that produces a desired net internal distributed reflectivity in both magnitude and phase. Two of the transducers can be made placed on a single substrate and be unidirectional and caused to radiate towards each other to form a filter. A resonator, a delay line, or the like can also be formed.

Abstract: An end face reflection type surface wave resonator utilizing SH type surface waves capable of providing a plurality of resonance characteristics is formed as a single element. In the surface wave resonator, surface waves are reflected between two opposite end faces of a piezoelectric substrate. The surface wave resonator has IDTs that form first and second resonant units. The distance L between the two end faces is selected to be within a range expressed by (.lambda..sub.1 /2).times.N.sub.1 .+-.(.lambda..sub.1 /20) (N.sub.1 is an integral number) where .lambda.1 represents the wavelength of a surface wave excited by the first resonant unit. The distance L is chosen to be out of a range expressed by (.lambda..sub.2 /2).times.N.sub.2 .+-.(.lambda..sub.1 /20) (N.sub.2 is an integral number) where .lambda..sub.2 represents the wavelength of a surface wave excited by the second resonant unit.

Abstract: A method for making an acoustic wave device (500, 600, 701, 801, 901, 1001), and an acoustic wave device (500, 600, 701, 801, 901, 1001) made by the method. The method comprises steps of providing a substrate (11) capable of supporting acoustic wave propagation and disposing a first transducer (518, 518') thereon. Disposing the first transducer (518, 518') includes disposing first through fourth electrode groups on the substrate. The first group couples to a first electrical interconnection (17+). The second group couples to a second electrical interconnection (17-). The third group couples to a common electrical interconnection and is interleaved with the first group of electrodes. The fourth group couples to the common electrical interconnection and is interleaved with the second group.

Abstract: A cascaded surface wave device filter comprises two 2-pole surface wave device filters connected in cascade. The 2-pole filters each provide a balun function between balanced and unbalanced signal connections, and have either their unbalanced or their balanced signal connections interconnected in the cascade to reduce electromagnetic feedthrough and improve spurious mode suppression. The 2-pole filters are conveniently longitudinally coupled double mode surface wave resonators which are described, or transversely coupled double mode surface wave resonators. Higher order filters can be provided by connecting further 2-pole filters in the cascade. The cascaded filter is particularly useful for filtering at radio and intermediate frequencies in cellular radio equipment.

Abstract: A surface acoustic wave device including a piezoelectric substrate having NSPUDT behavior and a directionality reversed electrode structure including positive electrode, negative electrode and floating electrode. Positive and negative electrode fingers each having a width of .lambda./8 are arranged interdigitally at a pitch of .lambda. and floating electrode fingers having a width of 3 .lambda./8 are arranged between successive positive and negative fingers with an edge distance of .lambda./8. A directivity due to NSPUDT behavior of the substrate can be reversed. Positive and negative electrode fingers are arranged interdigitally at a pitch of .lambda. and between successive positive and negative electrode fingers are arranged floating electrode fingers having a reflecting coefficient different from that of the positive and negative electrodes.

Abstract: A surface acoustic wave (SAW) position-sensing device comprising a piezoelectric substrate, an input interdigital transducer (IDT) T formed on an upper end surface of the piezoelectric substrate, and an output IDT R formed on the upper end surface of the piezoelectric substrate such that the finger direction of the IDT R is slanting to that of the IDT T by an angle .alpha.. The thickness d of the piezoelectric substrate is larger than three times an interdigital periodicity P of the IDT T. An interdigital periodicity P.sub.N along the vertical direction to the finger direction of the IDT R is equal to the product of the interdigital periodicity P and cos .alpha.. An overlap length L.sub.P along the finger direction of the IDT R is equal to the product of an overlap length L of the T and sec .alpha.. When an electric signal is applied to the IDT T, the SAW is excited on the upper end surface of the piezoelectric substrate, and is transducer to electric signals E.sub.j with phases .theta..sub.

Abstract: An elastic wave position-sensing device comprising two elastic wave transducing units X and Y, a nonpiezoelectric plate, and a controlling system connected with the units X and Y. Each unit consists of a piezoelectric substrates P.sub.T and P.sub.R, interdigital transducers T.sub.0 and T.sub.i (i=1, 2, . . . , N) formed on one end surface of the piezoelectric substrate P.sub.T, interdigital transducers R.sub.0, R.sub.i1 and R.sub.i2 (i=1, 2, . . . , N) placed on one end surface of the piezoelectric substrate P.sub.R. Each of the interdigital transducers R.sub.i1 and R.sub.i2 is placed such that the finger direction thereof is slanting to that of the interdigital transducer T.sub.i by an angle .alpha.. The thickness d of the piezoelectric substrates P.sub.T and P.sub.R is smaller than an interdigital periodicity P of the interdigital transducers T.sub.0, T.sub.i and R.sub.0. The thickness of the nonpiezoelectric plate is smaller than two times the thickness d, the piezoelectric substrates P.sub.T and P.sub.

Abstract: A single-chip piezoelectric resonator using SH type surface waves has an interdigital transducer formed on a piezoelectric substrate. The interdigital transducer is designed to have two or more resonance characteristics, for example, by using a pair of thinned-out comb-shaped electrodes with mutually interlocking fingers protruding towards each other. Such an interdigital transducer may be formed also by using a pair of comb-shaped electrodes with the lengths of their mutually pointing fingers varied. A trap circuit with two sufficiently separated trap frequencies and improved attenuation characteristics at these two trap frequencies can be formed by forming two interdigital transducers of the kind described above on a single piezoelectric substrate so as to provide two resonant units each having two resonance characteristics. Alternatively, two piezoelectric resonators of the kind described above may be connected in parallel to provide two resonance characteristics.

Abstract: A surface acoustic wave device includes a piezoelectric substrate, first and second input transducers formed on the substrate and adapted for respectively generating surface acoustic waves corresponding to input signals, the first and second input transducers each having a shape to focus the surface acoustic waves generated thereby, an output transducer formed between the first and second input transducers on the substrate and adapted for obtaining a convolution -signal of the surface acoustic waves generated by the first and second input transducers, and conductive films, one formed between the first input transducer and the output transducer and another between the second input transducer and the output transducer on the substrate.

Abstract: Passive recognition tags are disclosed that function along with a transceiver and a processor in a system which identifies distant items. Each tag includes a SAW substrate on which sync and tap transducers are commonly connected between positive and negative buses across which an interrogating signal is applied through an antenna. In response to that signal, in phase identification code signals pass to the antenna from both the sync transducer and the tap transducers. Transducer spacing is minimized relative to acoustic reflection considerations by disposing the tap transducers in a plurality of channels which are aligned in parallel across the width of the substrate on both output sides of the sync transducer.

Abstract: A surface acoustic wave filter has pairs of interdigital transducers and reflectors formed on a 36.degree. Y-X LiTaO.sub.3 substrate, the reflectors sandwiching the interdigital transducers in between. The film thickness h of the electrode fingers of the interdigital transducers and the reflectors is such that 0.06.ltoreq.h/.lambda..ltoreq.0.01 where .lambda. is the wavelength of the surface acoustic wave adapted to be generated by the filter. The width-to-pitch ratio M/P of these electrode fingers for the interdigital transducers and the reflectors is such that M/P.gtoreq.0.6 in order to improve the shape factor of the filter.

Abstract: A resonator ladder surface acoustic wave (SAW) filter, which has a wide and flat pass band without spurious signals therein is provided. An input electrode, a serial arm SAW resonator, an output electrode, a parallel arm SAW resonator and a ground electrode are respectively formed on a 41.degree.-rotated Y-cut X-propagation lithium niobate substrate. The serial arm SAW resonator comprises a pair of interdigital transducers (IDTs) to excite SAW, one of which is connected to the input electrode. The output electrode is connected to the other IDT of the serial arm SAW resonator. The parallel arm SAW resonator comprises a pair of IDTs to excite SAW, one of which is connected to the output electrode. And the ground electrode is connected to the other IDT of the parallel arm SAW resonator. The IDTs are metal films of Al or Al-based alloy, and the thickness of the metal films ranges from 2.5% to 7.5% of the electrode cycle of the IDT of the parallel arm SAW resonator.

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 device using a quartz substrate has a larger electromechanical coupling coefficient than conventional devices. The SAW device is constructed by forming a thin ZnO film on a quartz substrate and disposing comb-like electrodes on the ZnO film.

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 surface wave resonator suitable for use in the frequency band range of about 70 to 200 MHz has a wide frequency band characteristic. The resonator is a free edge reflective-type surface wave resonator having a pair of comb-like electrodes formed on the upper surface of a piezoelectric substrate made of 41.degree. Y-cut X propagating piezoelectric single crystals of LiNbO.sub.3, wherein SH-type leaky waves are reflected between two opposing free edges of the resonator.

Abstract: A method for making an acoustic wave device. The method has steps of providing a substrate suitable for acoustic wave devices and processing the substrate to provide a patterned metallization thereon. The patterned metallization includes an acoustic wave filter pattern. The method also has steps of measuring a sheet resistance associated with the acoustic wave filter pattern, determining a resistance of a test pattern associated with the acoustic wave filter pattern to provide a measured resistance and computing an estimated average linewidth for the acoustic wave filter pattern from the measured resistance and the sheet resistance.

Abstract: An embodiment of a sensing apparatus includes an ultrasonic delay sensor having a delay related to the sensed quantity; and a time domain analysis circuit for recirculating pulses through the ultrasonic delay sensor or device and for generating the output signal related to the sensed quantity. In particular, the time domain analysis circuit may include a pulse generator for generating a series of input pulses to the ultrasonic delay sensor; a pulse detector for detecting a series of output pulses after propagation through the ultrasonic delay sensor; and a pulse recirculating circuit for causing the pulse generator to generate the series of input pulses based upon respective previously detected output pulses from the pulse detector. The apparatus also preferably includes circuits for suppressing the undesirable reflections generated by the ultrasonic delay sensor.

Abstract: A surface acoustic wave device including a substrate made of a lithium tetraborate single crystal (Li.sub.2 B.sub.4 O.sub.7) whose cut and propagating direction are determined such that Euler cut angles (.psi., .theta., .phi.) are .psi.=+5.degree..about.-5.degree., .theta.=9.degree..about.29.degree. and 32.degree..about.86.degree. and .phi.=85.degree..about.95.degree., and an electrode structure formed on a surface of the substrate to realize a natural single-phase unidirectional transducer property together with an anisotropy of said substrate. A lithium tetraborate substrate having cut angles of (0.degree., 51.degree., 90.degree.) shows an ideal NSPUDT and a lithium tetraborate substrate having cut angles of (0.degree., 78.degree., 90.degree.) reveals a zero temperature coefficient of delay. A directionality reversed electrode structure or a directionality corrected electrode structure may be advantageously used.

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 acousto-optic deflector device having a piezoelectric thin film and IDT formed on a substrate for deflecting a light by causing an SAW generated at an SAW generator region to interact with the light at a light waveguide region. The piezoelectric thin film is constructed of a first piezoelectric thin film having a relatively high resistance and a high piezoelectricity in the SAW generator region, and a second piezoelectric thin film having a smaller light propagation loss than the first piezoelectric thin film 3a in the light waveguide region.