Abstract: Improved coupling coefficients and desirable filter characteristics are exhibited in a SAW filter including an electrode pattern deposited on a piezoelectric substrate bonded directly to an anti-reflective layer, wherein the anti-reflective layer is bonded to a carrier through an adhesive layer such that a preselected thickness of the anti-reflective layer is sufficient for enhancing an acoustic match between the piezoelectric substrate and the adhesive layer.

Abstract: An acoustic wave device includes electrodes carried on a surface of a piezoelectric material and an array of reflective obstacles such that elastic energy resulting from a piezoelectric effect is preferentially directed along a primary wave propagation path. The array of reflective obstacles are positioned generally parallel to the surface of the piezoelectric material and redirect acoustic waves typically reflected in other than a desirable direction to along a desired direction generally along the primary propagation path. The obstacles improve performance for SAW and BAW devices by effecting reflected energy and suppressing spurious modes.

Abstract: A SAW ladder filter includes grating pads extending from opposing bus bars and interdigital transducer electrodes extending from the grating pads for defining an acoustic aperture. The metalization ratio for the grating pads is greater than that for the interdigital transducer electrodes. Reflector electrodes are disposed on opposing longitudinal sides of the interdigital transducer electrodes. Operation of the filter results in a velocity of the SAW along the grating pads slower than a SAW velocity along the plurality of interdigital transducer electrodes, thus producing a wave guiding effect for optimizing SAW propagation within the acoustic aperture. The grating pads may be longitudinally offset from cooperating interdigital transducer electrodes using minor bus bars.

Abstract: A SAW device includes a LiNbO3 single crystal piezoelectric substrate having an orientation defined by Euler angles (?,?,?), with angle ? ranging from ?5° to +5°, angle ? ranging from about ?74° to about ?65°, and angle ? ranging from ?5° to +5°. Electrode patterns on a surface of the substrate form element resonators having a metallization ratio ranging from about 0.3 to about 0.8 and electrode thicknesses ranging from about 12% to about 17.5% of an acoustic wavelength of a strongly coupled non-leaky surface acoustic wave, excited on the surface of the substrate, if Al is used as electrode material, and in a range from about 6% to about 10% of an acoustic wavelength, if Cu is used as electrode material. Such orientations simultaneously combined with an optimized electromechanical coupling of spurious surface acoustic mode provide for improved performance in RF applications with a widened passband.

Abstract: A SAW filter includes a piezoelectric substrate of Lithium Niobate or optionally Lithium Tantalate having a thickness of at least twice an acoustic wavelength. The piezoelectric substrate is bonded to a surrogate substrate of a silicon material. The surrogate substrate is characterized by a resisitivity of at least 100 ohm-cm and an expansion coefficient compatible with the piezoelectric substrate. A catalytic bonding film between the piezoelectric substrate and the surrogate substrate is formed from a first catalytic bonding film deposited onto a surface of the piezoelectric substrate and a second catalytic bonding film deposited onto a surface of the surrogate substrate. The piezoelectric substrate is bonded to the surrogate substrate through a compression force sufficient for providing a bonding at a normal temperature.

Abstract: A SAW filter includes a piezoelectric substrate of Lithium Niobate or optionally Lithium Tantalate having a thickness of at least twice an acoustic wavelength. The piezoelectric substrate is bonded to a surrogate substrate of a silicon material. The surrogate substrate is characterized by a resisitivity of at least 100 ohm-cm and an expansion coefficient compatible with the piezoelectric substrate. A catalytic bonding film between the piezoelectric substrate and the surrogate substrate is formed from a first catalytic bonding film deposited onto a surface of the piezoelectric substrate and a second catalytic bonding film deposited onto a surface of the surrogate substrate. The piezoelectric substrate is bonded to the surrogate substrate through a compression force sufficient for providing a bonding at a normal temperature.

Abstract: A longitudinally coupled leaky surface acoustic wave (LSAW) resonator filter has a wide bandwidth, low insertion loss and return loss characteristics, and high power handling capability. The LSAW resonator filter includes a plurality of longitudinally coupled LSAW resonator tracks disposed upon a piezoelectric substrate and connected in series. The resonator tracks each include reflective gratings and interdigital transducers (IDTs) disposed end-to-end. Acoustic resonant cavities are formed between each IDT and its neighboring IDTs or gratings by chirping the fingers of the IDT in the vicinity of the cavities. Phase discontinuity is eliminated; reflective bulk acoustic wave scattering is reduced; and improved insertion loss and power handling capability are achieved.

Abstract: A SAW filter includes a piezoelectric substrate of a single crystal LiNbO3 and SAW resonators having an electrode thickness ranging from about 8% to about 9% of an acoustic wavelength of a high velocity SAW excited on the surface of the substrate. The piezoelectric substrate has an orientation defined by Euler angles (&lgr;, &mgr;, &thgr;), with angle &lgr; in a range from −5° to +5°, angle &mgr; in a range from about 75° to about 85°, and angle &thgr; in a range from 85° to 95°. A metalization ratio for the resonators ranges from about 0.3 to about 0.9, with resonators in a parallel arm of the filter having a metalization ratio from 1.1-1.4 times larger than the metalization ratio for resonators in the series arm of the filter. Such orientations simultaneously combined with an optimized electrode thickness and optimized metalization ratios provide an improved performance in RF applications.

Abstract: A hybrid leaky surface acoustic wave (LSAW) resonator filter has a wide bandwidth, low insertion loss and return loss, and excellent rejection of frequencies outside the passband, and includes one or more longitudinally coupled LSAW resonator filter tracks with chirp-type resonant cavities, reflective gratings, and a plurality of interdigital transducers (IDTs) disposed end-to-end therebetween. An acoustic resonant cavity is formed between each of the IDTs and its neighboring IDTs or gratings by chirping the fingers of the IDTs in the vicinity of the cavity. A one or more LSAW impedance element filters are disposed upon the same substrate and connected in series and/or shunt with the longitudinally coupled LSAW resonator tracks. The frequencies of the LSAW impedance-element filters are chosen such that their combination with the longitudinally coupled LSAW resonator filter tracks results in the formation of deep nulls in the overall transfer function at frequencies just outside of the passband.

Abstract: A SAW filter includes a piezoelectric substrate of Lithium Niobate or optionally Lithium Tantalate having a thickness of at least twice an acoustic wavelength. The piezoelectric substrate is bonded to a surrogate substrate of a silicon material. The surrogate substrate is characterized by a resisitivity of at least 100 ohm-cm and an expansion coefficient compatible with the piezoelectric substrate. A catalytic bonding film between the piezoelectric substrate and the surrogate substrate is formed from a first catalytic bonding film deposited onto a surface of the piezoelectric substrate and a second catalytic bonding film deposited onto a surface of the surrogate substrate. The piezoelectric substrate is bonded to the surrogate substrate through a compression force sufficient for providing a bonding at a normal temperature.

Abstract: A SAW filter includes a piezoelectric substrate of a single crystal LiNbO3 and SAW resonators having an electrode thickness ranging from about 8% to about 9% of an acoustic wavelength of a high velocity SAW excited on the surface of the substrate. The piezoelectric substrate has an orientation defined by Euler angles (&lgr;, &mgr;, &thgr;), with angle &lgr; in a range from −5° to +5°, angle &mgr; in a range from about 75° to about 85°, and angle &thgr; in a range from 85° to 95°. A metalization ratio for the resonators ranges from about 0.3 to about 0.9, with resonators in a parallel arm of the filter having a metalization ratio from 1.1-1.4 times larger than the metalization ratio for resonators in the series arm of the filter. Such orientations simultaneously combined with an optimized electrode thickness and optimized metalization ratios provide an improved performance in RF applications.

Abstract: A surface acoustic wave device includes a piezoelectric substrate of a single crystal LiNbO3 and an electrode pattern provided on a surface of the piezoelectric substrate which forms a resonator having an electrode thickness in a range of about 0.1% to about 8% of an acoustic wavelength of a surface acoustic wave excited on the surface of the substrate. The piezoelectric substrate has an orientation defined by Euler angles (&lgr;,&mgr;,&thgr;), with angle &lgr; in a range from −20° to +20°, angle &mgr; in a range from about −45° to about −10°, and angle &thgr; in a range from about (−1.16&lgr;−1.5)° to (−1.16&lgr;+1.5)°, wherein one of angle &lgr; and &thgr; is not equal to zero degrees. Such orientations simultaneously combined with an optimized propagation loss at resonant and anti-resonant frequencies provide for improved performance in RF applications.

Abstract: A surface-acoustic-wave die includes a generally rectangular die that comprises a piezoelectric material, atop which is positioned a surface-acoustic-wave electrode pattern. The pattern has a generally rectangular footprint, and the footprint has a top edge that is positioned at an acute, nonzero angle to a top end of the die. A pair of generally rectangular electrode pads are both in electrical contact with the electrode pattern, each pad adjacent diametrically opposed corners of the die. The device addresses the inefficiency in the conventional die layout technique, and provides a method for reducing the width of the die for SAW coupled resonator filters resulting in a smaller package.

Abstract: A surface acoustic wave device includes a piezoelectric substrate of a single crystal LiNbO3 and an electrode pattern provided on a surface of the piezoelectric substrate which forms a resonator having an electrode thickness in a range of about 0.1% to about 8% of an acoustic wavelength of a surface acoustic wave excited on the surface of the substrate. The piezoelectric substrate has an orientation defined by Euler angles (&lgr;,&mgr;,&thgr;), with angle &lgr; in a range from −20° to +20°, angle &mgr; in a range from about −45° to about −10°, and angle &thgr; in a range from about (−1.16&lgr;−1.5)° to (−1.16&lgr;+1.5)°, wherein one of angle &lgr; and &thgr; is not equal to zero degrees. Such orientations simultaneously combined with an optimized propagation loss at resonant and anti-resonant frequencies provide for improved performance in RF applications.

Abstract: A surface acoustic wave device includes a piezoelectric substrate of a single crystal LiTaO3 and an electrode pattern provided on a surface of the piezoelectric substrate which forms a resonator having an electrode thickness in a range of about 1% to about 15% of an acoustic wavelength of a surface acoustic wave excited on the surface of the substrate. The piezoelectric substrate has an orientation defined by Euler angles (&lgr;, &mgr;, &thgr;), with angle &lgr; in a range from −4° to +4°, angle &mgr; in a range from about −52° to about −36°, and angle &thgr; in a range from about (−1.365 &lgr;−4)° to (−1.365 &lgr;+4)°. Such orientations simultaneously combined with an optimized propagation loss at resonant and anti-resonant frequencies provide for improved performance in RF applications.

Abstract: A surface acoustic wave device includes a piezoelectric substrate of a single crystal LiTaO3 and an electrode pattern provided on a surface of the piezoelectric substrate which forms a resonator having an electrode thickness in a range of about 1% to about 15% of an acoustic wavelength of a surface acoustic wave excited on the surface of the substrate. The piezoelectric substrate has an orientation defined by Euler angles (&lgr;, &mgr;, &thgr;), with angle &lgr; in a range from −4° to +4°, angle &mgr; in a range from about −52° to about −36°, and angle &thgr; in a range from about (−1.365&lgr;−4)° to (−1.365&lgr;+4)°. Such orientations simultaneously combined with an optimized propagation loss at resonant and anti-resonant frequencies provide for improved performance in RF applications.

Abstract: A surface-acoustic-wave die includes a generally rectangular die that comprises a piezoelectric material, atop which is positioned a surface-acoustic-wave electrode pattern. The pattern has a generally rectangular footprint, and the footprint has a top edge that is positioned at an acute, nonzero angle to a top end of the die. A pair of generally rectangular electrode pads are both in electrical contact with the electrode pattern, each pad adjacent diametrically opposed corners of the die. The device addresses the inefficiency in the conventional die layout technique, and provides a method for reducing the width of the die for SAW coupled resonator filters resulting in a smaller package.

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 crystal-controlled oscillator circuit is modified by the present invention by replacing the crystal with the first signal port of a two-port SAW resonator filter that has a low-loss primarily inductive characteristic and taking the oscillation output from the other port of the filter to provide an oscillator frequency with harmonics that are reduced significantly when compared to the output of a crystal-controlled oscillator.

Abstract: A Lithium Tantalate crystal, defined by the Euler angles lambda (.lambda.) equal to about 0.degree. and mu (.mu.) equal to about 90.degree. with an acoustic wave propagation direction angle theta (.theta.) in the range of plus 130.degree. to plus 150.degree. and preferably equal to about plus 141.25.degree., offers unique properties for surface acoustic wave device applications.