Abstract: In embodiments, a piezoelectric acoustic wave (PBAW) device may include a substrate and a resonator comprising a plurality of electrodes coupled with the surface of the substrate. A dielectric overcoat may be disposed over the substrate and the resonator. In embodiments, and electrode in the resonator electrode may have a width that is based at least in part on a period of the resonator. By selecting the width of the electrode based at least in part on the period of the resonator, a spurious-mode of the passband of the PBAW device may be suppressed.

Abstract: In embodiments, a piezoelectric acoustic wave (PBAW) device may include a substrate and a resonator comprising a plurality of electrodes coupled with the surface of the substrate. A dielectric overcoat may be disposed over the substrate and the resonator. In embodiments, and electrode in the resonator electrode may have a width that is based at least in part on a period of the resonator. By selecting the width of the electrode based at least in part on the period of the resonator, a spurious-mode of the passband of the PBAW device may be suppressed.

Abstract: An elastic guided acoustic wave coupling resonator filter includes a dielectric layer interposed between piezoelectric substrates, with interdigital transducers on each substrate generally positioned at an interface between the substrates and the dielectric layer. The interdigital transducers on one substrate are aligned with the transducers on the opposing substrate and include cascaded filter tracks. The cascaded orientation between the two filter tracks includes either a differential connection or a balanced connection. As a result, the interdigital transducers are electrically isolated yet acoustically coupled to each other.

Abstract: An acoustic wave device operable as a piston mode wave guide includes electrodes forming an interdigital transducer on a surface of the piezoelectric substrate, wherein each of the plurality of electrodes is defined as having a transversely extending center region and transversely opposing edge regions for guiding an acoustic wave longitudinally through the transducer. A Silicon Oxide overcoat covers the transducer and a Silicon Nitride layer covers the Silicon Oxide overcoat within only the center and edge regions. The thickness of the Silicon Nitride layer is sufficient for providing a frequency modification to the acoustic wave within the center region and is optimized with a positioning of a Titanium strip within each of the opposing edge regions. The Titanium strip reduces the acoustic wave velocity within the edge regions with the velocity in the edge regions being less than the wave velocity within the transducer center region.

Abstract: An acoustic wave device operable as a piston mode wave guide includes electrodes forming an interdigital transducer on a surface of the piezoelectric substrate, wherein each of the plurality of electrodes is defined as having a transversely extending center region and transversely opposing edge regions for guiding an acoustic wave longitudinally through the transducer. A Silicon Oxide overcoat covers the transducer and a Silicon Nitride layer covers the Silicon Oxide overcoat within only the center and edge regions. The thickness of the Silicon Nitride layer is sufficient for providing a frequency modification to the acoustic wave within the center region and is optimized with a positioning of a Titanium strip within each of the opposing edge regions. The Titanium strip reduces the acoustic wave velocity within the edge regions with the velocity in the edge regions being less than the wave velocity within the transducer center region.

Abstract: A piezoelectric boundary acoustic wave (PBAW) device includes a slotted dielectric body disposed over one surface of a piezoelectric body and electrodes forming an IDT at the interface between the piezoelectric body and the dielectric body. The thickness of the electrode is set so that the acoustic velocity of the boundary acoustic waves is less than acoustic waves propagating in the piezoelectric body.

Abstract: A SAW coupled resonator filter providing improved rejection outside the passband frequencies includes at least two filter tracks on a piezoelectric substrate with each track having a plurality of acoustically cascaded transducers disposed along a longitudinal axis of the filter track. At least one filter track includes signal pads driven in a differential mode or a balanced mode. The two tracks are electrically connected with crossover bridges crossing over connecting lines between the tracks such that voltages across the crossover bridges are approximately the same in magnitude but substantially out-of-phase. The connecting lines extend between opposing bus bars of split transducers within each of the filter tracks.

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: An interdigital transducer includes an edge gap length between ends of electrodes and the opposing busbar increased sufficiently for reducing or even eliminating tunneling effects through the gap. As a result, a wave velocity of the acoustic wave within the longitudinally extending edge regions is less than the wave velocity within the transducer center region, and the wave velocity within the opposing gap regions is greater than a velocity in the transducer center region, thus an essentially flat propagation mode results within the aperture of the transducer. A SAW transducer or a SAW resonator on a high coupling substrate will thus guide the energy in the transducer region without a need for apodization. Higher equivalent coupling factors as well as lower losses are obtained.

Abstract: An interdigital transducer includes an edge gap length between ends of electrodes and the opposing busbar increased sufficiently for reducing or even eliminating tunneling effects through the gap. As a result, a wave velocity of the acoustic wave within the longitudinally extending edge regions is less than the wave velocity within the transducer center region, and the wave velocity within the opposing gap regions is greater than a velocity in the transducer center region, thus an essentially flat propagation mode results within the aperture of the transducer. A SAW transducer or a SAW resonator on a high coupling substrate will thus guide the energy in the transducer region without a need for apodization. Higher equivalent coupling factors as well as lower losses are obtained.

Abstract: A SAW transducer includes a pair of opposing bus bars formed on a surface of a piezoelectric substrate with a plurality of interdigital electrodes extending from each of the opposing bus bars. A center region and opposing edge regions are formed, wherein each edge region is proximate each bus bar and includes free end portions of the electrodes such that a wave velocity in each edge region is substantially lower than a wave velocity in the bus bars and in the center region, and wherein electro-acoustic sources extend into the edge regions for providing a SAW transducer having the piezoelectrically excited strongest mode is a piston mode with an amplitude distribution generally flat across most of the resonator area.

Abstract: The invention relates to a remotely interrogable SAW (surface acoustic wave) temperature sensor comprising. At least two resonators (T1, saw, T2, saw) have transducers having interdigitated electrodes connected to control buses of design such that they have different characteristic operating frequencies. A first resonator has a first surface acoustic wave propagation direction, parallel to one of the axes of the substrate, and a second resonator has a surface acoustic wave propagation direction making a nonzero angle (?) with the propagation direction of the first resonator. The control buses of the second transducer are inclined at a nonzero angle (?) to the normal to the interdigitated electrodes of the second transducer so as to compensate for the power flow divergence of the acoustic waves along the second transducer.

Abstract: The invention relates to a remotely interrogable SAW (surface acoustic wave) temperature sensor comprising, on the surface of a quartz substrate cut along the direction Y? making an angle ? with the direction Y, at least two resonators (T1,SAW, T2,SAW) comprising transducers consisting of interdigitated electrodes connected to control buses of design such that they have different characteristic operating frequencies; and a first resonator having a first surface acoustic wave propagation direction, parallel to one of the axes of the substrate, and a second resonator having a surface acoustic wave propagation direction making a nonzero angle (0) with the propagation direction of the first resonator, characterized in that the control buses of the second transducer are inclined at a nonzero angle (?) to the normal to the interdigitated electrodes of said second transducer so as to compensate for the power flow divergence of the acoustic waves relative to the direction of propagation of the surface acoustic waves

Abstract: The invention relates to interfaces acoutics wave components made of lithium tantalate. Two substrate make up the filter have the same cut and the same crystal orientation, the invention gives the best cut angles in particular for optimizing the electromechanical coupling coefficient that determines the final performance characteristics of the component produced. Curves giving the variations of the coupling coefficient an the attenuation as a function of the cut angles and of the direction of propagation are provided. The values of the main acoustic characteristics of the component for these optimum cut angles are also given. The application of this type of device are, on the on hand, uses as a passive component such a resonator or a filter or a delay line, or as an integrated device, either in a measurement chain or in any array of devices operating according to the principle of recognition of the device by a phase code.

Abstract: The invention relates to interface acoustic wave components made of lithium tantalate. In the case in which the two substrates making up the filter have the same cut and the same crystal orientation, the invention gives the best cut angles in particular for optimizing the electromechanical coupling coefficient that determines the final performance characteristics of the component produced. Curves giving the variations of the coupling coefficient and the attenuation as a function of the cut angles and of the direction of propagation are provided. The values of the main acoustic characteristics of the component for these optimum cut angles are also given. The applications of this type of device are, on the one hand, uses as a passive component such a resonator or a filter or a delay line, or as an integrated device, either in a measurement chain or in an array of devices operating according to the principle of recognition of the device by a phase code.

Abstract: A filter with surface acoustic wave resonators using an equivalent electrical bridge structure to obtain a good form relationship, i.e., a relationship between the filter rejection band and its pass band. Bridge arms advantageously include the paralleling of several resonators, thereby not requiring additional electrical elements as in the background art which provides for the use of series-connected resonators. Particular implantation methods for preparing equivalent structures to paralleling several resonators are also disclosed.

Abstract: A low-loss surface acoustic wave filter on a quartz substrate with optimized cutting. A range of cutting angles and directions of propagation of the waves on the quartz substrate are defined, making it possible to obtain high coefficients of reflection of the electrodes used in the filter. The range of cutting angles and directions of propagation of the waves are decisive factors for the making of the filter.

Abstract: A surface acoustic wave filter having three acoustic pathways. The first acoustic pathway is made up of a first transducer including a first and second bonding pad and is arranged between two reflectors to form a first resonator. The second acoustic pathway is made of a second transducer including a third and fourth bonding pad and is arranged between two reflectors to form a second resonator. A third acoustic pathway is made of a third transducer including a fifth and sixth bonding pad and is arranged between two reflectors to produce a third resonator. Each bonding pad of the transducers is linked to a specified potential.

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: The disclosure relates to differential input/output surface acoustic wave devices with proximity coupling. The disclosed device comprises a whole number N of acoustic channels, where N is at least equal to two. The acoustic channels are coupled together by proximity. A first acoustic channel comprises at least one transducer separated into several parts electrically connected in parallel with one another to form a first differential port (E+) and a second differential port (E-). The polarities of the different parts of the transducer are chosen so that the first differential port (E+) and the second differential port (E-) are electrically symmetrical. Application in particular to surface acoustic wave filters for portable telephones.