Abstract: A method for producing a piezoelectric thin-film resonator includes forming a sacrificial layer on a substrate, performing a plasma treatment on the sacrificial layer so that the surface roughness (Ra) of end surface portions of the sacrificial layer is about 5 nm or less, forming a strip-shaped dielectric film so as to be continuously disposed on the surface of the substrate and the end surface portions and the principal surface of the sacrificial layer, forming a piezoelectric thin-film area including a lower electrode, an upper electrode, and a piezoelectric thin-film disposed therebetween so that a portion of the lower electrode and a portion of the upper electrode surface each other at an area on the dielectric film, the area being disposed on the upper portion of the sacrificial layer, and removing the sacrificial layer to form an air-gap between the substrate and the dielectric film.

Abstract: A composite electronic component provided is one with sufficient impact resistance. In this resonator 1, a capacitive element 3 has a projection 37 projecting outside a piezoelectric element 2, from a portion of the capacitive element 3 coinciding with a vibration region 2a. The projection 37 is provided on each of two sides of the capacitive element 3 in a direction substantially perpendicular to a longitudinal direction of the capacitive element 3. This causes the projections 37 of the capacitive element 3 to be buried in a mold resin 5, whereby the capacitive element 3 is sufficiently fixed to the mold resin 5 even if the mold resin 5 is provided with a vibration space 5a containing the vibration region 2a of the piezoelectric element 2. Therefore, an improvement is made in impact resistance of the resonator 1.

Abstract: A piezoelectric thin-film resonator includes a device substrate and a laminated body provided on the device substrate and composed of a lower electrode, an upper electrode and a piezoelectric film sandwiched between the lower and upper electrodes. The laminated body has a membrane portion in which the upper and lower electrodes overlap with each other through the piezoelectric film, and a gap has a dome shape being formed between the device substrate and the lower electrode and located below the membrane portion.

Abstract: The present invention relates to piezoelectric vibrators such as a resonator used as a timing element, discriminator, filter or the like, and fabricating methods thereof. The piezoelectric vibrators of the present invention may be fabricated by forming a piezoelectric body of piezoelectric sheets, of which the thickness is controlled, and simultaneously sintering the sheets along with cover layers, on which grooves are formed. Also, the piezoelectric vibrator of the present invention is fabricated by laminating the piezoelectric sheets, of which the thickness is controlled, providing internal electrodes between the sheets, and forming external electrodes insulated from the internal electrodes.

Abstract: An apparatus and method for measuring a target environmental variable (TEV) that employs a film-bulk acoustic resonator with motion plate. The film-bulk acoustic resonator (FBAR) includes an acoustic reflector formed in an FBAR wafer and a surface. A first electrode is formed on the surface of the acoustic reflector and has a surface. A piezoelectric layer is formed on the surface of the first electrode and has a surface. A second electrode is formed on the surface of the piezoelectric layer. A motion plate is suspended in space at a predetermined distance relative to the surface of the second electrode and is capacitively coupled to the FBAR.

Abstract: A piezoelectric vibrating element includes a main vibration section vibrating in a constant direction, an open edge formed at least at one edge among edges provided in a vibration direction of the main vibration section, an outer frame section formed so as to surround the main vibration section, and a junction section being disposed between the main vibration section excluding the open edge and the outer frame section, having groove parts being recessed with respect to both surfaces of the main vibration section and flat parts being substantially flush with the both surfaces of the main vibration section, and being formed so as to integrally connect the main vibration section with the outer frame section.

Abstract: The present invention provides a film bulk acoustic wave resonator (FBAR) filter that can keep the Q factor high. The FBAR filter comprises a first FBAR with a first resonant frequency and a second FBAR with a second resonant frequency, formed on a same substrate. The FBAR filter has such a structure that a first underlayer is formed between the substrate and a first bottom electrode layer and a second underlayer is formed between the substrate and a second bottom electrode layer, the first underlayer thickness being different from the second underlayer thickness.

Abstract: An energy trap piezoelectric resonator makes use of a harmonic wave in a thickness longitudinal vibration mode and can effectively suppress a spurious fundamental wave in a thickness longitudinal vibration mode without significantly suppressing the harmonic wave that is used for the resonator. The energy trap piezoelectric resonator has a first excitation electrode disposed at an upper surface of a piezoelectric substrate polarized in a thickness direction and a second excitation electrode disposed at a lower surface, and a floating electrode disposed at least one of the upper surface and/or the lower surface of the piezoelectric substrate so as to extend towards and away from the first excitation electrode with respect to a node of an electric potential distribution based on electric charges generated by the fundamental wave that is propagated when an energy trap vibration portion where the excitation electrodes oppose each other is excited.

Abstract: A method for fabricating an apparatus is disclosed. A substrate is provided and a seed layer is fabricated on the substrate. A thin-film resonator is fabricated on the substrate, the resonator including a portion of a bottom electrode layer and a portion of a top electrode layer. Then, at least one aligned opening is etched through the bottom electrode layer and the seed layer. Finally, at least one bonding pad is fabricated, the bonding pad extending through the aligned opening such that bonding pad contacts the substrate forming a Schottky diode.

Abstract: The present invention relates to a resonator structure, temperature compensation method and temperature control apparatus for controlling local temperature of a resonator structure. At least one heating element (55) is integrated on a substrate of the resonator structure, and a temperature control signal generated based on a stored temperature characteristic is applied to the at least one integrated heating element (55). Thereby, the at least one heating element (55) and an optional integrated sensing element can be provided very close to the resonator. It is thus possible to control or calibrate variations of sensing elements, heating elements and resonator out from every sample.

Abstract: Embodiments of an acoustically-coupled transformer have a first stacked bulk acoustic resonator (SBAR) and a second SBAR. Each of the SBARs has a lower film bulk acoustic resonator (FBAR) and an upper FBAR, and an acoustic decoupler between the FBARs. The upper FBAR is stacked atop the lower FBAR. Each FBAR has opposed planar electrodes and a piezoelectric element between the electrodes. The piezoelectric element is characterized by a c-axis. The c-axes of the piezoelectric elements of the lower FBARs are opposite in direction, and the c-axes of the piezoelectric elements of the upper FBARs are opposite in direction. The transformer additionally has a first electrical circuit connecting the lower FBAR of the first SBAR to the lower FBAR of the second SBAR, and a second electrical circuit connecting the upper FBAR of the first SBAR to the upper FBARs of the second SBAR.

Abstract: An apparatus comprises a signal source, a driver and an electro-mechanical transducer. The signal source is configured to output a haptic feedback signal. The driver is configured to receive the haptic feedback signal and output a drive signal. The electro-mechanical transducer is configured to receive the drive signal. The electro-mechanical transducer is configured to have a set of operational modes. Each operational mode from the set of operational modes has at least one resonant mode from a set of resonant modes.

Abstract: A piezoelectric thin-film resonator includes a lower electrode provided on a substrate, a piezoelectric thin film provided on the lower electrode, and an upper electrode provided on the piezoelectric thin film. A membrane region is defined by a region where the upper electrode and the lower electrode overlap each other to sandwich the piezoelectric thin film therebetween and has an elliptical shape, and the lower electrode is also provided at an outer side of the membrane region in a region in which neither an extraction electrode of the upper electrode nor an extraction electrode of the lower electrode is provided.

Abstract: A polymer bulk acoustic resonator that includes an active semiconductor layer, a first thin film electrode layer applied to the semiconductor layer, a thin film electro-active polymer layer applied to the first thin film electrode layer; and a second thin film electrode layer applied to the thin film electro-active polymer layer.

Abstract: Shielding cases each include a pair of opposed first surfaces with catching pieces protruding therefrom and a pair of second surfaces without catching pieces. A motherboard forms substrates each including a pair of opposed first side surfaces with catching grooves and a pair of second side surfaces without catching grooves when it is divided. The shielding cases are mounted on the motherboard such that the intervals A between the second surfaces of two adjacent shielding cases are equal to or less than the widths B of cutting allowances for cutting the motherboard. The motherboard is cut from the opposite side of a surface of the motherboard on which the shielding cases are mounted at predetermined positions where the second side surfaces are formed on each substrate. In this manner, the motherboard is divided into electronic components with shielding cases.

Abstract: An apparatus and method for detecting a target environmental variable (TEV). A first film-bulk acoustic resonator (FBAR) oscillator that includes a first FBAR with a first response to the target environmental variable generates a first frequency. A second film-bulk acoustic resonator (FBAR) oscillator that includes a second FBAR with a second response to the target environmental variable generates a second frequency. A circuit that is coupled to the first FBAR oscillator and the second FBAR oscillator determines the target environmental variable (e.g., changes in the TEV) based on the first frequency and the second frequency.

Abstract: The present invention relates to a film bulk acoustic wave device and a method of manufacturing the same, wherein comprising an acoustic reflective layer which is formed on a substrate by removing a sacrificial layer on the substrate and becomes an empty space; an oxidation protective film or etch protecting film which is formed in a pattern that divides a resonance region to form the acoustic reflective layer on the sacrificial layer; a thermal oxidation film which is formed by partially thermally oxidizing the sacrificial layer in an electrode region where the oxidation protective film or the etch protecting film is not formed; and a lower electrode, a piezoelectric thin film, and an upper electrode all of which are disposed on the thermal oxide. Further, the present invention is directed to a method of manufacturing the same.

Abstract: A piezoelectric thin-film resonator includes a film laminate formed on a device substrate, the film laminate including a lower electrode, a piezoelectric film provided on the device substrate and the lower electrode, and an upper electrode provided on the piezoelectric film. At least one of the upper and lower electrodes has an electrode leading portion that extends from an membrane in which the upper electrode overlaps with the lower electrode through the piezoelectric film and has a width narrower than that of the membrane.

Abstract: A piezoelectric/electrostrictive device is provided, including a pair of mutually opposing thin plate sections and a fixation section for supporting the thin plate sections. A piezoelectric/electrostrictive element is arranged on each of the thin plate sections. The piezoelectric/electrostrictive device also includes movable sections defined by at least first end portions of the thin plate sections and a material which is different from that of the thin plate section.

Abstract: A capacitive membrane ultrasonic transducer which includes a membrane supported by a substrate in which ultrasonic bulk waves at the frequency of operation of the transducers are suppressed by configuring the substrate and a method of suppressing the ultrasonic bulk waves.

Abstract: A bulk acoustic wave device includes: a bulk acoustic wave element including a piezoelectric layer formed on a substrate, a lower electrode contacting a lower surface of the piezoelectric layer, and an upper electrode contacting an upper surface of the piezoelectric layer and partially overlapping the lower electrode, a lower hollow section being formed between the substrate and the lower surface of the piezoelectric layer, a first through-hole reaching the lower hollow section being formed through the bulk acoustic wave element in a direction perpendicular to a surface of the piezoelectric layer; an upper hollow section forming layer forming an upper hollow section with the upper surface of the piezoelectric layer, a second through-hole reaching the upper hollow section being formed therethrough in a direction perpendicular to a surface thereof; and a sealing layer covering the upper hollow section forming layer and filling up the second through-hole.

Abstract: Aspects of the invention provide piezoelectric resonator element having a plurality of grooves for suppressing propagation of the thickness shear vibration from the center portion to the outer peripheral portion of the main surface being placed in enclosure-like shapes surrounding the center portion of at least one of the main surfaces.

Abstract: A packaging system for piezoelectric devices is provided that substantially reduces and avoids the deleterious effects of environmental vibrations and shocks with gas or fluid-filled chambers that drastically improve the resonator's ability to withstand unwanted disturbances and decrease or eliminate the attendant frequency shifts. The damped piezoelectric resonator packaging system combines a resonator package, a membrane and gas/fluid-filled chambers that dampen dynamic amplification of the resonator and firmly restrain the resonator within the packaging system. The selection of gas or fluid for the chamber depends upon variables such as the type of waves being propagated and interaction with the piezoelectric substrate.

Abstract: A piezoelectric thin-film resonator includes a substrate, a lower electrode provided on the substrate, a piezoelectric film provided on the lower electrode, and an upper electrode provided on the piezoelectric film so as to have a portion that overlaps the lower electrode across the piezoelectric film. At least a part of an outer end of the piezoelectric film is further in than an outer end of an opposing region in which the upper and lower electrodes overlap each other across the piezoelectric film.

Abstract: A filter includes piezoelectric thin-film resonators having a substrate, a lower electrode supported by the substrate, a piezoelectric film provided on the lower electrode, and an upper electrode provided on the piezoelectric film. At least one of the piezoelectric thin-film resonators has a portion in which the upper electrode overlaps the lower electrode across the piezoelectric film. The above portion has a shape different from shapes of corresponding portions of other piezoelectric thin-film resonators, so that a spurious component in the above at least one of the piezoelectric thin-film resonators occur at a frequency different from frequencies of spurious components that occur in the other piezoelectric thin-film resonators.

Abstract: Various frequency control devices and their methods of use are provided. In one aspect, a bulk acoustic wave (BAW) device may include a diamond layer disposed between piezoelectric layers, and a pair of electrodes coupled to the piezoelectric layers. In such a configuration, the pair of electrodes may be configured such that an electrical signal introduced across the pair of electrodes can generate an acoustic wave in the diamond layer as a result of movement in the piezoelectric layers. The pair of electrodes may be a pair of electrode layers, and the diamond layer and the two piezoelectric layers may be disposed at least partially therebetween.

Abstract: A piezoelectric thin-film resonator includes a first excitation electrode and a second excitation electrode, the first excitation electrode being disposed opposite the second excitation electrode; a piezoelectric thin film disposed between the first excitation electrode and the second excitation electrode; and a substrate supporting the first excitation electrode, the substrate being composed of a LiTaO3 single crystal or a LiNbO3 single crystal, the first excitation electrode including an acoustic reflecting layer, the acoustic reflecting layer containing (a) at least one epitaxially grown first sublayer being composed of a conducting material and having a relatively high acoustic impedance; and (b) at least one epitaxially grown second sublayer being composed of another conducting material and having a relatively low acoustic impedance.

Abstract: A piezoelectric resonator of the present invention is structured such that on a substrate 5 having a cavity 4 formed therein, a lower electrode 3, a piezoelectric body 1, a spurious component control layer 16, and an upper electrode 2 are formed in this order from bottom up. The spurious component control layer 16 is a layer for controlling a spurious frequency, and composed of, for example, a metallic material, a dielectric material, or a piezo electric material. By additionally providing the spurious component control layer 16, it is made possible to cause variation of the spurious frequency due to unwanted variation to become greater than variation in resonance frequency of the main resonance of the piezoelectric resonator. Thus, it is possible to realize a piezoelectric resonator having an admittance frequency response where no spurious component occurs between resonance frequency fr and antiresonance frequency fa.

Abstract: A piezoelectric resonator suitable for use in a high frequency band is provided, in which variation in the piezoelectric material is reduced, variation in performance is reduced, and production can be performed without the need for a polarization treatment step. In the piezoelectric resonator, a piezoelectric material made of a wurtzite structure compound crystal is disposed, the crystal epitaxially grown in such a way that a (1,1,?2,0) crystal face becomes parallel to a surface of the R-plane sapphire substrate having a (0,1,?1,2) crystal face parallel to the substrate surface, and a pair of excitation electrodes are disposed on a pair of principal surfaces opposite to each other in the thickness direction of the piezoelectric material in such a way that the pair of excitation electrodes sandwich the C plane which is a (0,0,0,1) crystal face perpendicular to the (1,1,?2,0) crystal face of the tabular piezoelectric material.

Abstract: A piezoelectric device of the present invention includes first and second piezoelectric resonators. The first piezoelectric resonator has a structure in which a cavity, a lower electrode, a piezoelectric layer, and an upper electrode are formed on a substrate. The second piezoelectric resonator has a structure in which a cavity, a lower electrode, a piezoelectric layer, and an upper electrode are formed on the substrate. A feature of the above-structure piezoelectric device is that the piezoelectric layers, have the same film thickness, and the depth of the cavity of the first piezoelectric resonator is different from the depth of the cavity of the second piezoelectric resonator.

Abstract: In the case where an ultraminiature piezoelectric substrate, which has a resonating portion formed by making a concavity by etching in the surface of the piezoelectric substrate made of an anisotropic crystal material, is mass-produced by batch operation using a large-area piezoelectric substrate wafer, an annular portion surrounding each concavity is formed sufficiently thick to prevent cracking from occurring when the wafer is severed.

Abstract: An acoustic resonator device includes a substrate, a first acoustic resonator and a second acoustic resonator. The first acoustic resonator is formed on the substrate, and has a first upper electrode, a first piezoelectric layer, and a first lower electrode layer, and resonates in a ?/4 mode at a first resonant frequency. The second acoustic resonator is formed on the substrate, and has a second upper electrode layer, a second piezoelectric layer, and a second lower electrode layer, and resonates in a ?/2 mode at a second resonant frequency different from the first frequency. In the acoustic resonator device, materials and thicknesses of the first lower electrode layer and the second lower electrode layer are common and substantially equal, and materials and thicknesses of the first piezoelectric layer and the second piezoelectric layer are common and substantially equal.

Abstract: A piezoelectric element of the present invention includes a substrate, a lower electrode layer, a piezoelectric layer, an upper electrode layer, a cavity portion formed below a piezoelectric vibrating portion, and at least two bridging portions. The at least two bridging portions are formed so as not to be line-symmetric with respect to any line segment traversing the piezoelectric vibrating portion and/or so as not to be point-symmetric with respect to any point in the piezoelectric vibrating portion in a projection of the piezoelectric vibrating portion in the laminating direction.

Abstract: A system having a harmonic frequency actuator system is provided including providing an actuator body, the actuator body having more than one set of fingers for generating a motion for a semi-rigid element, and attaching a high frequency actuator to the actuator body forming a harmonic frequency actuator to provide motion at predetermined frequency pairs.

Abstract: The present invention provides a voltage controlled oscillator comprising an thin film BAW resonator and a variable capacitor element. The thin film BAW resonator includes an anchor section formed on a Si substrate, a lower electrode supported on the anchor section and positioned to face the Si substrate, a first piezoelectric film formed on the lower electrode, and an upper electrode formed on the first piezoelectric film. On the other hand, the variable capacitor element includes a stationary electrode formed on a Si substrate, an anchor section formed on the Si substrate, a first electrode supported on the anchor section and positioned to face the Si substrate, a second piezoelectric film formed on the first electrode, and a second electrode formed on the second piezoelectric film.

Abstract: A film bulk acoustic resonator, and a method for manufacturing the same. The film bulk acoustic resonator includes a substrate, a protection layer vapor-deposited on the substrate, a membrane vapor-deposited on the protection layer and at a predetermined distance from an upper side of the substrate, and a laminated resonance part vapor-deposited on the membrane. Further, the manufacturing method includes vapor-depositing a membrane on a substrate, forming protection layers on both sides of the membrane, vapor-depositing a laminated resonance part on the membrane, and forming an air gap by removing a part of the substrate disposed between the protection layers. Accordingly, the membrane can be formed in a simple structure and without stress, and the whole manufacturing process is simplified.

Abstract: A crystal unit for high frequency use includes: a crystal blank having a central portion that is used as a vibration region and a peripheral portion that surrounds the central portion and that is provided with a greater thickness than the central portion; a pair of excitation electrodes provided respectively on both major surface of the crystal blank in said vibration region; a pair of extending electrodes led out from the pair of excitation electrodes toward ends of the crystal blank, respectively; and an opposition region in which the extending electrodes overlap each other with the crystal blank interposed. Each of the extending electrodes connects to a corresponding excitation electrode over at least half of the outer circumference of the excitation electrode, and the thickness of the crystal blank is greater in the opposition region than in the vibration region.

Abstract: A ladder-type film bulk acoustic resonator (FBAR) filter comprises two series FBARs and two parallel FBARs. Each FBAR has a top electrode, a bottom electrode, and a piezoelectric layer sandwiched between the top and bottom electrodes. The top electrodes of the two series FBARs form part of a signal line of a coplanar waveguide transmission line. The top electrodes of the two series FBARs are connected to associated circuitry. The two series FBARs have a common bottom electrode.

Abstract: A method for adjusting a frequency characteristic of an edge reflection type surface acoustic wave device includes the step of obtaining a frequency characteristic of an edge reflection type surface acoustic wave device having a piezoelectric substrate. The edge reflection type surface acoustic wave device has a pair of edges of the piezoelectric substrate which define a predetermined distance therebetween. The piezoelectric substrate is cut at a position which defines a distance that is shorter than the predetermined distance when a final frequency characteristic of the edge reflection type surface acoustic wave device is to be higher than the obtained frequency characteristic. The piezoelectric substrate is cut at a position which defines a distance that is longer than the predetermined distance when a final frequency characteristic of the edge reflection type surface acoustic wave device is to be lower than the obtained frequency characteristic.

Abstract: Thin film bulk acoustic wave sensors with coatings of biological and chemical materials, multiple electrode depositions and a piezo-active thin film transducer layer are hosted on a substrate. The thin film bulk acoustic wave sensor suite, or T-BASS, produces a low-voltage, IC-compliant thickness-directed electric field that is substantially uniform over a substantial portion of the active area of the BAW structure. The BAWs produced are essentially extensional plane waves propagating away from the substrate surface and having phase progression substantially oblique to the substrate surface. For BAW applications requiring sensing by an active layer, it would be most desirable to have an electrode structure that is both IC-compliant and can be energized from a low-voltage source of electrical energy. The thin film BAW sensors are compatible with IC fabrication and processing techniques, such as photolithography. Both single channel and multiple channel thin film bulk acoustic wave sensors are provided.

Abstract: An insulating film including an aluminum nitride film is provided on a support substrate to be supported thereby. Then, a lower electrode, a piezoelectric thin film, and an upper electrode are provided in that order on the aluminum nitride film. The piezoelectric film is disposed between the lower electrode and the upper electrode which oppose each other. Furthermore, the aluminum nitride film is subjected to a plasma treatment in an oxygen-containing atmosphere to form an oxide layer on the aluminum nitride film, the oxide layer being made smoother than the aluminum nitride film.

Abstract: An electronic component (1) includes a substrate (2) and at least two piezoelectric resonators (3, 4) each having an active element (6, 9), a lower electrode (5, 8) and an upper electrode (7, 10). The lower electrode (5) of the first resonator (3) is made of a material that is different from that of the lower electrode (8) of the second resonator (4) such that the resonators exhibit different resonance frequencies.

Abstract: A process for manufacturing a resonator including the steps of: forming on an insulating substrate a first portion of a conductive material and a second portion of another material on the first portion; forming an insulating layer having its upper surface flush with the upper part of the second portion; forming by a succession of depositions and etchings a beam of a conductive material above the second portion, the beam ends being on the insulating layer on either side of the second portion, the upper surface of the second portion being exposed on either side of the beam, a third portion of a piezoelectric material on the beam and a fourth portion of a conductive material on the third portion above the beam portion located above the second portion; and removing the second portion.

Abstract: A film bulk acoustic wave resonator of the invention includes a substrate; a resonant structure provided on the substrate constituted by a lower electrode, a piezoelectric film and an upper electrode; and an acoustic multilayer of a plurality of reflective films provided between the substrate and the resonant structure. At least one of the reflective films of the acoustic multilayer has a specified crystal plane orientation, and an X-ray rocking curve full width at half maximum that is preferably not greater than 10 degrees, and more preferably is not greater than 3 degrees. This makes it possible to obtain better resonance characteristics than in the case of the prior art, by increasing the efficiency with which bulk waves propagating towards the substrate are reflected.

Abstract: An acceleration insensitive piezo-microresonator provides substantially reduced acceleration sensitivity with a plano—plano piezo-microresonator, upper gap and lower gap embedded in a rigid structural supporting member holding major surfaces of the piezo-microresonator firm and steady. The piezo-microresonator has neither electrodes on its surfaces nor contacts with any electrodes. Electrodes are doped regions incorporated into the support member. The upper and lower gaps are adjacent to the major surfaces of the piezo-microresonator, permitting it to vibrate freely. The support member surrounds and supports the plano—plano piezo-microresonator plate, upper gap and lower gap, maintaining a constant upper gap height and lower gap height. The electrodes provide a thickness-directed electrical field exciting the piezo-microresonator. A method of desensitizing a resonant frequency of a piezo-microresonator to acceleration stresses is also provided.

Abstract: A lead portion 10 is made of a rod-like metal conductor and has a step portion 13 at its end portion. A first side plate 11 and a second side plate 12 are formed by using thinned portions of the end portion of the lead portion 10. The first and second side plates 11 and 12 face each other with a distance. One end of the first side plate 11 and one end of the second side plate 12 are continued to each other while the other end of the first side plate 11 and the other end of the second side plate 12 form open end edges 111 and 121 respectively.

Abstract: A crystal unit comprises an AT-cut crystal blank, and an excitation electrode formed on each of opposing main surfaces of the crystal blank in an oscillation region of the crystal blank. The ratio b/a is 0.014 or less, and preferably 0.012 or less where a represents the thickness of the crystal blank in the oscillation region and b represents the thickness of the excitation electrode. The thickness a is typically 5 ?m or less.

Abstract: A reactance filter, which is constructed from BAW resonators, has at least one basic element that has a first resonator in a first branch and a second resonator in a second branch. In one branch, there is situated a resonator having a greater ratio of dynamic to static capacitance than in the second branch, so that a filter is obtained having a resulting passband in which one edge is set steeper than the other edge. The selection of the edge that is to be set steeply takes place through the allocation of the first branch to the serial or to the parallel branch.

Abstract: A piezoelectric/electrostrictive film-type device is provided which includes a ceramic substrate having a thin diaphragm portion and a peripheral thick portion, a lower electrode, an auxiliary electrode, a piezoelectric/electrostrictive film, and an upper electrode. The lower electrode, the auxiliary electrode, the piezoelectric/electrostrictive film, and the upper electrode are layered in that order on the ceramic substrate. The upper electrode has a length of 30 to 70% relative to the length of the thin diaphragm portion, and preferably has a width of 70% or more relative to the width of the thin diaphragm portion.

Abstract: A method and apparatus that converts energy provided by a chemical reaction into energy for charging a quantum well device. The disclosed apparatus comprises a catalyst layer that catalyzes a chemical reaction and captures hot electrons and hot phonons generated by the chemical reaction, and an interface layer placed between the catalyst layer and a quantum well. The interface layer facilitates the transfer of hot electrons and hot phonons from the catalyst layer into the quantum well layer. The interface layer can also convert hot electrons into hot phonons, and vice versa, depending upon the needs of the particular quantum well device. Because the hot electrons and the hot phonons are unstable and readily degrade into heat energy, the dimensions of the catalyst layer and the interface layer are very small. To improve the efficiency of the transfer of hot electrons and hot phonons to the quantum well, other interface layers, such as a catalyst interlayer and a catalyst interface, may be utilized.