696 results about "Piezoelectric resonators" patented technology

Piezoelectric resonators utilizing a differentially offset reflector. One or more piezoelectric resonators are supported upon a substrate by one or more intervening layers of material, which intervening layers of material act as a reflector. The reflector isolates the resonators from the substrate. A portion of one or more of the intervening layers of material includes a differential layer of material, which differential layer shifts the resonant frequencies of the resonators that overlie the differential layer as compared with the resonant frequencies of those resonators that do not overlie the differential layer of material.

A piezoelectric resonator is disclosed. In one embodiment the piezoelectric resonator includes a resonating member having a bi-directionally adjustable resonance frequency, the resonating member including a semiconductor material of a semiconductor-on-insulator wafer, the semiconductor-on-insulator wafer including an oxide layer adjacent to the semiconductor material and a handle layer adjacent to the oxide layer, the oxide layer disposed between the handle layer and the semiconductor material, and electrode, and a piezoelectric material disposed between the semiconductor material and the electrode, and a capacitor created by the semiconductor material and the handle layer separated by an air gap formed out of the oxide layer, wherein the capacitor is configured to receive a direct current voltage that adjusts the resonance frequency of the resonating member.

The layer of the cover electrode, or an additional layer on the cover electrode is formed with holes, preferably produced lithographically, or similar structures. The structures have a mean spacing from one another which is smaller than the wavelength for operating the component. The structures are preferably distributed with a uniformity sufficient to effect a uniform change in the mass of the layer per area, thus producing a specific setting of the resonant frequency / frequencies, and are preferably, on the other hand, distributed so irregularly that diffraction effects are avoided.

Disclosed is a piezoelectric resonator, a process for the fabrication thereof and its use as a sensor element, which implemented in a through-flow cell, is integratable in a measurement system for the determination of the concentration of a substance contained in a liquid and / or for the determination of the physical properties of the liquid. The piezoelectric resonator is designed plane and is provided on its surface with electric contact areas for an electrode and a counter electrode, which is connectable to a signal source as well as to a measurement device. For measuring, the piezoelectric resonator is brought into contact with the to-be-examined liquid on one side, with the resonator responding to the accumulation of the mass of the to-be-detected substance or to a change in the physical properties of the liquid by changing its resonance frequency and / or oscillation amplitude.The present invention is distinguished by the fact that the piezoelectric resonator is provided with contact electrode areas which is contactable from one single side of the resonator. The resonator is the heart piece of a sensor element, which is integrated in a through-flow cell. The through-flow cell us insertable module-like in a measurement arrangement for determining the concentration of a substance contained in a liquid and / or determining the physical properties of the liquid.

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.

A piezoelectric filter and other electronic components are constructed such that the accuracy of frequency adjustment can be increased and an improvement in efficiency of the adjustment operation can be achieved. The piezoelectric filter includes a plurality of piezoelectric resonators including a substrate and a vibration portion provided on the substrate, the vibration portion having a structure in which the top and bottom surfaces of a thin film portion including at least one piezoelectric thin film are sandwiched between at least a pair of an upper electrode and a lower electrode facing each other, wherein the upper electrode of a predetermined piezoelectric resonator is made of a material having susceptibility to etching that is different from that of the upper electrode of the other piezoelectric resonator.

A resonator device includes a piezoelectric resonator having a detuning layer sequence arranged on the piezoelectric resonator. The detuning layer sequence includes at least a first layer having a high acoustic impedance and a second layer having a low acoustic impedance.

A resonator apparatus has a piezoelectric resonator as well as an acoustic reflector which has a layer having a high acoustic impedance and a layer having a low acoustic impedance. The thickness of one layer is set different from a quarter of the wavelength in this layer at the operating frequency due to technological limitations in the manufacturing of this layer, and the thickness of the other layer is set dependent from the one layer, such that a predetermined minimum quality of the acoustic reflector is attained.

A thin film piezoelectric resonator includes a substrate having a cavity; a first electrode extending over the cavity; a piezoelectric film placed on the first electrode; and a second electrode placed on the piezoelectric film, the second electrode having a periphery partially overlapping on the cavity and tapered to have an inner angle of 30 degrees or smaller defined by a part of the periphery thereof and a bottom thereof.

A piezoelectric thin film resonator having a stabilized temperature characteristic of resonant frequency, a method for manufacturing the same, and a communication apparatus using the piezoelectric thin film resonator are provided. The piezoelectric thin film resonator is provided with a substrate having an opening, first and second insulation films which are provided on one surface of the substrate while covering the opening and which primarily include SiO2 and Al2O3, respectively, Al2O3 having oxygen defect and being in an amorphous state, and a piezoelectric thin film which is provided on the second insulation film and is sandwiched between electrodes and which primarily includes ZnO.

a thin film piezoelectric resonator includes a substrate having a cavity, and a resonance portion located on the substrate and right above the cavity. The resonance portion includes a lower electrode layer located at a side of the cavity, an upper electrode layer opposite to the lower electrode layer, and a piezoelectric thin film located between the upper electrode layer and the lower electrode layer. A side of the piezoelectric thin film and a side of the lower electrode layer are located in a common plane.

An array of piezoelectric resonators used in a sensor device in order to identify chemical and biological agents. The resonators can operate as bulk acoustic wave (BAW), surface acoustic wave (SAW), or Love mode devices. The sensor device integrates gravimetric, calorimetric, thermal gravimetric, voltage gravimetric and optical detection methods into one sensor system, improving the accuracy of identifying hazardous agents. For gravimetric detection, dual-mode resonators provide simultaneous calorimetric and gravimetric data, one type from each mode. Resonators with heaters on the surfaces will provide thermal gravimetric data. An optical detector can be used to analyze the optical signal from the surface of a coated resonator. Additionally, voltage gravimetric measurements can be made with an electric field set up between the resonator and an external electrode. Thermal voltage gravimetric measurements can be made by adding an integrated heater on the resonator with an external electrode. An alarm can be activated upon the identification of a hazardous agent. The sensor device can utilize other valuable information, including traceable time, GPS location, and variables related to temperature, humidity, air speed, and air direction.

A piezoelectric thin film of the present invention includes an aluminum nitride thin film that contains scandium. A content ratio of scandium in the aluminum nitride thin film is 0.5 atom % to 50 atom % on the assumption that a total amount of the number of scandium atoms and the number of aluminum atoms is 100 atom %. According to this arrangement, the piezoelectric thin film of the present invention can improve a piezoelectric response while keeping characteristics of elastic wave propagation speed, Q value, and frequency-temperature coefficient that the aluminum nitride thin film has.

A thin-film piezoelectric resonator including a piezoelectric thin film having piezoelectric characteristic, and an upper electrode and a lower electrode arranged on opposite surfaces of the piezoelectric thin film for applying an excitation voltage to the piezoelectric thin film, wherein: each of the upper electrode and the lower electrode includes a resonant portion, and a lead-out portion; and the electrode thickness of at least one part of the lead-out portion in at least one of the upper electrode and the lower electrode is larger than the electrode thickness of the resonant portion formed to be continued from the lead-out portion.

A piezoelectric resonator element includes: a base in a predetermined length, the base being made of a piezoelectric material; a plurality of resonating arms extending from a first end of the base; a joining part connected to a second end apart from the first end of the base by a predetermined distance; a connecting part connected to the joining part and extending in a width direction of the piezoelectric resonator element; a supporting arm connected to the connecting part and extending in a same direction as the resonating arm at an outer side of the plurality of resonating arms. A ratio L3 / h is 40% or less where h is a length dimension from the first end of the base to the second end opposite to the resonating arms of the piezoelectric resonator element, and L3 is a width dimension of the connecting part connecting the supporting arm to the base through the joining part.

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.

A piezoelectric thin film of the present invention includes an aluminum nitride thin film that contains scandium. A content ratio of scandium in the aluminum nitride thin film is 0.5 atom % to 50 atom % on the assumption that a total amount of the number of scandium atoms and the number of aluminum atoms is 100 atom %. According to this arrangement, the piezoelectric thin film of the present invention can improve a piezoelectric response while keeping characteristics of elastic wave propagation speed, Q value, and frequency-temperature coefficient that the aluminum nitride thin film has.

A thin film piezoelectric device includes a substrate (12) having via holes (22) and a piezoelectric laminated structure (14) consisting of a lower electrode (15), a piezoelectric film (16), and an upper electrode (17) formed on the substrate (12) via an insulation layer (13). A plurality of thin film piezoelectric resonators (210, 220) are formed for the via holes (22). The piezoelectric laminated structure (14) includes diaphragms (23) located to face the via holes (22) and a support area other than those. The thin film piezoelectric resonators (210, 220) are electrically connected by the lower electrode (15). When the straight line in the substrate plane passing through the centers (1, 2) of the diaphragms (23) of the thin film piezoelectric resonators (210, 220) has the length D1 of the segment passing through the support area and the distance between the centers of the diaphragms of the thin film piezoelectric resonators (210, 220) is D0,the ratio D1 / D0 is 0.1 to 0.5. The via hole (22) is fabricated by the deep graving type reactive ion etching method.

The piezoelectric resonator according to the invention includes a tuning fork shaped part with two parallel vibrating arms, connected to each other by a linking part, from which protrude a central arm located between both vibrating arms of the tuning fork shaped part, wherein at least one groove is formed on at least one of a front side and a rear side of each vibrating arm.

A thin film piezoelectric device includes a substrate (12) having via holes (22) and a piezoelectric laminated structure (14) consisting of a lower electrode (15), a piezoelectric film (16), and an upper electrode (17) formed on the substrate (12) via an insulation layer (13). A plurality of thin film piezoelectric resonators (210, 220) are formed for the via holes (22). The piezoelectric laminated structure (14) includes diaphragms (23) located to face the via holes (22) and a support area other than those. The thin film piezoelectric resonators (210, 220) are electrically connected by the lower electrode (15). When the straight line in the substrate plane passing through the centers (1, 2) of the diaphragms (23) of the thin film piezoelectric resonators (210, 220) has the length D1 of the segment passing through the support area and the distance between the centers of the diaphragms of the thin film piezoelectric resonators (210, 220) is D0,the ratio D1 / D0 is 0.1 to 0.5. The via hole (22) is fabricated by the deep graving type reactive ion etching method.

A thin-film piezoelectric resonator and method of fabrication that includes a barrier layer of material between the underlying electrode and a layer of piezoelectric material. For example, in a resonator that uses zinc oxide for the layer of piezoelectric material, a barrier layer of aluminum nitride is deposited upon an underlying aluminum electrode to protect the aluminum electrode from oxidation or structural deformation during the subsequent deposition of the piezoelectric layer of zinc oxide. The barrier layer of aluminum nitride is deposited in a manner so as to provide a substrate having a substantial degree of uniformity of crystal orientation upon which the layer of piezoelectric material may then be deposited in a manner such that the piezoelectric layer will, itself, also have a substantial degree of uniformity in the orientations of its crystals. The resonator includes a second electrode deposited upon the upper surface of the piezoelectric material or upon the upper surface of a second barrier layer of aluminum nitride that is deposited upon the upper surface of the piezoelectric layer.

A piezoelectric resonant LED driving circuit, wherein a rectifier is used to rectify an AC voltage provided by the supply main into a DC voltage. Then, a quasi-resonant switching module performs resonance by means of the DC voltage to produce an induced current, to raise resonance frequency to operation frequency of a piezoelectric oscillator. Finally, the piezoelectric oscillator performs resonance and filtering using the induced current, to generate a sine wave current. Then, the sine wave current is rectified to output a DC current to drive an LED module.

A piezoelectric resonator structure, comprising: (i) a substrate, (ii) an acoustic mirror, (iii) a first electrode, (iv) a piezoelectric layer, and (v) a second electrode, wherein each of the substrate, the acoustic mirror, the first electrode, the piezoelectric layer, and the second electrode has a top surface and a bottom surface, a first end portion and an opposite, second end portion, and a body portion defined therebetween, wherein the overlapped area of body portions of the substrate, the acoustic mirror, the first electrode, the piezoelectric layer and the second electrode is defined as an active area A. A plurality of air gaps and interference structures is formed at the first end portion of the piezoelectric layer and the second electrode, and the second end portion of the piezoelectric layer and the second electrode to enhance the performance of the piezoelectric resonator.