An analog to digital converter includes an error integration circuit configured to receive an input charge from a detector and to integrate a difference between the input charge and one or more feedback charge pulses to create an error voltage. A quantizer is in operable communication with the error integration circuit and is responsive to the created error voltage. An accumulator having a mantissa component and a radix component is in operable communication with the quantizer. A charge feedback device in operable communication with the quantizer and the radix component of the accumulator. The charge feedback device is configured to generate the one or more feedback charge pulses proportional to the radix component of the accumulator and an output of the quantizer. Digital focal plane read out integrated circuits including the analog to digital converter are also disclosed.

The disclosure relates to a circuit for stabilizing a digital-to-analog converter reference voltage. One example embodiment is a circuit for stabilizing a voltage on a reference node. The circuit includes a digital-to-analog converter that includes an array of capacitors and arranged for: receiving an input voltage via an input node, receiving a voltage via a reference node and a digital-to-analog code via a controller node, and outputting a digital-to-analog output voltage. The circuit also includes a capacitive network on the reference node comprising a fixed capacitor arranged to be pre-charged to an external reference voltage and a variable capacitor arranged to be pre-charged to an external auxiliary voltage. Further, the circuit includes a measurement block. In addition, the circuit includes a calibration block arranged for determining an updated setting of the variable capacitor based on the digital-to-analog code and the measured voltage on the reference node.

For continuous-time multi-stage noise shaping analog to digital converters (CT MASH ADCs), quantization noise cancellation often requires estimation of transfer functions, e.g., a noise transfer function of the front end modulator. To estimate the noise transfer function, a dither signal can be injected in the front end modulator. However, it is not trivial how the dither signal can be injected, since the dither signal can potentially leak to the back end modulator and cause overall noise degradation. To address some of these issues, the dither signal is injected post the flash analog to digital converter (ADC) of the front end modulator. Furthermore, dummy comparator structures can be used to synchronize the dither with the quantization noise of the targeted flash ADC.

A circuit and a method for converting an analog signal to a digital value representation is disclosed. In one aspect, the circuit includes an incremental sigma-delta analog-to-digital converter (ADC). The circuit further includes a first input line for providing a primary analog signal representing a sensor measurement to the incremental sigma-delta ADC. The circuit further includes a second input line for providing a secondary analog signal to the incremental sigma-delta ADC. The incremental sigma-delta ADC receives the primary and secondary analog signals during a first period (TADC1) and a second period (TADC2), respectively. The circuit further includes a filter configured to weight the digital values in a sequence of digital values output by the incremental sigma-delta ADC, and to output a single digital value representing the sensor measurement.

A remote control for a wireless load control system, the remote control comprising: a housing having a front surface and an outer periphery defined by a length and a width; an actuator provided at the front surface of the housing; a wireless transmitter contained within the housing; and a controller contained within the housing and coupled to the wireless transmitter for causing transmission of a wireless signal in response to an actuation of the actuator, the wireless transmitter and the controller adapted to be powered by a battery contained within the housing; wherein the length and the width of the housing are slightly smaller than a length and a width of a standard opening of a faceplate, respectively, such that the outer periphery of the housing is adapted to be received within the standard opening of the faceplate when the housing and the faceplate are mounted to a vertical surface.

The present disclosure pertains to systems and methods for monitoring a plurality of analog-to-digital converters. In one embodiment, a plurality of input channels may each be in communication with a different phase of a three-phase electric power delivery system. The input channels may be configured to receive analog signals from the different phases. A composite signal subsystem may be configured to generate a composite signal based on the plurality of input channels. An analog-to-digital converter subsystem may be configured to produce a digitized representation of each of the plurality of input channels and a digitized representation of the composite signal. An analog-to-digital converter monitor subsystem may identify an error in the analog-to-digital conversion based on the digitized representation of the composite signal and the digitized representations of the plurality of input channels.

A semiconductor device having an analog/digital conversion circuit converting an analog signal to a digital signal, includes a holding circuit outputting an analog signal having a value according to a value of an analog signal supplied in a first period; and a prediction circuit generating a first digital signal based on bit position information from a prediction table corresponding to the supplied analog signal.

System and methods for input path matching in pipelined continuous-time Analog-to Digital Converters (ADCs), including pipelined Continuous-Time Delta Sigma Modulator (CTDSM) based ADCs, includes an input delay circuit disposed in a continuous-time input path from an input of an analog input signal to a first summing circuit of the continuous-time ADC. At least one digital delay line is disposed between an output of an earlier stage sub-ADC (of a plurality of pipelined sub-ADCs) and a sub-digital-to-analog converter (DAC) that is coupled to the first summing circuit, and between the earlier stage sub-ADC and a digital noise cancellation filter. The digital delay line(s) is configured to enable calibration of delay of output of the earlier stage sub-ADC provided to the sub-DAC and the digital noise cancellation filter in accordance with process variations of the input delay match circuit to minimize residue output at first summing circuit.

A system of systems to monitor data for carbon flux, for example, at scales capable of managing regional net carbon flux and pricing carbon financial instruments is disclosed. The system of systems can monitor carbon flux in forests, soils, agricultural areas, body of waters, flue gases, and the like. The system includes a means to identify and quantify sources of carbon based on simultaneous measurement of isotopologues of carbon dioxide, for example, industrial, agricultural or natural sources, offering integration of same in time and space. Carbon standards are employed at multiple scales to ensure harmonization of data and carbon financial instruments.

A liquid separator system having a gas phase zone, an aqueous phase zone and a denser liquid zone is used to separate mixtures of fluids. The separator can be used for separating molten sulfur from liquid redox solution or reslurry water. The system includes a vessel with a top part and a bottom part. The vessel has a larger diameter at the top part than at the bottom part. The system also includes an inlet for introducing a redox solution or reslurry water and molten sulfur, which is denser than redox solution or reslurry water, into the vessel. An outlet near the bottom part of the vessel allows a flow of the molten sulfur from the vessel. An interface control structure senses an interface level between the redox solution or reslurry water and the molten sulfur, and the interface control structure controls the flow of molten sulfur from the outlet. The interface control structure is adjusted to optimally alter the vertical height of the interface level within the vessel so that the residence time of the molten sulfur in the vessel does not decrease as the sulfur production throughput decreases, and so that the interface area of the molten sulfur and the redox solution is reduced as the sulfur throughput decreases. A pressure controller monitors the pressure in the vessel and adds or removes gas from a gas phase zone in the vessel to maintain a predetermined pressure regardless of the vertical height of the interface.

Method for producing a uranium concentrate in the form of solid particles, by precipitation from a uranium-containing solution using a precipitating agent, in a vertical reactor comprising a base, a top, a central part, an upper part, and a lower part, the solid particles of the uranium concentrate forming a fluidized bed under the action of a rising liquid current which circulates from the base towards the top of the reactor successively passing through the lower part, the central part and the upper part of the reactor, and which is created by introducing a liquid recycling current (flow) at the base of the reactor, said liquid recycling current being tapped at a first determined level (A) in the upper part of the reactor and sent back without settling to the base of the reactor, excess liquid being also evacuated via an overflow located at a second determined level (B) in the upper part of the reactor; a method in which the upper limit (C) of the fluidized bed of solid particles is controlled so that it is positioned at a level below the first and second determined levels.

The present invention relates to a process for the wet production of granules from powdered materials, in particular raw materials for the production of glass. The process of the invention comprises the following successive steps: (i) the powdered materials to be granulated are divided into at least two portions: a first portion and a second portion; (ii) a binder liquid is added to the first portion of powdered materials; (iii) the first mixture thus obtained is agglomerated in the granulator in order to obtain granules (a); (iv) the second portion of powdered materials is added to the granulator; and (v) the new mixture obtained is agglomerated in the granulator in order to obtain granules (b). This sequenced granulation process allows granules to be obtained that have a degree of moisture that assures their stability and their ease of handling eliminating the drying step.

Method for the production of a coarse-grained ammonium sulphate product by crystallization and installation for carrying out the method from an ammonium sulphate solution in a DTB type crystallizer having an internal suspension circuit and a clarifying zone, from which a clarified partial flow of solution is constantly drawn off into an external circuit, is heated in a heat exchanger to dissolve the solids contained therein and is guided back as a clear solution into the lower region of the crystallizer. A fine crystal suspension flow is drawn off from the clarifying zone as a further partial flow and guided back into the internal circuit of the crystallization stage without any previous dissolution of the solid proportion contained therein.

The invention provides a process comprising: a crystallization step of concentrating and crystallizing the ammonium salt of sulfuric acid from an aqueous solution that contains the ammonium salt of sulfuric acid; a solid-liquid separation step of solid-liquid separating the ammonium salt of sulfuric acid obtained in the crystallization step, and a crystallization mother liquid recycling step of recycling a crystallization mother liquid obtained in the solid-liquid separation step to at least one step selected from the crystallization step and one or more steps that precede the crystallization step, in which not all of the crystallization mother liquid is recycled.

A method of processing bundles of carbon nanotubes (CNTs). Bundles of CNTs are put into a solution and unbundled using sonication and one or more surfactants that break apart and disperse at least some of the bundles into the solution such that it contains individual semiconducting CNTs, individual metallic CNTs, and remaining CNT bundles. The individual CNTs are separated from each other using agarose bead column separation using sodium dodecyl sulfate as a surfactant. Remaining CNT bundles are then separated out by performing density-gradient ultracentrifugation.

Mineral, cosmetic, pharmaceutical, agricultural, nutraceutical, and other compositions are produced using a mineral composition containing minimal concentrations of cadmium, lead, arsenic, and mercury and containing relatively high concentrations of micro and macro mineral elements, of rare earth elements, of calcium, and of silica. The mineral concentrations are produced by processing naturally occurring clay soil to concentrate mineral elements naturally occurring in the soil.

Highly compactable granulations and methods for preparing highly compactable granulations are disclosed. More particularly, highly compactable calcium carbonate granulations are disclosed. The granulations comprise powdered materials such as calcium carbonate that have small median particle sizes. The disclosed granulations are useful in pharmaceutical and nutraceutical tableting and provide smaller tablet sizes upon compression than previously available.

A method of producing a surface-treated carbon black powder dispersion includes subjecting carbon black fine particles having a volume average particle size of 100 nm to 20 μm to wet granulation and drying by heating to obtain granulated carbon black having a hardness of 12 cN or less and a pH of less than 7, grinding the granulated carbon black to obtain a ground product having a volume average particle size of 20 nm to 20 μm, and subjecting the ground product to wet oxidization in an aqueous medium. The resulting surface-treated carbon black powder dispersion exhibits excellent print density, print quality, discharge stability, and storage stability when used as an inkjet printer aqueous black ink.

This invention relates to novel methods for affecting, controlling and/or directing various crystal formation, structure formation or phase formation/phase change reaction pathways or systems by exposing one or more components in a holoreaction system to at least one spectral energy pattern. In a first aspect of the invention, at least one spectral energy pattern can be applied to a crystallization reaction system. In a second aspect of the invention, at least one spectral energy conditioning pattern can be applied to a conditioning reaction system. The spectral energy conditioning pattern can, for example, be applied at a separate location from the reaction vessel (e.g., in a conditioning reaction vessel) or can be applied in (or to) the reaction vessel, but prior to other (or all) crystallization reaction system participants being introduced into the reaction vessel.

A process for producing granules containing one or more complexing agent salts of the general formula from an aqueous starting solution, containing the one or more complexing agent salts in a concentration of from 10 to 80% by weight, based on the total weight of the aqueous starting solution, in a jet apparatus.

A method for growing crystals in solution is suitable for the rapid, controlled and effective preparation of crystals of large dimensions from a solution supersaturated with a compound. The crystal growth is carried out under static conditions. To do this: the growth is performed in a crystallization chamber kept at a constant temperature Tc, which chamber is in fluid communication with a saturation chamber at a temperature Ts, similarly constant and different from Tc, with solubility of the compound at the temperature Ts greater than the solubility of the compound at the temperature Tc. A continuous circulation of the solution between the crystallization and saturation chambers is established, thus maintaining a constant supersaturation rate within the crystallization chamber. Furthermore, the circulating solution is subjected to a treatment for eliminating and inhibiting the formation of aggregates, enabling the nucleation of parasitic crystallites to be inhibited.

The present invention pertains to a process for producing sodium chloride comprising the steps of (i) preparing a brine comprising at least 150 g/l of sodium chloride by dissolving a sodium chloride source in water, (ii) subjecting the resulting brine to a eutectic freeze crystallization step by indirect cooling of said brine, resulting in the formation of ice, sodium chloride dihydrate, and a mother liquor, (iii) separating the sodium chloride dihydrate formed in step (ii) from the ice and optionally mother liquor at the eutectic temperature, such that a sodium chloride dihydrate-rich stream is formed, and (iv) feeding said sodium chloride dihydrate-rich stream to a recrystallizer to form sodium chloride and a mother liquor.

The invention provides a process for increasing the crystallinity of at least one solid material which is less than 100% crystalline, comprising applying ultrasound to the substantially dry solid material.

The present invention relates to compositions and methods to increase the output of a high quality product from the precipitation liquor crystallization process exemplified through the aluminum hydroxide recovery processes such as the Bayer process. The invention is a method of increasing the size of precipitates from a liquor. The invention in one embodiment relates to the use of a crystal growth modifier compositions added to the precipitation process to increase the particle size distribution of the precipitated alumina trihydrate.

A reaction-crystallization apparatus for carrying out reaction and/or solvent extraction and/or crystallization of soluble salts has an upper section having a top and a decanter. The decanter has a vertical vessel having a horizontal weir at the top of the upper section. The top of the upper section has an outlet for removing a light phase at the top of the decanter. The apparatus has a lower section, including a crystallizer. The crystallizer includes: a coaxial draft tube; a feed pipe; an agitator inside the draft tube; and at least one outlet at the bottom for crystal slurry removal. The apparatus has an intermediate section sandwiched between the lower section and the upper section such that the sections are in fluid communication and includes at least one coaxial vertical baffle with a gap between the draft tube and the coaxial vertical baffle and is adjustable by moving the baffle.

A process for the production of sodium carbonate and sodium bicarbonate out of trona, comprising crushing trona ore and dissolving it in a leaching tank containing a solution comprising sodium carbonate and sodium bicarbonate, and an additive selected from the group consisting of: phosphates, phospholipids, carboxylates, carboxilic acids, and combinations thereof, saturated in sodium bicarbonate, in order to produce solid particles suspended in a production solution comprising sodium carbonate, the solid particles containing insoluble impurities and at least 65% by weight of sodium bicarbonate. The solid particles are separated from the production solution containing sodium carbonate. At least part of the production solution containing sodium carbonate is taken out of the leaching tank.

The present invention pertains to a process for producing sodium chloride comprising the steps of: (i) preparing a brine having a sodium chloride concentration which is higher than the sodium chloride concentration of the eutectic point but lower than the sodium chloride concentration of a saturated brine by dissolving a sodium chloride source in water; (ii) cooling the resulting brine by indirect cooling in a self-cleaning fluidized bed heat exchanger/crystallizer to a temperature lower than 0° C. but higher than the eutectic temperature of the resulting brine, thereby forming a slurry comprising sodium chloride dihydrate and a mother liquor; (iii) feeding the sodium chloride dihydrate to a recrystallizer to form sodium chloride and a mother liquor, and (iv) recycling at least part of the mother liquor obtained in step (ii) and/or step (iii) to step (i).

An object of the present invention is to provide a method for producing composite carbon fibers in which two or more carbon fibers are dispersed in a nearly homogenous state, the composite carbon fibers capable of being easily dispersed in a matrix such as a resin without leaving aggregate, and imparting low resistance. Disclosed is a method for producing composite carbon fibers, which comprises imparting a cavitation effect to slurry containing 6% by mass or less of two or more carbon fibers each having a different average fiber diameter under a pressure of 100 MPa or more and less than 245 MPa thereby to form a composite.

The present invention relates to a process for the preparation of articles of manufacture made of or based on sulphur, which comprises cooling of liquid sulphur in a volume of containment until the sulphur mass solidifies and forming of the product, characterized in that elastic pressure waves are applied to the cooling mass of liquid sulphur to produce a crystalline suspension of solid sulphur in liquid sulphur.

Process for the combined regeneration of at least two soluble salts contained in a residue of an industrial process comprising heavy metals, comprising: adding an amount of reactive aqueous solution needed to completely dissolve the salts which are desired to be regenerated to the residue; subjecting the resulting aqueous suspension to a separation to obtain an aqueous production solution on the one hand and insoluble impurities on the other hand, which are removed; successively subjected the aqueous production solution to at least two selective crystallization steps intended to crystallize, separately, the at least two soluble salts which are desired to be regenerated, which are washed, dried and regenerated separately; and adjusting the concentration of at least one of the soluble salts to be regenerated in the aqueous production solution, at the moment when such solution is subjected to the step of crystallization of this salt, to give rise to the selective crystallization of this salt, by addition of a controlled amount of this salt to the aqueous production solution upstream of the crystallization step.

A device for taking up a silicon melt comprises at least one block of a refractory with a capillary structure.

Provided is a method and an apparatus for purifying potassium nitrate from the solid waste produced by a chemical glass-strengthening process. In the method, the solid waste is melted into a liquid waste at first. Potassium nitrate of various purity grades can be obtained by batch processing the liquid waste through stepwise cooling processes of cooling the liquid waste to a first temperature facilitating the potassium nitrate contained in the liquid waste to be crystallized at a first rate and then cooling the liquid waste to a second temperature close to the freezing point of the potassium nitrate at a second rate that is slower than the first rate. The recovered potassium nitrate from the solid waste can be recycled and reused.

The invention provides a method of agglomeration (10) which has the steps of mixing a feedstock (12) of small particles which have an average particle size of 3 mm or less with a binder (14) which is in the form of a polyvinyl alcohol in the form of an aqueous polyvinyl alcohol solution in a first blender (16) to form a binder mixture (18), reacting a gelling agent (20) with the feedstock and the binder and processing the binder mixture to deliver an agglomerate (22).

A process is provided for preparing a salt product with reduced sodium content including the step of providing a concentrated brine, which is typically seawater, to which has been added potassium chloride. The mixture is transferred to a crystallizer unit where at least a portion of the mix is transferred to the crystallizer through a washing column. Liquid is evaporated from the crystallizer such that crystals form, crystals are passed from the crystallizer through said washing column to a separating unit such that in the passing through the washing column the crystals are rinsed with the brine portion being transferred as a counter current through the column. The inventive process is characterized by recycling of the brine from which the salt crystallizes, thus all main ingredients of the mixed input brine reach a steady equilibrium concentration in the mother liquor in the crystallizer. These will then precipitate as crystals, as more of the respective substances gets added to the mother liquor through inflow of mixed input brine. None of the liquor is purged out of the system as in conventional salt crystallizers. All the components in the feed are substantially contained in the product from the crystallizer either as crystalline material or soluble ingredients.

An object of the present invention is to provide a fine crystal particle production method and device that are excellent in mixing efficiency. This object is achieved by a method for producing fine crystal particles, comprising: a swirl flow producing step at which a swirl flow of liquid a comprising reactant A is supplied into a cylinder having a circumferential surface partially or wholly composed of a porous membrane; and a reaction step at which liquid b comprising reactant B which is reactive with the reactant A is supplied through the porous membrane to the swirl flow to effect mixing, whereby the reactants A and B are reacted to precipitate fine crystal particles.

Methods and apparatus for precipitating dissolved materials from a solution involve reduction of fines. In an embodiment, the method comprises: introducing a solution into a reactor, causing the dissolved materials in the solution to precipitate into crystals under a first reaction condition, adjusting the reaction condition from the first reaction condition to a second reaction condition, maintaining the reaction condition in the second reaction condition to cause a sub-population of the crystals to dissolve, and adjusting the reaction condition from the second reaction condition to the first reaction condition. In an embodiment, the apparatus comprises a reaction tank, a recycling path and at least an acid injector which is configured for dosing an acid into solution flow in the recycling path.

An application of carbon nanotubes on agglomerates of ore fines to increase the mechanical strength is provided. A process for the preparation of ore agglomerates having enhanced mechanical strength by the application of the carbon nanotubes is also provided.

A production saltwater disposal facility comprising a separator configured to receive production saltwater from a pipeline or a vehicle and separate hydrocarbons from the production saltwater, wherein the production saltwater received from the pipeline or vehicle is substantially the same composition as when the production saltwater was located in a subterranean formation, a hydrocarbon storage tank configured to receive hydrocarbons from the separator, a settling pit configured to receive the production saltwater from the separator and separate metals and/or other solids from the saltwater, an evaporator in fluid communication with the settling pit and comprising a nozzle configured to emit a stream of the saltwater along a path in air such that water in the saltwater evaporates, and a collection pit positioned under the path and configured to collect the salt from the saltwater after the water has evaporated.

The present invention provides a kiln for the combustion of agricultural waste. The kiln includes a central cylindrical combustion chamber. The central cylindrical combustion chamber includes a system for the control of combustion air to the combustion chamber. The kiln includes a second concentric cylinder surrounding the central cylindrical combustion chamber. The second concentric cylinder includes a system for the flow of cooling water through the first annulus between the central cylindrical combustion chamber and the second concentric cylinder. The kiln includes a system for the feeding of the agricultural waste into the central combustion chamber. The kiln includes a temperature sensing device to measure and display the temperature within the central combustion chamber during the combustion of the agricultural waste. The kiln includes a system for the recovery of ash from the kiln. In operation, the temperature of combustion is controlled to between 550° C. and 650° C. by a combination of increasing the supply of combustion air when the temperature in the central combustion chamber falls to near 550° C. and the introduction of cooling flowing water when the temperature in the central combustion chamber approaches 600° C.

Catalyst activator, in particular, a catalyst activator for heat conditioning a catalyst. The activator includes a vessel for containing a catalyst charge having an internal diameter of at least 1.2 meters and/or an internal volume of at least 5 m3; a fluidisation grid plate disposed in the vessel, the fluidisation grid plate having an upper major surface and a lower major surface; an array of generally conical depressions in the upper major surface that overlap by less than 17%; and an array of holes perforating the fluidisation grid plate, the holes extending from at least some of the generally conical depressions through the lower surface.

The Damn Virus: Local governments await budget slaughter; supes to investigate county hospital. Local governments across the East Bay are now entering budget season. Alameda County Administrator Susan Muranishi is expected to provide the Board of Supervisors with an update on the Fiscal Year 2020-21 budget this week.…

Small, little-known companies are selling CBD as a cure-all. While the Trump Administration has deregulated right and left — for instance, allowing polluters to go hog wild — the Food and Drug Administration isn't effing around when it comes to cracking down on companies selling supposed cures for the COVID-19 virus. Several of those targeted companies make CBD.…

Conversely, greater infection rate suggests much lower fatality rate. A recent Stanford University study of COVID-19 infection in Santa Clara County suggests that the disease is vastly more widespread in the Bay Area than official data shows. Because the test was performed on volunteers rather than a randomized population, it is likely to have over-reported the rate of infection among its subjects.…

More than a month since officials closed schools due to Covid-19, California leaders said a two-week blitz led by First Partner Jennifer Siebel Newsom has brought in 70,000 computers and other devices that will be distributed to needy students this week. Gov. Gavin Newsom has stressed the importance of distance learning and education multiple times during the past month—even talking about helping his own children with school work.…

An acoustic resonator and a method of manufacturing the same are provided. An acoustic resonator includes a resonating part disposed on a substrate, a cap accommodating the resonating part and bonded to the substrate, and a bonded part bonding the cap and the substrate to each other, the bonding part including at least one block disposed between a bonding surface of the cap and a bonding surface of the substrate to block a leakage of a bonding material that forms the bonded part during a bonding operation.

An elastic wave device including a substrate, an interdigital transducer (IDT) electrode provided on an upper surface of the substrate, a first wiring electrode provided on the upper surface of the substrate and connected to the IDT electrode, a dielectric film that does not cover a first region of the first wiring electrode but covers a second region of the first wiring electrode above the substrate, the first wiring electrode including a cutout in the second region, and a second wiring electrode that covers an upper surface of the first wiring electrode in the first region and an upper surface of the dielectric film in the second region above the substrate.

A resonator is provided that suppresses vibration of a retainer caused by undesired vibration of a vibrating portion and also achieves size reduction. Specifically, the resonator includes a vibrating member that includes a semiconductor layer, a first piezoelectric film formed on the semiconductor layer, and a first upper electrode formed on the first piezoelectric film. Moreover, a retainer is provided to retain the vibrating member such that the vibrating portion can vibrate and one or more coupling members are provided to couple the vibrating member to the retainer. Finally, the resonator includes a vibration suppressing member that includes a second piezoelectric film formed on the retainer and a second upper electrode formed on the second piezoelectric film.

An acoustic resonator and a method of manufacturing the same are provided. The acoustic resonator includes a resonating part including a first electrode, a second electrode, and a piezoelectric layer; and a plurality of seed layers disposed on one side of the resonating part.

An acoustic resonator structure comprises: a substrate having a cavity, which has a plurality of sides; a first electrode disposed over the cavity; a piezoelectric layer disposed over a portion of the first electrode and extending over at least one of the sides; and a second electrode disposed over the piezoelectric layer, an overlap of the first electrode, the piezoelectric layer and the second electrode forming an active area of the FBAR. The active area of the FBAR is completely suspended over the cavity.

A resonator is provided that suppresses frequency variations with etching without decreasing the strength of vibration arms. The resonator includes a base portion, a first vibration portion extending from the base portion in a first direction and having a first width, and a second vibration portion extending from the base portion in the first direction with a first gap between the first and second vibration portions and having the first width. The first and second vibration portions perform out-of-plane bending vibration with opposite phases at a predetermined frequency. The predetermined frequency varies in accordance with the first width and the first gap. The ratio of the first gap to the first width is within a range that causes an absolute value of rates of variations in the predetermined frequency with respect to variations in the first width and in the first gap to be not more than about 100 ppm.