145 results about "Antiresonance" patented technology

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.

This invention is a method for binaural localization using a cascade of resonators and anti-resonators to implement an HRTF (head-related transfer function). The spectrum of the cascade reproduces the magnitude spectrum of a desired HRTF. The proposed method provides a considerably more computationally efficient implementation of HRTF filters with no detectable deterioration of output quality while saving memory when storing a large quantity of HRTFs due to the parameterization of its resonators and anti-resonators. Finally, the method offers additional flexibility since the resonators and anti-resonators can be manipulated individually during the design process, making it possible to interpolate smoothly between HRTFs, reduce spectral coloring or achieve higher accuracy at perceptually relevant frequency regions. These HRTF are useful in stereo enhancement and multi-channel virtual surround simulation.

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 four-degrees-of-freedom (DOF) nonresonant micromachined gyroscope utilizes a dynamical amplification both in the drive-direction oscillator and the sense-direction oscillator, which are structurally decoupled, to achieve large oscillation amplitudes without resonance. The overall dynamical system is comprised of three proof masses. The second and third masses form the sense-direction oscillator. The first mass and the combination of the second and third masses form the drive-direction oscillator. The frequency responses of the drive and sense-mode oscillators have two resonant peaks and a flat region between the peaks. The device is nominally operated in the flat regions of the response curves belonging to the drive and sense-mode oscillators, where the gain is less sensitive to frequency fluctuations. This is achieved by designing the drive and sense anti-resonance frequencies to match.

An acoustic wave filter device is capable of increasing the steepness of a filter characteristic at a boundary between a passband and an attenuation band and achieving a low loss in the passband. The acoustic wave filter device has a ladder circuit configuration including a plurality of series arm resonators and at least one parallel arm resonator. The anti-resonant frequency of the series arm resonator is different from that of the series arm resonator. The series arm resonator having the lowest anti-resonant frequency has a resonant frequency located in the passband and an electromechanical coupling coefficient less than an average of electromechanical coupling coefficients of the series arm resonators.

A four-degrees-of-freedom (DOF) nonresonant micromachined gyroscope utilizes a dynamical amplification both in the 2-DOF drive-direction oscillator and the 2-DOF sense-direction oscillator, which are structurally decoupled, to achieve large oscillation amplitudes without resonance. The overall 4-DOF dynamical system is comprised of three proof masses. The second and third masses form the 2-DOF sense-direction oscillator. The first mass and the combination of the second and third masses form the 2-DOF drive-direction oscillator. The frequency responses of the drive and sense-mode oscillators have two resonant peaks and a flat region between the peaks. The device is nominally operated in the flat regions of the response curves belonging to the drive and sense-mode oscillators, where the gain is less sensitive to frequency fluctuations. This is achieved by designing the drive and sense anti-resonance frequencies to match.

A boundary acoustic wave device includes a first medium layer made of a first dielectric material and a second medium layer made of a second dielectric material having an acoustic velocity different from the acoustic velocity of the first dielectric material. The first medium layer and the second medium layer are disposed on a piezoelectric substrate, and an IDT electrode is arranged along the interface between the piezoelectric substrate and the first medium layer. When the fast transverse bulk wave of the piezoelectric substrate has an acoustic velocity V1 and a higher-order mode boundary acoustic wave has an acoustic velocity Va at an anti-resonance point, the boundary acoustic wave device satisfies the relationship Va>V1.

The invention provides a passive vibration isolation system for dampers of ceilings and sheds and a parameter determination method thereof. By the aid of antiresonance of an 'inertial container-spring-weight' vibrating state converting system, resonance of isolated weights is converted into resonance of inertial containers, resonance of the isolated weights is eliminated, on that basis, damper stride across the inertial containers to be connected with the isolated weights in parallel, and are prevented from striding across the isolated weights to be connected with the initial containers, and the technical problem that dampers of perfect ceilings and perfect sheds need to be connected with inertial reference frames is resolved. In the passive vibration isolation system and the parameter determination method, the dampers do not need to be connected with inertial reference frames, functions of the perfect ceilings and the perfect sheds can be realized to the greatest extent, vibration of the isolated weights is restrained, and technical shortcomings that in an active or semi-active implementation method, external energy input is required, the structure is complex, and instantaneity and reliability are poor are overcome.

The present invention provides a piezoelectric actuator that enjoys excellent practicality. The piezoelectric actuator includes a piezoelectric element (2) including a sheet of piezoelectric ceramic and electrodes formed at least part of the surface of the sheet of piezoelectric ceramic, and a holding member (4) holding the piezoelectric element (2). The piezoelectric at least one of the requirements (a) to (e) described below. (a) The bulk density shall be equal to or smaller than 5 g / cm3, and the Young's modulus Y11E calculated according to a resonance-antiresonance method shall be equal to or larger than 90 GPa. (b) The coefficient of thermal conductivity shall be equal to or larger than 2 Wm−1K−1. (c) The coefficient of thermal expansion shall be equal to or larger than 3.0 ppm / ° C. over a temperature range from −30° C. to 160° C. (d) The pyroelectric coefficient shall be equal to or smaller than 400 μCm−2K−1 over the temperature range from −30° C. to 160° C. (e) The mechanical quality factor Qm calculated according to the resonance-antiresonance method shall be equal to or smaller than 50 over a temperature range from −30° C. to 80° C.

The invention relates to a vehicle hanger bracket, in particular to a hydraulic interconnection ISD (Inerter-Spring-Damper) hanger bracket. Hydraulic cylinders of a rear overhang hydraulic ISD hanger bracket are reversely connected in series, namely, the upper cavity of the left side hydraulic cylinder and the lower cavity of the right side hydraulic cylinder are connected, and the lower cavity of the left side hydraulic cylinder and the upper cavity of the right side hydraulic cylinder are connected; when the bounce directions of left and right wheels are consistent, liquid interaction is realized by a connecting pipe, and the loads borne by the two side wheels are balanced; when the bounce directions of left and right wheels are inconsistent, liquid is capable of converting the pressure difference between the upper cavity and the lower cavity into an inertia force by a hydraulic motor, the dynamic stroke of the hanger bracket is reduced, and the aim of preventing sidesway of a vehicle is reached. On the basis of an antiresonance technology of the hydraulic ISD hanger bracket, and through the combination of the interconnection sidesway prevention, the hydraulic interconnection ISD hanger bracket has the advantages that for a complicated work condition road, under the premise that the riding comfort is not influenced by negative effects, the vehicle driveability is improved, the coordination control is realized for the smoothness and the handling stability, four modalities relative to the movement of a vehicle body, of wheels are independently decoupled by an interconnection hanger bracket system, and the structure is simple and reliable, the cost is low and the implementation is easy in comparison with a driving hanger bracket.

Band reject filters are disclosed. A band reject filter includes a first acoustic resonator and a second acoustic resonator, each of which has either shunt resonators adapted to resonate substantially at respective resonance frequencies defining a rejection frequency band or series resonators adapted to anti-resonate substantially at respective anti-resonance frequencies defining the rejection frequency band. These resonators are connected through a phase shifter which imparts an impedance phase shift of approximately 45° to 135°. Exemplary applications of the band reject filters disclosed herein include implementation as an inter-stage band reject filter for a base station power amplifier for a wireless communication system, as a radio frequency band reject filter in a duplexer for a wireless communication terminal, and in a low noise amplifier input stage.

There is provided a resonance circuit using piezoelectric vibrator such as a quartz resonator, a coil, a capacitor, or an element equivalent to them in combination. When two resonance circuits having different resonance frequencies are combined, it is possible to configure an oscillation circuit and a filter capable of freely adjusting the frequency characteristic by utilizing the phenomenon that by changing the excitation current or voltage of the respective resonance circuits independently from each other, antiresonance frequency of the entire composite resonance circuit can be changed.

A piezoelectric substrate and interdigital electrode portions are covered with an insulating layer with an insulating thin film interposed therebetween. The piezoelectric substrate is made of LiTaO3 and the insulating thin film and the insulating layer are made of silicon oxide. By intentionally making the upper surface of the insulating layer flat, the deterioration of propagation efficiency of surface acoustic waves can be suppressed, so that it is possible to reduce increase in insertion loss of a resonator. Since the upper surface of the insulating layer is flat, it is also possible to reduce variation in resonant frequency and anti-resonant frequency due to the temperature change of the surface acoustic wave device.

An acoustic film resonator comprises a first piezoelectric film (101); a pair of primary electrodes (103,104) that are formed on the first piezoelectric film and to which an electric signal is applied; a second piezoelectric film (102) that is disposed such that oscillation occurring in the first piezoelectric film propagates to the second piezoelectric film; a pair of secondary electrodes (104,105) that are formed on the second piezoelectric film and that outputs an electric signal; a load (108) connected between the secondary electrodes; and a control part (109) that controls the value of the load. Thus, an acoustic film resonating element is configured wherein an electric signal from the primary electrodes is outputted from the secondary electrodes through a piezoelectric effect and wherein the resonance frequency and the antiresonance frequency can be varied by controlling the value of the load. Both the resonance frequency and the antiresonance frequency can be varied at the same time without degrading the resonance characteristic.

A SAW (Surface Acoustic Wave) filter includes serial arm resonators and parallel arm resonators interconnected in pairs in a multiple-stage, ladder configuration. A resonating device is serially connected to any one of the serial arm resonators and has an attenuation pole frequency higher than that of the serial arm resonator. At the attenuation pole frequency of the serial arm resonator, the resonating device functions as capacitance without performing attenuation. The resonating device has an antiresonance frequency 1.8 times or more but 2.2 times or less, or 2.7 times or more but 3.3 times or less, as high as the antiresonance frequency of the serial arm resonator.

A preform (10) for an antiresonant hollow core optical fibre comprises an outer jacket tube (12) having an inner surface and a central longitudinal axis (24); a plurality of antiresonant cladding tubes (14) spaced apart at predefined peripheral locations around the inner surface of the outer jacket tube (12), each antiresonant cladding tube (14) in contact with the inner surface such that a central longitudinal axis (26) of each antiresonant cladding tube (14) is at a first radial distance from the central longitudinal axis (24) of the outer jacket tube (12); and a plurality of spacing elements (22) disposed alternately with the antiresonant cladding tubes (14) and each in contact with an outer surface of each of two adjacent antiresonant cladding tubes (14) at one or more contact points (28), the contact points (28) at a second radial distance from the central longitudinal axis (24) of the outer jacket tube (12), the second radial distance being greater than the first radial distance.

The invention belongs to the technical field of fiber couplers, and particularly relates to a hollow-core antiresonance photonic crystal fiber coupler and application thereof. The fiber coupler is formed by two hollow-core antiresonance fibers with polished side faces. The basic structure of each hollow-core antiresonance fiber comprises a fiber core, a circle of micro-capillary inner covering layer around the fiber core and an outer covering layer covering the exterior of the micro-capillary inner covering layer. The polished faces of the hollow-core antiresonance fibers are arranged on the outer covering layer and are attached to each other and subjected to fusion or tapering, so a fiber coupler is manufactured. Before the tapering or during the tapering, the ring distance of two rings near the attached faces is reduced or increased, so the mode coupling of the fiber core of the two hollow-core antiresonance fibers is optimized. The fiber coupler is simple in design and highly practical, can be used for pulse laser, especially, full-fiber coupling and laser beam splitting of femtosecond laser and can be applied in a hollow-core fiber gyroscope to replace a solid fiber coupling module.

An acoustic wave filter device is capable of increasing the steepness of a filter characteristic at a boundary between a passband and an attenuation band and achieving a low loss in the passband. The acoustic wave filter device has a ladder circuit configuration including a plurality of series arm resonators and at least one parallel arm resonator. The anti-resonant frequency of the series arm resonator is different from that of the series arm resonator. The series arm resonator having the lowest anti-resonant frequency has a resonant frequency located in the passband and an electromechanical coupling coefficient less than an average of electromechanical coupling coefficients of the series arm resonators.

A method for manufacturing an inkjet head includes producing a flow path unit, producing an actuator unit, bonding the actuator unit with the flow path unit to produce a bonded structure; measuring a frequency characteristic of impedance of the piezoelectric structure of the bonded structure in each of regions facing at least one of the pressure chambers, and determining whether or not the bonded structure is a good product on a basis of at least one of a distribution of (Fa−Fr) in the plural regions where Fa represents antiresonance frequency of each region at which impedance of each region are maximal and Fr represents resonance frequency of each region at which impedance of each region is minimal, a distribution of Fr in the plural regions, and a distribution of Zr in the plural regions, where Zr represents impedance of each region at the resonance frequency of each region.

Aspects of the disclosure relate to an elastic wave device. The elastic wave device includes a sub-wavelength thick piezoelectric layer, an interdigital transducer electrode on the piezoelectric layer, and a high velocity layer with a higher bulk velocity than the velocity of an elastic wave. The high velocity layer can inhibit an elastic wave from leaking from the piezoelectric layer at anti-resonance.

The invention discloses an energy dissipation vibrator and a standing wave area power protecting system and method and belongs to the technical field of underground engineering. The energy dissipation vibrator comprises an upper shell, a lower shell, a telescoping rod, a mass block, a first spring and a second spring. A first blocking part is arranged at the lower end of the upper shell. A second blocking part is arranged at the upper end of the lower shell and located between the first blocking part and the shell. The first blocking part limits the second blocking part. One end of the telescoping rod is connected with the upper shell, and the other end of the telescoping rod is connected with the lower shell. The telescoping rod is sleeved with the mass block, the first spring and the second spring. One end of the first spring is connected with the upper shell, and the other end of the first spring is connected with the mass block. One end of the second spring is connected with the lower shell, and the other end of the second spring is connected with the mass block. The first spring and the second spring are in the compressed state. The energy dissipation vibrator organically combines the traditional antiresonance principle, the deformation energy-absorbing principle and the standing wave principle together, and integrates and has multiple advantages of various single principles.

The invention discloses a method for improving out-of-band rejection of a piezoelectric filter, the piezoelectric filter is of a trapezoidal structure, the trapezoidal structure of each order comprises a series resonator and a parallel resonator, and the method comprises the following steps: adjusting the thickness of one or more of the series resonator and the parallel resonator in the trapezoidal structure of at least one order, and / or adjusting the thickness of one or more of the series resonator and the parallel resonator in the trapezoidal structure of at least one order; and adjusting materials of all series resonators and / or parallel resonators, so that the anti-resonance frequency corresponding to the high-order parasitic resonance of the parallel resonators in the trapezoidal structure is greater than the resonance frequency corresponding to the high-order parasitic resonance of the series resonators, or the difference value between the anti-resonance frequency and the resonance frequency is less than a set value. According to the technical scheme of the invention, the thickness of layers in the resonators is adjusted, so that high-order parasitic resonance positions of the parallel resonators is moved from a position far lower than the high-order parasitic resonance positions of the series resonators to a position equivalent to or even higher than the high-order parasitic resonance position of the series resonators, thereby suppressing or eliminating the pseudo passband phenomenon of the high-order parasitic resonance region. Therefore, the out-of-band rejection performance of the filter is improved.

The invention discloses a gas-liquid elastic dual-frequency vibration isolator, and belongs to the technical field of vibration isolation design. The gas-liquid elastic dual-frequency vibration isolator comprises a shell, an inner cylinder, elastic rubber, a piston body, a lower cover body and an air cavity additionally-arranged air chamber; one end of the inner cylinder is arranged inside the shell, the elastic rubber is arranged between the shell and the inner cylinder, and the side face of the elastic rubber, the shell and the inner cylinder are bonded to form a sealed upper liquid cavity;anti-falling bolts are arranged in the circumferential direction of the shell to prevent the elastic rubber from falling off; one end of the inner cylinder is provided with an air compensating cavity,the air compensating cavity is provided with the piston body, a lower liquid cavity is formed between the piston body and the inner cylinder, and the lower liquid cavity communicates with the upper liquid cavity; the air compensating cavity is provided with a lower cover body in an internally screwed mode, and the cavity between the lower cover body and the piston body communicates with the air cavity additionally-arranged air chamber for changing the supporting rigidity of the piston body; and the gas-liquid elastic dual-frequency vibration isolator is arranged in a main supporting reductionrod of a helicopter through the shell and the lower cover body and used for isolating vibration. The gas-liquid elastic dual-frequency vibration isolator has the advantages that the structure is simple, the weight is small, the frequency band of vibration isolation is wide, and the dynamic stiffness of antiresonance points is low.

A hybrid multiplexer includes a filter configured to allow a high-frequency signal of an HB to pass therethrough, and a filter configured to allow a high-frequency signal of an MB to pass therethrough, in which the filter includes a matching circuit, a first resonance circuit defined by one of an LPF and an HPF, and a second resonance circuit defined by the other of the LPF and the HPF, the LPF includes an inductor and a parallel arm resonator, the HPF includes a serial arm resonator and an inductor, and a resonant frequency of the parallel arm resonator and an anti-resonant frequency of the serial arm resonator are both located between a frequency at a low-band end of the HB and a frequency at a high-band end of the HB.

Filter circuitry is provided with a series element and a parallel element. The filter circuitry transmits signals that fall within a certain passband and attenuates signals that don't fall within the certain passband. The series element is comprised of a resonance element having antiresonance characteristics, and the parallel element is comprised of a series circuit including an inductor and a capacitor.

An optical resonator is provided. The optical resonator comprises: an optical resonator coil comprising a first port and a second port; wherein the optical resonator coil comprises antiresonant nodeless fiber; a resonator loop closure optics system; and wherein the antiresonant nodeless fiber has a length such that the resonant frequencies the optical resonator of the desired polarization state of light and of the undesired polarization state of light are separated by between a tenth of a free spectral range and nine tenths of a free spectral range to minimize gyroscope errors.