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260 results about "Phase velocity" patented technology
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The phase velocity of a wave is the rate at which the phase of the wave propagates in space. This is the velocity at which the phase of any one frequency component of the wave travels. For such a component, any given phase of the wave (for example, the crest) will appear to travel at the phase velocity. The phase velocity is given in terms of the wavelength λ (lambda) and time period T as vₚ=λ/T. Equivalently, in terms of the wave's angular frequency ω, which specifies angular change per unit of time, and wavenumber (or angular wave number) k, which represents the proportionality between the angular frequency ω and the linear speed (speed of propagation) νₚ, vₚ=ω/k.
An improved E-field generator including a slow-wave transmissionline structure is provided herein. In some cases, the improved E-field generator may include an inductively-loaded slow-wave transmissionline structure driven by a power source at one end of the structure and terminated by a load at the other end of the structure. In other cases, the improved E-field generator may include a capacitively-loaded slow-wave transmissionline structure. In either case, the improved E-field generator provides a frequency-independent, significantly increased electric field at a distance spaced from the generator without altering the dimensions of the generator and / or the input power supplied to the generator. The increase in generated field intensity is achieved by decreasing the phase velocity of the electromagnetic wave propagating along the parallel elements of the generator.
A fixed frequency continuously beam-steerable leaky-wave antenna in microstrip is disclosed. The antenna's radiating strips are loaded with identical shunt-mounted variable-reactance elements, resulting in low reverse-bias-voltage requirements. By varying the reverse-bias voltage across the variable-reactance elements, the main beam of the antenna may be scanned continuously at fixed frequency. The antenna may consist of an array of radiating strips, wherein each strip includes a variable-reactance element. Changing the element's reactance value has a similar effect as changing the length of the radiating strips. This is accompanied by a change in the phase velocity of the electromagnetic wave traveling along the antenna, and results in continuous fixed-frequency main-beam steering. Alternatively, the antenna may consist of two long radiating strips separated by a small gap, wherein identical variable-reactance elements are mounted in shunt across the gap at regular intervals. A continuous change in the reactance value has a similar effect as changing continuously the width of the radiating strips. This results in a continuous change in the phase velocity of the electromagnetic wave traveling along the antenna, thereby achieving continuous fixed-frequency main-beam steering.
A fixed frequency continuously beam-steerable leaky-wave antenna in microstrip is disclosed. The antenna's radiating strips are loaded with identical shunt-mounted variable-reactance elements, resulting in low reverse-bias-voltage requirements. By varying the reverse-bias voltage across the variable-reactance elements, the main beam of the antenna may be scanned continuously at fixed frequency. The antenna may consist of an array of radiating strips, wherein each strip includes a variable-reactance element. Changing the element's reactance value has a similar effect as changing the length of the radiating strips. This is accompanied by a change in the phase velocity of the electromagnetic wave traveling along the antenna, and results in continuous fixed-frequency main-beam steering. Alternatively, the antenna may consist of two long radiating strips separated by a small gap, wherein identical variable-reactance elements are mounted in shunt across the gap at regular intervals. A continuous change in the reactance value has a similar effect as changing continuously the width of the radiating strips. This results in a continuous change in the phase velocity of the electromagnetic wave traveling along the antenna, thereby achieving continuous fixed-frequency main-beam steering.
A system, method and program product for analyzing multiphase flow in a wellbore. A system is provided that includes: an input system for receiving pressure and temperature readings from a pair of sensors located in the wellbore; a computation system that utilizes a flow analysis model to generate a set of wellbore fluid properties, wherein the set of wellbore fluid properties includes at least one of: a fluid mixture value, a phase velocity value, a flow rate, a mixture density, a mixture viscosity, a fluid holdup, and a slip velocity; and a system for outputting the wellbore fluid properties.
This invention discloses a two-phase flow digital particle image speed test method and its device, which uses suitable particles to trace flow of fluids and uses high speed CCD camera to register motion images for tracing particles, liquid drops or gas bubbles, applies an image process method to separate the images of scattered phase particles drops or bubbles from original images and extracts velocities of them from their images and applies an improved cross correlation technology based on quick Fourier transformation to extract the velocity field of the tracing particles to realize the synchronous measurement to the two phase flows with different phase velocity fields. The device includes a HeNe laser, a triple prism and a cylinder lens, a high speed CCD camera, an image collecting card and a control and image process computer.
The invention discloses a method and a device for analyzing the dispersion and attenuation of unsaturated double-porosity medium earthquake waves. The method comprises the following steps of: 1, acquiring geological data including penetration rate, porosity, shale content and mineral components and generating a reservoir rock dry framework model according to the geological data; 2, acquiring measured data including drilling data, logging data, logging information and fluid experiment measured data and generating a reservoir fluid model according to the measured data and a Van derWaals equation; 3, solving plane waves according to the reservoir rock dry framework model, the reservoir fluid model and a Biot-Rayleigh equation for describing the spread of the unsaturated double-porosity medium earthquake waves, and generating phase speed and inverse quality factors of longitudinal waves and horizontal waves; and 4, generating relationships between frequency and each of speed, attenuation,wave impedance, AVO (Amplitude Versus Offset) response characteristic and the like according to the phase speed and inverse quality factors of the longitudinal waves and the horizontal waves.
An ultrasonic image scanning system for scanning an organic object includes a beam former that provides a phase velocity adjustment function for producing an ultrasonic image with a programmable phase velocity. The ultrasonic image scanning system further includes a beam profile analysis function for calculating an optimal phase velocity with a user controller to adjust the phase velocity until a scan image of best image quality is achieved. Alternately, the system may provide an automatic phase velocity-scanning controller for automatically scanning through a range of phase velocities and selecting a best phase velocity generating a scanning image of a best quality. The system further includes a region of interest (ROI) controller for a user to select a region for scanning with a specific focal area for optimizing the phase velocity. The system may further provide a maximum gradient analyzer for selecting an image of a best quality in optimizing the phase velocity. A digital controller may also provide a real time programmable control by applying different control algorithms with combination of phase velocity and attenuation adjustment. A hardness computational processor is implemented to determine a tissue hardness using the phase velocity and in combination with the attenuation parameter.
A variable discretization method for general multiphase flow simulation in a producing hydrocarbon reservoir. For subsurface regions for which a regular or Voronoi computational mesh is suitable, a finite difference / finite volume method (“FDM”) is used to discretize numerical solution of the differential equations governing fluid flow (101). For subsurface regions with more complex geometries, a finite element method (“FEM”) is used. The invention combines FDM and FEM in a single computational framework (102). Mathematical coupling at interfaces between different discretization regions is accomplished by decomposing individual phase velocity into an averaged component and a correction term. The averaged velocity component may be determined from pressure and averaged capillary pressure and other properties based on the discretization method employed, while the velocity correction term may be computed using a multipoint flux approximation type method, which may be reduced to two-point flux approximation for simple grid and permeability fields.
Methods and apparatus for implementing standing wave oscillators (SWOS) using coplanar striplines (CPS). One example is given by a quarter-wavelength (λ / 4) coplanar striplinestanding wave oscillator (SWO), while another implementation utilizes a closed-loop coplanar stripline configuration. In various aspects, SWOs are configured to optimize sinusoidal performance at high frequencies with low power dissipation by incorporating various features that dramatically increase the quality factor Q of the oscillator. In particular, in one aspect, an amplitude-dependent tailored distributed amplification scheme is employed as a mode control technique using multiple amplifiers having different gains along the length of the coplanar stripline. In another aspect, a coplanar stripline configured such that its resistance per unit length R and conductance per unit length G are discreet or continuous functions of position along the coplanar stripline is employed to reduce SWO losses. In another aspect, an enhancement of the quality factor Q is achieved while at the same time reducing the phase velocity of waves propagating in the SWO, thereby also facilitating the fabrication of relatively smaller devices. In yet another aspect, SWOs are configured with frequency adjustability that is again optimized to reduce power dissipation while facilitating significant adjustments of oscillator frequency.
Aspects of the present invention are directed to using surface acoustic wave (SAW) sensors mounted on a disc coupling component in a powertrain to measure the torque generated by an automobile engine. The sensor may be positioned and oriented on the disc coupling component so that the phase velocities of SAWs propagating through active elements of the SAW sensors are aligned with principal strain components due to torque in the disc coupling component. The torque may be calculated by determining the difference between resonant frequencies of the active elements to suppress common-mode interference factors. In addition, SAW resonant frequencies may be communicated in a non-contacting manner by utilizing rotary and stationary couplers employing radio frequency (RF) signals. Moreover, SAW sensors may be activated and interrogated by employing targeted RF pulses having different carrier frequencies at or near respective resonant frequencies of each resonator in a SAW sensor.
A surface acoustic wave element is provided including an IDT and reflectors provided on both sides of the IDT that are on a surface of a quartz plate. The quartz plate is made from an in-plane rotated ST cutquartz plate whose cutting angle is expressed as (0°, 113°-135°, ±(40°-49°)) by defining and using Euler angle. The IDT and reflectors are arranged at a slant of PFA±3° with respect to a direction of a phase velocity of a surface acoustic wave in the quartz plate. If the cutting angle of the quartz plate is expressed by the Euler angle (φ°, θ°, Ψ°), the power flow angle PFA is expressed that the PFA=0.374 (θ°−90°)−10.0°.
In a surface acoustic wave (SAW) device, such as a SAW resonator or a SAW filter, loss is minimized and steep characteristics are improved. IDT electrodes and a reflector are provided to a piezoelectric substratecut out at a cut-angle which allows the substrate to excite a leaky surface acoustic wave (LSAW). The IDT electrodes have a given film thickness and a given pitch “p” of finger-electrodes. A phase velocity of the SAW is reduced to slower than a phase velocity “vb”of a slow shear wave propagating on the piezoelectric substrate, and a resonance frequency “f” satisfies a relation of 2×p≦vb / f. This structure allows the use of a Rayleigh surface acoustic wave (RSAW) which does not produce propagation loss, and improving insertion-loss and steep characteristics from those of a conventional SAW device using the LSAW.
ActiveCN103233727AObtain changes in mechanical/acoustic parameters in real timeObtain real-time changes in mechanical/acoustic parameters of the dominant mechanical/acoustic parameters near the wellBorehole/well accessoriesFull waveQuadrupole
The invention relates to an inversion method of stratum shear wave velocity radial sections. The inversion method includes: performing acoustic logging while drilling and while drilling stratum density and well diameterlogging in a depth interval, and obtaining while drilling monopole and quadrupole array acoustic full wavetrain data, a while drilling stratum density logging curve and a while drilling well diameterlogging curve; obtaining stratum longitudinal wave velocity and shear wave velocity at the position of processing depth through calculation, and extracting phase velocityfrequency dispersion data of while drilling quadrupole wave; calculating a theoretical while drilling quadrupolewave frequencydispersion curve at the position of the processing depth; constructing an inversion objective function in a combined mode; outputting equivalent alteration velocity and thickness; calculating continuously variable stratum shear wave velocity radial sections; and repeating the steps until processing of the whole depth interval is finished, and obtaining the stratum shear wave velocity radial sections changing continuously along with logging depth. The inversion method of stratum shear wave velocity radial sections has the advantages of obtaining changes of mechanics / acoustic parameters nearby a well in real time, solving the problem of ununiqueness of inversion, and improving reliability of inversion results.
The invention discloses a quasi-surface plasmon-based leaky-wave antenna, and belongs to the technical field of microwaves. The leaky-wave antenna comprises a feed network and a radiating element, wherein the feed network comprises a gradient matching structure; the gradient matching structure is used for achieving conversion of an electromagnetic wave between a TEM mode or a quasi-TEM mode and a quasi-surface plasmon mode; and the radiating element is a quasi-surface plasmonwaveguide capable of enabling the phase velocity of the transmitted quasi-surface plasmon to discontinuously change. Compared with the prior art, the radiating element of the leaky-wave antenna is achieved on the basis of the quasi-surface plasmonwaveguide for a phase velocity modulation; the quasi-surface plasmon-based leaky-wave antenna is simple in structure, relatively small in interference to an external circuit and relatively easy to process, and does not need metal ground; and omnidirectional radiation and frequency scanning functions are relatively easy to achieve.
The present invention proposes a coupling device, comprising a substrate (1), a conductive layer (2) covering a first surface of said substrate (1), at least two electromagnetically coupled lines (3a, 3b) being provided opposite to said first surface and at least one thereof being covered by at least one cover layer (4, 5) wherein at least one capacitor (C1, C2, C3, C4) is connected between a first end of at least one of said at least two lines (3a, 3b) and said conductive layer (2). The at least one capacitor is a buried capacitor grounded in order to equalize unequal phase velocities otherwise degrading the performance of e.g. broadside coupled structures in an inhomogeneous substrate structure such as for example microstrips in a multilayer LTCC. Therefore the present invention enables coupling devices having a high performance and offering in that way the best of all possible design scenarios in terms of wideband performance, size and cost.
A surface acoustic wave element is provided including an IDT and reflectors provided on both sides of the IDT that are on a surface of a quartz plate. The quartz plate is made from an in-plane rotated ST cutquartz plate whose cutting angle is expressed as (0°, 113°-135°, ±(40°-49°)) by defining and using Euler angle. The IDT and reflectors are arranged at a slant of PFA±3° with respect to a direction of a phase velocity of a surface acoustic wave in the quartz plate. If the cutting angle of the quartz plate is expressed by the Euler angle (φ°, θ°, Ψ°), the power flow angle PFA is expressed that the PFA=0.374 (θ°−90°)−10.0°.
The invention provides a metal plate micro-defect detection method based on nonlinear Lamb waves. The metal plate micro-defect detection method comprises the following steps of: S1, acquiring a phasevelocity frequency dispersion curve and a group velocityfrequency dispersion curve of a metal plate; S2, acquiring an excitation frequency, Lamb waves of a specific mode and an incident angle of theLamb waves of the specific mode as model parameters according to the phase velocityfrequency dispersion curve and the group velocity frequency dispersion curve; S3, deriving a relative nonlinear coefficient beta' according to the Lamb waves of the specific mode in the S2, wherein the relative nonlinear coefficient beta' is used for representing the depth of a defect; S4, establishing a nonlinearultrasonic test system according to the model parameters; and S5, testing the metal plate according to the nonlinear ultrasonic test system established in the step S4, judging whether the relative nonlinear coefficient beta' is reliable or not, and if so, representing the defects of the tested metal plate by utilizing the relative nonlinear coefficient beta'. According to the metal plate micro-defect detection method, the relative nonlinear coefficient beta' represents the defects of the tested metal plate, the defects of the metal plate can be effectively represented, and the detection precision is improved.
A method for detecting isotropic material surface Young modulus by using surface acoustic wave technology. The method is as below: exciting broadbandsurface acoustic wave in an isotropic specimen surface to obtain a dispersion curve on a surface acoustic wave propagation direction; fitting the actual phase velocity data to obtain a closest truth-value phase velocity and a phase velocity fluctuation section; establishing a Cartesian coordinate geometry model to obtain a surface wave basic propagation equation containing unknown medium Young modulus, Poisson ratio, direction cosine of the propagation direction, amplitude attenuation coefficient given according to experience value, wave number and wave velocity; calculating assumption corresponding relation between wave velocity and wave number in the Cartesian coordinate geometry model and simultaneous theoretical relationship, to obtain mutual relationship of velocity, frequency and Young modulus under ideal conditions; and conducting reverse calculation to obtain the Young modulus in medium according to the mutual relationship of velocity, frequency and Young modulus under ideal conditions and the dispersion curve under actual conditions. The invention realizes effective measurement of isotropic material surface young modulus.
The invention discloses a frequency-domain higher-order sound wave equation forward modeling method based on directional derivative, belongs to the technical field of seismic exploration, and aims at providing a frequency domain two-dimensional scalar sound wave equation forward modeling simulation method with the higher simulation precision. The method comprises the steps: building a fourth-order 17-point finite difference equation comprising a plurality of weighting coefficients according to a frequency domain scalar sound wave equation through the directional derivative; carrying out the normalized phase velocityfrequency dispersion analysis, and solving an optimal weighting coefficient through an optimization algorithm; constructing a finite difference equation with the absorbing boundary condition; carrying out the seismic wavefield datasimulation through the fourth-order 17-point finite difference equation, and obtaining a seismic wave forward modeling record. The method can inhibit the frequency dispersion to the greatest extent, improves the simulation precision of the seismic wavefield data, and also can adapt to a condition that the longitudinal and lateral grid sizes are not equal. The method is mainly used in the technical field of seismic exploration, and provides basic data and technological support for the simulation and analysis of a seismic wave field, the seismic inversion imaging, and geologic modeling.