206 results about "Frequency coupling" patented technology

A broadband antenna includes a coupling loop and a number of radiation bodies. The coupling loop is electrically coupled to a chip and the chip records several pieces of data. The radiation bodies respectively form a number of resonance loops with the coupling loop for providing a number of resonance frequencies of the broadband antenna. The coupling loop can feed in signals for reading data in the chip according to the resonance frequencies.

A plasma reactor for processing a workpiece includes a reactor chamber and a workpiece support within the chamber, the chamber having a ceiling facing the workpiece support, a capacitively coupled plasma source power applicator comprising a source power electrode at one of: (a) the ceiling (b) the workpiece support, and plural VHF power generators of different fixed frequencies coupled to the capacitively coupled source power applicator, and a controller for independently controlling the power output levels of the plural VHF generators so as to control an effective VHF frequency applied to the source power electrode. In a preferred embodiment, the reactor further includes a plasma bias power applicator that includes a bias power electrode in the workpiece support and one or more RF bias power generators of different frequencies coupled to the plasma bias power applicator.

A double-frequency coupled antenna with a metal frame comprises the metal frame, a printed circuit board (PCB) arranged in the metal frame, and an antenna unit, wherein the metal frame comprises a closed loop metal frame formed by a first frame, a second frame, a third frame and a fourth frame, the PCB comprises a circuit area and a clearance area, the antenna unit comprises a feed line and a coupling line, the feed line is connected with a feed source, the coupling line is electrically connected with the fourth metal frame, and two ends of the fourth frame are connected with a ground of the PCB to form a closed-loop radiation loop. According to the double-frequency coupled antenna with the metal frame, the metal frame is designed as a part of an antenna irradiator, and projection areas of the PCB of the antenna are reduced; the metal frame does not need slotting, by means of a coupled feeding manner, current of the antenna in the whole radiation loop can be more evenly distributed, and the problem that finger touch affects properties of the antenna of mobile terminals is solved; by means of a slotting manner, the requirement of the antenna for PCB clearance environments is reduced, and thus, the antenna is applicable to more complicated mobile phone environments.

A plasma reactor for processing a workpiece includes a reactor chamber and a workpiece support within the chamber, the chamber having a ceiling facing the workpiece support, an inductively coupled plasma source power applicator overlying the ceiling, and an RF power generator coupled to the inductively coupled source power applicator, a capacitively coupled plasma source power applicator comprising a source power electrode at one of: (a) the ceiling (b) the workpiece support, and plural VHF power generators of different fixed frequencies coupled to the capacitively coupled source power applicator, and a controller for independently controlling the power output levels of the plural VHF generators so as to control an effective VHF frequency applied to the source power electrode. In a preferred embodiment, the reactor further includes a plasma bias power applicator including a bias power electrode in the workpiece support and one or more RF bias power generators of different frequencies coupled to the plasma bias power applicator.

A method for processing a workpiece in a plasma reactor chamber includes coupling RF power at a first VHF frequency f1 to a plasma via one of the electrodes of the chamber, and providing a center ground return path for RF current passing directly between the ceiling electrode and the workpiece support electrode for the frequency f1. The method further includes providing a variable height edge ground annular element and providing a ground return path through the edge ground annular element for the frequency f1. The method controls the uniformity of plasma ion density distribution by controlling the distance between the variable height edge ground annular element and one of: (a) height of ceiling electrode or (b) height of workpiece support electrode.

A plasma reactor includes an electrostatic chuck in the chamber for supporting the workpiece, a ceiling electrode facing the electrostatic chuck and an ESC electrode in the electrostatic chuck with an electrostatic clamping voltage supply coupled to the ESC electrode. The reactor further includes at least a first RF bias source of an LF or HF frequency coupled to the pedestal electrode, and first and second VHF power sources of different frequencies coupled to the same or to different ones of the electrodes. The first and second VHF power sources are of sufficiently high and sufficiently low frequencies, respectively, to produce center-high and center-low plasma distribution non-uniformities, respectively, in the chamber.

The invention discloses a displacement buffer which can reduce a frequency coupling effect and a displacement buffer unit; wherein every level of the displacement buffer unit comprises at least a lifting driving module, a lifting module, at least a pull-down module and a pull down driving module; wherein, before a first frequency signal waveform or a second frequency signal waveform used by the lifting module forms an ascending edge, the pull-down driving module opens the conduction of the pull-down module for a particular period according to a first periodic signal; and / or before the first frequency signal waveform or the second frequency signal waveform used by the lifting module forms an descending edge, the pull-down driving module closes the conduction of the pull-down module for a particular period according to a second periodic signal; therefore, when the coupling effect of the frequency signal appears at that time, the pull-down module has enough ability to resist so as to improve the output waveform of the displacement buffer unit.

The invention discloses a stability analysis method for a grid-connected inverter system under the coexistence condition of multiple frequency coupling factors. The method is applied to a grid-connected inverter system, wherein the situation that multiple frequency coupling factors coexist is considered. A frequency coupling characteristic analysis model of a grid-connected inverter is establishedin a phase sequence coordinate system, and a power grid impedance matrix is obtained through calculation under the condition that the frequency coupling is considered. The method is realized based onthe generalized Nyquist stability criterion, and the stability of the grid-connected inverter system is judged by utilizing the generalized impedance ratio matrix of the grid impedance matrix and thefrequency coupling characteristic matrix of the grid-connected inverter. Therefore, the method can be used for analyzing the system stability under the complex condition of the coexistence of multi-frequency coupling factors. Compared with an existing stability analysis method based on the impedance of the grid-connected inverter, the method is more complete. Therefore, analysis errors caused byignoring frequency coupling are avoided. The stability of the grid-connected inverter system under the complex condition can be analyzed more accurately.

A method of processing a workpiece in a plasma reactor chamber includes coupling RF power via an electrode to plasma in the chamber, the RF power being of a variable frequency in a frequency range that includes a fundamental frequency f. The method also includes coupling the electrode to a resonator having a resonant VHF frequency F which is a harmonic of the fundamental frequency f, so as to produce VHF power at the harmonic. The method controls the ratio of power near the fundamental f to power at harmonic F, by controlling the proportion of power from the generator that is up-converted from f to F, so as to control plasma ion density distribution.

The invention relates to a frequency variable coupling feeding device used in boardband microstrip antenna which includes coplanar waveguide and coupling slit thereon, and a varicap device whose two pins are fixed to two sides of the center of the coupling slit of the coplanar waveguide. Feeding manner is changed by regulating the varicap device, and the provided device can switch frequency resonant points of the antenna in a very wide band thereby realizing frequency conversion when feeding for the antenna; in the state of fixed antenna dimension and fixed shape of the coupling slit, the invention can improve the antenna performance such as better bandwidth and plus only by regulating the varicap device. The invention provided device is fit for the broadband or multi-frequency wireless communication field.

A plasma reactor includes a ceiling electrode facing a workpiece support pedestal and a pedestal electrode in the pedestal and first and second VHF power sources of different frequencies coupled to the same or to different ones of the ceiling electrode and the pedestal electrode. The first and second VHF power sources are of sufficiently high and sufficiently low frequencies, respectively, to produce center-high and center-low plasma distribution non-uniformities, respectively, in the chamber. The reactor further includes a controller programmed to change the relative output power levels of the first and second VHF power sources to: (a) increase the relative output power level of the first VHF power source whenever plasma ion distribution has a predominantly edge-high non-uniformity, and (b) increase the relative output power level of the second VHF power source whenever plasma ion distribution has a predominantly center-high non-uniformity.

A gas turbine and method are disclosed by which the gas turbine can be safely operated at nominal speed with reduced margin to a surge limit of a compressor. The gas turbine, via a directly driven generator which generates alternating current with an operating frequency and which is connected in a frequency-coupled manner to an electricity grid, can deliver electric power to this grid. In the case of an underfrequency event the compressor of the gas turbine is unloaded by controlled, fast closing of the variable compressor guide vanes (VGV) and as a result maintains a sufficient margin to the surge limit of the compressor.

The invention discloses a terahertz wave detector. A gallium nitride high electron mobility transistor is used as a base structure of the terahertz wave detector. The terahertz wave detector comprises a transistor, a source-drain contact testing electrode and lead part and a terahertz wave coupling antenna; the terahertz wave coupling antenna is the special frequency coupling antenna and is used as a contact electrode to be connected with a nano-structure grid electrode of the transistor; the terahertz wave coupling antenna is positioned at two sides of a source electrode and a drain electrode of the transistor, and contact electrodes of the source electrode and the drain electrode are introduced from two antenna sections; the nano-structure grid electrode of the transistor is connected only with one side of a double-slit opening of the terahertz wave coupling antenna; the source electrode and the drain electrode of the transistor are asymmetrically arranged relative to the terahertz wave coupling antenna. According to the terahertz wave detector, the impedance of a metal electrode of the detector antenna to incident terahertz wave is in match with the input impedance of the grid electrode of the transistor, and therefore, the terahertz wave can be efficiently detected, and the detection sensitivity is high.

Disclosed is a loudspeaker assembly incorporating innovations resulting in an enclosure of very small volume to which is integrated a large area, shallow and lightweight acoustic diaphragm assembly capable of a natural resonant frequency of a few Hertz. This is achieved by incorporating a vacuum chamber in conjunction with a chamber containing compressed gas or vapor that acts against a movable pressure boundary of changeable area being mechanically coupled with the acoustic radiating diaphragm. In an alternative operating mode, the apparatus also serves as a passive low frequency acoustic attenuator.

The invention discloses a method for testing the dynamic characteristics of a lubricating film of a sliding bearing. The method comprises the following steps of: (1) assembling a test platform and a signal acquisition system, adjusting the rotating speed of a main shaft and the temperature and the flow rate of a lubricant, supplying a lubricating medium and starting a drive motor and a signal acquisition instrument; (2) applying excitation force on the main shaft by an electromagnet loading device of the invention, measuring the excitation force by a pressure sensor, measuring the vibration response of the main shaft in horizontal and vertical directions by electric vortex sensors and acquiring and storing signals; (3) changing the rotating speed of the main shaft, keeping the temperature of the lubricant unchanged, and repeating the steps; (4) changing the temperature of the lubricant, and repeating the steps; (5) carrying out time-frequency domain analysis processing on the acquired signals and recognizing the dynamic characteristic parameters of the lubricating film by using an equation of solving frequency domain response by a least square method of solid and virtual frequency coupling; and (6) fitting and analyzing the eight dynamic characteristics parameters of the lubricating film at different rotating speeds and different lubricating temperatures, namely obtaining the three-dimensional dynamic characteristics of the lubricating film of the sliding bearing at varied speeds and varied temperatures.

The invention discloses a stability evaluation method and system for a multi-machine multi-node power generation system. The method comprises the steps of carrying out power flow calculation, and calculating a steady-state control signal of a converter connected with each node and the steady-state harmonic content of an electric parameter according to the obtained voltage amplitude, phase and power of each node in a steady-state operation state; establishing the impedance of each converter considering a frequency coupling effect, and substituting the steady-state control signal and the steady-state harmonic content of the electric parameter to obtain the impedance considering the frequency coupling effect under a specific working condition; connecting the impedance considering the frequency coupling effect and the impedance of a passive element under all specific working conditions according to network topology to obtain a network node admittance matrix, and further obtaining equivalent network impedance aggregated to a set node; and applying a stability criterion to the equivalent network impedance aggregated to the set node to evaluate the system stability. According to the invention, the generation mechanism of the harmonic oscillation of the multi-machine multi-node power generation system can be analyzed, and the stability of the multi-machine multi-node power generation system can be accurately evaluated.

The invention relates to an object steering detection device based on vortex light rotation Doppler effect. The device mainly comprises a vortex light preparation part and scattered light signal detection part. The vortex light preparation part mainly comprises an He-Ne laser, a polaroid, a lens group, a spatial light modulator and a plane mirror, and the scattered light signal detection part mainly comprises a combination imaging telescope, a multi-mode optical fiber, a photoelectric detector and a micro oscilloscope. Firstly, a Gaussian beam is generated by a laser, and a spatial light modulator loaded with a specific hologram is irradiated and loaded after being collimated to prepare vortex light; secondly, the vortex light transmission rotating speed is omega d, and then is irradiatedon a rotating object, and after the object is scattered, scattered light is collected through the convex lens group, beat-frequency coupling is realized under the action of the beam splitter prism andthe original vortex light; and finally, the intensity change of the coupling light beam is detected by utilizing the photoelectric detection and transmitting the signal to the oscilloscope, Fourier transformation is carried out on the oscilloscope, and object steering can be judged according to the frequency spectrum information. The device is simple in structure and can still work effectively under various extreme conditions.

The invention relates to a multi-frequency coupled vibration energy capturer comprising multiple piezoelectric cantilever beams (1), a base frame (3), and an electric control plate (4). The piezoelectric cantilever beams (1) are installed on the base frame (3). Permanent magnets (2) are disposed on the piezoelectric cantilever beams (1). The multiple piezoelectric cantilever beams (1) have same length and different thicknesses. The permanent magnets (2) are arranged on the same positions of the multiple piezoelectric cantilever beams (1). The multiple piezoelectric cantilever beams (1) are connected with the electric control plate (4) through a line. Each piezoelectric cantilever beam (1) is composed of a metallic sheet (5), a piezoelectric patch (6), and a silver electrode surface (7). Compared with a product in the prior art, the multi-frequency coupled vibration energy capturer is novel and simple in structure and uses the magnetic coupling of the multiple piezoelectric cantilever beams with different inherent frequencies. When being seriously deformed, any piezoelectric cantilever beam forces other piezoelectric cantilever beams to deform. Thus, more energy can be captured in a wider frequency domain and high energy capture efficiency is achieved.

The invention discloses a grid-connected inverter frequency coupling impedance characteristic extraction method based on multi-sine-wave signal injection. The method comprises the steps: adopting an impedance measuring device based on a model predictive control method to realize the low-impedance characteristic in a broadband range; decomposing the multi-input and multi-output frequency coupling impedance characteristics of the grid-connected inverter into four single-input and single-output subsystems and performing independent measurement; measuring the broadband frequency coupling impedancecharacteristics of the grid-connected inverter through one-time signal injection, so enough measurement precision and rapidity are ensured. Compared with an existing frequency coupling impedance characteristic extraction method, the frequency coupling impedance characteristic extraction method has the advantages that the impedance characteristic extraction efficiency is remarkably improved whilethe measurement precision is guaranteed, and faster and more efficient frequency coupling impedance characteristic extraction can be achieved.

The invention relates to a double-fed grid-connected system subsynchronous oscillation analysis method by considering a frequency coupling effect. The method comprises the following steps of: firstly,inputting the fan parameter, the operation state and the grid-connected parameter of the doubly-fed grid-connected system; and establishing a doubly-fed fan external impedance analytical model basedon a harmonic linearization method. The method is mainly characterized in that the frequency coupling effect of output harmonic current of the doubly-fed fan under single-frequency harmonic voltage disturbance is considered, and meanwhile, according to two operating states of the doubly-fed fan, the external impedance analytical model of the fan is derived under different operating states; a polecriterion expression suitable for the characteristic equation of the doubly-fed grid-connected system is given in combination with grid-connected parameters; and finally, the subsynchronous oscillation stability of the target is judged system according to the calculated poles of the system characteristic equation. The subsynchronous oscillation mechanism of the doubly-fed grid-connected system isdisclosed quantitatively, and the subsynchronous oscillation stability of the target doubly-fed grid-connected system can be quantitatively analyzed.

Disclosed are a closed loop automatic level control method and a device used for the TDD mode communication system. The method is that during the coupling process of the input radio-frequency signal which is processed with radio-frequency coupling, radio-frequency attenuation and power amplification firstly, the input signal is detected in advance to extract the signal envelope for the voltage comparator of a singlechip and the signal envelop is compared with the preset voltage value to obtain the synchronous signal time sequence; then the level of the output signal is detected and is transmitted to the A / D converter of the singlechip; the A / D converter of the singlechip samples and outputs the detection signal; the singlechip judges the signal level; then the radio-frequency attenuator in the link circuit is controlled by the singlechip to realize the stable closed loop automatic level control. The device comprises a serial connection of a radio-frequency coupler (7), a radio-frequency switch (1), a radio-frequency attenuator (2), a drive amplifier (3), a power amplifier (4) and a radio-frequency coupler (8); the control end of the radio-frequency attenuator (2) is connected with a singlechip (9) in which a voltage comparator and an A / D converter are imbedded; the output ends of the radio-frequency couplers (7, 8) are respectively connected with radio detectors (5, 6); the radio detector (5) is connected with the input end of the voltage comparator of the singlechip; the outputted signal of the radio detector (6) is connected with the input end of the A / D converter of the singlechip; the output end of the singlechip (9) is connected with the control end of the radio-frequency switch (1).

The invention discloses an electrically adjusting common mode rejection filter based on selective frequency coupling. The electrically adjusting common mode rejection filter based on selective frequency coupling comprises an upper-layer microstrip structure, loading capacitors, loading variable capacitance diodes, a dielectric substrate and a bottom-layer metal ground plate, wherein the upper-layer microstrip structure is attached to the upper surface of the dielectric substrate, and the lower surface of the dielectric substrate is provided with the bottom-layer metal ground plate; the upper microstrip structure is composed of four half-wavelength resonators, four feeder lines and four ports; both ends of every feeder line form symmetric coupling with both ends of the corresponding half-wavelength resonator; every port is formed in the middle of every feeder line; the loading variable capacitance diodes are arranged at the open ends of the half-wavelength resonators for adjusting the central frequency; the loading capacitors are arranged at the tail ends of the feeder lines and the connecting positions among the feeder lines for controlling external quality factors.

The invention provides a wind power active power / frequency coupling electrical power system frequency characteristic calculation method based on pitch control. According to a one-time frequency modulation response transfer function model of a single wind turbine unit, a single steam turbine-speed governor model transfer function and a single water turbine-speed governor transfer function, a weighted equivalent polymerization method is used for separately calculating out a wind power plant one-time frequency modulation response transfer function model, a multiple steam turbine-speed governor model transfer function, a multiple water turbine-speed governor transfer function. A one-time frequency modulation control strategy based on the pitch control is taken into consideration, and electrical power system equivalent inertial time constants in different wind power permeability are calculated and solved. By the combination of the models and parameters, an improved SFR frequency response model is constructed, and a closed-loop system transfer function is calculated and solved according to the improved SFR frequency response model, wherein power shortage disturbance serves as input and system frequency deviation serves as output, and therefore a system frequency deviation frequency domain / time domain analytical solution is calculated under a sudden load increase step response. Finally, the validity and accuracy of a calculation method are systematically verified through a simulation example.

The invention discloses a frequency coupling modeling method for a single-phase LCL-type grid-connected inverter considering a phase-locked loop. A frequency domain expression of an inverter modulation signal considering the output phase angle deviation of the phase-locked loop is obtained through a harmonic linearization method; and then a frequency coupling impedance model of the single-phase grid-connected inverter is established according to a main circuit topology and the modulation signal frequency domain expression, and the problem of accurate modeling of the impedance of the single-phase grid-connected inverter is solved; based on the model, system stability and the influence of all system parameters on the frequency coupling degree can be analyzed; and from the established model,it can be seen that the frequency coupling phenomenon mainly occurs at the low frequency, and the coupling current component generated at the high frequency can be almost negligible. According to thefrequency coupling modeling method, the theoretical basis is provided for stability analysis of a new energy grid-connected system.

The doubly-fed variable-speed pumped storage unit is a novel hydroelectric system, and due to the fact that the rotating speed is continuously adjustable under a water pumping working condition, on the premise that a static lift is guaranteed, the input power adjusting range of the unit is widened through variable-speed operation. For the potential that an excavator unit participates in power grid frequency modulation, the invention relates to an active power-frequency coupling control method based on an electromechanical transient model of a doubly-fed variable-speed pumped storage unit under a water pumping working condition. The method comprises the following steps of: firstly, establishing a simplified electromechanical transient model of a variable-speed unit under a water pumping working condition; according to the model, on the basis of the operation characteristics of a pump turbine with the reversible water pumping working condition, considering the dynamic characteristics of fluid in an overflowing pipeline, and considering the additional friction effect of guide vanes; revealing the essential reason of the frequency modulation capability of the water pumping working condition unit from the angle of hydraulic power; clarifying a mechanism of improving power grid frequency characteristics by a water pumping working condition unit, and giving recommendation range of controller parameters; and finally, through simulation and experiment results, verifying the capability of improving the frequency characteristic of the power grid of the water pumping working condition unit.

The invention discloses an admittance model and impedance model acquisition method and device of a voltage source converter. The method comprises the steps that multiple converter parameters are acquired; multiple converter control parameters are acquired; a grid-connected system is run, and when the grid-connected system is in a steady state, multiple steady state values of the grid-connected system are collected; based on the multiple converter parameters, the multiple converter control parameters and the multiple steady state values, an admittance model transfer function is obtained, and through the admittance model transfer function, a frequency coupling admittance model and impedance model of the converter when the frequency of a small disturbance signal is fs are obtained. By means of the method, the coupling relationship between sub-synchronization and super synchronization can be considered, the influence of outer loop control is also considered, and the frequency coupling admittance model and impedance model of the converter are obtained based on the obtained small disturbance signal, so that the stability of a power system is accurately analyzed.

The invention discloses a sequence impedance modeling and stability analysis method of a load virtual synchronous machine. Influences of a direct-current voltage controller, a reactive power controller, an active power controller, an alternating-current controller and positive and negative sequence disturbance frequency coupling of a load virtual synchronous machine are comprehensively considered,a harmonic linearization method is adopted to establish an accurate sequence impedance model of a load virtual synchronous machine, so a problem of small signal impedance modeling of the load virtualsynchronous machine under the influence of multi-loop control and frequency coupling is solved. The influence of different power grid impedances on the stability of a grid-connected system of the load virtual synchronous machine is analyzed by utilizing the established sequence impedance model of the load virtual synchronous machine, the established power grid impedance model and the establishedNyquist stability criterion. Analysis results show that the load virtual synchronous machine can still operate stably under the condition of large power grid impedance, namely a weak power grid, and does not interact with the power grid easily to generate oscillation. The invention provides a model and a method for analyzing the stability of the small signal of the load virtual synchronous machineaccessed to the power grid, and popularization and application of the load virtual synchronous machine are facilitated.

The invention discloses a direct-drive fan subsynchronous oscillation electrical quantity analysis method considering a frequency coupling effect. The method comprises the steps: firstly, inputting adirect-drive fan parameter to be analyzed, and building a direct-drive fan simplified model; secondly, establishing an external impedance analytical model of a direct-driven fan based on a harmonic linearization method, wherein the establishment process is mainly characterized in that the frequency coupling effect of output harmonic current of the direct-driven fan under single-frequency harmonicvoltage disturbance is considered; and then, applying a single-frequency fp disturbance harmonic voltage to a grid-connected point of the direct-driven fan, calculating fp and 2f1-fp harmonic components in output current, giving an analytical expression of an output current frequency coupling relation, and comprehensively analyzing subsynchronous oscillation response characteristics of the direct-driven fan. The method quantitatively reveals a subsynchronous oscillation electrical quantity coupling response mechanism of the direct-drive fan under harmonic voltage disturbance, and the quantitative relation among the three can be provided only by inputting the parameters of the direct-drive fan.

A mode-switching transformer including a first conductive line between two common-mode access terminals and a second conductive line between two differential mode access terminals, the lines being coupled and sized according to a central operating frequency of the transformer, each line being formed of two stacked spirals in two different metallization levels and each spiral of a line being interdigited with a spiral of the other line.