135results about How to "Fast frequency" patented technology

Adaptive antenna array techniques for use in an orthogonal frequency division multiplexed spread-spectrum multi-access (OFDM-SSMA) cellular wireless system or other type of wireless communication system. A base station of the system includes an antenna array and a base station receiver. The base station receiver implements an adaptive antenna gain algorithm which estimates a spatial covariance matrix for each of K mobile stations communicating with the base station. The spatial covariance matrix for a given one of the mobile stations is determined at least in part based on a unique hopping sequence of the mobile station, and provides a correlation between signals received from the mobile station at different antenna elements within the antenna array. An average spatial covariance matrix for a set of received signals is also generated. The individual spatial covariance matrices and the average spatial covariance matrix are processed to generate an estimate of an interference matrix for the K mobile stations, and the estimate of the interference matrix is further processed to generate array responses for each of the mobile stations. The array response for a given mobile station is processed to determine an antenna weighting which is applied to a signal received from the given mobile station in order to facilitate detection of a corresponding transmitted symbol.

An interface includes an encoder to receive a stream of input symbols and, in response, to output a corresponding stream of output symbols of substantially equal weight via multiple signal lines, which can improve noise / speed performance. The encoder outputs the stream of output symbols so that no output symbol is consecutively repeated. A repeat symbol is used to indicate that the current symbol is identical to the immediately preceding symbol. This encoding allows an interface receiving the stream of output symbols can extract a clock signal from the stream.

A phase locked loop, PLL, is described with multiple parallel charge pumps that are selectively disabled as phase lock is approached. A lock detection circuit is described that enabled reference currents to be fed to the parallel charge pumps. The error signal from a phase detector is arranged as UP and a DOWN signals that are averaged in the lock detector. When the average error is large, all the reference currents feed the charge pumps that provide a high loop gain to reduce the lock time. As the lock becomes closer selective reference currents are disabled to reduce loop gain so that a smooth transition to lock is made. Selectively switching currents into a low pass filter that usually follows a charge pump in a PLL circuit automatically reduces switching noise by the operation of the low pass filter.

The invention relates, inter alia, to a transmitter device, in particular for a base transceiver station in a mobile radio system, which has a digital modulator for making available a signal containing a phase information, and a modulation closed loop having a digital phase comparator operating at baseband whose first input is connected to the output of the digital modulator. In addition, a controllable oscillator is provided for generating an RF transmission signal at a controllable transmission frequency, a device which is assigned to the controllable oscillator and has the purpose of converting the RF transmission signal into a baseband signal containing a phase information. The output of the converter device is connected to a second input of the digital phase comparator.A GSM transmitter which has such a modulation closed loop exhibits, in terms of its out-band noise and interference characteristics, significantly improved properties in comparison with a GSM transmitter which does not include a modulation loop.

Improved approaches to providing thermal and power management for a computing device are disclosed. These approaches facilitate intelligent control of a processor's clock frequency and / or a fan's speed so as to provide thermal and / or power management for the computing device.

The invention relates to a frequency and time synchronization of a receiver (E) for receiving OFDM signals on a fixed carrier frequency. The inventive method is characterized by determining in a first step the approximate nominal value of the frequency and of the time origin of the OFDM signal via a two-dimensional frequency-time search mode and the determination of the area point with the optimum quality criterion of the OFDM signal or via the evaluation of a synchronization sequence transmitted by the transmitter. In a subsequent second step the phase of at least one of the pilot signals transmitted together with the OFDM signal is determined in the receiver (E) and is averaged across several OFDM signal blocks; and a more exact nominal value of the frequency and of the time origin of the OFDM signal is determined therefrom. The receiver (E) is then synchronized to the frequency so determined and the OFDM signal is demodulated with the time origin value so determined.

Provided herein is a pulse laser generator including a modulator configured to receive a continuous wave laser, and to modulate an intensity and phase of the continuous wave laser to generate a first pulse laser; and a chirping unit configured to chirp the first pulse laser to generate a second pulse laser.

A frequency synthesizer capable of using a voltage controlled oscillator (VCO) with a low value of gain Kvco, having a short automatic frequency calibration time and automatically coping with environments and a frequency calibration method are provided. The frequency synthesizer includes a reference divider, a phase detector, a main divider, a charge pump, a loop filter, a first switch, a second switch, a VCO, and an automatic frequency calibration block. The frequency calibration method includes an initialization step, an N-target algorithm step, an auxiliary search algorithm step, and a post search algorithm step.

An oscillator circuit comprises a first, high-Q crystal oscillator and a second, low-Q oscillator arranged for kick-starting the crystal oscillator at switch-on by coupling the second oscillator to the first oscillator for a time period. The oscillator circuit is arranged to select the frequency of the second oscillator by placing the second oscillator in a phase locked loop with the first oscillator providing a reference frequency, and adjusting the frequency of the second oscillator towards the frequency of the first oscillator.

The electrosurgical systems and methods according to the present disclosure use a multi-stage power converter for generating electrosurgical energy. The electrosurgical systems include an electrosurgical generator having a power converter coupled to an electrical energy source and configured to generate electrosurgical energy. The power converter includes a boost converter configured to convert a first direct current from the electrical energy source to a second direct current, and a phase-shifted pulse width modulation (PS-PWM) resonant inverter configured to invert the second direct current to an alternating current. The electrosurgical generator also includes a plurality of sensors configured to sense a voltage and a current of the generated electrosurgical energy and a controller coupled to the power converter and the plurality of sensors. The controller includes a signal processor configured to determine tissue impedance based on the sensed voltage and current, and an output controller configured to select one of a plurality of output characteristics based on the determined tissue impedance, and to generate control signals to control the boost converter and the PS-PWM resonant inverter, according to the selected output characteristic.

An oscillator includes a reference stage and multiple phase stages. The reference stage has a reference transistor having a gate coupled to a voltage reference and a drain coupled to a reference current source. Each phase stage includes a transistor, two current sources, a capacitor, switch, inverter, and latch. The transistor has a drain coupled to a first current source, a gate coupled to a node and a source coupled to the reference transistor's source. The capacitor and switch couple between the node and ground. The second current source couples to the node. The transistor's drain couples to the inverter's input. The inverter's output couples to the latch's set input. The latch's output couples to the switch. The inverter output also couples to the reset input of a subsequent phase stage's latch. The inverter output for a last stage couples to the reset input of a first stage latch.

A frequency synthesizer capable of using a voltage controlled oscillator (VCO) with a low value of gain Kvco, having a short automatic frequency calibration time and automatically coping with environments and a frequency calibration method are provided. The frequency synthesizer includes a reference divider, a phase detector, a main divider, a charge pump, a loop filter, a first switch, a second switch, a VCO, and an automatic frequency calibration block. The frequency calibration method includes an initialization step, an N-target algorithm step, an auxiliary search algorithm step, and a post search algorithm step.

A method and a system for tuning a resonance module in a radio base station is disclosed. The resonance module has tuning means, a transmitter connection, and an antenna connection. High-frequency input and output signals on the transmitter and antenna connection, respectively, are sensed and processed to tune the resonance module to a frequency of the input signal on the transmitter connection. The processing of the sensed input and output signals includes processing in a low-frequency range. Prior art methods are improved by the invention through the use of a quadrature modulator to increase adjustment speed and overall applicability of the resonance module to be tuned.

Homogeneous water oxidation catalysts (WOCs) for the oxidation of water to produce hydrogen ions and oxygen, and methods of making and using thereof are described herein. In a preferred embodiment, the WOC is a polyoxometalate WOC which is hydrolytically stable, oxidatively stable, and thermally stable. The WOC oxidized waters in the presence of an oxidant. The oxidant can be generated photochemically, using light, such as sunlight, or electrochemically using a positively biased electrode. The hydrogen ions are subsequently reduced to form hydrogen gas, for example, using a hydrogen evolution catalyst (HEC). The hydrogen gas can be used as a fuel in combustion reactions and / or in hydrogen fuel cells. The catalysts described herein exhibit higher turn over numbers, faster turn over frequencies, and / or higher oxygen yields than prior art catalysts.

The invention relates to a method for achieving synchronous control of a main shaft and an auxiliary shaft by means of a PLC. The method aims to achieve synchronous control of the two shafts on the premise of low cost. According to the technical scheme, a complex function needing to be achieved through multiple steps in a high-functioning medium or large PLC of other companies just needs to be realized through one instruction in the small PLC used in the method. If the complex function is achieved by using multiple instructions, the sampling period depends on the scanning period of the PLC in most cases; when a PLC program is large, the scanning period is very long, consequently a response lag of the auxiliary shaft is caused, the output pulse interval is large, a motor runs unstably, and positional accuracy is poor. The synchronization instruction is convenient to use and good in synchronization performance. Meanwhile, the execution efficiency of the PLC is greatly improved, and the scanning period of the whole PLC is shortened. Thus, the industrial movement control response is rapider, and position control is more accurate.

A constant ON-time or constant OFF-time switching power converter includes a control circuit for controlling a power switch. The control circuit includes: a constant ON-time or constant OFF-time calculation circuit, for calculating a constant ON-time or constant OFF-time; a logic circuit having inputs for receiving an output of the constant ON-time or constant OFF-time calculation circuit and a clock signal, respectively, wherein the clock signal has a frequency which is the desired fixed frequency; and a flip-flop for generating an output signal according to a set input and a reset input, wherein one of the set input and the reset input receives an output of the logic circuit, and the other one of the set input and the reset input receives a trigger signal which determines a start time of the ON-time or OFF-time.

The invention provides a frequency modulating single frequency fiber laser which comprises a novel rare earth doping phosphate glass optical fiber, a narrow band Prague fiber grating, a dichroic mirror or a broadband Prague fiber grating, a single-mode semiconductor pump light source, a wavelength division multiplexer, a fiber optic isolator and PZT (Pbbased Lanthanumdoped Zirconate Titanates) piezoelectric ceramics. The PZT piezoelectric ceramics is adopted by a laser short cavity structure to modulate a single longitudinal mode frequency of a short phosphate glass fiber laser resonant cavity, so that frequency modulating fiber laser output with good single frequency performance is realized, wherein the frequency modulation range can reach up to 1 GHz. The frequency modulating single frequency fiber laser can be applied to the detecting field of laser ranging and Doppler laser speed measuring radar with ultrahigh precision and ultra distance.

The invention discloses a dielectric ultrasonic transducer driving power, comprising a main controller, a sampling circuit, an adjusting circuit and a driving circuit; the sampling circuit and the adjusting circuit gain signals from the dielectric ultrasonic transducer; the output terminal of the sampling circuit and the adjusting circuit is connected with the main controller which receives the signals emitted by external controls and is connected with the dielectric ultrasonic transducer by the driving circuit; the main controller comprises a phase demodulation unit, a control unit, a direct digital frequency synthesizer, an amplitude modulating and limiting unit; the phase demodulation unit is connected with the output signal of the sampling circuit; the phase demodulation unit, the control unit, the direct digital frequency synthesizer and the amplitude modulating and limiting unit are sequentially connected in series and subsequently output the signals to the driving circuit. Compared with ultrasonic powers based on DSP and other controllers, the driving power has the advantages of rapid phase locking speed, high precision, programmable adjustment of output power, etc.

A communications apparatus and method use tapped delay lines as multiplexers and demultiplexers. In one embodiment, a receiver (100) uses a tapped delay line (110) as a demultiplexer to acquire a burst communication at very high data rates in the range of 2.5 to 80 Gbps with low preamble overhead. A sliding window correlator (114) continually samples the delay line (110) to determine when a PN encoded word is contained therein. The transmission frequency is pre-acquired before any data is present through the use of a ring oscillator frequency calibration loop (130) that is imbedded within the tapped delay line (110).

A time variant droop-based inertial control method of a wind generator includes the steps of acquiring a nominal frequency value and a system frequency value of a power system; calculating a difference between the system frequency value and the nominal frequency value; calculating a rate of change of the system frequency; acquiring a droop coefficient Rvariant using the rate of change of the system frequency; and controlling the wind generator based on the difference between the system frequency value and the nominal frequency value and the droop coefficient Rvariant.

An oscillator includes a reference stage and multiple phase stages. The reference stage has a reference transistor having a gate coupled to a voltage reference and a drain coupled to a reference current source. Each phase stage includes a transistor, two current sources, a capacitor, switch, inverter, and latch. The transistor has a drain coupled to a first current source, a gate coupled to a node and a source coupled to the reference transistor's source. The capacitor and switch couple between the node and ground. The second current source couples to the node. The transistor's drain couples to the inverter's input. The inverter's output couples to the latch's set input. The latch's output couples to the switch. The inverter output also couples to the reset input of a subsequent phase stage's latch. The inverter output for a last stage couples to the reset input of a first stage latch.

The invention discloses a Brillouin optical time domain analysis meter capable of locking frequencies of two lasers based on an optical phase-locked loop, relates to a Brillouin optical time domain analysis meter, and solves the problems of high price, complicated structure and large volume of the conventional device for detecting a beat frequency signal obtained after frequency mixing of the two lasers by utilizing a microwave frequency counter, and slow frequency scanning speed and narrow frequency scanning range caused by slow response speed of an optical delay line due to frequency locking and scanning between two distributed feedback type semiconductor lasers through the optical delay line. The Brillouin optical time domain analysis meter comprises a 1# laser, a 2# laser, a 1# optical fiber coupler, a 2# optical fiber coupler, a 3# optical fiber coupler, a phase-locked loop module, an electro-optical modulator, a pulse generator, a scrambler, a detection amplification module, an optical attenuator, an erbium doped fiber amplifier, a circulator, a photoelectric detector and a data acquisition module. The invention is suitable for the Brillouin optical time domain analysis meter.

The invention belongs to the field of welding devices, particularly relates to a wire feeding system of a double-motor combined welding wire coordinating mechanism. The wire feeding system specifically comprises an upper computer (1), an interface circuit (2), a push-pull wire motor control unit (3), a push-pull wire feeding servo motor unit (4), a welding wire coordinating mechanism (5), a push wire motor unit (6) and a PWM speed adjusting circuit (7), wherein the upper computer is connected with the push-pull wire motor control unit via the interface circuit and connected with the PWM speed adjusting circuit, and used for totally controlling the whole push-pull wire feeding system; the push-pull wire motor control unit is used for closed loop control of the push-pull wire feeding servo motor unit; the PWM speed adjusting circuit is used for driving and controlling the push wire motor unit; the welding wire coordinating mechanism is an intermediate link for connecting the push wire motor unit with the push-pull wire feeding servo motor unit. The wire feeding system is mainly combined with a digital welding power source and capable of realizing various welding technological methods based on high-frequency feed-draw welding wires.

A method of altering the frequency of blades (1) having an airfoil (2) with a suction side (6), a pressure side (5), a leading edge (10), a trailing edge (7) and a blade tip (9), and including a blade root (3), in particular turbine blades, for thermal fluid-flow machines. A metallic coating (8) formed of a material identical to the parent material is applied to the blade (1), already ready for use, in the region of the blade tip (9), the thickness of the coating (8) tapering continuously at the trailing edge (7) and in the radial direction toward the blade root (3).

The invention discloses binocular stereo vision-based guide eyeglasses for a blind person. The binocular stereo vision-based guide eyeglasses comprise special glasses (1), a main control box (2), a vibration waistband (3), a headphone line (5), an earplug (6), a video cable (4) and a battery. After power-on, an image acquisition module (8) configures image sensor parameters of two micro cameras (7) and simultaneously collects image data, the image data is transmitted to the main control box (2) through the video cable (4) and then is processed, a headphone broadcasts information to the blind person and simultaneously transmits the information to the vibration waistband (3), a vibration control module (10) controls the vibration of a waistband motor (11) to remind the blind person to pay attention to the front obstacle, and a user can use a dedicated dialing keyboard (9) to realize speed dial. The binocular stereo vision-based guide eyeglasses for a blind person has high detection accuracy,, a wide range, fast frequency, wearing convenience, light weight, long duration time and a wide application prospect.

A method and mobile terminal for searching for alternative frequencies is provided for facilitating alternative frequency search. The mobile terminal having an alternative frequency search function includes a control unit having a radio data decoder for decoding radio data containing a program identifier and for differentiating the radio data by type, a radio data filter for extracting the program identifier from the radio data and for comparing the extracted program identifier with a previously stored program identifier, and a radio data updater for updating an alternative frequency list in response to an instruction of the radio data filter, and a storage unit for storing the alternative frequency list and the differentiated radio data. The alternative frequency search method and mobile terminal of the present invention facilitates alternative frequency search by updating the alternative frequency list only when the program identifier decoded from Radio Data System (RDS) data is substantially identical with the previously stored program identifier.

The invention discloses a broadband low-noise frequency modulation signal source. A high-stability clock module has two clock signals as output, the first clock signal as output is directly connected with the reference clock end of a DDS module, and the second clock signal is connected with the input end of a power divider; the power divider divides the second clock signal into haves and respectively outputs the two haves through two output ends, wherein one half is output to a DDS configuration module; the DDS configuration module outputs a configuration signal to the DDS module, the DDS module, after receiving the configuration signal, generates a frequency modulation signal by use of a phase synthesis and table look-up method and outputs the frequency modulation signal through a waveform output end; the waveform output end is respectively connected with a first phase-locked loop circuit and a second phase-locked loop circuit through a low-noise amplifier; output of the first phase-locked loop circuit is taken as an emission local oscillator; and output of the second phase-locked loop circuit is taken as a receiving local oscillator. The signal source provided by the invention can meet the demands for high linearity and low phase noise of a broadband frequency modulation signal source.

The invention discloses a single phase locking device. In the device, a Kalman filter is used for combing a zero crossing point detection phase locker and a DQ coordinate system phase locker and performing Kalman filtration on frequency values, phase positions and amplitude values sent by the zero crossing point detection phase locker and the DQ coordinate system phase locker so as to obtain a final phase position, a final amplitude and a final frequency. The invention also discloses a single phase locking device which can realize a rapid and accurate phase locking function on an input signal sent by a single-phase electrical system by utilizing the advantages that sampling errors can be greatly eliminated due to the Kalman filtration and the recursive computation is high in response speed, so that the device is far better than a traditional phase locking ring in dynamic performance and static performance, overcomes the shortcomings that a traditional single phase locking method is low in speed and easy to affect, and realizes a rapid and accurate phase locking function on the phase position, amplitude and frequency of an input signal of a single-phase power grid.

A method and a system for tuning a resonance module in e.g. a radio base station are disclosed. The resonance module has tuning means, a transmitter connection, and an antenna connection. First frequency input and output signals on the transmitter and antenna connection, respectively, are sensed and processed to tune the resonance module to a frequency of the input signal on the transmitter connection. The processing of the sensed input and output signals includes processing in a second frequency range. Prior art methods are improved by the invention through e.g. the use of a quadrature modulator to increase adjustment speed and overall applicability of the resonance module to be tuned.