87 results about "Pulse envelope" patented technology

A selective nerve stimulation patch includes a substrate having a top surface and a bottom surface, integrated components overlying the top surface of the substrate and being electrically interconnected with one another for generating at least one nerve stimulating signal, electrodes integrated into the substrate and exposed at the bottom surface thereof for applying the at least one nerve stimulating signal to a target nerve, a waterproof, breathable cover overlying the substrate and the integrated components, and a support flange surrounding the substrate and coupling the cover and the substrate together. The support flange has a top surface that slopes downwardly toward an outer perimeter thereof, and at least a portion of the cover conforms to the sloping top surface of the support flange. In one embodiment, the patch generates a high frequency waveform with properties such as amplitude, frequency and the like chosen so as to overcome tissue impedance and the stimulation threshold of the target nerve. The modulated waveform is the waveform obtained by modulating the carrier waveform by a pulse envelope.

An Implantable Pulse Generator (IPG) includes a surgically implantable housing, a battery, a first waveform generator, a second waveform generator, a modulator, and electrodes. The IPG produces a pulse envelope, a carrier waveform, and a modulated waveform. The pulse envelope is a low frequency waveform with specific pulse width, amplitude and shape to selectively stimulate a target nerve or body part. The carrier waveform is a high frequency waveform with properties such as amplitude, frequency and the like chosen so as to overcome tissue impedance and the stimulation threshold of the target nerve. The modulated waveform is the waveform obtained by modulating the carrier waveform by the pulse envelope.

The invention provides a novel method of transmit beamforming, which allows compact analog implementation of complex digital algorithms without compromising their features. It is aimed to support envelope shaping, apodization, and phase rotation per channel and per firing. Each of three embodiments represents a complete transmit channel driven by pulse-width modulated (PWM) waveforms stored in a conventional sequence memory. PWM signals controls the transmit pulse envelope (shape) by changing the duty cycle of the carrier. Beamformation data are loaded prior to a firing via serial interface. Under the direction of a controller, the circuitry allows high precision (beyond sampling rate) phase rotation of the carrier. It also provides transmit apodization (aperture weighting), which maintains an optimal trade-off among low sidelobe level and widening of the mainlobe. Implementing such an IC, the manufacturing cost of a high-end ultrasound system can be reduced. Equally, the proposed solution makes the benefits of digital transmit beamformers available to midrange and entry-level machines since it merely requires a modified programming of the sequence memory.

The invention relates to a femtosecond laser carrier envelope offset frequency lock system based on a heterodyne interferometric method. The system is characterized by comprising a femtosecond laser light source system, an acousto-optic modulator, a controllable optical path retardation device, a light splitting prism, a first photoelectric detector, a phase lock amplifier, a phase difference voltage conversion device and a PID controller. Heterodyne interferometry can be conducted on first-level phase-shift diffraction light modulated by the acousto-optic modulator and zero-level diffraction light which is not modulated, and after mixing of interference signals with different wavelengths, direct-current level lock pulse envelope alignment is achieved; optical frequency comb envelope offset frequency is locked by means of interference signal phase, the linear process does not exist, high non-linear optical fibers, frequency doubling crystals and the like are not needed, and the system is simple in structure and low in requirement for laser energy.

The invention relates to the field of the photoelectric technology, in particular to a microwave signal optical analog-digital conversion method and device based on time stretching. The differential envelope removal technology is adopted for the method, differential processing is conducted on a numeric field according to complementary output characteristics of two output modulators, distortion caused by pulse envelope heterogeneity is eliminated, and the aim of envelope removal is achieved. Two paths of complementary output signals are stretched in two independent time sequences of dispersive media of the same band, and consistency of the stretching multiple is guaranteed while the cost of the dispersive media is reduced. More importantly, limitation of a Jalali differential envelope removal scheme to the maximum stretching multiple is effectively avoided. The effective simulation bandwidth and the effective sampling speed of a continuous time optical analog-digital conversion system is remarkably increased.

The invention relates to a target simulator of an external field of a radar adopting a carrier wave extraction video storage method, which is characterized by comprising a receiving unit, a local oscillation frequency-division unit, an intermediate-magnification unit, a carrier wave extraction unit, a frequency synthesis unit, a signal processing unit, a single-side band modulation unit and an emission unit, wherein the receiving unit comprises a first frequency mixer and a first band-pass filter, the local oscillation frequency-division unit comprises a first magnifier, a power distributor and a frequency divider, the intermediate-magnification unit comprises a second magnifier and a pulse envelope extraction device, the signal processing unit comprises a first digital direct synthesizer DDS1, a second digital direct synthesizer DDS2, a single chip computer and a modulation pulse storage time delayer, the single-side band modulation unit comprises a single-side band modulator, a third magnifier and a second band-pass filter, and the emission unit comprises a third isolator, a fourth magnifier and a pulse modulator. The invention has the advantages of simple structure, low power consumption, strong versatility and convenient use of the external field.

The invention discloses a pulse signal detection method based on multi-pulse envelope spectrum matching. The method comprises the following steps: step 1, acquiring a sampling data sequence of a to-be-processed pulse signal; 2, calculating discrete Fourier transform of a sampling data sequence; 3, generating filter parameters according to known pulse signal frequency parameters; 4, performing frequency domain filtering on the multi-pulse signal by utilizing the generated filter parameters; 5, extracting an envelope of the multi-pulse signal after frequency domain filtering; 6, calculating theamplitude spectrum of the envelope by using Fourier transform; and 7, carrying out detection judgment on the pulse signal by utilizing the multi-pulse signal envelope spectrum. According to the multi-pulse detection method, the pulse string signal envelope is extracted through frequency domain filtering, high signal-to-noise ratio gain can be obtained, the envelope spectrum of the multi-pulse signal is matched with the ideal periodic rectangular signal frequency spectrum, the matching result is detected and judged, the detection probability of the pulse signal can be improved, and the false alarm probability can be reduced.

The invention provides a laser processing method for an LED wafer. According to the processing method, by adopting a pulse laser, the pulse laser outputs lasers in form of pulse trains or pulse envelopes. Each of the pulse trains or pulse envelopes comprises a plurality of sub pulses, and the time interval of each of the pulse trains or pulse envelopes is fixed. According to the laser processing method, the focuses formed on the LED wafer are round. The pulse trains or pulse envelopes on the laser cut LED wafer output lasers, so that the peak power of lasers for cutting the LED wafer is effectively reduced, the influence of the lasers on an LED wafer light-emitting region is reduced, and the electrical parameter yield of the LED wafer is improved, for example, forward voltage Vf, reverse current Ir, brightness and the like. The laser processing method for the LED wafer provided by the embodiment of the invention has a wide application space in the LED wafer laser cutting industry.

The embodiment of the invention discloses a low-signal-to-noise-ratio complex radar pulse envelope signal detection method and device. The device includes a digital channelization module, a signal envelope extraction module, a channel number-based envelope correction module and a double-threshold pulse detection module. First an input radar signal is subjected to channelization processing, and noise outside a channel is filtered; then a multipath channel signal envelope is extracted; then the signal envelope is corrected; and finally, a double-threshold pulse detection algorithm is adopted to ensure that a complete complex radar pulse signal is detected.

The invention discloses an individual characteristic identification method based on pulse envelope rising edge characteristic search matching. According to the rising edge envelope characteristics ofa radar signal, the purpose of performing individual characteristic identification on a radiation source through a Hausdorff distance-based rising edge envelope matching method guided by intentional identification is achieved; spurious modulation due to random change of magnetron parameters of a radar transmitter can cause that envelopes of transmitted signals have difference; therefore, radar fingerprint characteristics are formed; but, multi-path and noise influence on the pulse envelope rising edge is relatively low; when being practically used, the method has relatively high reliability; therefore, the rising edge envelope information of the radar signal is used as the fingerprint of the radar signal; and, in combination with intentional identification guide, the matching success ratein practical application can be increased.

The invention discloses a testing method for pulse modulated signals, which comprises the following steps: (1) converting a pulse-modulated signal to a sampled digital signal through an AD sampling unit; (2) converting the sampled digital signal to a pulse baseband signal by a digital frequency converter; and (3) processing the pulse baseband signal in two paths, wherein the first path is used for forming a triggering pulse for controlling and selecting data segments, the second path is stored in a buffer through a data storage/selection control unit; (4) generating a profile envelope of the whole pulse-modulated signal by an envelope demodulating unit; (5) generating a pulse triggering signal from the profile envelope by a pulse envelope shaping unit; (6) generating a triggering data gating signal from the pulse triggering signal by a triggering parameter setting unit; and (7) outputting a corresponding pulse baseband signal to a pulse parameter analyzing unit by a the data storage/selection control unit under control by a gating signal; and performing pulse baseband signal calculation and analysis by the pulse parameter analyzing unit.

The invention provides a calibration system and method of a pulse power standard, and overcomes the problems such as pulse waveform distortion, and mismatching between a radio-frequency source and a power meter in a pulse power meter calibration factor testing process. In the calibration system of the pulse power standard, the pulse power standard is used for generating a radio-frequency signal, and a waveform analysis module analyzes a pulse envelope and calculates a waveform correction coefficient; a reflection analysis module tests and calculates a reflection coefficient; and a control and data handling module controls a radio-frequency pulse signal, collects test data, calculates a calibration factor, analyzes precision, and accesses data. The calibration method of the pulse power standard comprises the steps of: test condition control, waveform correction coefficient testing, reflection coefficient testing and power testing, calibration factor calculation, precision analysis and the like. By collecting, storing, analyzing and correcting the test data in real time, the measurement uncertainty is lowered, the test processing is simplified, the test efficiency is improved and the precision is improved.

The invention discloses a long-distance pulse compression and short-distance pulse envelope detection delay measurement combined distance measuring method. The method comprises the following steps of during long-distance range measurement, measuring a distance by adopting the conventional pulse compression method, wherein a selected signal bandwidth can meet the requirement of the long-distance distance measuring accuracy; and during short-distance measurement, extracting linear frequency modulated signal envelope by adopting an envelope detection method after switching a received echo signal to a medium frequency through down-conversion in a receiver, finding a delay point on a detection envelop front edge by adopting a constant-ratio time point discriminant approach, so as to generate a delay pulse, and comparing differential delay between the delay pulse and a transmission detection pulse signal to obtain high-accuracy target distance information. According to the method, the distance measuring accuracy is increased effectively.

The invention discloses a TDC-based pulse carrier frequency detecting device and method. The system comprises a signal conditioning unit, a band frequency dividing unit, a power and pulse envelope detecting unit, a TDC unit, a power processing unit, and a signal processing unit. The signal conditioning unit, the band frequency dividing unit, the TDC unit, and the signal processing unit are sequentially connected; the signal conditioning unit, the power and pulse envelope detecting unit, the power processing unit, and the signal processing unit are sequentially connected; and the band frequencydividing unit and the e signal processing unit are connected. Therefore, the frequency test cost of the pulse modulation signal is lowered; and the accuracy of the frequency test is improved. The capability of measurement of the pulse parameters like the pulse width, the rising time, and the falling time of the pulse modulation signal and the frequency of the continuous radio-frequency signal isenhanced; and power measurement of the pulse modulated signal and the continuous radio-frequency signal is provided.

The invention provides an edge feature extraction-based pulse signal arrival time and pulse width estimation method. The method comprises the steps of extracting a pulse signal envelope from a pulse signal sampling data sequence, and based on this, performing normalization and difference value sequence calculation on the pulse envelope; and then calculating comprehensive evaluation factors of rising and falling edges of a pulse signal, and estimating arrival time and pulse width of the pulse signal. According to the method, through evaluation factors of front and back edge features of a pulse,the front and back edge features of the pulse are fully utilized; accurate estimation of the arrival time and the pulse width of the sonar pulse signal can be realized with a relatively small calculation amount; and the method is high in engineering practicality and suitable for real-time signal processing.

The invention discloses a time-of-arrival detection device and method. By setting multiple comparison circuits and time-to-digital conversion circuits in the time-of-arrival detection device, receivedpulse signals are sampled at multiple points, the envelope of the pulse signals is fitted out, and the envelope is matched with pre-stored pulse envelopes to identify the received pulse signals as useful signals or interference signals. Furthermore, a reference point is set according to the matching result, and the time of arrival or the time-of-arrival difference of the pulse signals is obtainedaccurately by measuring the time values of the reference point on a pulse signal transmitting envelope and the pulse signal receiving envelopes of the time-of-arrival detection device and other time-of-arrival detection devices. The technical problem that interference signals cannot be excluded in a single comparison circuit and time-to-digital conversion circuit and the technical problem that the time of arrival of a pulse signal cannot be determined accurately due to the fluctuation of the amplitude of the pulse signal in the prior art are solved.

The invention relates to a water turbine cavitation state online evaluation method based on rapid envelope spectrum kurtosis. The method comprises the following steps that S1, collecting original cavitation signals of a water turbine; S2, calculating an optimal band-pass filter according to the kurtosis of the fast envelope spectrum; S3, performing band-pass filtering by adopting an optimal band-pass filter to obtain an impact pulse signal waveform; S4, solving an impact pulse envelope waveform by adopting digital envelope demodulation; S5, obtaining the number of impact pulses, the time widthof each impact pulse and the amplitude of the pulse through the recognition of the envelope signal; S6, performing integral calculation on accumulated pulse impact energy in unit time and counting impact pulse density in unit time; and S7, evaluating the cavitation state of the water turbine d according to the accumulated pulse impact energy per unit time and the statistical impact pulse densityper unit time. The cavitation development degree of the rotating wheel is evaluated on line by utilizing the density and the impact energy intensity of the impact pulse.

A novel method for analyzing the pulse train resulting from a scanned beam particle monitor is described. The method enhances signal-to-noise ratio and significantly reduces particle false alarm rate. Performed in the time domain, the method filters noise pulses that do not occur at the scanner frequency. The analysis further identifies particle-pulse-envelopes (PPE's) by performing a forward-looking and backward-looking autocorrelation. Gaussian fits are subsequently applied to identified particle-pulse envelopes, to determine particle characteristics, such as size and speed.

Based on signal of one GSM frame lasts out eight pieces of time slot, thus, when making online comm, one user uses one time slot. If there is no online user, then the time slot has no signal. Analog signal represents generated pulse envelope. Pulse generated from analog signal is input to singlechip. Based on feature of the signal, the method obtains how many users communicate online in one GSM frame. In GSM hopping frequency sector, user operates at different frequency points (FP). In single FP, making statistics for hopping frequency number * n time in a period of time, the method obtains quantity of user in time of n frame for all FPs in a sector. Converting signal in RF carrier to IF signal, the method detects quantity of user carried by the carrier wave in the frame after following processes including amplification in low noise, RF sound surface filtering, IF amplification, demodulation etc on inputted RF signal by monitoring module for service of each carrier wave.