39 results about "Pulse propagation" patented technology

A synchronous delay circuit contains a first delay circuit for propagating a pulse for a fixed period of time, a second delay circuit for passing the pulse over a length proportional to the length of the first delay circuit along the path that the pulse propagated, and a circuit for outputting a monitor signal when a clock period is propagating through a clock driver. The first delay circuit measures a clock period tCK, and the second delay circuit reconstructs the measured clock period. External clock signals travel through a path from an input buffer through a first switch of a clock driver. The time corresponding to a delay time of the input buffer (td1) and a delay time of the clock divider (td2) is subtracted from the clock period tCK producing a delay circuit with a delay of tCK-(td1+td2). When the clock pulse passes through the delay circuit whose delay is tCK-(td1+td2), the internal clock delay becomes equal to the clock cycle tCK. Thus, the internal clock is free of clock skew.

A system and method for performing a test for characterizing high frequency operation of PCB boards. More particularly, a system and methodology is provided to implement a time-domain short pulse propagation (SPP) technique on the production line, on large, multi-layer, product-level PCB boards, for large volume testing, by people who are not familiar with advanced, delicate, measurement techniques, who need robust test facilities, and cannot afford the time or expense of other lab-type approaches.

Pulse propagation analysis to ascertain whether and anomaly such as surface corrosion exists on a section of conductive member such as pipe. Anomalies such as surface corrosion result in localized velocity changes of pulses propagating along a conductive member. These localized velocity changes exhibit themselves in changes in waveform, rise and fall time, amplitude, and time delay of a pulse with respect to a fixed time reference. To allow such anomalies to be located, two pulses are generated such that they intersect at intersecting locations along the conductive member. The resulting modified pulses are analyzed for perturbations indicative of localized velocity changes.

The invention discloses a single-station Doppler distance-measuring and positioning method, which comprehensively uses a Doppler shift relation, an equal propagation time difference relation and a plane geometric relation and realizes the measurement of the distance and speed of a target in constant linear motion through only three times of successive Doppler shift measurement. According to the three times of successive Doppler shift measurement of adjacent nodes, two ratio equations irrelevant to flight speed can be obtained; according to a condition that stationary periodic pulse propagation time differences on a propagation path are equal, an independent equation irrelative to the flight speed is obtained; and, in addition, suppose that the target performs linear motion, an equation of lead angles is obtained according to internal and external angle theorem in plane geometry. Thus, the total number of the equations needed for solving three lead angles is obtained. After the solution of the lead angles, the moving speed of the target is obtained according to the shit relation, and the radial distance of the target is obtained according to the plane geometric relation. The method of the invention has the advantages of low detection system cost, high measurement accuracy, simple algorithm, good astringency and the like.

The method relates to the field of hydraulic fracturing of subsurface formations. A mathematical simulation model of a pressure pulse propagation inside a wellbore and inside a fracture is created. Pressure pulses are sent to the wellbore, and the response of the well to the pressure pulses is registered. Then, a bottom-hole pressure corresponding to each pulse is determined. An average fracture width is derived by using the mathematical simulation model of pressure pulse propagation inside the wellbore and inside the fracture, and a ratio between the simulated average fracture width and the determined bottom-hole pressure is determined. The said ratio is extrapolated to a zero-width point, and the closure pressure is determined as the bottom-hole pressure corresponding to the zero width.

The invention provides a backing distance measuring method, a backing distance measuring device and a backing radar, which are suitable for the field of application of automobiles. The method comprises the following steps of: emitting an ultrasonic pulse signal by using a probe; acquiring a reflected pulse signal, and converting the pulse signal into first voltage; comparing the first voltage with preset first reference voltage; when the first voltage is not higher than the first reference voltage, comparing the first voltage with reference voltages in a preset reference voltage set sequentially, wherein the reference voltage set is a set of a group of reference voltages of which the voltage values are decreased sequentially and is relevant to pulse propagation time respectively; and acquiring a first reference voltage which is less than the first voltage from the reference voltage set, setting the reference voltage to be a second reference voltage, and acquiring a first obstruction distance according to time corresponding to the second reference voltage. The sensitivity of the backing radar can be flexibly changed.

The invention discloses a measuring method and a measuring device for pulse wave propagation time. The method comprises: synchronously collecting a pulse wave signal and an electrocardiogram signal ofa measured person, extracting characteristic points of the pulse wave signal and the electrocardiogram signal, and calculates a pulse conduction time PAT. The pre-ejection PEP was calculated according to the electrocardiogram signal. The pulse wave propagation time (PTT) is obtained by subtracting the pre-ejection PEP from the calculated pulse propagation time (PAT). The invention eliminates theinfluence of the pre-ejection period and improves the measurement accuracy of the pulse wave propagation time PTT.

Systems, methods, and computer readable medium described herein relate to techniques for characterizing and/or anomaly detection in integrated circuits such as, but not limited to, field programmable gate arrays (FPGAs) and application-specific integrated circuits (ASICs). In one example aspect of certain example embodiments, a fully digital technique relies on the pulse width of signals propagated through a path under test. In another example aspect, the re-configurability of the integrated circuit is leveraged to combine the pulse propagation technique with a delay characterization technique to yield better detection of certain type of Trojans and the like. Another example aspect provides for running the test through reconfigurable path segments in order to isolate and identify anomalous circuit elements. Yet another example aspect provides for performing the characterization and anomaly detection without requiring golden references and the like.

Disclosed are multiphase oscillators comprising a plurality of delay stages serially coupled in a loop by a plurality of nodes, with the loop being folded to provide two concentric rings of delay stages with equal numbers of allocated nodes. A second plurality of negative-resistance elements are provided, each element having a first output coupled to a node on the first concentric ring and a second output coupled to a node on the second concentric ring. Each such output switches between first and second voltage levels, and provides a negative resistance to a signal coupled to it during at least a portion of the transition between voltage levels. The outputs of an element switch to opposite voltage levels. With this construction, a high-voltage pulse propagates around the loop of delay stages, with a low-voltage pulse propagating behind it. Also disclosed are circuits to control the direction of pulse propagation.

The invention discloses a novel control automation type electrostatic protection test system and an electrostatic protection test method for power devices. According to the switch control device of the system, a plurality of semiconductor power devices are respectively arranged between a power supply and a charging transmission line, and the controls signals of the power devices are connected intoa microprocessor. Another plurality of semiconductor power devices are respectively arranged between the charging transmission line and a pulse propagation transmission line, and the controls signalsof the power devices are also connected into the microprocessor. According to the invention, the semiconductor power devices are adopted as the switch device of the system. In combination with a plurality of power device switch devices, a proper charging transmission line and a combination thereof are selected. Therefore, a pulse testing system with various pulse widths can be realized. Accordingto the system, the semiconductor power devices are used as the switch device to realize the multi-path control, so that the advantages of low cost, easy manufacture and debug, convenient maintenance,good stability, flexible usage and the like are realized. In combination with an automatic test system composed of a micro-controller, the system can be applied to the automatic testing of electrostatic protection and the like, and can completely meet the requirements of the multi-pulse width test.

The invention relates to a high energy coherent bandwidth continuous spectrum generating apparatus. The apparatus is composed of a first dispersion compensating apparatus, a light splitting apparatus,a spectrum broadening apparatus, a second dispersion compensating apparatus, a quarter-wave plate and a broadband mirror along an incident laser pulse propagation path. According to the high energy coherent bandwidth continuous spectrum generating apparatus, a common femtosecond, even picosecond laser spectrum can be widely spread. An applicable spectral range covers from deep ultraviolet to farinfrared bands, with great flexibility. The invention is applicable to higher pulse energy and incident light source with high average power.

Laser ultrasonic testing includes a laser apparatus; a splitting unit that splits a pulsed laser from the laser apparatus into first and second lasers; a first pulse width conversion unit that converts a pulse width of the first laser; a first optical system that guides the first laser having the converted pulse width to a test object; a second pulse width conversion unit that converts a pulse width of the second laser; a pulse propagation time adjustment unit that adjusts a propagation time of the second laser having the converted pulse width; a second optical system that guides the second laser having the converted pulse width and adjusted propagation time to the test object; and a detection unit that detects a surface displacement change of the test object caused by an ultrasonic wave generated by the first laser when the second laser is reflected by the test object.

The invention discloses a shortest path acquisition method and device based on a memristor pulse coupling neural network, and the method comprises the steps: directly mapping edges and vertexes of a weighted graph to synapses and neurons on the memristor-based pulse coupling neural network, recording the activation time of the neurons and the connectivity of the given neurons, and obtaining the shortest path from the starting neuron to all other neurons through highly parallel pulse propagation. According to the pulse coupling neural network based on the memristor, high parallelism of physical characteristics of the memristor is fully utilized, and the shortest path is obtained with low time complexity and space complexity; and 100% path optimality is obtained in the eight-vertex weighted graph, and the energy consumption is as low as 0.33 [mu]J.

The invention discloses a high-resolution time jittering delay measuring device and method based on non-linear correlation detection. The device comprises a first to-be-measured pulse input interface, a second to-be-measured pulse input interface, a time delay line, a non-linear frequency multiplication crystal and a photoelectric probe, wherein the time delay line and the non-linear frequency multiplication crystal are successively arranged in a first pulse spreading path, the non-linear frequency multiplication crystal is also arranged in a second pulse spreading path, the non-linear frequency multiplication crystal generates frequency multiplication related pulses based on first and second to-be-measured pulses, and the photoelectric probe collects the frequency multiplication related pulses. According to the technical scheme of the invention, high-resolution time jittering delay can be measured in the field of high-precision time synchronization, the measuring precision can reach 1ps, and the device and method are also characterized by high resolution and simple structure.

The present invention relates to a polyimide film. The present invention provides a polyimide film having characteristics such as small variations in size and the like. In the polyimide film, both thelinear expansion coefficient [alpha]MD in the transport direction (MD) of the film and the linear expansion coefficient [alpha]TD in the transverse direction (TD) are both 7 ppm/DEG C or less, and the the anisotropy index AI shown by the following equation when measuring the propagation velocity V of the ultrasonic pulse is 15 or less over the entire width. AI=(VMAX^2-VMIN^2)/(VMAX^2+VMIN^2), wherein VMAX^2 represents the square of the maximum value of the pulse propagation velocity, and VMIN^2 represents the square of the minimum value of the pulse propagation velocity.

The invention discloses a device and a method for monitoring high-voltage electric pulse energy and direction with a controllable electrode angle, and belongs to the field of high-voltage electric pulse rock breaking and fracturing. The device comprises a high-voltage power supply, a transmission cable, a capacitor, an output cabinet, a spark gap switch, a computer, a blasting vibration meter, a sealed cavity and a high-voltage electric pulse electrode angle controllable device; the high-voltage electric pulse electrode angle controllable device comprises an electrode head, a rubber base plate, a high-voltage electrode, a grounding electrode, a fixed frame, a rotatable frame and a scale disc; and the high-voltage electric pulse electrode angle controllable device is located in the sealed cavity, and the center of the rotatable frame is located in the center of the sealed cavity. According to the monitoring device, the angle between the electrode and the vertical direction can be changed, and therefore the pulse propagation direction and energy changes at different angles can be obtained, monitoring at any angle of 360 degrees can be achieved through one electrode, and therefore the changes of the angle and pulses are analyzed.

Examples of the disclosure relate to at least apparatus, methods, and computer programs, configured to control capture of two images of an area, across which a pulse propagates, using different shutter scanning directions. Either the images are converted into pulse-phase maps of the area and a pulse-phase difference map obtained which identifies differences between the pulse-phase maps of the area, or a colour difference map is obtained which identifies differences between the two images and the colour difference map is converted into a pulse-phase difference map. A shutter-time difference map is obtained which identifies differences between capture times of corresponding locations in the two images. Using the shutter-time difference map, the pulse-phase difference map is corrected to obtain a map of pulse-phase changes which have occurred over a duration of a shutter scan.

The invention belongs to the field of lightning detection, artificial intelligence and deep learning, particularly relates to a lightning electromagnetic wave positioning method, system and equipment based on single-station detection, and aims to solve the problems that an existing single-station lightning positioning method is large in positioning error, low in efficiency and small in range, and a positioning system is prone to interference. The method comprises the following steps: collecting lightning electromagnetic pulse waveform data in real time through lightning electromagnetic pulse detection equipment, and demodulating a received GPS or Beidou time service signal into high-precision time service information; calculating the propagation distance of the lightning electromagnetic pulse through the trained lightning electromagnetic pulse propagation distance prediction model; based on the collected lightning electromagnetic pulse waveform data, calculating the wave orientation of the lightning electromagnetic pulse; and fusing the propagation distance and the wave orientation of the lightning electromagnetic pulse to obtain a positioning result of the lightning electromagnetic pulse. According to the invention, high-precision detection of various types of lightning electromagnetic pulses can be realized, the detection range of a single station exceeds 1000 kilometers, and the positioning precision is superior to 5%.

The invention relates to a power cable deterioration detection device and a method thereof. The power cable degradation detection device includes a memory storing a power cable degradation detection program and a processor executing the program. The processor configures a diagnostic pulse train including a plurality of short pulses of different sizes and widths and performs pulse propagation characteristic analysis.