237 results about "Rectangular pulse" patented technology

An impulse radio-based ultra wideband communication system, using an ultra wideband impulse and a 1-bit high-speed digital sampler, includes a transmitting RF module, a receiving RF module, a signal recovery unit, a transmitting signal processor, a receiving signal processor, and an ultra wideband antenna. The transmitting RF module includes an integrated impulse generator capable of implementing on-off-keying modulation and pulse position modulation, and an amplifier for amplifying output of the integrated impulse generator. The receiving RF module includes a two stage envelope detector for detecting a received signal and a comparator for converting the detected signal into a rectangular pulse. The signal recovery unit restores the signal from the receiving RF module to a digital signal using the 1-bit digital sampler. The signal processor includes a receiving signal processor for synchronizing the digital signal and decoding the detected signal. The ultra wideband antenna transmits and receives an ultra wideband signal.

A random number generator has a simple configuration using know inexpensive electronic parts and can generate the true physical random numbers at a required generation speed. Such a random number generator can provide the true physical random numbers to any sectors of society at dramatically low cost A random pulse generator comprises a thermal noise generating element (2) having a resistor, a conductor or a semiconductor such as a diode adapted to generate thermal noises Hen no electric current is supplied to them, an analog-amplifier circuit for amplifying the irregular potential generated from the thermal noise generating element and a waveform shaping circuit (6) adapted to take out the output of the amplifier circuit as random rectangular pulse signals. A thermal noise random number generator comprises, in addition to the above components, an n-bit counter (n being an integer) for measuring the time interval between a random pulse signal output from the waveform shaping circuit (6) and the immediately succeeding random pulse signal and is adapted to output the count of the n-bit counter as natural random number.

A high-voltage bipolar rectangular pulse generator using a high efficiency solid-state boosting front-end and an H-bridge output stage is described. The topology of the circuit generates rectangular pulses with fast rise time and allows easy step-up input voltage. In addition, the circuit is able to adjust positive or negative pulse width, dead-time between two pulses, and operating frequency. The intended application for such circuit is algae cell membrane rupture for oil extraction, although additional applications include biotechnology and plasma sciences medicine, and food industry.

The invention provides a CNN (convolutional neural network) based method for identifying communication interference signals at large dynamic SNR (signal to noise ratio), relates to the field of interference signal type identification and aims to solve the problems that the conventional interference signal type identification method is high in feature extraction difficulty, complex in form and low in accuracy of interference signal classification due to adoption of artificial extraction of features such as statistics, high-order cumulant and the like. With adoption of the method, totally 15 interference signals including 5 common interference signals and pairwise combinations of the 5 interference signals can be identified, the 5 interference signals include an audio interference signal, a same-frequency-band narrow-band interference signal, a sweeping interference signal, a rectangular pulse interference signal and a spread spectrum interference signal, and the feature that the interference signals have strong robustness at the large dynamic SNR is extracted by establishing a CNN model; SVM (support vector machine) classifiers for the 15 classes are constructed to classify the 15 interference signals and used for classifying the interference signals.

To provide a unit-layer post-treatment catalyst vapor-deposition apparatus and unit-layer post-treatment film forming method capable of improving in-face uniformity, step coverage, and film quality of a silicon nitride film or the like and forming a thin film by performing surface treatment after forming a film for each unit layer.

A thin film post-treated for each unit layer is laminated by using a film forming step of introducing mixed gas of silane gas and ammonia gas into a reactive vessel 2 as a source gas like a rectangular pulse and contacting with and thermal-decomposing the source gas by a catalyst body 8, and forming a silicon nitride film on a substrate 5, one surface treating step of bringing ammonia gas into contact with the catalyst body 8 and then bleaching the ammonia gas on the surface of a silicon nitride film on the substrate 5 and other surface treating step of bleaching hydrogen gas on the surface of the silicon nitride film on the substrate 5 after bringing hydrogen gas into contact with the catalyst body 8 as one cycle and repeating the step of one cycle.

A permanent invisible magnetic marking and positioning system of unfinished steel rods, spring steel bars, workpieces, and the like. A midpoint or center of the rod, bar or workpiece is automatically located and a high-energy pulse is applied for an embedded magnetic marker in the workpiece. Meanwhile, the magnetizing heads can also be repositioned to various points on a workpiece for imparting manufacturing and product identification data. In the case of leaf springs, the center of a spring steel bar is located a magnetic marker is embedded there. A high-energy rectangular pulse imparts a permanent invisible magnetic marks and data. The embedded indicators having peak magnetic strength allow manual or automatic positioning for perfect alignment in bending, tapping and other forming processes.

The invention discloses a digitized gapless phase noise measurement method based on group phase characteristic processing. The method comprises the following steps of: shaping a reference signal provided by a reference source into a rectangular pulse signal, carrying out frequency conversion on a signal to be measured and the rectangular pulse signal under the action of a controller, feeding the two signals which are subjected to the frequency conversion into a coincident point detection circuit together, and carrying out phase coincidence detection, wherein the phase shift processing is carried out on the rectangular pulse signal so as to accelerate a phase detection speed and accurately capture phase coincidence points; meanwhile, taking the phase coincidence points between the two signals as a measurement gate, and simultaneously starting up a counter to carry out gapless counting measurement on gate time, and reflecting the amplitude of phase noise by using the change of count values among the phase coincidence points; and finally, carrying out digital signal processing on time domain data which are measured when no gap gates exist, and displaying the single-sideband phase noise curve of the signal to be measured under the cooperation of a fast Fourier transform algorithm. The digitized gapless phase noise measurement method has the characteristics of simple circuit, high accuracy, capability of directly carrying out phase coincidence point detection on different-frequency signals, and the like.

The invention relates to a direct-current pulse-controlled molten drop deposition 3D printing device and a printing method. Rectangular pulse high voltage is generated through a direct-current high-voltage pulse generator, melt is stimulated to spray liquid drops instantly by connecting an upper electrode with a lower electrode, and with cooperation with three-dimensional movement of a forming substrate, the molten drops are deposited point by point and layer by layer to form a three-dimensional part. The direct-current pulse-controlled molten drop deposition 3D printing device is simple in structure, easy to control, high in melt liquid drop formation response frequency, and high in printing speed, and can be used for manufacturing parts in any complex shapes, and conducting diversified printing. In addition, materials are melted through a heating crucible, the temperature application range is wide, and the requirement for the types of the materials is low; material adaptability is high, for example, reliable 3D printing of various high polymer materials, metallic aluminum, tin and other materials can be achieved through the device; and printing efficiency and quality are high.

The invention discloses an all-fiber structural laser system capable of generating high-energy wave-free split rectangular pulse, which aims to solve the technical problems that the current erbium-doped fiber laser has low pulse energy and poor stability and is difficult to realize rectangular pulse output. The all-fiber structural laser system comprises two wavelength division multiplexers, an erbium-doped fiber, a first polarization controller, a polarization dependent isolator, a second polarization controller and an output coupler connected in turn through an intra-cavity single mode fiber, wherein the input ends of the two wavelength division multiplexers are provided with pumping light sources. The length of the erbium-doped fiber is 10 to 20 meters, the total length of the single mode fiber is 5 to 10 meters, and the whole intra-cavity net dispersion is kept in a large positive value. The all-fiber structural laser system has the advantages of simple structure, low price, good stability and the like on application; and compared with a solid laser for generating high-energy rectangular pulse, the all-fiber structural laser system has the advantages of high pumping efficiency, adjustment convenience, good pulse quality and the like, and is easy for fiber coupling.

A method and system for increasing the spectral efficiency of binary coded signals includes encoding an input binary bit sequence such that the input binary bit sequence is converted into a series of rectangular pulses having varying repetition rates. A continuous wave carrier signal is then modulated via a control signal representative of the encoded signal. The modulated optical signal is filtered by a narrow band optical filter to generate a minimum shift keying (MSK) encoded optical signal. In accordance with the present invention, an input binary bit sequence is encoded via a minimum shift keying (MSK) modulation format to improve the spectral efficiency of a binary coded digital signal and to contemporaneously limit distortion of the optical signal induced by optical nonlinear effects during transmission in an optical transmission system.

The invention relates to a process and a device for thermal measuring the flow rate (v) of a fluid (3). In conventional thermal sensors the heating power P is supplied in the form of rectangular pulses. According to the invention, the sensor means (1b) are supplied by a heating control (2b) with non-constant heating pulses having a sublinear build-up dynamics P(t). Thereby, a nonlinear behaviour of the threshold value time (t_S), until a threshold value temperature (T_m) is reached, as a function of the flow rate (v) can at least partially be compensated. Embodiments concern inter alia a build-up dynamics P(t) proportional to t^m and/or to a time-independent amplitude factor (1+R_S/R_I)⁻¹, wherein m is a Reynolds-number-dependent exponent and R_S, R_l are thermal transfer resistances. The advantages are an improved precision, a shorter measuring time and an enlarged measuring range for the flow rate v.

Constituted from revolving frisbee type mechanical spark switch driven by step motor, electric copper converts output voltage from DC high voltage power source to ultra low frequency square wave pulse in high voltage. Output characteristics of pulse power source in high voltage are: (1) amplitude of output pulse as 2-100kV adjustable; (2) repetition rate range of output pulse 0.5-l00Hz; (3) width range of output pulse 0.5ms-1.9s; (4) current of output pulse larger than 300 microampere; (5) flat top drop of output pulse lower than 2%. The disclosed power source meets needs of polarizing nonlinear crystal material in each thickness, measuring optimal experimental parameters for periodic polarizing reversion for nonlinear crystal material, and batch production experiment for ferroelectric domain crystal in periodic reversed structure.

Provided herein are various methods and systems for analyzing natural products by quantitative proton nuclear magnetic resonance (qHNMR). A method is provided for quantitative and qualitative determination of a natural product by ¹HNMR and decoupling ¹³C nuclei from the protons in the sample containing the natural product. The resultant spectrum wherein the decoupling provides a cleaner spectrum is used to provide both structural and quantitative information about species within the sample. In an aspect, the decoupling is provided by globally optimized alternating-phase rectangular pulses (GARP). The methods presented herein are optionally used to detect impurities in a reference material and verify the purity level of a reference material.

The invention provides a flexible electromagnetic ultrasonic guided wave sensor for a tube, and a detection method. The sensor comprises a runway type pulse bias magnetic field coil, a foldback type electromagnetic ultrasonic excitation coil, a foldback type electromagnetic ultrasonic receiving coil and a flexible protection layer; the electromagnetic ultrasonic excitation coil and the receiving coil are respectively stuck to the bottoms of two sides of the pulse bias magnetic field coil, the three coils are respectively connected with a shielded lead wire, and the other end of the shielded lead wire is connected with a two-pin plug; and the whole sensor is a flexible, flat and openable-closable structure. The detection method comprises the following steps: tying the sensor around the a detected pipeline, applying a rectangular pulse current to the bias magnetic field coil to generate a pulsed bias magnetic field, and applying a high-power radiofrequency current to the electromagneticultrasonic excitation coil to realize non-contact excitation and reception of ultrasonic guided waves. The sensor can be used for rapid detection of narrow space environments and pipelines with different diameters.

The invention relates to a power spectrum analysis method. The method comprises the steps: converting particle energy into an initial pulse signal, processing the initial pulse signal into a step pulse signal, converting the step pulse signal into a rectangular pulse signal after pulse shaping of the step pulse signal, enabling the pulse amplitude of the rectangular pulse signal to be a set value, enabling a corresponding relation to be formed between the pulse width of the rectangular pulse signal and the pulse amplitude of the step pulse signal, measuring the pulse width of the rectangular pulse signal and corresponding pulse counting to obtain the pulse width spectrum of the rectangular pulse signal, converting the pulse width spectrum into a pulse amplitude spectrum according to the corresponding relation between the rectangular pulse width and the step pulse amplitude or directly converting the pulse width spectrum into a power spectrum of particles according to a corresponding relation between the rectangular pulse width and the energy of particles. The invention also relates to a power spectrum analysis system and a Gamma ray detection system. The invention helps to solve the problem of the prior art that a power spectrum analysis process contains a complicated A/D converting circuit and thus the integration level is difficult to improve.

The invention discloses a low-pressure pulse vacuum nitriding method and a low-pressure pulse vacuum nitriding device for a titanium alloy. The low-pressure pulse vacuum nitriding method comprises the steps of firstly putting a titanium alloy sample into an inner cavity of a reactor tank after preprocessing the surface of the titanium alloy sample, vacuumizing the reactor tank subjected to sealing and leakage detecting, simultaneously heating the reactor tank to maintain the temperature of the inner cavity of the reactor tank at 700-1000 DEG C, and adding a nitriding gas medium into the inner cavity of the reactor tank in a pulse gas filling manner (namely repeatedly and periodically adding the nitriding gas medium by carrying out ventilation, closing-maintaining, air exhausting and closing-maintaining while ventilating), so as to change the pressure of the nitriding gas medium in the inner cavity of the reactor tank in a rectangular pulse manner, wherein the period range of a rectangular pulse is 10-200 minutes, and the pressure of the nitriding gas medium is maintained within a range of 0-0.050MPa. The low-pressure pulse vacuum nitriding device has the advantages of simplicity in operation, suitability in batch production, high machining efficiency, good and stable product quality and the like.

The invention belongs to the field of the inverter power supply in the field of microgrid, relates to inverter power output control and protection under the low voltage impedance environment, particularly relates to a control method of a low voltage microgrid inverter based on adaptive virtual impedance, and solves the problems in the background technology. The rectangular pulse trigger signals ofthe a, b and c phases of all the switching tubes obtained by cooperative control of the PQ power decoupling control, the transient current limiting control, the steady-state current sharing control and the power angle cooperative control act on a three-phase chopping bridge, thereby realizing the power control of the inverter under the low voltage microgrid. The adaptive virtual impedance is constructed on the basis of decoupling and drooping control of the inverter, and the power angle is adjusted according to the change intensity of the adaptive virtual impedance to perform cooperative control so as to improve the power equalization degree and the current limiting stability in case of grid connection of the inverter.

When a gate voltage having a rectangular-shaped pulse is supplied, the voltage of a pixel electrode is pulled down and fluctuated by a fall of the gate voltage due to a parasitic capacitor formed between a gate line and the pixel electrode, i.e. a so-called drop voltage is generated. As the drop voltage depends on a time constant of a change in the gate voltage, it can be diminished by smoothing the falling edge of the gate voltage. This is achieved by, for example, providing a current discharging transistor of a gate driver 8 with a small channel width to decrease the maximum current value. By utilizing such a gate voltage, a liquid crystal display device with a small drop voltage can be provided, even when the capacitance of the parasitic capacitor is great.