914 results about "Waveform distortion" patented technology

A color barcode symbology is disclosed that can be accurately decoded despite severe distortions, misreads or altered symbols. This disclosed barcode is a color transition barcode having linear growth properties designed to resist the single or combined effects of: scaling distortions, perspective distortions, shear distortions, and wave distortions of both the uniform and non-uniform type distributed across the barcode's vertical or horizontal axis. This color barcode symbology is also resistant to missing symbols and altered symbols while offering, high security, error checking, and double error correcting capability.

Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals are individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and/or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion.

Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals are individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and/or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion.

A driver circuit transmits a signal to a receiver circuit through a signal transmission line. The driver circuit has an output driver, a front driver, and a level adjuster. The front driver drives the output driver, and the level adjuster adjusts the output level of the front driver. The output driver generates a signal whose level is variable in response to an output level of the front driver.

In a magnet-exciting rotating electric machine system, a rotor surface has magnetic salient poles and island-shaped magnetic poles alternately in circumferential direction, and the island-shaped magnetic poles are constituted so that magnetic flux coming from an external source does not flow through. A magnetic excitation part magnetizes the island-shaped magnetic poles and the magnetic salient poles collectively in the same direction, and then control a flux amount flowing through an armature. The armature has armature coils that face the magnetic salient pole and the island-shaped magnetic pole simultaneously so that driving torque fluctuation or power generation voltage waveform distortion is controlled. The magnetic excitation part changes magnetization state of a field magnet irreversibly, or changes an excitation current to an excitation coil to control a flux crossing the armature.

The invention discloses an output power-based diagnosis method for an open-circuit fault of an insulated gate bipolar transistor (IGBT) of a three-phase inverter. The method comprises the following steps of: A, respectively measuring three-phase voltages and three-phase currents by using a potential transformer (PT) and a current transformer (CT) installed on the output phase in the inverter, and respectively calculating the half-wave power corresponding to six half-wave currents of the three phases of the current period; and B, comparing the six half-wave power values with a set open-circuit fault power threshold value P0, if one or two half-wave power values are less than the set open-circuit fault power threshold value P0, judging that the corresponding IGBT causes an open-circuit fault; or if three half-wave power values are less than the set open-circuit fault power threshold value P0, judging that the IGBTs corresponding to the two half-wave power values on the same side cause the open-circuit fault. By the method, any one or two IGBTs which cause the open-circuit fault can be detected and positioned, so that a controller of the inverter can take a tolerance strategy and reduce waveform distortion conveniently; the inverter can be maintained in time; and the loss enlargement and accidents are avoided effectively.

An objective is to provide a digital receiver and a method of compensating waveform that are capable of compensating waveform distortion without increasing the circuit size. A digital receiver 100 according to the present invention includes distortion compensation filters 103 that compensate waveform distortion included in an input signal, skew compensation amount setting units 106 for setting a skew compensation amount used for compensating phase distortion among the waveform distortion, amplitude compensation amount setting units 107 for setting an amplitude compensation amount used for compensating amplitude of the input signal that attenuates upon the compensation of the phase distortion using the skew compensation amount, and filter coefficient calculation circuits 108 for determining a filter coefficient to be set to the distortion compensation filters 103 based on the skew compensation amount and the amplitude compensation amount.

In a memory device having a controller and multiple memory modules both of which are mounted together on a motherboard, a high-speed operation is executed by suppressing waveform distortion caused by signal reflection. Since signal reflection occurs when a controller performs the writing/reading of data relative to memory units on memory modules, active terminator units are included in the controller and the memory units. These active terminator units are provided for a data bus and/or a clock bus in order to terminate these buses in memory units. The active terminator units provided for the controller and the memory units may be put into an inactive state when data is to be received.

A demodulator controls gains of an RF-AGC amplifier and an IF-AGC amplifier so as to maintain an input level to the demodulator constant. In this case, the demodulator estimates a signal level of an RF input based on the sum of the gains directed to the both AGC amplifiers, and changes methods for distributing a gain to the AGC amplifiers, according to whether or not the signal level exceeds a predetermined Take Over Point. Further, a first detection and smoothing circuit detects an output level of the RF-AGC amplifier, and a second detection and smoothing circuit detects an output of a mixer. Besides, a comparison circuit controls the gain of the RF-AGC amplifier so that a difference between the output levels comes to be a predetermined value. With this structure, an automatic gain control circuit which can achieve high receiving sensitivity and low waveform distortion simultaneously can be realized even when manufacturing dispersion is caused.

A distortion compensator, an optical receiver and a transmission system including an operation selectively compensating for linear waveform distortion exerted on an optical signal via a plurality of distortion compensators and compensating for nonlinear waveform distortion exerted on the optical signal using nonlinear distortion compensators.

The present invention enables modulated wave signals having extremely small waveform distortion to be generated using a relatively simple circuit, and thereby it is possible to hold down vibrations and noise of a motor, which are attributable to torque ripples. In order to remove defects of the conventional techniques, the circuit generates a plurality of trapezoidal wave signals having at least two constant levels based on position sensing signals of magnetic pole of a motor, generates quasi-sinusoidal wave signals at a quasi-sinusoidal wave modulator based on the plurality of trapezoidal wave signals, and compares the quasi-sinusoidal wave signals with a carrier wave so as to perform PWM control of an inverter.

A device, system, and method are provided for a power amplifier arrangement. In embodiments of a Vdd modulated power amplifier arrangement, a memory correction block includes a Vdd predictor for predicting waveform distortions of a Vdd modulated power supply and a main-path corrector for pre-distorting the input to the power amplifier arrangement as a function of the input to the power amplifier arrangement, an input envelope signal determined as a function of the input to the power amplifier arrangement, and an output of the Vdd predictor. Embodiments of the invention provide for operating power amplifier arrangements having memory. In some embodiments, methods of training the Vdd predictor and the main-path corrector of the memory correction block are provided.

The present invention relates to an electromagnetic vibrating table, comprising a table body. The table body comprises a first magnet, a first transition block, a central magnetic conducting pole, a second transition block and a second magnet, and the central magnetic conducting pole is housed by a moving coil; the table body also comprises a moving table and two frame-shape air-bearing guide rails, and the moving table can be arranged in the air-bearing guide rails in a sliding manner; the table body also comprises a drive motor and a lead screw connected with the drive motor, the lead screw is connected with a base plate, and both the leading wire and the air pipe are connected with the base plate; a grating scale is also arranged on the air-bearing guide rails, a grating read head opposite to the grating scale and a communication block connected with the grating read head are also arranged on the moving table; the communication block is connected with a controller; and the drive motor is connected with the controller signal. The invention provides an electromagnetic vibrating table with a complete peripheral device; the motor is controlled by the controller to drive the lead screw to pull the base plate to make simultaneous movement following the moving table, thereby, the subsidiary load of the air inlet pipe and the electrified lead wire does not influence the big-travel and low-frequency waveform distortion degree of the vibrating table.

An optical access network system having a function of correcting upstream signal waveform distortions occurring in the PON section, wherein a central office side apparatus comprises a main controller to notify each subscriber connection apparatus of a transmission grant period, an equalizer of a tap gain adaptive control type to correct waveform distortions of signals received from the subscriber connection apparatuses, an equalizer controller, and a parameter table for storing, for each subscriber connection apparatus, the initial values of tap gains to be set for the equalizer. The main controller issues a switchover request for switching the equalization characteristic to the equalizer controller each time notifying a subscriber connection apparatus of a transmission grant period, and the equalizer controller retrieves the initial values of the tap gains for the subscriber connection apparatus from the parameter table in response to the switchover request, and sets these values to the equalizer.

Disclosed is a method of producing a hologram through a two-beam laser interfering exposure process, which comprises emitting a coherent laser light with a pulse width (τ) ranging from greater than 900 femtoseconds to 100 picoseconds and a laser power of 10 μJ/pulse or more using a solid-state laser as a light source, dividing the pulses light from the laser into two beams, controlling the two beams temporally and spatially in such a manner that the two beam are converged on a surface of or inside a workpiece for recording a hologram while matching the respective converged spots of the two beams with one another temporally and spatially to create the interference therebetween so as to record a surface-relief hologram on the surface of the workpiece or an embedded hologram inside the workpiece in an irreversible manner. The present invention can solve a problem with a conventional process of recording a hologram in a non-photosensitive material in an irreversible manner using interfering femtosecond laser pulses, specifically, distortion in the waveforms of pulsed laser beams and resulting instability in recording of an embedded hologram due to a non-linear optical interaction between the femtosecond laser pulses and air/the material.

The invention provides an isolation type DC/DC (direct current/direct current) converter based on a modularized multilevel current converter. The converter comprises an input end modular multilevel current converter, a high-frequency transformer and an output end modular multilevel current converter, wherein the input end modular multilevel current converter is connected with the output end modular multilevel current converter through the high-frequency transformer. The input end modular multilevel current converter and the output end modular multilevel current converter respectively adopt MMC (multi media card) sub modules, high voltage is born, the voltage level is high, the transmission capacity is great, the expandability is high, in addition, the alternating current conversion link waveform distortion factor in the middle process is small, the harmonic wave content is low, and the electric isolation can be effectively realized on the input and output side of the converter.