46results about How to "Improve linearization" patented technology

An amplifier system is provided that switches between a linear mode of operation, an envelope tracking mode of operation and a polar mode of operation. The amplifier system switches between modes of operation based upon a characteristic of an input signal relative to a first threshold level and a second threshold level. A mode selector selects the operation mode by transmitting an amplitude modulated signal plus a variable headroom voltage to a supply terminal of a power amplifier during the envelope tracking mode, an amplitude modulated signal to the supply terminal and phase modulated input signal during the polar mode and a substantially constant amplitude signal to the supply terminal during the linear mode.

An amplifier system is provided that switches between operation in a polar mode and a linear mode based on a characteristic of an input signal relative to a threshold level. The system operates as a polar amplifier in the polar mode, and as a linear amplifier in the linear mode. A mode selector controls whether polar components of the input signal are sent to a power amplifier or whether a composite signal is amplified.

The invention relates to a method of digitally linearizing an amplifier having non-linearity, the method being of the type comprising: a prior stage in which correction parameters for correcting said non-linearity are determined, and a linear amplification stage performed by applying predistortion followed by amplification. In the invention, stage in which the correction parameters are determined comprises the following steps: acquiring said amplified test signal in the form of samples in baseband; defining a modelled amplifier, by computing parameters of a predetermined amplifier model on the basis of said samples of the amplified test signal; and computing said correction parameters on the basis of said modelled amplifier so that they make it possible to linearize said modelled amplifier. The invention also relates to a corresponding system for digitally linearizing an amplifier.

A polar loop transmitter includes separate phase and envelope paths providing a linearising scheme for an efficient non-linear power amplifier. Loop filters are included in each of the phase and envelope paths to enable the path characteristics to be matched to one another. A polar loop transmitter and other types of envelope elimination and restoration transmitters control the output envelope of the power amplifier by connecting the output of the envelope detector, or in an envelope feedback transmitter, the envelope error signal, to the bias control input of the power amplifier. The transmitter can further include compensation means for compensating for non-linearities in the envelope control means and a loss of feedback control detector to ensure that the feedback signal remains within acceptable limits.

Systems for detecting and tracking of objects and co-registration are described which utilizes methods to create a linearized view of a lumen using multiple imaged frames. In reality a lumen has a trajectory in 3-D, but only a 2-D projected view is available for viewing. The linearized view unravels this 3-D trajectory thus creating a linearized map for every point on the lumen trajectory as seen on the 2-D display. In one mode of the invention, the trajectory is represented as a linearized display along 1 dimension. This linearized view is also combined with lumen measurement data and the result is displayed concurrently on a single image. In another mode of the invention, the position of a treatment device is displayed on the linearized map in real time. In a further extension of this mode, the profile of the lumen dimension is also displayed on this linearized map.

An RF transmitter (60) generates non-DC bias signals (104, 106) configured to improved power-added efficiency (PAE) in the operation of an RF amplifier (94). The RF amplifier (94) generates an amplified RF signal (126) which, due to the addition of the bias signals (104, 106), includes bias-signal-induced RF distortion (48, 50). The bias signals (104, 106) drive a bias-induced distortion cancellation circuit (152) that adjusts the bias signals to compensate for the influence of impedances experienced by the bias signals (104, 106) before being applied to the RF amplifier (94). After mixing with a baseband communication signal (64), adjusted bias signals (186, 188) are combined into a composite baseband signal (76), upconverted to RF in an upconversion section 84, and applied to the RF amplifier (94) where they cancel at least a portion of the bias-signal-induced RF distortion (48, 50).

The invention discloses a Doherty envelope tracking power amplifier and a method for treating a radio frequency signal. The amplifier comprises a power divider, a peak amplifier, a carrier amplifier, a coupler, an envelope extraction unit and a first linear amplification unit, the input end of the radio frequency signal is respectively connected with the input end of the power divider and the input end of the envelope extraction unit by the coupler, the output end of the power divider is respectively connected with the input end of the peak amplifier and the input end of the carrier amplifier, the output end of the carrier amplifier is connected with the output end of the peak amplifier in a coupling way, and the output end of the envelope extraction unit is connected with the grid electrode end of the carrier amplifier by the first linear amplification unit. According to envelope changes of the input radio frequency signal and under the conditions of ensuring the basic changeless output signal gain, the carrier amplifier enables the linearization of output signals to reach real-time optimization and improves the linearization of the output signals of the carrier amplifier, thereby improving the efficacy of the Doherty envelope tracking power amplifier.

The invention relates to a single-bit DPD (Digital Pre-Distortion) method for a power amplifier. The single-bit DPD method comprises the steps of: carrying out time delay estimation by a frequency domain method, and carrying out time delay compensation in a digital domain; taking difference values of input and output signals; replacing a conventional feedback branch circuit ADC (Analog-to-Digital Converter) with a 1bit ADC or a comparator, sequentially carrying out sampling on the difference values of the input and output signals, i.e., x still represents an input signal sequence, and carrying out difference value taking processing on output y signals; estimating a step length required in iteration; and carrying out iteration by employing an iteration format suitable for 1bit after carrying out the processing to complete parameter extraction of DPD. According to the method, a 1bit technology developed in the field of digital signal processing in recent years is used for a DPD technology of the power amplifier, the single-bit DPD method is formed, power consumption and cost of a feedback loop can be greatly reduced, a bandwidth range of the DPD technical application also can be greatly improved and is expected to reach hundreds of MHz, and the broadband DPD technical requirements of 5G (5th-generation) communication are possibly solved.

An apparatus and method to improve broadband amplifier linearization. The present circuits make use of pre-distortion techniques to improve the 3rd order distortion of an amplifier to reduce the amount of DC power required to achieve a given system requirement. In addition, the amplifiers have broadband characteristics which lend themselves to simplified pre-distortion. A pre-distortion linearizer circuit is connected across the input terminals of an amplifier. The linearizer circuit includes multiple diodes to improve the clipping performance of the linearizer. In addition, RC circuits align the phase of the linearizer distortion to be opposite that of the amplifier.

The invention discloses a monocular camera and inertial measurement unit relative mounting angle calibrating method and belongs to the field of sensor calibration. The method comprises the following steps of, firstly, rotating a measurement module to collect calibrating data, wherein the measurement module is composed of a monocular camera and an inertial measurement unit; secondly, extracting relative attitude information from images collected by the monocular camera; thirdly, solving a mounting matrix through a nonlinear least square method. With dependence on absolute reference information,the monocular camera and inertial measurement unit relative mounting angle calibrating method can avoid calibrating errors resulting from absolute reference information measurement errors; besides, during the calibrating process, the data collecting period is short and the calibrating precision is high, so that the monocular camera and inertial measurement unit relative mounting angle calibratingmethod can meet the requirements of combined configuration of the monocular camera and the inertia measurement unit on spatial alignment during practical application.

Control of blade clearance gaps between rotating turbine blades and an associated casing in a gas turbine engine is important in order to maintain operational efficiency. It is desirable to achieve accurate gap control but previous passive and scheduled thermal gap adjustment systems have been relatively course. By provision of a winding through which a specific electrical current is passed in order to create electro-magnetic force for displacement of an armature associated with a seal forming part of the casing it is possible to adjust the gap between that seal and a tip part of a rotating blade assembly. Normally a blade gap monitoring technique is used in association with specific operational requirements with respect to the gap by the control in order to determine the electrical current presented to the winding. As a fail-safe measure a permanent magnet or bias or some other form can be provided to ensure displacement to a fail-safe position with an adequate blade gap clearance for continued operation should there be power failure or an excess electrical current presented to the winding.

Systems for linear mapping of lumens are described which utilizes methods to create a linearized view of a lumen using multiple imaged frames. In reality a lumen has a trajectory in 3-D, but only a 2-D projected view is available for viewing. The linearized view unravels this 3-D trajectory thus creating a linearized map for every point on the lumen trajectory as seen on the 2-D display. In one mode of the invention, the trajectory is represented as a linearized display along 1 dimension. This linearized view is also combined with lumen measurement data and the result is displayed concurrently on a single image. In another mode of the invention, the position of a treatment device is displayed on the linearized map in real time. In a further extension of this mode, the profile of the lumen dimension is also displayed on this linearized map.

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 (tS), until a threshold value temperature (Tm) 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 tm and / or to a time-independent amplitude factor (1+RS / RI)−1, wherein m is a Reynolds-number-dependent exponent and RS, Rl are thermal transfer resistances. The advantages are an improved precision, a shorter measuring time and an enlarged measuring range for the flow rate v.

The invention discloses a Fresnel zone plate spectrum confocal measurement method. The method comprises the following steps: constructing a spectrum confocal measurement device, performing direct chromatic dispersion focusing by using the Fresnel zone plate which replaces a lens or a lens group; monitoring an axial location of a standard plane mirror, calibrating linear axial focusing range of theFresnel zone plate and the wavelength-location relation of the spectrum confocal measurement device; replacing the standard planar mirror as the to-be-measured sample, placing a to-be-measured surface of the sample in the measurement range of the device to perform measurement; performing the chromatic dispersion on the composite light source along the axial direction of the Fresnel zone plate, thereby producing color zones corresponding to different wavelengths, returning the light field with the wavelength corresponding to the focal point focused on the sample surface along an original lightpath, enabling a spectrograph to detect a return signal intensity point diffusion function, computing a peak coordinate location by utilizing a centroid method, and obtaining the location informationof the sample measurement point according to the wavelength-location calibration curve. Compared with the traditional spectrum confocal measurement, the method has the advantages of being simple in structure, flexible in design, and low in cost.

A device for pretreating a signal (S1) to be transmitted over a transmission path, wherein the transmission path comprises a band-pass filter (14) whose pass-band width is smaller than a predetermined bandwidth and a non-linear amplifier (16), includes a linearization means (20) for performing a linearization of the signal (S1) to be transmitted before the transmission of the same, such that a non-linearity caused by the non-linear amplifier (16) is counteracted. Further, the device includes a signal-shaping means (22) downstream to the linearization means (20) comprising a frequency response such that the overall frequency response of the signal-shaping means (22) and the band-pass filter (14) corresponds to the frequency response of a filter whose pass-band width is at least equal to the predetermined bandwidth.

A driver system, a driver calibration circuit arrangement for calibration of an impedance of a driver circuit arrangement, and a method for calibration of an impedance of a driver circuit arrangement can achieve improved driver behavior, with respect to undesirable distortions of the slew rate caused by off-chip drivers of DDR memory modules. A driver system has a first driver part with at least one variable impedance by which an operating point of the first driver part is determined with respect to a first potential and a second potential. The potentials supply the first driver part. A first monitoring device adjusts an impedance value of the variable impedance such that the operating point differs from a mid-point of the first and of the second potential.

The invention discloses an on-chip integrated broadband linearizer based on a variable capacitor, and belongs to the technical field of microwave and millimeter wave monolithic circuits. A linearizedcircuit control module is used for controlling a direct-current voltage drive provided for a reflective pre-distortion signal generator and a cold-mode pHEMT transistor compensation correction circuit, so as to adjust the size of the generated linearized signal. Then, a reflective pre-distortion signal generator and a cold mode pHEMT transistor compensation correction circuit are combined; the pre-distortion signals are generated and compensated, pre-distortion linearized signals are finally generated to counteract nonlinearity of the power amplifier, and the reflective pre-distortion signal generator and the cold mode pHEMT transistor compensation correction circuit are matched with a low-loss matching module to further reduce insertion loss. According to the broadband linearizer, the problem that a traditional linearizer cannot be applied to a broadband is solved, and the bandwidth is better broadened. The filter has the characteristics of low insertion loss, wide application bandwidth, compact structure and remarkable linearization improvement.

An audio apparatus comprises a circuit (201) for applying a dynamic range adjustment processing to an input signal to generate an output signal for rendering by a loudspeaker (101). The dynamic range adjustment processing is dependent on a set of dynamic range adjustment parameters. A first linear echo-cancellation filter (203) generates a first compensated signal from the audio input signal and a first adapter (205) determines a set of filter parameters for the first linear echo-cancellation filter (203) in response to the first compensated signal and a microphone signal. An audio circuit (207, 209) generates a second compensated signal by applying the dynamic range adjustment processing and a second echo-cancellation filter (209) to the input signal where the second echo-cancellation filter (209) corresponding to the first echo-cancellation filter (203). A second adapter (211) determines the set of dynamic range adjustment parameters in response to the second compensated signal and the microphone signal. The approach can increase linearity and echo-cancellation for many systems.

The invention discloses a real-time monitoring device and monitoring method of a cable force. The monitoring device comprises a cage-structure force measurement ring, wherein a groove is formed in a side wall of the cage-structure force measurement ring, a plurality of long-gauge length fiber grating precision strain sensors are arranged at a middle part of the side wall of the force measurement ring, average strain of an intermediate segment of the intermediate ring within a certain range is measured, a fiber grating temperature sensor is arranged to compensate a temperature, the strain is converted to an optical signal by the fiber grating sensors, the optical signal is transmitted to a fiber grating demodulator for demodulation by an optical cable, and the optical signal is transmittedto a computer by a network cable. Load test is performed in a laboratory, average strain data acquired by the plurality of long-gauge length stress sensors is combined to perform least square fit analysis, and a relation curve of the pressure of the test ring and equivalent axis average strain is calibrated. The controller is used for analyzing real-time monitoring data of a force measurement ring, the cable force is solved, and automatic real-time monitoring of the cable force is achieved.

This invention relates to line motor vector control theta iterate compensation method, which belongs to line motor servo movement control method and mainly applied in permanent line motor servo control field. The method comprises the following steps: estimating the real value of theta angle and stabling identification formula; getting n times of theta angle estimation value to compute the above formula after dispersion according to the identification formula. The invention compares the estimation value with the real measured value through repeated iterated compensation to make the theta orderly near the real time.

The invention is directed at the problem that relative humidity sensors for land meteorological elements hardly adapt to high humidity, high salt mist and high corrosion of a marine environment and brings forward a relative humidity sensor for marine meteorological elements. According to the invention, a high precision humidity sensitive element is employed, and the variation of relative air humidity is converted into a frequency signal through a frequency generation circuit; then the frequency signal is converted into a voltage signal through a frequency voltage converting circuit; a linearization conditioning circuit carries out linearization treatment on changed voltage signals so as allow variation of voltage to linearizedly correspond to variation of relative air humidity; and adaptability of the relative humidity sensor for marine meteorological elements to a marine environment is achieved through a special structure and a reliable design. According to testing results, the relative humidity sensor for marine meteorological elements has the advantages of high measurement precision, good linearization performance and capacity of adapting to a marine environment.

The invention relates to an optimal control method for real-time safety correction of gateway electric power of a multi-energy system and belongs to the technical field of integrated energy system operation and control. The method has the advantages that by utilizing the characteristics of multi-energy coupling and complementing, the purpose of reducing the gateway electric power of the multi-energy system is achieved through the cooperative control of various energy devices such as electrical energy devices, thermal energy devices, cold energy devices and the like and the optimal real-time safety corrective control is realized by using linear optimization; an optimal control model for the real-time safety correction is provided, the linearization of the optimal model is realized by specifying the adjustment direction of each device and the rapid solving and the engineering application are benefited; and the method can be applied to the real-time online operation control of the multi-energy system and when the situation that the gateway electric power exceeds the upper limit is monitored, the adjustment amount of each device is calculated through the method, the gateway electric power is reduced and the safe operation of the multi-energy system is guaranteed.