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36results about How to "Improve spurious-free dynamic range" patented technology
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Successive approximation type analog-to-digital converter and calibration method
ActiveCN110880934AImprove linearityNo loss of accuracyElectric signal transmission systemsAnalogue-digital convertersConvertersA d converter
The invention provides a successive approximation type analog-to-digital converter and a calibration method. The successive approximation type analog-to-digital converter comprises a sampling / holdingcircuit, a digital-to-analog converter, a comparator, a successive approximation logic circuit, a clock generation circuit and a digital pseudo-random signal generator. An analog input signal is connected to the sampling / holding circuit. Positive and negative input ends of the comparator are connected with the digital-analog converter and the sampling / holding circuit respectively, and the output end of the comparator is connected with the successive approximation logic circuit; the successive approximation logic circuit and the digital pseudo-random signal generator are connected to the inputof the adder, and the output of the adder is connected with the digital-to-analog converter; the successive approximation logic circuit and the digital pseudo-random signal generator are connected tothe input of a subtracter, and the output of the subtracter is a final output result; and the clock generation circuit is respectively connected with the comparator and the successive approximation logic circuit. Harmonic energy is reduced, the spurious-free dynamic range of the ADC is improved, and the linearity of the core ADC is effectively improved.
Owner:SHENZHEN GRADUATE SCHOOL TSINGHUA UNIV
Pipelined successive approximation analog-to-digital converter and conversion method
ActiveCN112019217AStable Input SwingImprove linearityAnalogue/digital conversionElectric signal transmission systemsCapacitanceControl theory
The invention provides a pipelined successive approximation analog-to-digital converter and a conversion method. The pipelined successive approximation analog-to-digital converter comprises a first-stage successive approximation analog-to-digital conversion module, a second-stage successive approximation analog-to-digital conversion module and a digital code error correction logic module, whereinthe first-stage successive approximation analog-to-digital conversion module comprises a first capacitor array unit, an amplification unit, a latch comparison unit, a first register logic control unitand a control switch, and the amplification unit is multiplexed as a residual amplifier and a pre-amplifier of a comparator in the first-stage successive approximation analog-to-digital converter. Bymultiplexing the residual amplifier pre-amplifier, input offset voltage mismatch existing between the residual amplifier pre-amplifier and the residual amplifier pre-amplifier is completely eliminated, the input swing of the residual amplifier is stabilized, the linearity of the residual amplifier is improved, and the area of a chip is saved; and the gain error is obtained by multiplexing the second-stage successive approximation type analog-to-digital conversion module, so that the gain error of the residual amplifier is reduced, and the conversion accuracy of the whole pipelined successiveapproximation type analog-to-digital converter is improved.
Owner:ZHEJIANG UNIV
Sampling clock generation circuit and analog-digital converter
ActiveCN104702281AImprove conversion accuracyHigh adjustment accuracyPulse automatic controlGenerating/distributing signalsElectricityCapacitance
The invention discloses a sampling clock generation circuit and an analog-digital converter and belongs to the digital signal processing field. The sampling clock generation circuit comprises a variable-resistance circuit, a NOT gate type circuit and a capacitor, the input end of the NOT gate type circuit receives pulse signals of which the period is T, the output end of the NOT gate type circuit is connected with one end of the capacitor, the other end of the capacitor is connected with the ground, the power supply end of the NOT gate type circuit is connected with a power supply, the ground end of the NOT gate type circuit is connected with one end of the variable-resistance circuit, and the other end of the variable-resistance circuit is connected with the ground; the NOT gate type circuit is used for outputting low level when the pulse signal has high level and outputting high level when the pulse signal has low level; the variable-resistance circuit is used for regularly changing the resistance according to a time length T, the resistance change period is n*T, the resistance is different after each change in each period, and n is an integer larger than or equal to 2. The sampling clock generation circuit and the analog-digital converter enable the conversion accuracy of the ADC to be improved.
Owner:HUAWEI TECH CO LTD
Zero-intermediate frequency receiver
InactiveCN106452474AImprove isolationImprove spurious-free dynamic rangeTransmissionIntermediate frequencyVIT signals
The invention discloses a zero-intermediate frequency receiver, relates to the technical field of communications, and aims to solve the problems of narrow band, low frequency, poor isolation, I / Q imbalance and low dynamic range in an existing zero-intermediate frequency receiver. In the zero-intermediate frequency receiver disclosed by the invention, a laser is connected with an optical divider; the optical divider is respectively connected with a first electro-optical modulation module and a second electro-optical modulation module; a radio frequency signal receiving module is connected with the first electro-optical modulation module; a local oscillation signal generator is connected with the second electro-optical modulation module; the first electro-optical modulation module and the second electro-optical modulation module are connected with a raster processing module; the raster processing module is connected with a photoelectric detection module; and the photoelectric detection module is connected with an analog-to-digital conversion and signal processing module.
Owner:BEIJING UNIV OF POSTS & TELECOMM +1
Method for suppressing third-order and fifth-order intermodulation distortion of microwave photon down-conversion link
ActiveCN112217565AImprove spurious-free dynamic rangeRealize the modulation effectDistortion/dispersion eliminationRadio-over-fibreFirst lightMechanical engineering
The invention relates to a method for suppressing third-order and fifth-order intermodulation distortion of a microwave photon down-conversion link, and the method comprises the following steps that:a laser emits a light beam, and the light beam is modulated by a local oscillation signal received by a third phase modulator and then is output, wherein the modulation of the third phase modulator iscontrolled by controlling the power of the local oscillation signal, so as to suppress the third-order and fifth-order intermodulation distortion; a signal modulated by the third phase modulator passes through a 3dB coupler, and the optical signal is divided into a first light beam and a second light beam, wherein the first light beam is modulated by a first phase modulator, then passes through afirst optical filter and is output to a first input end of the balance detector, so a first branch is formed; the second light beam is output to the second phase modulator after passing through the optical attenuator, is output to the second optical filter after being modulated by the second phase modulator, and is output to the second input end of the balance detector after passing through the second optical filter, so a second branch is formed.
Owner:AIR FORCE EARLY WARNING ACADEMY
High SFDR folding interpolation analog-to-digital converter
ActiveCN101980447AImprove spurious-free dynamic rangeAnalogue-digital convertersDigital down converterHarmonic
The invention provides a high SFDR (spurious free dynamic range) folding interpolation analog-to-digital converter structure adopting cascade folding interpolator inter-stage switch 'pseudo random disorder sequence'. The folding interpolation analog-to-digital converter comprises a folding unit analog preprocessing module or an interpolation analog preprocessing module; the cascade folding interpolator inter-stage switch 'pseudo random disorder sequence' is a logic sequence for pseudo-randomly selecting a folding interpolation signal path for analog signals in a preprocessing process, and a folding interpolation circuit of each stage comprises two groups of switch logics, namely a positive disorder sequence switch logic and a corresponding negative disorder sequence removal switch logic. Moreover, the switch disorder sequence logics are divided into intra-stage disorder sequence logic and inter-stage disorder sequence combined logic. The intra-stage and inter-stage switch disorder sequence logics of the cascade folding interpolation circuit average the input equivalent imbalance between a folder and an interpolator in the processed adjacent quantification ranges to average the harmonic components introduced by mismatch into the noise floor so as to improve the spurious free dynamic range (SFDR) of the whole analog-to-digital converter.
Owner:FUDAN UNIV
A segmented current steering digital-to-analog converter circuit and a calibration method
ActiveCN109921798AImprove linearityImprove spurious-free dynamic rangeDigital-analogue convertorsAnalogue/digital conversion calibration/testingDigital analog converterEngineering
The invention discloses a segmented current-steering digital-to-analog converter circuit and a calibration method. The current-steering digital-to-analog converter circuit comprises a current source array, a current source switch array, an encoding circuit, a serial-to-parallel conversion circuit, a latch circuit and a calibration circuit. The circuit is integrated into the circuit; on-chip calibration realized, meanwhile, the defect that a binary current source in the sectional type current steering digital-to-analog converter cannot be calibrated by a traditional calibration circuit is overcome; the current source of each bit in the segmented current steering digital-to-analog converter is calibrated in sequence, so that the matching degree between the current sources is improved, and the static linearity, the spurious-free dynamic range and other performances of the digital-to-analog converter are improved.
Owner:CHENGDU CORPRO TECH CO LTD
Time-interleaved ADC mismatch optimization method based on random truncation
ActiveCN110690902AIncrease randomnessRealize random schedulingAnalogue-digital convertersAnalogue/digital conversion calibration/testingRandom orderReal-time computing
A time-interleaved ADC mismatch optimization method based on random truncation comprises: firstly, establishing an idle queue comprising time-interleaved ADC sub-channels, wherein the idle queue at the initial moment comprises M sub-channels; then, enabling the time-interleaved ADC to start to sample and quantize, wherein the mismatch optimization process in each sampling quantization period is asfollows: when each sampling quantization period starts, selecting one sub-channel from the current idle queue in sequence or randomly for sampling quantization; and randomly truncating i bits from the quantization bits of the selected sub-channels in each sampling quantization period, adding the quantized sub-channels into an idle queue for selection of the next sampling quantization period, andadding the plurality of sub-channels into the idle queue according to a random sequence when the plurality of sub-channels finish quantization at the same time. According to the method, randomized scheduling of the channels can be realized under the conditions of not adding extra channels and not increasing the working frequency of the sub-channels, so that residual mismatch is optimized and balanced, and the spurious-free dynamic range of the time-interleaved ADC and the speed of the time-interleaved ADC are improved.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA +1
Microwave photonic link SFDR (Spurious Free Dynamic Range) enlarging method based on automatic light gain control
ActiveCN104639246AImprove spurious-free dynamic rangeDistortion/dispersion eliminationRadio-over-fibreBeam splitterGrating
The invention provides a new microwave photonic link SFDR (Spurious Free Dynamic Range) enlarging method. According to the method, an automatic light gain control function is additionally increased in front of a photodetector of a link, light power entering into the photodetector is traced and tuned, so that the total power of third-order cross modulation is less than a noise bottom, furthermore fundamental frequency item power greater than the noise bottom is ensured, and thus, the purpose of enlarging the SFDR is achieved. The automatic gain link is composed of a light beam splitter, a circulator, a fiber bragg grating, the photodetector, a voltage conversion module and a light intensity modulator, wherein the received light is split into two beams by the light beam splitter, one light beam serves as monitoring light, after carrier wave is filtered out by the grating, the monitoring light is subjected to photoelectric conversion, so that a control voltage signal is formed. The control voltage is injected into the direct current bias input port of the light intensity modulator in front of the photodetector, the intensity of the other light beam is controlled by use of the optical interference theory, and the automatic light gain control function is achieved, so that the SFDR of the whole link is enlarged.
Owner:BEIJING UNIV OF POSTS & TELECOMM
Design method of four-channel single-bit digital receiver and receiver thereof
ActiveCN113162641AImprove instantaneous dynamic rangeImprove real-time processing performanceWave based measurement systemsTransmission monitoringControl theoryDigital signal
The invention discloses a four-channel single-bit digital receiver and a design method thereof. The method comprises the steps: carrying out the single-bit sampling of a signal, obtaining a single-bit digital signal, analyzing the harmonic characteristics of the single-bit digital signal in a Nyquist sampling frequency band, and obtaining four frequency bands which do not contain a target harmonic component; designing a four-channel single-bit digital receiver model according to the four frequency bands without the target harmonic component; and performing a simulation test according to the four-channel single-bit digital receiver model and preset test parameters to obtain a test result. Through the design of the special frequency band, higher harmonics can be effectively avoided, the spurious-free dynamic range of single-bit digital signals in each channel can be effectively improved, the instantaneous dynamic range of the receiver can be improved, the real-time processing capacity of the receiver can be enhanced, and the designed four-channel single-bit digital receiver has the advantages of simple structure and low cost. The device has the advantages of simple structure, strong anti-noise capability, high instantaneous dynamic range and the like.
Owner:湖南国科雷电子科技有限公司
Method for enlarging SFDR (spurious free dynamic range) of signal after data truncation
InactiveCN103577152AImprove spurious-free dynamic rangeReduce harmonic amplitudeRandom number generatorsComplex mathematical operationsHarmonicComputer science
The invention provides a method for enlarging an SFDR (spurious free dynamic range) of a signal after data truncation. A uniformly distributed random integer signal sequence in a certain amplitude range is generated through design, the bit width of the random integer signal sequence is identical with the truncated bit width, the random integer signal sequence is stacked on a signal before truncation, then bit width truncation is performed, and a random signal after truncation is obtained, so that the harmonic amplitude of the truncation error is decayed rapidly, harmonic distortion caused by direct truncation is eliminated, and the dynamic range of the random signal after truncation is enlarged.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA
Broadband receiver nonlinear blind recognition and compensation method
ActiveCN103929212AImprove spurious-free dynamic rangeImprove the ability to extract weak signalsTransmitter/receiver shaping networksDistortionBroadband
The invention relates to the field of wireless monitoring, in particular to a broadband receiver nonlinear blind recognition and compensation method. In the method, a distorted signal is compensated for to obtain a mixed signal, a cost function of short-time energy information of distortion components in the mixed signal is worked out, the compensation parameter corresponding to the minimum distortion compensation is worked out, compensation parameters in the compensation model are updated, the steps are carried out repeatedly until the distortion components are well inhibited, and therefore the spurious-free dynamic range of the receiver is expanded, and the weak-signal extraction ability is improved as well.
Owner:成都电科慧安科技有限公司
Digital control oscillator and magnetic resonance imaging system
ActiveCN104639160AImprove signal-to-noise ratioQuantization noise energy reductionPulse automatic controlDiagnostic recording/measuringUltrasound attenuationSignal-to-noise ratio (imaging)
Disclosed are a digital control oscillator and a magnetic resonance imaging system. The digital control oscillator comprises a phase accumulation unit, a quantitative shaping unit and a conversion unit. The phase accumulation unit is used for accumulating frequency control words to generate first phase signals; the quantitative shaping unit is used for quantizing the first phase signals to generate second phase signals, performing low-frequency attenuation and high-frequency amplification on quantizing noises generated from quantization and performing low-pass filtering on the quantizing noises subjected to low-frequency attenuation and high-frequency amplification; the conversion unit is used for outputting waveform data corresponding to the second phase signals. Since the quantizing noises are shaped by the digital control oscillator, the signal to noise ratio and the stray-free dynamic range of outputted periodic signals are increased.
Owner:SHANGHAI UNITED IMAGING HEALTHCARE
Spurious-free dynamic range improving method based on single sideband modulation
ActiveCN111901043AImprove spurious-free dynamic rangeEnhanced inhibitory effectElectromagnetic transmittersSoftware engineeringCarrier signal
The invention relates to a spurious-free dynamic range improvement method based on single sideband modulation. The spurious-free dynamic range improvement method comprises the following steps that: step 1, a laser device emits an optical carrier S1; step 2, a radio frequency input signal S2 modulates an optical signal S1 output by a laser through using a phase modulator so as to obtain and outputa phase modulation signal S3; step 3, the phase modulation signal S3 passes through a third-order intermodulation distortion suppressor, and then a single-sideband phase modulation signal S4 with a certain carrier-to-sideband ratio is output; and step 4, a photoelectric detector demodulates the signal S4 to suppress third-order intermodulation distortion in a output radio frequency signal S5, andan output signal of the photoelectric detector is input into a frequency spectrograph to be analyzed. The third-order intermodulation distortion suppressor obtains the single-sideband signal with a certain ratio of an optical carrier to +2-order sideband amplitude after carrying out amplitude-frequency processing on the signal, and the signal is extracted by the photoelectric detector in the step4, so that a spurious-free dynamic range of a spurious-free dynamic range link is improved.
Owner:AIR FORCE EARLY WARNING ACADEMY
Time-interleaved ADC mismatch optimization method based on task scheduling
InactiveCN110518910AImprove the mismatchImprove spurious-free dynamic rangeAnalogue/digital conversion calibration/testingComputer scienceSpurious-free dynamic range
The invention discloses a time-interleaved ADC mismatch optimization method based on task scheduling. The quantization time of a channel corresponding to a current quantization period is shortened orthe time length of the current quantization period is increased. The corresponding channel is quantified in advance to enter an idle state in the current quantization period. All the quantized channels are marked as idle channels, and then one channel from all the idle channels is randomly selected for sampling and quantization when the next quantization period comes by adopting a task schedulingalgorithm, so as to realize channel randomization to optimize inter-channel mismatch. According to the invention, the residual quantization time of the ADC of each channel is fully utilized, the purpose of random channels can be realized without additionally adding auxiliary channels, the spurious-free dynamic range of the time-interleaved ADC is improved, and the speed of the time-interleaved ADCand the adaptability under each condition are improved.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA
Multi-octave microwave transmission device and multi-octave microwave transmission method
ActiveCN112448768AImprove spurious-free dynamic rangeReduce distortionRadio-over-fibreFiber chromatic dispersionCarrier signal
The invention provides a multi-octave microwave transmission device. The multi-octave microwave transmission device comprises a light source, a signal modulation unit, an optical polarizer, an opticalfiber and a photoelectric detector, the light source is used for generating and outputting an optical carrier; wherein the signal modulation unit is used for receiving an optical carrier and a microwave signal to be transmitted, and modulating the microwave signal to be transmitted to the optical carrier in a state of working in a carrier single sideband suppression state so as to form a modulated optical signal; the optical polarizer is used for receiving the modulated optical signal and performing polarization processing on the modulated optical signal to form a polarized optical signal; the optical fiber is used for transmitting the polarized light signal to the photoelectric detector; and the photoelectric detector is used for converting the polarized light signal into an electric signal. The invention further provides a multi-octave microwave transmission method. According to the invention, high-linearity long-distance transmission can be carried out on multi-octave microwave signals, and the problem of power attenuation caused by optical fiber dispersion can be overcome in microwave signal transmission.
Owner:JINAN UNIVERSITY
High-RF-frequency analog fiber-optic links using optical signal processing
InactiveCN107408984ARaise the level of performanceHigh link gainRadio-over-fibreElectromagnetic receiversFiberLow noise
Wide band phase modulators used with high power laser carriers convert high-frequency RF signals to phase-modulated optical signals. Higher laser optical power to the modulator produces larger RF signal sidebands. A carrier attenuation filter passes the attenuated carrier and non- attenuated RF modulation sidebands. Carrier attenuation leaves the larger RF signal sidebands. A demodulation filter used with a photodetector or a balanced photodetector pair converts the phase-modulated optical signal back to an electrical signal. Carrier-only attenuation allows high power laser use, avoids photodetector damage or saturation, and provides increased RF link gain, low noise figure (NF) and high spurious-free dynamic range (SFDR). Filtered-out carrier power fed back to the laser source increases to overall system efficiency. An additional optical delay filter with dual outputs used with a polarization multiplexer or a coherent combiner coupler combines signal power to a single photodetector to further increase electro-optic signal conversion efficiency.
Owner:EOSPACE
Double time interleaving current-steering-type DAC (digital-to-analog converter) with DRRZ (digital random retum-to-zero) correction function
ActiveCN109639276AHigh bandwidthImprove spurious-free dynamic rangeElectric signal transmission systemsAnalogue/digital conversion calibration/testingDouble-timeRandomization
The invention belongs to the field of digital-to-analog conversion, and discloses a double time interleaving current-steering-type DAC (digital-to-analog converter) with a DRRZ (digital random retum-to-zero) correction function. Clock signals are utilized to control two DACs to alternately work in a DDRZ correction mode and a data output mode; in the first half of a clock cycle, a first DAC carries out random dynamic zeroing, corrects a high current source unit, and is connected with a virtual end through a DAC output control logic module, and at the same time, a second DAC carries out digital-to-analog conversion, outputs an analog signal corresponding to an input code, and is connected to an output end through the DAC output control logic module; and in the last half of the clock cycle,functions of the first DAC and the second DAC are interchanged. Transient states of DAC switch conversion are enabled to be nonlinearly randomized through DRRZ correction, a spurious free dynamic range (SFDR) of the current-steering-type DAC at high frequency is improved, and matching errors between current sources are mitigated.
Owner:HUAZHONG UNIV OF SCI & TECH
Broadband signal generation device and method based on adaptive correction
ActiveCN112073064AOvercome differencesAchieve correctionPulse automatic controlTransmissionControl cellTransformation unit
The invention discloses a broadband signal generation device and method based on adaptive correction. The device comprises a phase accumulation unit module, a phase amplitude conversion unit module, aDAC circuit module, a radio frequency processing circuit module, an ADC circuit module, a signal detection and processing unit module, a spurious control unit module and a spurious correction signalgeneration unit module. The method comprises the following steps: performing feedback at a DDS signal output end to perform high-speed sampling, adaptively realizing stray extraction and feature analysis of broadband output signals, obtaining frequency, amplitude and phase information of stray signals, additionally outputting N paths of correction signals or driving a parallel DAC to output N paths of correction signals in a signal generation structure, generating same-frequency, anti-phase and basically equal-amplitude correction signals, and realizing spurious suppression through synthesis of the output signals and the correction signals, wherein N > = 1. The spurious suppression effect is achieved, and the false-free dynamic range of broadband DDS output signals is widened.
Owner:SOUTHWEST CHINA RES INST OF ELECTRONICS EQUIP
Multi-octave microwave transmission device and multi-octave microwave transmission method
ActiveCN112448768BImprove spurious-free dynamic rangeReduce distortionRadio-over-fibreFiber chromatic dispersionPhotodetector
The invention provides a multi-octave microwave transmission device, which includes: a light source, a signal modulation unit, an optical polarizer, an optical fiber and a photodetector; the light source is used to generate and output an optical carrier; the signal modulation unit It is used to receive the optical carrier and the microwave signal to be transmitted, and modulate the microwave signal to be transmitted onto the optical carrier in the state of suppressing the single sideband of the carrier to form a modulated optical signal; the optical polarizer is used to receive the modulated optical signal , and perform polarization processing on the modulated light signal to form a polarized light signal; the optical fiber is used to transmit the polarized light signal to the photodetector; the photodetector is used to convert the polarized light signal into electric signal. The invention also provides a multi-octave microwave transmission method. The invention can carry out long-distance transmission with high linearity to multi-octave microwave signals, and can overcome the power attenuation problem caused by optical fiber dispersion in microwave signal transmission.
Owner:JINAN UNIVERSITY
A Nonlinear Blind Identification and Compensation Method for Wideband Receiver
ActiveCN103929212BImprove spurious-free dynamic rangeEnhanced inhibitory effectTransmitter/receiver shaping networksEngineeringBroadband
Owner:成都电科慧安科技有限公司
Pipeline successive approximation analog-to-digital converter and conversion method
ActiveCN112019217BStable Input SwingImprove linearityAnalogue/digital conversionElectric signal transmission systemsCapacitanceDigital converter
Owner:ZHEJIANG UNIV
A method for improving the spurious-free dynamic range of microwave photonic links
ActiveCN104639246BImprove spurious-free dynamic rangeDistortion/dispersion eliminationRadio-over-fibreGratingPhotodetector
The invention provides a new microwave photonic link SFDR (Spurious Free Dynamic Range) enlarging method. According to the method, an automatic light gain control function is additionally increased in front of a photodetector of a link, light power entering into the photodetector is traced and tuned, so that the total power of third-order cross modulation is less than a noise bottom, furthermore fundamental frequency item power greater than the noise bottom is ensured, and thus, the purpose of enlarging the SFDR is achieved. The automatic gain link is composed of a light beam splitter, a circulator, a fiber bragg grating, the photodetector, a voltage conversion module and a light intensity modulator, wherein the received light is split into two beams by the light beam splitter, one light beam serves as monitoring light, after carrier wave is filtered out by the grating, the monitoring light is subjected to photoelectric conversion, so that a control voltage signal is formed. The control voltage is injected into the direct current bias input port of the light intensity modulator in front of the photodetector, the intensity of the other light beam is controlled by use of the optical interference theory, and the automatic light gain control function is achieved, so that the SFDR of the whole link is enlarged.
Owner:BEIJING UNIV OF POSTS & TELECOMM
Channel randomization circuit and method based on time-interleaved ADC
PendingCN114244362AAvoid early outputImprove spurious-free dynamic rangeAnalogue-digital convertersDistribution controlControl signal
The invention provides a channel randomization circuit and method based on a time-interleaved ADC, and the circuit comprises a channel selection module which is used for outputting M clock receiving control signals and N coded data receiving control signals according to a main clock and a generated random number; the multi-phase clock distribution module is used for generating N multi-phase clocks according to a sampling main clock, redistributing the multi-phase clocks according to the clock receiving control signal, and outputting M redistributed clock signals; the time-interleaved ADC module is used for outputting M pieces of output data and a corresponding number of channel quantization completion signals according to the redistribution clock signal; the adjustable delay module is used for setting the delay size of the data receiving control signal; and the time sequence distribution control module is used for controlling the output data to be sequentially arranged and output according to a time sequence according to the delayed data receiving control signal and the channel quantization completion signal.
Owner:CHONGQING GIGACHIP TECH CO LTD
N-bit digital-to-analog conversion apparatus
InactiveCN102739256BImprove spurious-free dynamic rangeDigital-analogue convertorsNumber generatorComputer science
The invention relates to an N-bit digital-to-analog conversion apparatus, which is used for receiving a digital signal and a clock signal. The clock signal is switched between a first state and a second state. Besides, the N-bit digital-to-analog conversion apparatus comprises a decoder, a random number generator and a conversion module. More specifically, the decoder is used for converting a digital signal into a multi-bit thermometer code. The random number generator is used for outputting a reset signal in a random number state; the rest signal has a plurality of bits that are arranged alternatively and randomly, wherein the arrangement mode is changed at different time; and in the reset signal, the number of the bits that are in a logic high level is equal to the number of the bits that are in a logic low level. When the clock signal is in the first state, the conversion module converts the thermometer code into an analog voltage relating to the digital signal; and when the clock signal is in the second state, the conversion module enables the analog voltage to be reduced to zero according to the reset signal. According to the invention, a spurious free dynamic range can be enlarged.
Owner:SPRING FOUND OF NCTU
A Spurious Free Dynamic Range Improvement Method Based on Single Sideband Modulation
ActiveCN111901043BImprove spurious-free dynamic rangeEnhanced inhibitory effectElectromagnetic transmittersPhotodetectorCarrier signal
Owner:AIR FORCE EARLY WARNING ACADEMY
A Nonlinear Correction Method for Improving the Spurious-Free Dynamic Range of Analog-to-Digital Converters
ActiveCN111654286BHarmonic suppressionSuppressed intermodulationAnalogue-digital convertersNonlinear distortionConverters
The invention discloses a nonlinear correction method and device for improving the stray-free dynamic range of an analog-to-digital converter, including a training signal generation module, a network parameter detection and extraction unit, an analog-to-digital converter and a nonlinear correction processing unit. The present invention realizes the nonlinear correction of the analog-to-digital converter by setting the network parameter detection and extraction unit and the nonlinear correction processing unit, effectively suppressing the nonlinear distortion of the analog-to-digital converter such as harmonics, intermodulation, and high-order correlation spurs, At the same time, the non-linear distortion and spurs generated by quantization such as DNL and INL are also greatly suppressed, which significantly improves the spurious-free dynamic range of the analog-to-digital converter.
Owner:SHEN YANG JIA LIAN ZHI CHENG TECH CO LTD
Method for enhancing dynamic range of magnetic resonance signal through scrambling technology
ActiveCN112763956AInterference will notImprove dynamic rangeMeasurements using NMR imaging systemsFrequency spectrumDigital converter
The invention discloses a method for enhancing the dynamic range of a magnetic resonance signal through a scrambling technology, and the method comprises the following steps of: S1, adding a noise scrambling source distributed in an interval of m1-m2MHz at the signal input end of a magnetic resonance signal collection board, with the amplitude of the noise scrambling source being n LSBs; S2, performing analog-to-digital conversion on the magnetic resonance signal mixed with the noise scrambling source; S3, acquiring a signal of a signal output end of the magnetic resonance signal acquisition board, inputting the signal into a notch filter, and removing additional spectrum components introduced by the noise scrambling source through the notch filter; and S4, carrying out orthogonal demodulation and decimation filtering on the signal. According to the invention, a noise interference source is applied to be mixed into a receiving signal of the magnetic resonance signal acquisition unit, distortion harmonic components caused by coherent sampling and quantization errors in the sampling and quantization process of the analog-to-digital converter are reduced, and the spurious-free dynamic range of the magnetic resonance analog-to-digital converter is improved, so that the dynamic range of magnetic resonance signals is improved.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA
A graphene Mach-Zehnder intensity modulator and its linearization method
ActiveCN108388034BImprove linearityImprove spurious-free dynamic rangeNon-linear opticsConstant powerRidge waveguides
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA
N-bit digital-to-analog conversion apparatus
InactiveCN102739256AImprove spurious-free dynamic rangeDigital-analogue convertorsNumber generatorComputer science
The invention relates to an N-bit digital-to-analog conversion apparatus, which is used for receiving a digital signal and a clock signal. The clock signal is switched between a first state and a second state. Besides, the N-bit digital-to-analog conversion apparatus comprises a decoder, a random number generator and a conversion module. More specifically, the decoder is used for converting a digital signal into a multi-bit thermometer code. The random number generator is used for outputting a reset signal in a random number state; the rest signal has a plurality of bits that are arranged alternatively and randomly, wherein the arrangement mode is changed at different time; and in the reset signal, the number of the bits that are in a logic high level is equal to the number of the bits that are in a logic low level. When the clock signal is in the first state, the conversion module converts the thermometer code into an analog voltage relating to the digital signal; and when the clock signal is in the second state, the conversion module enables the analog voltage to be reduced to zero according to the reset signal. According to the invention, a spurious free dynamic range can be enlarged.
Owner:SPRING FOUND OF NCTU
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