121 results about "Intermodulation" patented technology

The invention relates to the technical field of electronic component testing for investigating or analyzing internal microstructures and physical properties of materials by utilizing an electrical means, and discloses an online testing and analyzing method for physical properties of electronic component materials, which comprises the following steps of: constructing a composite excitation signal formed by linearly superposing a main carrier voltage and a perturbation wave voltage; applying the signal to a to-be-tested electronic component and acquiring response current; and extracting an intermodulation current amplitude at an intermodulation frequency point in the frequency spectrum of which the linear response interval is excluded, calculating a nonlinear response coefficient of the material in combination with the excitation amplitude, and comparing the nonlinear response coefficient with a preset degradation threshold so as to judge whether the nonlinear response coefficient is qualified or not. By extracting intermodulation components which cannot be generated by linear contact resistance, physical isolation of external contact noise in a frequency domain is realized, and the problem that contact resistance fluctuation and material intrinsic aging cannot be distinguished in a traditional linear impedance test is solved.

The invention relates to the technical field of on-line monitoring, in particular to an insulation fault on-line monitoring method and system for a medical IT system control cabinet. The method comprises the following steps: selecting a non-integer frequency multiplication detection frequency according to equivalent ground distributed capacitance in a previous monitoring period, and superposing the non-integer frequency multiplication detection frequency with a fundamental frequency to form a composite signal injection system; collecting signals to calculate a voltage instantaneous harmonic distortion rate change gradient, and selecting a time window to split the leakage current according to the change gradient; on the basis of dispersion estimation signal-to-noise ratio weighted fusion current vectors, insulation resistance and distributed capacitance are calculated; constructing a four-dimensional original feature vector composed of the insulation parameter, the phase difference and the intermodulation component energy; constructing a diagonal weighting matrix based on the resistance-capacitance ratio and the gradient to transform a feature vector, and determining the fault attribution through the Mahalanobis distance calculation with the fault template library. According to the scheme, harmonic interference can be avoided, calculation stability can be improved, insulation instantaneous sudden change can be quickly responded, and different fault types can be accurately distinguished to guide maintenance.

An electronic device may include wireless circuitry. The wireless circuitry can include a first input transistor, a first capacitance neutralization having a source terminal coupled to a tail node, and a second order intermodulation generation circuit configured to produce second order intermodulation signals at the tail node. The wireless circuitry can further include a second input transistor and a second capacitance neutralization transistor having a source terminal coupled to the tail node. The first and second capacitance neutralization transistors can be cross-coupled with the input transistors. A fixed or adjustable current source can be coupled to the tail node. The second order intermodulation generation circuit can include a transistor biased in a weak inversion mode.

The invention discloses a time interference double-target electrical stimulation system, which comprises a signal generation unit used for generating multiple paths of carrier signals and adjusting the frequency, amplitude and / or phase of the carrier signals; the current output unit is used for converting the multiple paths of carrier signals into multiple paths of carrier currents, and electrical isolation and intermodulation suppression are provided between the multiple paths of carrier currents; the electrode unit is electrically connected with the current output unit and comprises a plurality of electrodes and a position subunit, the plurality of electrodes are used for receiving the multi-channel carrier current so as to discharge in an attached target area, and the position subunit is used for determining the attaching position of each electrode; and the control unit is used for controlling the discharge of the plurality of electrodes, detecting the impedance and carrier current at the plurality of electrodes to assist the position subunit in determining the fitting position and detecting the frequency and / or phase of the plurality of carrier current to control the signal generation unit to adjust the frequency and / or phase of each path of carrier signal. The system realizes independent stimulation of two target spots in a hardware-level time interference mode, has signal output with high stability and low mutual interference, and can perform real-time feedback regulation and safety protection.

The invention discloses a train running gear bearing state prediction and early warning method and system, and the method comprises the steps: synchronously collecting vibration, noise and temperature data, and building a standard vibration reference based on rotation period segmentation; extracting a component characteristic frequency and confirming fault information by adopting a frequency spectrum decomposition and intermodulation analysis technology, and determining a monitoring working frequency and a component weight table; a temperature confrontation processing mechanism is introduced, decoupling parameters are generated through a heat distribution matrix and directional heat flow analysis, and accurate separation of temperature influence and mechanical wear signals is achieved; constructing an equivalent transformation matrix based on a noise dependency relationship, and performing standardized transformation on pure vibration data to generate a comparable state index; through abrasion tracking and vibration transmission analysis, path reconstruction is carried out in combination with transfer parameters, and accurate positioning and evolution prediction of faults are achieved; and finally, dynamically adjusting the component weight based on the path control signal, establishing a four-level grading early warning system, and realizing real-time monitoring and intelligent early warning of the running state of the bearing.

The invention relates to a model training method and device and a signal conversion method. The model training method comprises the following steps: inputting an original digital signal sent by a digital signal source into an initial model to obtain a sample digital signal output by the initial model; performing digital-to-analog conversion on the sample digital signal through a digital-to-analog conversion circuit in the signal processing chip to obtain a sample analog signal corresponding to the sample digital signal; determining a predicted value of a nonlinear distortion index of the digital-to-analog conversion circuit according to the sample digital signal and the sample analog signal; wherein the nonlinear distortion index comprises a total harmonic distortion index and / or an intermodulation distortion index; and performing parameter adjustment on the initial model according to the predicted value and the expected value of the nonlinear distortion index to obtain a digital signal conversion model. The digital signal conversion model obtained through training of the method can process original digital signals so as to compensate nonlinear distortion of a digital-to-analog conversion circuit.

The embodiment of the present application provides a kind of intermodulation correction method and device, it is applied to distributed base station, the distributed base station includes convergence unit and radio frequency remote unit, convergence unit includes first processing unit, transmitting end, receiving hybrid unit, the method includes: first processing unit receives first correction signal, first correction signal is transmission signal, or, first correction signal is the signal received from receiving channel, first intermodulation interference signal is obtained by the receiving hybrid unit to the second intermodulation interference signal received from radio frequency remote unit and is hybrid;First processing unit carries out nonlinear cancellation to first correction signal and exports second correction signal, second correction signal is used to subtract or add with first intermodulation interference signal or send to receiving channel, receiving channel sends the signal to first processing signal, i.e. first correction signal for next cycle.The method and device provided in the application can effectively reduce processing cost and save resources.

The present application relates to the technical field of power battery health state evaluation and abnormality identification, and particularly relates to a remote health state analysis and abnormality identification method for an electric bicycle battery, which comprises: applying a small signal active excitation under an admitted working condition and synchronously collecting to form an opportunity diagnosis excitation data window; developing time-frequency coupling modeling, including equivalent impedance, harmonic and intermodulation fingerprint, Koopman operator modeling and entropy coefficient difference, and generating a multi-domain response package, a physical invariant vector and an uncertainty matrix by constructing a spectral measure geometry distance with an optimal transmission; gating and layering standardization according to the geometry distance and consistency score, obtaining a health state estimation record and an abnormal event set by using a shape-constrained health mapping model; combining the mapping Jacobian and the dual potential, generating a next-period opportunity diagnosis excitation plan by using D-optimal test design and updating the population health manifold, so as to realize remote health evaluation and early abnormality identification across environments and devices and with traceability.

The invention provides a dual-frequency single-port intermodulation tester, and the tester comprises an intermodulation control module which comprises an intermodulation controller, a first frequency source and a second frequency source, and the intermodulation controller controls the first frequency source and the second frequency source to generate two carrier signals with different frequencies through receiving a configuration instruction; and the multiplexer module comprises a plurality of power amplifier modules and a multiplexer, the plurality of power amplifier modules are used for amplifying the two paths of carrier signals, synthesizing the two paths of carrier signals through the multiplexer, outputting the synthesized two paths of carrier signals to a tested piece, and receiving and processing intermodulation products reflected back from the tested piece at the same time. According to the invention, the accuracy, the integration level and the field applicability of the intermodulation test are effectively improved.

The application relates to the technical field of tunable N-path filter, in particular to a tunable N-path reflection-free filter and a superheterodyne receiver. The tunable N-path reflection-free filter comprises a signal source, an N-path band-pass filter unit, an N-path band-stop filter unit, an output resistor and a phase-splitting clock generating circuit. The output end of the signal source is connected with one end of the N-path band-pass filter unit and the N-path band-stop filter unit respectively, the other end of the N-path band-stop filter unit is connected with the output resistor, the gate of a plurality of MOS switches in the N-path band-pass filter unit and the N-path band-stop filter unit is connected with the phase-splitting clock generating circuit, and the phase-splitting clock generating circuit outputs a control signal. The tunable N-path reflection-free filter provided by the application has excellent frequency selectivity, can effectively suppress high-order harmonics, and can adjust the passband and the stopband by changing the switching frequency. Meanwhile, the filter can eliminate the reflected signal, prevent the intermodulation interference and gain fluctuation of the mixer and the high-gain amplifier in the system.

The application discloses a medical image segmentation method based on deep learning, and relates to the technical field of medical image data processing and segmentation, which comprises the following steps: obtaining a body mask based on three-dimensional gray data and constructing a radial distance map; calculating the median in the mask according to the pixel level equal-width ring band and performing logarithmic linear fitting to obtain a radial low-frequency slope sequence and an axial radial low-frequency intermodulation index; generating an intermodulation compensation field according to the slope and the distance and correcting the original image by multiplication; calculating the radial and slice direction gradients to obtain an anisotropic boundary uncertainty ratio and a local anisotropy map; and constructing a position adaptive threshold field and completing segmentation according to the anisotropic boundary uncertainty ratio and the local anisotropy map. The application can improve the stability and cross-device consistency of medical image segmentation.

The present application provides a resonator, filter, duplexer, multiplexer and communication device, the resonator comprises a resonant cavity, the resonant cavity has a resonant cavity and an open end, the resonator further comprises a deformed cover plate covering the open end and connected with the resonant cavity, a resonant tube located in the resonant cavity, and an adjusting mechanism arranged on the deformed cover plate, a groove is formed on the side of the deformed cover plate away from the resonant cavity, the adjusting mechanism is arranged in the groove and is used to provide a force in the axial direction of the resonant tube, so that the bottom of the groove is continuously deformed to adjust the distance between the deformed cover plate and the resonant tube. The present application can improve the intermodulation performance and high-power performance of the product, and at the same time, the production pass rate of the product can be improved, the product scrap rate and maintenance cost can be reduced, and the market competitiveness of the product can be improved.

To provide an amplifier in which intermodulation distortion is reduced.SOLUTION: The auto-zero amplifier circuit 2122 includes a transconductance amplifier 211221 and sampling capacitors CM1 and CM2. A modulation chopper circuit 31,32 modulates an input signal and inputs the modulated signal to a mutual conductance amplifier 211,221. The auto-zero switch circuit 41 includes auto-zero switches S31 and S32, and the auto-zero switch circuit 42 includes auto-zero switches S33 and S34. One end of the dummy switch Sd1 is connected between the input-terminal INM and the connection point of the auto-zero switches S31 and S32. One end of the dummy switch Sd2 is connected between the input-terminal INP and the connection point of the auto-zero switches S33 and S34. A capacitor C4 is connected between the other ends of the dummy switches Sd1, Sd2 and a ground line.SELECTED DRAWING: Figure 1

The present invention provides an efficient scheme for improved cross-product high frequency reconstruction (HFR), where a new frequency component of Q Ω + r Ω 0 is generated based on the existing components Ω and Ω + Ω 0.SOLUTION: The present invention performs a block-wise harmonic transposition, wherein time blocks of complex subband samples are processed with a common phase modification. The superposition of the modified samples has the advantageous effect of limiting unwanted intermodulation products, thereby allowing a coarser frequency resolution and / or a lower degree of oversampling to be used. The present invention in one embodiment uses a window function suitable for use with an improved block-based cross product HFR. A hardware embodiment of the present invention includes an analysis filter bank (101), a subband processor (102) configured by control data (104), and a synthesis filter bank (103).SELECTED DRAWING: Figure 1

The present application relates to the field of wireless communication technology, provide a kind of detection method, system and storage medium of IIP3 of low noise amplifier, detection method includes steps: S1, by respectively to first signal source and second signal source calibration, obtain first output insertion loss and second output insertion loss;The output spectrum analyzer insertion loss of spectrum analyzer is measured;S2, open power supply to the low noise amplifier to be measured and make it normal work;S3, open first signal source and second signal source, and first preset frequency signal and second preset frequency signal are respectively output to the input end of the low noise amplifier to be measured;S4, the two main frequency signal powers of the output end of the low noise amplifier to be measured are detected by spectrum analyzer and two third-order intermodulation signal powers corresponding to two main frequency signal powers respectively and record;S5, according to preset relationship obtains the IIP3 of the low noise amplifier to be measured.The present application can improve the detection efficiency of the IIP3 of low noise amplifier.

The invention relates to a common-cavity phase shifter loaded with a bridge and an array antenna. The common-cavity phase shifter comprises a metal cavity and a circuit board. The circuit board comprises a dielectric substrate and a strip line circuit; the strip line circuit comprises a first phase-shifting circuit and a second phase-shifting circuit, and the first phase-shifting circuit and the second phase-shifting circuit each comprise a circuit body, a common input port and a plurality of output ports arranged in the second direction; and at least one pair of output ports in the first phase-shifting circuit and the second phase-shifting circuit are coupled and connected through the corresponding bridge structures. Thus, the bridge structure is integrated into the wiring of the first phase shift circuit and the second phase shift circuit of the strip line circuit, a connection interface between the bridge structure and the phase shift circuits is eliminated, and insertion loss and passive intermodulation risks possibly introduced by additional welding spots or connecting pieces are reduced fundamentally. And the electrical performance and the long-term reliability of the whole feed network are improved.

Embodiments of the present disclosure relate to a performance evaluator, a method performed thereby, a radio unit and a computer readable storage medium. According to an embodiment, the performance evaluator comprises a first parameter calculating module, a second parameter calculating module and an evaluating module. The first parameter calculating module is configured to calculate a first parameter based on traffic power of a transmission signal that generates passive intermodulation (PIM). The second paramter calculating module is configured to calculate a second parameter based on traffic power of a recepition signal in a reception path of the radio unit. The evaluating module is configured to evaluate a performance of PIM cancellation (PIMC) based on the fisrt parameter and the second parameter.

The invention relates to the technical field of digital pre-distortion, in particular to an adjacent multiband digital pre-distortion system and method, and the method comprises the steps: S1, extracting an intermodulation feature vector of an adjacent multiband input signal, and constructing a nonlinear coupling feature matrix based on the intermodulation feature vector; and S2, generating a frequency band cooperative compensation signal by using the nonlinear coupling characteristic matrix, wherein the frequency band cooperative compensation signal is used for compensating an asymmetric cross modulation effect between adjacent frequency bands. And S3, constructing a dynamic pre-distortion parameter optimization model based on the distortion characteristic analysis result of the frequency band cooperative compensation signal and the power amplifier output signal, and generating a final pre-distortion output signal through real-time feedback adjustment. According to the method, the nonlinear primary function set including the high-order intermodulation item and the inter-band cross modulation component is constructed, and the nonlinear coupling feature matrix extracted by singular value decomposition is combined, so that inter-band collaborative modeling and compensation signal generation are realized, and the adaptive capacity under the complex working condition is enhanced.

The method for avoiding third-order intermodulation based on radar waveform generation of the application comprises the following steps: obtaining image test results under different radar parameters based on a standard radar test, adjusting the relationship of the different radar parameters by a frequency spectrum analyzer, determining the relationship between the pulse repetition frequency (PRF) and the frequency difference of different radar signals, and the radar parameters including the radar pulse repetition frequency and the frequency difference between different radar signals; suppressing the third-order intermodulation when the radar transmits and receives multiple signals; after suppressing the third-order intermodulation, sending the generated signal carrier frequency information to the radar radio frequency part, generating corresponding multiple signals and radiating. In a manner without reducing the signal-to-noise ratio, the influence of the third-order component is avoided, thereby improving the signal detection performance of the radar.

The application provides a small-size ultra-wideband wall-hanging antenna with high stability, and specifically relates to a single-polarization directional wall-hanging antenna, which is vertically polarized and comprises a first radiating vibrator, a second radiating vibrator, a first coupling sheet, a second coupling sheet, a third coupling sheet, an antenna cover, a cable feeder and a reflecting plate. The first radiating vibrator and the second radiating vibrator form an asymmetric antenna dipole radiator, and the first coupling sheet and the leftmost part of the second radiating vibrator form an asymmetric structure. The second coupling sheet and the third coupling sheet are separately arranged on the left and right sides of the included angle formed by the first radiating vibrator and the second radiating vibrator. The technical scheme improves the feeding mode and feeding process of the existing wall-hanging antenna on the market, greatly reduces the production cost of the antenna, has the characteristics of low intermodulation, ultra-wideband, simple structure, low cost, stable electrical performance and the like, and can be perfectly applied to a mobile communication system with directional coverage requirements.

Embodiments herein relate to passive intermodulation (PIM) delay estimation for multiple sources. In some embodiments, there is proposed a method (1200) for estimating a time delay of a PIM source for a radio device having multiple PIM sources. In an embodiment, the method may comprise the step of determining (S1201) a time delay window with respect to one or more possible PIM sources of the radio device. The method may further comprise the step of determining (S1202) a plurality of time delay values in a time delay window. The method may comprise the steps of: for each of one or more primary functions, scanning (S1205) each of a plurality of time delay values in a time delay window by performing an adaptive algorithm based on the primary functions to obtain an adaptive set of parameters, and estimating (S1208) one or more time delays for each PIM source from the set of adaptive parameters. Through the embodiments herein, an adaptive scan delay estimation method is proposed in place of a correlation estimation method, which can improve delay estimation accuracy for multiple PIM sources.

This invention relates to a chopper amplifier, comprising a clock generator module, an input chopper module, an amplifier module, and an output chopper module. The clock generator module includes a zero-crossover aligned clock circuit, which outputs an intermediate clock based on the differential input signal and detects the zero-crossover point, aligning the edge of the intermediate clock to the zero-crossover point to generate an aligned chopper clock. The output chopper module is connected to a self-filling circuit, which, in conjunction with the chopper clock, samples the differential output voltage during the chopper steady-state phase and, during the chopper transition phase, forms a short circuit between the differential output nodes, causing the current polarity of the amplifier module to internally reverse, while simultaneously performing self-filling. By utilizing zero-crossover aligned chopper technology and / or self-filling technology, intermodulation distortion caused by chopping is suppressed or eliminated mechanistically without increasing power consumption or noise, significantly improving the linearity and usable input frequency range of the chopper amplifier.

The application relates to the technical field of wireless communication detection, in particular to a link state monitoring method of a radio frequency combiner. Based on the characteristics of radio frequency signals affected by the combined action of service load, thermal noise and abnormal interference, the downlink transmission power, uplink utilization rate and total received power are sampled in multiple time periods, the deviation and fluctuation of the received power and the expected load component are analyzed, the link environment stability is reflected, and then the residual power characteristics representing the link state complexity are obtained. The complexity is used to dynamically adjust the discrimination threshold or weight, so that the fault recognition fully considers the link dynamic characteristics, and the link state evaluation result is output through multiple rounds of correction and regression analysis. The method effectively avoids the interference of normal working conditions such as high load and temperature rise, and significantly improves the identification accuracy and reliability of nonlinear faults such as passive intermodulation (PIM) and external interference.

A bias compensation circuit that receives a detection signal from a detection circuit is provided. The detection circuit is configured to detect a radio frequency signal in an amplifier circuit. The bias compensation circuit includes a conversion circuit and a bias circuit. The conversion circuit is coupled to the detection circuit, and is used to adjust a phase or an amplitude of the detection signal to generate an injection signal, wherein the injection signal is a current signal. The bias circuit is coupled to the conversion circuit, and is used to generate a bias signal to the amplifier circuit based on the injection signal, wherein the bias signal varies with the detection signal.

A system includes a receiver (RX) configured to receive an RX output signal in an RX band, where the RX output signal has a first passive intermodulation (PIM) source in the RX band and a second PIM source in the RX band; and a processing device configured to: receive the RX output signal from the receiver on an RX path, receive a crest factor reduction (CFR) output signal from a CFR on a transmit (TX) path, identify the first PIM source and the second PIM source based on the RX output signal and the CFR output signal, calibrate the CFR output signal based on the first and second PIM sources in the RX output signal to generate a non-linear actuation (NA) input signal, and generate an intermodulation distortion signal by using an NA function on the NA input signal.

This invention relates to the field of radio frequency communication technology and discloses a communication frequency selection method and apparatus based on RSSI. The method includes: sweeping a target frequency band using step units to obtain a set of sweep points; performing peak detection on the sweep point set to obtain the peak received signal strength and interference frequencies; calculating at least one third-order intermodulation point within the target frequency band based on each interference frequency; fitting the sweep point set, each interference frequency, and each third-order intermodulation point to obtain a target sweep point set; performing weighted calculations on each target sweep point in the target sweep point set based on antenna weighting coefficients and the center frequency to obtain a received signal strength weighted value; and selecting the optimal frequency point based on each received signal strength weighted value. Therefore, implementing this invention can improve the accuracy and reliability of communication frequency selection, extend communication distance, and ensure the comprehensiveness and accuracy of frequency selection, thereby improving the stability and anti-interference capability of wireless audio communication.

An aspect of the disclosure relates to a method of reducing a third-order intermodulation component at a first terminal of a transistor, including: receiving an input radio frequency (RF) signal cycling with a first frequency at a control terminal of the transistor; generating a feedback RF signal cycling at a second frequency at a second terminal of the transistor, wherein the second frequency is substantially twice the first frequency; and generating a third-order intermodulation cancellation component at the first terminal including combining the input RF signal with the feedback RF signal, wherein the third-order intermodulation cancellation component has a magnitude and phase substantially equal to and opposite a magnitude and phase of the third-order intermodulation component at the first terminal of the transistor, respectively.

The utility model discloses a superposition intermodulation test system, and belongs to the technical field of superposition intermodulation. Comprising a PC communication end, the PC communication end is in communication connection with a signal source group, a frequency spectrograph, a power meter, a multi-channel carrier intermodulation module and a traditional intermodulation module, and the output end of the signal source group is connected with the input end of the multi-channel carrier intermodulation module and the input end of the traditional intermodulation module at the same time. The input end of the frequency spectrograph is connected with the output end of the traditional intermodulation module, the input end of the power meter is connected with the output end of the traditional intermodulation module, the output end of the multichannel carrier intermodulation module is connected with an antenna port intermodulation point, and the antenna port intermodulation point is connected with the input end of the traditional intermodulation module. And the output end of the multi-channel carrier intermodulation module is connected with the RX channel of the traditional intermodulation module through an R wave band port. According to the utility model, the communication efficiency is improved, the signal transmission quality is enhanced, the cost is reduced, and efficient, stable and reliable communication service is provided for a modern communication system.

The invention relates to the technical field of livestock breeding, and discloses a breeding system capable of accurately managing the breeding cycle of sows, which comprises an active piezoelectric platform module, a quasi-static fringe electric field detection array and a multi-mode signal processing unit. The active piezoelectric platform module is located at the bottom of the limiting fence, provides vertical mechanical excitation for the sow and monitors the body weight; the quasi-static fringe electric field detection array is located on the side wall, and a deep penetration non-contact detection electric field is constructed by using an active shielding technology. And the multi-mode signal processing unit cooperatively drives the mechanical excitation signal and the electromagnetic carrier signal, and extracts an intermodulation component synchronous with the mechanical frequency from the feedback of the quasi-static fringe field detection array. And the multi-mode signal processing unit calculates a weighted reproductive response index according to a demodulation result, and judges the reproductive cycle state of the sow by using a double-threshold logic tree. On the basis of the mechanical dielectric intermodulation principle, non-intrusive high signal-to-noise ratio monitoring of the oestrus state of the sow is realized by detecting the mechanical compliance change of biological tissues.

The present application belongs to but is not limited to the technical field of power amplifier chip, and particularly relates to a table-based frequency domain behavior model parameter extraction method and system, comprising: step 1, testing the output characteristics of the chip under different input powers; step 2, extracting the P2D model parameters of the power amplifier chip; step 3, extracting the bias current and third-order intermodulation product model files; step 4, dynamically calculating and realizing the third-order intermodulation and power added efficiency; and step 5, comparing and verifying the P2D model simulation and actual measurement of the power amplifier chip. The present application proposes a behavior model parameter extraction method capable of representing the power added efficiency and third-order intermodulation based on the table-based frequency domain P2D behavior model, and by combining the measured data of the dynamic drain current in the chip, the third-order intermodulation product output power of the chip and the simulation results of the fundamental wave output power of the chip, the dynamic calculation method of the power added efficiency and third-order intermodulation is broken through, and the simulation prediction of the power added efficiency and third-order intermodulation of the table-based frequency domain P2D model of the chip is realized.