197 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 power battery health state evaluation and anomaly recognition, in particular to a remote health state analysis and anomaly recognition method for an electric bicycle battery, which comprises the following steps of: under an access working condition, applying small-signal active excitation and synchronously acquiring to form an opportunity diagnosis excitation data window; time-frequency coupling modeling including equivalent impedance modeling, harmonic wave and intermodulation fingerprint modeling, Koopman operator modeling and entropy coefficient difference is carried out, and a spectral measurement geometric distance is constructed through optimal transmission to generate a multi-domain response packet, a physical invariant vector and an uncertainty matrix; according to the geometric distance and consistency score gating and hierarchical standardization, obtaining a health state estimation record and an abnormal event set by adopting a shape-limited health mapping model; and in combination with mapping Jacobian and dual potential, generating an opportunity diagnosis incentive plan of a next period by adopting D-optimal test design, and updating a group health manifold, thereby realizing cross-environment, cross-equipment and traceable remote health assessment and early anomaly recognition.

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.

The invention relates to the technical field of microelectronics, semiconductors and communication, and discloses a radio frequency switch chip, and the circuit structure of the radio frequency switch chip comprises a transformer type differential inductor T-L1, a transformer type differential inductor T-L2, a capacitor C1, an NMOS transistor M1, an NMOS transistor M2, a gate resistor RG1, and a gate resistor RG2. The radio frequency switch chip provided by the invention adopts a differential structure, so that the parasitic inductance effect of a grounding key and a wire during packaging and testing can be eliminated, and the insertion loss and the isolation performance are improved; compared with a single-end port, the lower impedance of the differential port is more beneficial to improving the power capacity of the switch; the differential structure allows the transformer type differential inductor to use differential signal characteristics, the equivalent quality factor of the inductor is improved, and the circuit performance is improved; the differential structure can improve the linearity of the circuit, especially the second-order intermodulation effect; the differential structure can be compatible with a modern silicon-based CMOS radio frequency system, and an additional balun is not needed for signal conversion.

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.

A wireless communication system includes a transmitter, a plurality of passive substantially linear medium portions including one or more first portions and a second portion, one or more passive substantially nonlinear medium portions disposed proximate the substantially linear medium portions, and for each first portion, a dielectrically lossy or magnetically lossy first material disposed on the first portion. When the transmitter transmits first and second radio waves, the substantially linear and nonlinear medium portions receive the first and second radio waves and generate first and second signals propagating therein, where at least one intermodulation signal is generated in the one or more substantially nonlinear medium portions from the first and second signals, and the one or more first materials reduces the generation of the at least one intermodulation signal by at least 2 dB.

The invention discloses a method for acquiring passive intermodulation interference caused by oxidation corrosion of a base station antenna, and aims to further supplement and improve the existing research so as to quantitatively evaluate the passive intermodulation interference generated after the oxidation corrosion of the base station antenna. An analysis object is set as the side surface of a microstrip line conductor, firstly, the amplitude coefficient AD2 of voltage of each point in the lower edge area of the side surface of an unoxidized and corroded microstrip line under the action of a single carrier signal is determined, and then after it is determined that the microstrip line is oxidized and corroded, the amplitude coefficient AD2 of voltage of each point is determined. According to the method, the tunneling current density JMIM and the total tunneling current IMIM of the oxidation corrosion areas are obtained according to the average voltage value of the oxidation corrosion areas, and on the basis, the third-order passive intermodulation voltage V3rd-PIM (t) is calculated, so that the passive intermodulation interference generated after oxidation corrosion of the base station antenna is quantitatively evaluated.

An electronic device may include wireless circuitry with a processor, a transceiver circuit, a front-end module, and an antenna. The front-end module may include amplifier circuitry such as a low noise amplifier for amplifying received radio-frequency signals. The amplifier circuitry may include non-linearity suppression circuitry that suppresses or reduces non-linear behavior of components such as a core amplification transistor and a degeneration inductor within the amplifier circuitry. The non-linearity suppression circuitry may include an intermodulation distortion suppression circuit having an auxiliary amplification transistor. The non-linearity suppression circuitry may include a frequency-selective filter coupled to the degeneration inductor.

The invention relates to the technical field of radio frequency cable testing, in particular to a method and device for improving cable intermodulation testing, and the method comprises the steps: pretreating a cable sample, cleaning a cable connector joint, and sleeving a welding part of a cable and a connector with a flexible protective sleeve; the test fixture is adapted, and the rotating shaft distance and the contact pressure of the dynamic test fixture are adjusted; carrying out multi-parameter collaborative testing, starting an intermodulation analyzer to load a test carrier, and collecting various data in real time; dynamic stress loading is carried out, a stepped vibration stress loading mode is adopted, and intermodulation value changes are monitored in real time; data storage and analysis: storing the data in the test process into a database to generate a test report; the device comprises a customized cleaning module, a test fixture module, a multi-parameter monitoring module, a welding part protection module and a control and data analysis module. The problem that an existing static test is separated from an actual working condition is solved, small-size cable test damage is avoided, and errors caused by manual operation are reduced.

The invention provides a base station OTA intermodulation test method based on a reverberation chamber. The reverberation chamber comprises a shielding shell which encloses a closed cavity, and a stirrer which is arranged in the closed cavity and is used for stirring electromagnetic waves transmitted in the closed cavity; and the tested base station and the interference signal antenna are arranged in the working area of the closed cavity in parallel at a preset interval. The method comprises the following steps: starting a tested base station, and enabling the tested base station to transmit a main signal of a first frequency and bandwidth in a preset transmitting power mode; providing an interference signal of a second frequency and bandwidth with a predetermined power level to an interference signal antenna to generate intermodulation interference on the tested base station so as to perform an intermodulation interference test; under the condition that the stirrer is started for electromagnetic wave stirring, electromagnetic wave signals in the closed cavity are collected; and analyzing and processing the acquired electromagnetic wave signal to obtain a measurement result of the intermodulation interference test index based on the total radiation power. The universality of the emission intermodulation test is realized, and the test cost and time are reduced.

A method for reducing receive band leakage may include: sensing, at a full duplexer, passive intermodulation distortion and power amplifier distortion; generating, at a processing device, a passive intermodulation distortion and power amplifier distortion cancellation signal; and cancelling, on a receive path, the passive intermodulation distortion and power amplifier distortion using the passive intermodulation distortion and power amplifier distortion cancellation signal.

The invention discloses an up-mixing harmonic energy communication system and method based on direct-mixing intermodulation signal suppression. The communication system includes a receive antenna and an integrated rectified transmitter. The integrated rectified transmitter includes a first branch and a second branch. The invention provides an integrated rectification transmitter with a double-branch structure, an IM2 modulation module is arranged at the tail end of a first branch, and a 90-degree phase shift network is arranged at the head end of a second branch, so that uncontrollable IMD3 signals generated in the first branch and the second branch have a phase difference of 180 degrees and are mutually counteracted; in this way, only the upmixing IMU3 signal which can be controllably and accurately modulated in the first branch is reserved in the uploaded backscattering signal, and more accurate and reliable wireless energy cooperative information transmission is achieved. According to the invention, the frequency of the IM3 signal for communication is close to that of the input dual-tone signal, so that multiplexing can be realized by only needing a small bandwidth in the design of the receiving and transmitting antenna.

Aspects of the subject disclosure may include, for example, detecting, by a monitoring system associated with a communication system, signals received at an array of orthogonally-polarized radiating elements of an antenna, causing, via a motorized drive assembly, the array of orthogonally-polarized radiating elements to sequentially rotate to a plurality of positions, obtaining, by a control system from the monitoring system and for each of the plurality of positions, data relating to signals from the array of orthogonally-polarized radiating elements, based on the data, determining, by the control system, an optimal position of the plurality of positions for the array of orthogonally-polarized radiating elements at which an impact of passive intermodulation (PIM) on the communications system is minimized, and controlling, by the control system, the motorized drive assembly to cause the array of orthogonally-polarized radiating elements to occupy the optimal position. Other embodiments are disclosed.

The invention relates to a multi-frequency sensitivity test evaluation method and system, the evaluation method is realized based on a multi-frequency sensitivity test device, and the device comprises a signal generator, an attenuator, a power amplifier, a directional coupler, a power meter, a frequency spectrograph and an interference applying module. According to the evaluation method, the sensitivity of the electronic product to single-frequency interference and multi-frequency interference in different frequency bands can be determined, modes such as frequency band sub-band division and reverse frequency spectrum monitoring are designed, the influence of multi-frequency-point signal intermodulation interference on a test result can be reduced, and the test accuracy is improved. The problem that the accuracy of a multi-frequency-point sensitivity test result is affected due to the fact that a traditional multi-frequency-point test method generates extra interference risks on the tested electronic product is solved. Meanwhile, under the condition that the multi-frequency sensitivity indication parameter provided by the invention meets a certain condition, a continuous wave sensitivity test method can be adopted to replace a multi-frequency point sensitivity test method, so that the test cost is reduced.

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 time-varying inter-harmonic torsional vibration signal generator, which comprises a main controller, an input end of the main controller is electrically connected with an output end of a first filter, a second filter and an analog-digital module, an input end of the analog-digital module is electrically connected with an output end of a third filter, the main controller is bidirectionally electrically connected with an SRAM module, a FLASH module, a network card chip, a USB chip and an RS232 module, and an output end of the main controller is electrically connected with an input end of a level module, an optical coupler and an analog-digital module. Compared with a mechanical torsional vibration test bench, the time-varying inter-harmonic torsional vibration signal generator has simple structure, can comprehensively cover test working conditions, can fully test the precision of a torsional vibration analysis device, can provide various linear signals or multi-frequency signals, and can evaluate the time-varying inter-harmonic signal processing situation of the torsional vibration analysis device.

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

To provide a Doherty amplifier circuit capable of suppressing an influence of intermodulation distortion while suppressing a circuit scale.SOLUTION: A Doherty amplifier circuit includes: a 90-degree hybrid coupler including an input terminal to which a first input signal is input, a first output terminal that outputs a first output signal based on the first input signal, a second output terminal that outputs a second output signal having a phase different from that of the first output signal by 90 degrees based on the first input signal, and an isolation terminal that ensures isolation with the input terminal; a carrier amplifier that amplifies the first output signal and outputs a first amplified signal; and a peak amplifier that amplifies the second output signal and outputs a second amplified signal. The isolation terminal is a terminal to which a second harmonic of a frequency band of a second harmonic of the first input signal is input.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.