347 results about "Intermodulation" patented technology

Aspects of the subject disclosure may include, for example, causing radio frequency (RF) signals to be transmitted via an antenna system in a plurality of directions, and responsive to transmission of the RF signals, monitoring signals that are received by the antenna system to detect an interference signal that originates from a passive intermodulation (PIM) source. Other embodiments are disclosed.

Aspects of the subject disclosure may include, for example, detecting an interference signal in two or more signals received via orthogonally-polarized elements of an antenna system, the interference signal originating from a passive intermodulation (PIM) source, measuring a polarization of the interference signal, by comparing the two or more signals, to estimate a shape of the PIM source, and generating information regarding the shape to facilitate locating of the PIM source. Other embodiments are disclosed.

Aspects of the subject disclosure may include, for example, causing radio frequency (RF) signals to be transmitted via an antenna system in a plurality of directions, and responsive to transmission of the RF signals, monitoring signals that are received by the antenna system to detect an interference signal that originates from a passive intermodulation (PIM) source. Other embodiments are disclosed.

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 provides a multi-port multi-band intermodulation test method and equipment, and the method comprises the following steps: controlling one or more signal sources to respectively generate carrier signals of two different frequency points in respective target frequency bands; combining the carrier signals into a mixed wave signal through a signal cross network, and distributing the mixed wave signal into multiple paths of test signals, so that each path of test signal comprises the mixed wave signal of one frequency band or multiple frequency bands so as to access a signal port of external passive equipment; and polling and collecting reflected signals generated by each path of test signals through a signal collection unit, and generating test data based on the reflected signals. According to the method, intermodulation testing of multiple frequency bands is achieved, multi-frequency-band intermodulation testing can be conducted on multiple external passive devices at the same time, or multi-frequency-band intermodulation testing can be conducted on multiple ports of the external passive devices, and therefore the intermodulation detection efficiency is improved.

The invention discloses a method for automatically setting a working frequency based on a field radio frequency environment, which relates to the technical field of wireless communication, and comprises the following specific steps of: acquiring field radio frequency environment data in real time through a wireless frequency data acquisition module, and storing the field radio frequency environment data in a database; the data processing module screens non-interference frequency points based on third-order intermodulation interference compatibility calculation, the working frequency of the receiver and the working frequency of the transmitter are dynamically adjusted through the equipment control module, and the database, the data processing module and the equipment control module cooperate to achieve automatic frequency switching. A receiver in the method is provided with a standby receiving sub-module, when it is detected that a current frequency point is interfered, the current frequency point is automatically switched to a standby frequency point, stable operation of a system is ensured, the transmitter synchronizes the frequency with the receiver through a communication protocol in a speaking state, signal transmission is stopped in a mute state, environment interference can be monitored in real time, manual intervention is not needed, and the method is suitable for popularization and application. Manual frequent manual operation for frequency adjustment is avoided, and the anti-interference capability of a wireless communication system is remarkably improved.

The invention provides a multi-port multi-frequency-band intermodulation test device, and the device comprises a plurality of signal sources which work in different frequency bands, and each signal source is used for generating two paths of carrier signals of different frequency points in the same frequency band; the signal cross network is used for combining two paths of carrier signals generated by each signal source of the same frequency band into a mixed wave signal and then distributing the mixed wave signal into multiple paths of test signals, and each path of test signal comprises the mixed wave signal of one or more frequency bands so as to be accessed to a signal port of external passive equipment; the signal acquisition unit is used for polling and acquiring reflection signals generated by each path of test signals; and the controller is used for controlling the signal source to generate a carrier signal and generating test data according to the reflected signal. The intermodulation test device can perform multi-band intermodulation test on a plurality of external passive devices at the same time, or perform multi-band intermodulation test on a plurality of ports of the external passive devices, so as to improve the intermodulation detection efficiency.

Systems and methods of passive intermodulation (PIM) detection in a radio frequency (RF) system including: injecting, from each port of a two-port PIM analyzer, two test tones or a wideband modulated carrier signal into the system one port at a time; receiving, at each port, a response signal from the system in response to the test tones or wideband modulated carrier signal; injecting, from two ports of the two-port PIM analyzer, test tones or a wideband modulated carrier signal into the system; receiving, at the two ports, a response signal from the system in response to the test tones or wideband modulated carrier signal; and identifying one or more PIM sources based on the response signals.

The invention discloses a broadband high-precision voltage compensation control method of a power amplifier, relates to the technical field of broadband compensation, and is used for solving the problem of low voltage compensation efficiency caused by cooperative distortion caused by mutual regulation and control when the signal frequencies of different input channels are close. Recording information of the input signal is called to judge the signal type of the input signal, when the multi-frequency signal exists in the analysis database, the signal amplitude and the signal frequency of the multi-frequency signal are collected, the high-order intermodulation distortion degree of the input signal is judged, and the distortion index of the multi-frequency signal is calculated; selecting to start intermodulation distortion processing or enter a frequency coexistence risk test mechanism according to the high-order intermodulation distortion degree of the multi-frequency signals, calculating frequency intermodulation characteristics of different single-frequency signals, and performing effect integration on the frequency intermodulation characteristics of all the single-frequency signals in the analysis database according to the number of the single-frequency signals; and judging whether to carry out intermodulation distortion processing or not by combining the distortion index of the multi-frequency signal.

A dual-mode radar arranged for harmonic and intermodulation operation, said dual-mode radar comprising a transmitter system arranged for detecting an object, said transmitter system comprising a main transmitter arranged for transmitting a first signal towards said object, said first signal having a first frequency, at least one auxiliary transmitter arranged for transmitting a second signal, simultaneously with said first signal, towards said object, said second signal having a second frequency, said second frequency being different, but in a same order of magnitude, to said first frequency, and a receiver system, comprising a receiver arranged for simultaneously receiving a harmonic return signal corresponding to said first signal and receiving an intermodulated return signal corresponding to said first and second signal.

The invention provides an intermodulation test network and a control method thereof. The method comprises the following steps: sending a test instruction to a plurality of intermodulation test devices through a switch; and receiving test data uploaded by the plurality of intermodulation test devices based on the switch, and generating an intermodulation test report based on the plurality of test data. According to the method, a test instruction is sent to a plurality of intermodulation test devices through a switch, so that the plurality of intermodulation test devices can work simultaneously, and a signal source is respectively controlled to generate carrier signals in a target frequency band. Compared with a traditional mode that a single device is tested one by one, the multi-device collaborative testing mode greatly shortens the testing time and improves the testing efficiency.

The invention relates to the technical field of radio frequency switches, in particular to a low-intermodulation and high-reliability coaxial radio frequency switch which comprises a connector assembly, a cavity cover assembly and a coil assembly, the connector assembly comprises a center connector and a branch connector, the cavity cover assembly comprises a cavity cover and a reed, a supporting medium is installed on the reed, a lower spring is arranged outside the supporting medium in a sleeving mode, and the coil assembly is arranged in the cavity cover. The coil assembly comprises a plurality of coils, iron cores provided with upper springs are arranged on the coils and connected with the corresponding supporting media, and during power failure, the compression elastic force of the upper springs is larger than that of the lower springs, so that the iron cores in the coils move downwards to drive the corresponding supporting media and the corresponding reeds to move downwards. When the coaxial radio frequency switch is switched on, the reed is respectively contacted and conducted with the central connector and one branch connector, so that when the coaxial radio frequency switch is not powered on or the switch fails, one path of the switch is still switched on, at the moment, a system connected with the switch can still work in a default state, and a failure mode can be guided to a safety mode.

The present invention relates to an audio-video signal processing apparatus, which comprises: an audio-video application circuit, a power supply circuit, and at least one impedance matching circuit, wherein the audio-video application circuit is configured to receive, process, and output audio and / or video intermodulation signals; the power supply circuit is configured to output a DC voltage to the audio-video application circuit for powering it; the impedance matching circuit includes a plurality of impedance elements, at least one input end, and at least one output end, and is arranged before or inside the audio-video application circuit. The audio-video signal processing apparatus of the present invention can perform impedance matching and timing adjustment on the power supply signal and the audio and / or video intermodulation signals, thereby reducing the intermodulation distortion generated by the audio and / or video intermodulation signals during transmission through the impedance matching circuit.

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 discloses an RRU multi-band passive intermodulation elimination method based on a sequence-to-sequence learning model, and the method comprises the steps: obtaining a transmitting signal and a receiving signal of a multi-band RRU, carrying out the feature extraction of the signals through adaptive transformation, and obtaining the multi-band intermodulation interference feature data; generating a nonlinear intermodulation feature vector based on the multi-band intermodulation interference feature data; training a PIM signal prediction model by using a sequence-to-sequence learning model, and performing residual compensation on a prediction result based on an error optimization mechanism; performing adaptive filtering processing on the predicted PIM interference signal to generate an optimized interference compensation signal; and dynamically updating the PIM signal prediction model by using an online learning mechanism based on the signal data after interference suppression. According to the method, the multi-band nonlinear intermodulation characteristics can be modeled in a self-adaptive manner, the PIM prediction precision is improved, and the calculation complexity is reduced.

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 discloses a system for simultaneously suppressing second-order nonlinearity and third-order nonlinearity in a direct modulation laser (DML), which belongs to the field of optical communication, and can simultaneously suppress the second-order nonlinearity and the third-order nonlinearity in the system under the condition of DSP-FREE through the combined action of a broadband pre-distortion circuit and an optical path push-pull structure. Wherein at a transmitting end, a set of Schottky diodes and Chebyshev gradient transmission lines which are connected in parallel reversely are adopted to build a DC-10GHz broadband pre-distortion module, and a radio frequency signal generates a reverse third-order intermodulation (IMD3) component through an analog pre-distortion circuit so as to counteract forward third-order nonlinearity of a laser; at a receiving end, a second-order intermodulation (IMD2) component is differentially eliminated through an optical path push-pull modulation architecture. Compared with a traditional DSP scheme, digital signal processing is not needed, the method has the advantages of being low in complexity and wide in bandwidth, and nonlinear accurate compensation of an optical communication system can be achieved.

The invention provides an intermodulation test network. The intermodulation test network comprises a control device, at least one switch and a plurality of intermodulation test devices. And the switch is used for connecting a plurality of intermodulation test devices to realize networking among the plurality of intermodulation test devices. The intermodulation test network realizes multi-band and multi-port synchronous intermodulation test through the cooperation of the control device, the switch and the plurality of intermodulation test devices. The switch is connected with the plurality of intermodulation test devices to realize networking, and the control device controls the plurality of intermodulation test devices to work cooperatively through the switch, so that the plurality of intermodulation test devices can test a plurality of frequency bands and a plurality of ports at the same time, and the requirements of multi-port passive products and intermodulation tests on a plurality of passive products at the same time are met; and the test efficiency is improved.

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.

A system and method for measuring and analyzing power flow parameters in RF-based excitation systems for semi-conductor plasma generators. A measuring probe is connected to an RF transmission line for receiving and measuring voltage and current signals from the transmission line. A high-speed sampling process converts the measured RF voltage and current signals into digital signals. The digital signals are then processed so as to reveal fundamental, intermodulation, triple beat, and harmonic amplitude and phase information corresponding to the original RF signals. The measurement system may also inhibit arcing by detecting when the amplitude of the intermodulation or triple beat signal exceeds a predetermined threshold, and indicating an alarm and / or reducing the power of the plasma generator when the predetermined threshold is exceeded.