20 results about "Analogue filter" patented technology

The invention discloses a zero-sequence current acquisition and analysis device and method for a power secondary circuit, and belongs to the field of power systems. The device comprises a current transformer, a temperature sensor, a front-end analog filter, an ADC, a rear-end digital filter, a self-adaptive wave trap, a processor and an alarm. Wherein the output end of the current transformer is connected to the processor through the front-end analog filter, the ADC and the rear-end digital filter in sequence; and the processor is also respectively connected with the temperature sensor and the alarm. According to the invention, real-time acquisition and early warning of the zero-sequence current are realized, and high precision and stability of an acquisition result in a full temperature range are ensured at the same time.

The invention relates to the technical field of broadband signal synthesis and high-speed digital-to-analog conversion, in particular to an oversampling-based real-time frequency interleaving digital-to-analog conversion system aliasing suppression method and system, and aims to solve the problem of spectrum aliasing caused by non-ideal characteristics of a digital sub-band decomposition filter and an analog filter under a real-time architecture of the system. In the invention, the sub-band decomposition is completed by adopting the linear phase complementary filter bank, so that distortion introduced by a transition band of a digital filter is avoided; by restraining system parameters such as passband and stopband frequencies and local oscillation frequency of a sub-band decomposition filter, a protection band is set by an oversampling mechanism, a frequency margin is reserved for a transition band of the filter, and aliasing components are suppressed. According to the method, extraction aliasing of a digital domain and mirror image aliasing of an analog domain are avoided at the same time from the system architecture, the frequency spectrum purity of output signals is improved, the method is suitable for a real-time system for processing continuous data streams, and technical support is provided for achieving a high-performance broadband signal source.

A data acquisition circuit includes a plurality of signal processors including a first analog chopper circuit, an amplifier, a second analog chopper circuit, and an analog filter that are coupled in series, respectively. The data acquisition circuit during a first mode converts analog signals from analog filters into a serial signal and converts the serial signal into a digital signal, and filters the digital signal after converting the digital signal into parallel signals. The data acquisition circuit during a second mode converts the analog signals from the amplifiers into the serial signal and converts the serial signal into the digital signal, outputs the digital signal to the digital chopper circuit, and filters the digital signal after converting the digital signal from the digital chopper circuit into parallel signals. Thus, biological information in the plurality of frequency bands can be appropriately acquired.

An analog filter circuit includes an active filter configured to filter a transmission signal, the active filter including an active element to which a power supply voltage is applied, and a passive filter connected to an output terminal of the active filter, the passive filter including a passive element having a dynamically variable impedance.

The utility model discloses a blasting data acquisition circuit based on an FPGA, and belongs to the technical field of blasting data acquisition. Comprising a field programmable gate array (FPGA) which is connected with an analog-to-digital converter (ADC) and an advanced RISC machine (ARM) processor. The input end of the analog-to-digital converter ADC is connected with three four-order analog filters, and the three four-order analog filters are respectively used for filtering X-direction, Y-direction and Z-direction signals; and the ARM processor is connected with a nonvolatile storage device FLASH, an SDRAM (Synchronous Dynamic Random Access Memory) and an external device. According to the utility model, through combination of the FPGA, the ADC and the ARM, the precision, real-time performance and flexibility of data acquisition can be improved, the overall power consumption is reduced, and the overall performance is improved. The FPGA is used for processing high-speed data, and the ARM is used for subsequent processing, so that the system delay can be reduced, and the throughput can be improved. And the FPGA is used for processing real-time tasks, and the ARM enters a low-power-consumption mode when being idle, so that the overall power consumption can be reduced.

Embodiments of the present disclosure relate to systems, methods, apparatuses, and computer program products that align filter configurations between a device and a network. A method can include transmitting capability information to a network element. The method can also include receiving a radio resource configuration from the network element, the radio resource configuration including parameters for support of frequency arrangement and dynamic analog filter bandwidth switching determined from a local oscillator, and at least one parameter range. The method can further include maintaining a current local oscillator arrangement and analog filter configuration, or switching to a new local oscillator arrangement and analog filter bandwidth configuration, based on the radio resource configuration.

An FMCW-radar based distance measuring device is characterized in that, in addition to analogue high-pass and low-pass filtering, the evaluation signal typical for FMCW additionally undergoes subsequent digital filtering. In this case, the analogue / digital conversion takes place by oversampling. As a result, according to the invention, all those frequencies in the evaluation signal that are above or below the frequency corresponding to the distance of the object are effectively suppressed. At the same time, the analogue filters can be constructed with a very low level of complexity. The space requirement and the costs of the analogue components is reduced thereby. In addition, the dependence on temperature of the distance measuring device is reduced thereby. The potentially high distance resolution is also maintained.

Variable Gauge Analog Filter The present invention relates to a variable gauge analog filter (10) comprising, between an input (18) for a frequency signal (22) to be filtered and an output (20) for a filtered signal (24). The filter comprises a set of filtering impedances (26) with at least one variable capacitor (28, 32) disposed between a high point and a low point, and comprising a control input (21) for a control voltage (of the capacitor's capacitance). The variable capacitor (28) is a main transistor (28) whose source and drain form the high and low points respectively, the control input (21) being connected to the drain, the source and gate being connected to electrical potentials for operation of the main transistor (28) in a cutoff state. Figure for the abstract: Figure 1

The application discloses a stopband residual compensation method and device of a digital filter, a storage medium and a computer program product, relates to the technical field of audio signal processing, and the method comprises the steps of collecting an original audio signal and a digital filtering signal; inputting the digital filtering signal and the original audio signal into a pre-constructed stopband residual noise dynamic compensation model synchronously for processing to obtain a smooth transition signal, wherein the stopband residual noise dynamic compensation model takes a hardware filtering signal output by a hardware analog filter as a target label; and superimposing the smooth transition signal and the digital filtering signal at a preset superimposition ratio to obtain a calibration signal. The stopband residual noise dynamic compensation model learns the smooth transition characteristics when the hardware analog filter reproduces parameter adjustment, takes into account the flexibility of the digital filter, thereby improving the response speed when the digital filter adjusts the cutoff frequency in real time at a high frequency, and suppressing the stopband residual energy at the moment of cutoff frequency adjustment.

The present invention provides a method and apparatus for generating RF signals. [Solution] A method and apparatus for generating an RF signal uses digital signal components to generate a composite RF signal having multiple frequency components. An analog filter is used to filter the composite RF signal. The analog filter is an adjustable active feedback circuit having one or more variable resonators and a variable gain block connected to a signal loop defined by a passband. The analog filter is adjusted so that the passband of the analog filter overlaps with one or more desired frequency components of the multiple frequency components of the composite RF signal, and the passband has a relative bandwidth of about 1% or less.

The invention relates to the technical field of wireless communication, in particular to a broadband IQ imbalance and group delay joint calibration implementation method and device and a storage medium, and the method comprises the following steps: arranging a correction filter between the input end of an I channel baseband signal and the input end of a Q channel baseband signal of a radio frequency transmission link; the correction filter is arranged behind the input end of the Q-channel baseband signal of the radio frequency transmitting link; converting the IQ two paths of baseband signals into analog signals through a DAC, processing the analog signals through an analog filter BBF, sending the processed analog signals into a frequency mixer, and outputting radio frequency signals; configuring an observation channel for the radio frequency signal; inputting the radio frequency signal, the I-channel baseband signal and the Q-channel baseband signal into a preset QEC calibration module to perform IQ calibration on a radio frequency transmitting link; the IQ calibration comprises initial calibration and real-time tracking calibration. According to the invention, IQ calibration and group delay calibration in a coverage full power range can be realized, temperature drift is suppressed, and performance and resource consumption are considered.

Analog FIR filter. An FIR filter (15) includes an input terminal for receiving an input signal, a first filter circuit including: a first transconductance device (30a) configured to generate a first current signal (i1) proportional to the input signal; a first analog switch (41a) commutated in n by a first digital gate signal (φ1) and configured to block the current signal when the first digital gate signal has a first value and to transmit the current signal to a first integrating capacitor (45a) when the first digital gate signal has a second value; characterized in that the first digital gate signal (φ1) includes a periodic series of pulses, wherein the pulses have a width proportional to the filter coefficients.

The invention belongs to the technical field of machining, and particularly relates to a frequency locking method for dynamically adjusting the vibration mode driving frequency of an ultrasonic broach, which comprises the following steps of: designing a hybrid PLL (Phase Locked Loop) system, and calculating a phase difference and accurately adjusting the driving frequency in combination with a digital phase discriminator and a CORDIC (Coordinated Rotation Digital Computer) algorithm; a dual-mode tracking strategy is adopted, a fault protection mechanism is added, and when the system detects that phase mutation exceeds 30 degrees, emergency stop is triggered, and a backup analog filter is automatically switched; by designing an accurate band-pass filter and combining hardware deployment and a dynamic frequency tracking technology, the position of a harmonic peak is detected in real time, and the passband range of the filter is correspondingly adjusted. According to the frequency locking method for dynamically adjusting the ultrasonic broach vibration mode driving frequency, the dynamic driving frequency can be adjusted in real time, it is ensured that the signal is close to the resonant frequency, an ultrasonic auxiliary broaching system is kept in the target vibration mode all the time, accurate control over the broach vibration mode is achieved, and the performance of ultrasonic machining equipment is improved.

A neuron pulse acquisition system is disclosed for capturing and processing neuron flow signals from the human body in a non-invasive manner. The system includes a pad with a skin sensor configured to detect neuron pulse potentials, a variable gain amplifier (VGA) to amplify detected signals, and an analog filter (A-FILTER) to remove noise. An analog-to-digital converter (ADC) digitizes the filtered signals, which are processed by a digital signal processing (DSP) and Bluetooth unit executing Fourier Transform and Cross-Correlation algorithms to analyze neuron flow characteristics in time and frequency domains. A D / A calibration module maintains analog accuracy, and a system software controller performs spectral analysis, cross-correlation, and machine learning-based predictive modeling. The system enables real-time monitoring, classification, and diagnostic interpretation of neuron flow behavior, thereby facilitating predictive analysis of neural conditions with high precision and reliability.

The invention belongs to the technical field of surface acoustic wave sensor signal processing, and discloses a surface acoustic wave sensor detection circuit based on LMS adaptive filtering, which comprises an analog detection circuit and a digital detection circuit, the analog detection circuit comprises an SAW oscillation circuit and a frequency mixing circuit, the digital detection circuit adopts an adaptive filtering module to filter a signal output by the analog detection circuit, and the frequency demodulator receives the filtered signal and performs frequency demodulation on the signal; the SAW oscillation circuit comprises a reference channel and a measurement channel, a reference channel signal and a measurement channel signal pass through the frequency mixing circuit to obtain an offset frequency signal, and the frequency of the offset frequency signal is the frequency of a physical quantity to be measured. Through the LMS adaptive filtering module, coefficients can be dynamically adjusted to suppress time-varying noise, the defect of fixed parameters of a traditional analog filter is overcome, the signal-to-noise ratio is improved, and the LMS adaptive filter is suitable for industrial automation, aerospace and other detection scenes.

The embodiment of the present specification discloses an active noise reduction audio device. The device comprises a speaker, a microphone, an analog filter and a processing circuit. The speaker is used to generate noise reduction sound, the microphone is used to collect environmental noise and noise reduction sound, and generate a first analog signal. The analog filter is used to provide gain for the first analog signal and generate a second analog signal, wherein the second analog signal drives the speaker to generate noise reduction sound. The processing circuit is used to send control instructions to the analog filter according to the first analog signal and the second analog signal, so as to adjust the gain and phase shift of the analog filter. The present specification can reduce the time delay caused by the signal transformation link and the digital filter processing by using the analog filter to adjust the amplitude and phase of the analog signal and generating the noise reduction sound, so that the audio device can timely respond to the noise reduction, thereby improving the noise reduction effect.

The invention relates to a measurement device for measuring weak magnetic fields, such as fields in the sub-picotesla range (e.g. lower than a few nanotesla). The measurement device comprises ultrasensitive magnetic sensors (or arrays of ultrasensitive magnetic sensors) coupled to low-noise processing circuitry. The processing circuitry comprises a two-stage design including low-noise amplifiers and analog filters. The invention is suitable for magnetocardiovascular (MCV) applications thanks to its ability to measure very small magnetic fields with good accuracy and very little noise.

The embodiment of the invention provides a variable fractional delay filter design method and system. The method is applied to the technical field of communication technology and signal processing, and comprises the following steps: constructing a function relationship between an analog filter and a digital filter through a sampling theory based on a VFD filter principle of a Farrow structure; the analog filter is cut off through a window function method, and a high-order FIR filter is obtained through calculation; the high-order FIR filter coefficient is decomposed into a plurality of different fractional delay filters, and a VFD filter coefficient of a Farrow structure is calculated by using a segmentation fitting method; and designing a variable fractional delay filter through a VFD filter coefficient of a Farrow structure based on the function relationship. In this way, the filter designed by the method has obvious advantages in frequency aliasing resistance, and the designed variable fractional delay filter has better application prospects.

An apparatus, which allows a radio frequency identification (RFID) reader to recover quickly from transient input to its receiving subsystem when transitioning from writing to an RFID transponder to reading its response. In particular, this apparatus is comprised of muting circuits, which both attenuate transients in its receiving subsystem while writing to a transponder, and help the receiving subsystem settle quickly after experiencing such transients.