1418results about "Amplifier modifications to reduce non-linear distortion" patented technology

The invention relates to the technical field of wireless communication, and provides a radio frequency low-noise amplifier which comprises an input matching module, a power amplification module, an output matching module, an RC attenuation module and an RC feedback module, the first end of the first inductor serves as the input end of the output matching module, the first end of the first inductor is connected with the output end of the power amplification module, the control end of the switch and the first end of the first adjustable resistor, and the second end of the first inductor is connected with the first end of the second inductor and the first end of the third capacitor. The output end of the switch is connected with the first end of the first capacitor and the first end of the second capacitor. The second end of the second capacitor is connected with the second end of the first adjustable resistor and the second end of the second inductor and used for being connected with a power supply. The second end of the first capacitor is connected with the second end of the third capacitor and serves as the output end of the output matching circuit. The radio frequency low-noise amplifier is adjustable in gain, low in noise and good in linearity performance.

The embodiment of the invention provides a closed-loop control method for power driving and protection, and the method comprises the steps: constructing a voltage feedback type circuit through a high-speed operational amplifier, and forming a closed-loop gain structure through a feedback network of the voltage feedback type circuit; the load current of the output end of the voltage feedback type circuit is monitored in real time, and when the load current exceeds a first set threshold value, a protection mechanism is triggered to turn off the output stage; the power-on surge current is limited through the soft start control circuit; phase information of a load reflection coefficient is obtained, an inductance / capacitance combination of the variable dynamic impedance matching network is selected according to phase information table look-up, inductance / capacitance parameters are switched through a relay, and the transmission standing-wave ratio between the power amplifier and a load is optimized; monitoring the temperature of the radiating fin of the power tube, and dynamically adjusting the resistance value of the feedback network; and performing cooperative control of short-circuit protection, over-temperature protection and surge suppression according to the priority. According to the embodiment of the invention, the performance bottleneck in a load fluctuation scene is broken through.

The invention discloses a power adaptive digital pre-distortion method, system and device based on sparse GRU and a medium. The method comprises the steps that input and output signals under different powers are collected, a composite feature vector is constructed through amplitude normalization and phase alignment, and a pre-distortion training target is generated in combination with indirect learning; constructing a sparse GRU neural network, introducing L1 regularization constraint, and obtaining a sparse pre-distortion model through joint optimization of mean square error and sparse constraint; partial weight updating is realized based on power grading, and weight fusion output is carried out during power interval switching so as to complete power adaptive optimization; pruning and compressing the sparse GRU model and then deploying the sparse GRU model in a pre-distortion module to compensate the nonlinearity of the power amplifier; according to the method, the model complexity is reduced through rarefaction, the dynamic working condition stability is improved through a power adaptive mechanism, pruning compression adapts to low-power-consumption hardware, high precision, low complexity and adaptive capacity are considered, and the method is suitable for the low-power-consumption and high-performance requirements of a broadband wireless communication system.

The invention discloses a digital pre-distortion method, system and device and a storage medium, and relates to the technical field of aerospace communication. The method comprises the following steps: acquiring a first input signal and a first actual output signal of the power amplifier, and acquiring a thermal state characteristic; constructing a three-dimensional dynamic baseline; superposing the detection sequence into the first input signal to obtain a second input signal, obtaining a corresponding second actual output signal, and predicting an ideal output signal of the second input signal; extracting a harmonic component generated after the detection sequence passes through a power amplifier, and determining a distortion early warning moment; recording a third input signal after the distortion early warning moment; constructing a virtual test signal according to the third input signal, and predicting to obtain a reference output signal; and comparing the difference between the distortion output signal and the reference output to obtain a distortion feature vector, constructing a dynamic increment compensation function, and correcting the signal processing flow of the power amplifier based on the dynamic increment compensation function. And the accuracy of digital pre-distortion is improved.

The utility model relates to a radio frequency power amplification circuit with a harmonic suppression function and a radio frequency chip. The radio frequency power amplification circuit comprises an input matching unit, a first-stage power amplification unit, a first-stage bias unit, a first-stage power supply unit, an inter-stage matching unit, a second-stage power amplification unit, a second-stage bias unit, a second-stage power supply unit and an output matching unit. According to the utility model, the LC type trap circuits are designed and used in the power supply unit and the inter-stage matching unit, so that secondary, tertiary and high-order harmonic suppression is realized in the radio frequency power amplification circuit; meanwhile, based on LC circuit structures in the power supply unit and the inter-stage matching unit, the inter-stage matching bandwidth is widened, and the linearity of the multi-stage power amplification unit is improved.

Method and device(s) for supporting performance of machine learning based CFR and DPD on multiple digital input signals relating to different frequency bands, respectively, in order to signal condition said signals before power amplification and subsequent transmission in said frequency bands by a wireless communication network. The device(s) obtain said multiple digital input signals as complex valued signals. The device(s) perform feature construction that takes said multiple digital input signals as input and provides constructed feature signals according to predefined constructed feature types as output. Said predefined constructed feature types relate to at least the following per complex valued sample of the obtained complex valued multiple digital input signals the real part of the sample, the imaginary part of the sample and at least one of the absolute value of the sample and the phase of the sample.

The invention relates to a digital pre-distortion method and system based on a hierarchical iterative neural network, and belongs to the field of digital pre-distortion of power amplifiers. According to the method, the pre-distortion process is decoupled into two stages of off-line generalization training and on-line specialization optimization. In the offline stage, a mixed data set containing multiple modulation modes and bandwidths is adopted to train an offline neural network, and a basic model with high generalization ability is constructed; in the online stage, aiming at a signal with a specific modulation mode and bandwidth, a single configuration data set is utilized to train an online neural network, and the accurate compensation capability of the model on a real-time input signal is enhanced. In practical application, a baseband signal is firstly subjected to targeted preprocessing through the online neural network, then is subjected to deep optimization through the offline neural network, and finally is input into the power amplifier PA. According to the method, through a generalization-specialization double-layer structure, the dynamic response capability and compensation precision of a digital pre-distortion system to a complex signal environment are remarkably improved.

The invention relates to the technical field of radio-frequency signal processing, and discloses a 5G radio-frequency signal amplification method and system, and the method comprises the steps: decomposing an obtained radio-frequency signal into a high-frequency sub-band and a low-frequency sub-band through a multilayer wavelet packet, judging whether the radio-frequency signal is sparse in a wavelet packet domain, and carrying out the sparse reconstruction of an LI norm minimization problem if the radio-frequency signal is sparse; obtaining feature data of each sub-band, extracting a nonlinear transfer function of each sub-band through a CNN-GRU network, and carrying out transfer learning pre-training and dynamic adaptation updating; on the basis of dynamic adaptation update ending, layered memory polynomial calculation and layered model joint output construction, layered model parameter optimization is converted into a least square problem to obtain an error compensation function, and resource allocation is dynamically adjusted according to the peak-to-average power ratio of an input signal; and based on power amplifier state data, holographic sensing is performed on nonlinear parameters of the device through a fusion model, and dynamic changes of the device are compensated through multi-stage calibration and calibration delay is controlled.

A logarithmic amplifier system is disclosed. The system includes first and second amplifiers respectively having first and second gains; a first multiplier having an input connected to an output of the first amplifier, and being configured to output a first multiplied signal based on an output signal of the first amplifier and based on a received first multiplication factor equal to a value K; a second multiplier having an input connected to an output of the second amplifier, and being configured to output a second multiplied signal based on an output signal of the second amplifier and based on a received second multiplication factor equal to 1 minus the value K; a transition shaping circuit configured to change the value K from 0 to 1 with a filtered transfer function; and a summing circuit having inputs coupled to outputs of the first multiplier and the second multiplier.

The invention discloses a C / X wave band ultra-wideband GaAs MMIC low-noise amplifier, and mainly relates to the technical field of radio frequency front ends. Comprising an input matching network used for receiving a radio frequency signal and performing impedance matching so as to effectively transmit the signal to a subsequent active amplification part; and the active amplification part adopts an improved cascode-cascode cascade amplification structure and is used for amplifying the radio frequency signal transmitted by the input matching network. The amplifier has the advantages that an improved cascode-cascode cascade amplification structure is adopted, the gain is improved through an improved Cascode structure, the noise coefficient of the circuit is reduced, and the performance indexes of ultra wide band, low noise and high gain are achieved. The design of the structure not only improves the overall performance of the amplifier, but also enables the amplifier to keep stable gain output in a broadband range, and effectively solves the problems of low gain and high noise of a traditional low-noise amplifier in broadband application.

The invention discloses a power synthesis amplifier which comprises two power amplification structures, and each power amplification structure is composed of an input matching circuit, a driving stage amplifier DA, an inter-stage matching circuit, a power stage amplifier PA and an output matching circuit. The input end of the power synthesis amplifier is connected by a T-junction power distribution network; the output end of the power synthesis amplifier is connected with the T-junction power synthesis network. The output power of the power amplifier is improved by adopting a two-path synthesis technology, specifically, the power amplifier can be expanded to multiple paths according to needs, and an output power synthesis network adopts a current type synthesis network, so that the amplitude-phase balance of two paths of output signals and the current processing capability of a circuit are ensured, and the output efficiency is improved; the output-stage matching circuit adopts a transformer with a high coupling coefficient to reduce signal loss, the input and inter-stage matching networks adopt a transformer with a low coupling coefficient to play a role in expanding bandwidth, and the multi-stage matching circuit can be widely applied to the technical field of mobile communication and radar detection.

A squelch detection device is provided. The squelch detection device receives first and second input signals and first and second threshold voltages. The squelch detection device determines a first common mode of the first and second input signals and a second common mode of the first and second threshold voltages. The squelch detection device averages the first common mode with the second common mode to produce an average common mode and sets the first common mode of the first and second input signals to the average common mode. The squelch detection device sets the second common mode of the first and second threshold voltages to the average common mode and determines a state of a squelch signal, indicative of whether the first and second input signals are attributable to noise, based on the first and second input signals and the first and second threshold voltages.

The invention relates to a folded cascode low noise amplifier. The disclosed low noise amplifiers (LNAs) include a common emitter amplifier (CE-A), a common gate amplifier (CG-A), and various passive devices located in CE-A and CG-A. The CE-A includes an NPN type bipolar junction transistor (BJT) having emitter and collector (E / C) regions, and a base region located between the E / C regions and connected to an input node. The CG-A includes a P-channel field effect transistor (PFET) having source and drain (S / D) regions, a channel region between the S / D regions, and a gate adjacent to the channel region. A drain region of the PFET is connected to the output node. Further, the common inductor, the collector region of the BJT, and the source region of the PFET are connected at an intermediate node. The LNA is implemented on a three-dimensional integrated circuit (3DIC) in which the BJT and the FET are located on different chips and the passive device is located in a back-end-of-line region between the BJT and the FET.

The invention provides a dynamic residual amplification circuit based on charge sampling, and relates to the technical field of integrated circuits, the dynamic residual amplification circuit comprises an integrating circuit, a logic circuit, a charge pump and a zero-cross detection circuit, the integrating circuit is connected with the logic circuit and the zero-cross detection circuit, the integrating circuit converts a sampled input differential signal into a constant current, and the constant current is connected with the charge pump. The output node is continuously charged or discharged, so that the input differential signal is converted into a current integral quantity; the zero-cross detection circuit monitors the output voltage of the integrating circuit in real time, and when the output voltage is greater than or equal to the common mode voltage VCM, the moment when the output voltage is equal to the common mode voltage VCM is converted into a digital clock edge; the logic circuit is connected with the charge pump and outputs digital pulses to the charge pump according to the digital clock edge so as to control the reset time sequence of the whole dynamic residual amplification circuit; the charge pump is configured to output a residual voltage modulated by the digital pulse in response to the digital pulse. The application helps to improve the linearity of the residual signal.

Techniques for echo cancellation in an RFID reader include incorporating an auxiliary error power amplifier (auxiliary PA) into the RFID reader, and dynamically adjusting a bias setting of the auxiliary PA based on a power level of a reflection of a signal transmitted by the RFID reader (“echo signal”) as measured at the RFID reader. When the measured echo signal power level is high, techniques herein set the auxiliary PA bias setting to a higher level to allow the auxiliary PA to account for the stronger echo signal. Inversely, when the measured echo signal power is low, techniques herein set the auxiliary PA bias setting to a lower level to reduce power consumption while the enabling the RFID reader to cancel echo phenomena and reliably detect signal responses from RFID tags in an environment.

The invention provides a self-adaptive linearization biasing circuit, a radio frequency module, a chip and electronic equipment. The self-adaptive linearization biasing circuit comprises a biasing sub-circuit and a commutator circuit. The output end of the bias sub-circuit, the control end of the commutator circuit and the radio frequency input end of the power amplifier are coupled to a first node, the output end of the commutator circuit is coupled to a voltage division node of the bias sub-circuit, and the commutator circuit is configured to generate a feedback signal according to the compensation current of the bias sub-circuit to the power amplifier, therefore, the bias sub-circuit reduces the compensation current while not influencing the linearity compensation function. According to the invention, AM-AM distortion is not deteriorated while the current of the power amplifier is reduced, so that the efficiency is optimized while the linearity compensation function is not influenced.

One or more aspects of the techniques and models described herein provide for bidirectional recurrent neural network (BiRNN)-based digital pre-distortion techniques for radio frequency (RF) power amplifiers (PAs). As an example, a digital pre-distorter (DPD) system may implement residual learning and long short-term memory (LSTM) projection layer features to reduce computational complexity and memory requirements. Implementing the described unconventional techniques of applying residual learning in RNN (e.g., in BiLSTM), using LSTM projection to develop a DPD structure, or both, may provide several advantages over preexisting techniques. For instance, the complexity in training and pre-distortion may be reduced and significantly less memory may be required to store the DPD neural network coefficients (e.g., while achieving similar or better linearization performance compared to other LSTM models). Further, faster training convergence speed may be achieved (e.g., compared to other LSTM models).

The invention discloses an ultra-wideband high-linearity power amplifier with a negative feedback structure. The ultra-wideband high-linearity power amplifier comprises an input matching network, a driving-stage amplifying circuit, an inter-stage matching network, a power-stage amplifying circuit, an output matching network, a negative feedback RLC (Radio Link Control) network and a self-adaptive biasing circuit, an input radio-frequency signal is transmitted to the driving-stage amplification circuit through the input matching network for primary amplification, transmitted to the power-stage amplification circuit through the inter-stage matching network for secondary amplification and output through the output matching network, and the driving-stage amplification circuit comprises a first transistor and a second transistor. The power level amplification circuit comprises a third transistor and a fourth transistor; the self-adaptive bias circuit is used for providing self-adaptive bias voltage for the first transistor and the third transistor; the negative feedback RLC network is used for controlling the gain and bandwidth of the amplifier and comprises a driving-stage negative feedback network and a power-stage negative feedback network. The working bandwidth of the power amplifier can be widened, and the gain, the output power and the linearity of the amplifier can be improved.

The present application discloses a low-cost and high-performance radio-frequency amplifier, comprising an input stage circuit, a common-gate stage circuit, and an output load circuit. The input stage circuit implements conversion from a single-ended signal to a differential signal, implements input impedance matching, and converts an inputted radio-frequency voltage signal into a radio-frequency current signal. The input stage circuit comprises a first three-coil transformer, consisting of a primary coil, a secondary coil, and a third coil. The common-gate stage circuit transmits the radio-frequency current signal outputted by the input stage circuit to the output load circuit, increases the withstand voltage and equivalent output impedance of the circuit, and implements gain control in at least two modes. The output load circuit converts the radio-frequency current signal from the common-gate stage circuit into a radio-frequency voltage signal, implements conversion from a differential signal to a single-ended signal, and outputs an amplified radio-frequency voltage signal. The present application provides a radio-frequency amplifier having a small size, broadband matching, high linearity, a large dynamic range, and low design complexity.

The invention relates to the technical field of weak signal conditioning circuits, and discloses a multi-light-source spurious noise suppression circuit based on a laser sensor and a signal conditioning method, and the circuit comprises a photoelectric conversion module which is used for converting a received optical signal into a current signal; the transimpedance conversion module is connected with the photoelectric conversion module, converts the current signal into a first voltage signal and suppresses common-mode noise; the first-stage amplification module is used for carrying out linear amplification on the first voltage signal and outputting a second voltage signal; the programmable filtering module is used for carrying out high-frequency noise suppression on the second voltage signal; the reverse phase adjusting module is used for adjusting the phase and the amplitude of the filtered signal so as to adapt to a post-stage load; and the feedback control module analyzes the frequency spectrum of the output signal in real time and dynamically adjusts the cut-off frequency of the programmable filtering module. The invention aims to solve the problems that in the prior art, a laser sensor circuit is poor in anti-interference performance in a multi-light-source environment, and measurement is inaccurate due to spurious noise.

Aspects of this disclosure relate to digital compensators, such as digital predistortion systems. Digital predistortion systems disclosed herein use a neural Volterra approach. Such digital predistortion systems can include a first processing path, an envelope processing path comprising an envelope artificial neural network, multipliers configured to multiply respective output signals of the first processing path and the envelope processing path, and a combiner configured to generate a combined output signal based on at least output signals of the multipliers. The combined output signal is a digitally predistorted version of the input signal.

Apparatus for causing a power amplifier (PA) to act as an idealized power amplifier (iPA). The apparatus comprises: a fixed digital predistortion (DPD) circuit; a PA coupled to the DPD circuit; at least one sensor adapted to determine at least one condition related to of the power amplifier; and a neural network adapted control a level of amplification provided by the power amplifier based on a measurement of the at least one condition as measured by the at least one sensor.

Certain aspects of the present disclosure provide techniques for pre-distortion training feedback via inductive coupling. An example apparatus includes a receive path; a transmit path comprising an amplifier having a first output that is inductively coupled to the receive path; a memory; and a processor coupled to the memory. The processor is configured to cause the apparatus to obtain a first signal, based on a second signal output by the amplifier, via the receive path being inductively coupled to the first output of the amplifier; determine a parameter for pre-distortion associated with the amplifier based at least in part on the first signal; pre-distort a third signal based at least in part on the parameter; amplify the pre-distorted third signal via the amplifier; and transmit the amplified third signal.

The invention relates to a switch adaptive bias circuit, which belongs to the technical field of radio frequency integrated circuits, is used for adjusting the bias state of a power amplification circuit, and comprises a linear bias module, a temperature compensation module and a switch control module, the linear bias module, the temperature compensation module and the switch control module are connected in sequence; the bias current output end of the linear bias module is connected with the base electrode of a power transistor of the power amplification circuit, and the linear bias module is used for outputting bias current to adjust the linearity of the power transistor; the temperature compensation module is used for suppressing the temperature drift of the power amplification circuit so as to realize temperature compensation; and the switch control module is provided with a switch control transistor, and an emitter of the switch control transistor is used as a switch interface. According to the invention, the linear bias module, the temperature compensation module and the switch control module are integrated, so that the integration level of the self-adaptive bias circuit is improved; the on and off of the switch self-adaptive bias circuit are realized through the control voltage of the switch interface, and wide-range stable switch regulation and control are realized.

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.

The invention discloses a Ka-band 2000W solid-state power amplifier, which relates to the field of power amplifiers, and comprises a Ka monitoring and pre-stage power amplifier, a Ka final-stage power amplifier and a Ka high-power synthesis network, the Ka monitoring and pre-stage output end is in flexible connection with the eight Ka last-stage power amplifiers, and the Ka last-stage power amplifiers are in hard connection with the Ka high-power synthesis network through waveguides. A solid-state system is adopted for design, a domestic GaN solid-state power amplifier chip is utilized for synthesis, the power amplifier adopts a low-voltage working mode, the power chip is long in service life, the linear index of the power amplifier is good, and the power amplifier is different from the defects that a vacuum tube power amplifier is large in size and weight, has breakdown risks during high-voltage working and cannot respond to emergency scenes immediately. The Ka-band high-power amplifier is a development trend of a Ka-band high-power amplifier, and has the advantages of high output power and convenience in maintenance.

The invention is suitable for the technical field of integrated circuits, and provides a high-voltage operational amplifier. Comprising a biasing circuit, a first current mirror circuit, a first slew rate boosting circuit, a first gain circuit, a second gain circuit, a second current mirror circuit, an input stage circuit, an output stage circuit, a chopping switch circuit, a first high-voltage protection circuit, a third current mirror circuit, a fourth current mirror circuit, a second slew rate boosting circuit and a fifth current mirror circuit. And a sixth current mirror circuit and a second high-voltage protection circuit. The precision of the operational amplifier under the 36V high voltage can be improved.

Methods, apparatus, systems, and articles of manufacture are described to correct non-linearity in transmitters. An example system includes an input stage, a driver, an input terminal of the driver coupled to an output terminal of the input stage; an output buffer, an input terminal of the output buffer coupled to an output terminal of the driver, an output terminal of the output terminal coupled to a first input terminal of the input stage via a resistor; and non-linear correction circuitry having an input terminal and an output terminal, the input terminal of the non-linear correction circuitry coupled to the output terminal of the output buffer and the first input terminal of the input stage via the resistor, the output terminal of the non-linear correction circuitry coupled to the output terminal of the input stage and the input terminal of the driver.

The invention discloses a final-stage voltage tracking anti-clipping circuit for an audio power amplifier, and relates to the technical field of power amplifiers, and the circuit comprises a voltage division circuit which is used for receiving final-stage voltage from target power amplifier equipment and generating a combined voltage signal; the audio attenuation module is used for receiving an audio input signal and a final-stage voltage, and judging whether amplitude limiting modulation is carried out on the audio input signal or not to complete power amplifier output by judging whether a starting signal is received or not; and the starting judgment module is used for receiving the combined voltage signal and the first output signal, and comparing the combined voltage signal with the first output signal to generate a starting signal. According to the invention, the collected final-stage voltage of the target power amplifier is set as the dynamic amplitude limiting threshold, so that an over-high signal can be effectively suppressed to a safe range quickly when the power supply drops instantaneously, and the effects of avoiding hearing deterioration caused by power amplifier signal waveform truncation and avoiding potential safety hazards caused by amplitude limiting and topping to the loudspeaker are achieved.

The utility model belongs to the technical field of human body pulse detection, and discloses a pulse amplifying circuit based on a pressure sensor and a pulse signal acquisition system, and the circuit comprises the pressure sensor, a first-stage amplifying circuit, a second-stage amplifying circuit, a third-stage amplifying circuit, a fourth-stage amplifying circuit and a reference circuit, the signal input end of the first-stage amplification circuit receives an original pulse signal output by a pressure sensor and then outputs a differential amplification signal, the signal input end of the second-stage amplification circuit receives the differential amplification signal and then suppresses a common-mode signal and outputs a second amplification signal, and the signal input end of the third-stage amplification circuit receives the second amplification signal and then outputs the third amplification signal. The isolated direct current passes through a signal and outputs an alternating current signal in a following mode, a fourth-stage amplifying circuit receives the alternating current signal and then amplifies and filters the alternating current signal, and an amplified pulse signal is obtained and output. According to the utility model, the cost of the product is reduced, the circuit is simplified, the practicability is enhanced, and the pulse signal can be accurately measured.