2616 results about "Audio power amplifier" patented technology

A logarithmic amplifier includes programmable gain amplifiers each having a different gain, wherein an input of each of the programmable gain amplifiers is coupled to an input of the logarithmic amplifier; and a summing circuit having inputs coupled to a corresponding output of each of the programmable gain amplifiers and an output coupled to an output of the logarithmic amplifier, wherein the summing circuit generates a logarithmic transfer function having piecewise linear segments.

Apparatus and methods for reconfigurable power amplifiers are disclosed. In certain embodiments, a mobile device includes a transceiver configured to generate a first radio frequency signal of a first frequency band and a second radio frequency signal of a second frequency band, and a front-end system including a push-pull power amplifier configured to selectively amplify one of the first radio frequency signal or the second radio frequency signal based on a band control signal. The push-pull power amplifier includes an input balun, an output balun, and a pair of amplifiers coupled between the input balun and the output balun. The band control signal is operable to control an output capacitance of the pair of amplifiers.

A system and method are used to maintain a variance in feedback factors of an amplifier between the first and second phases either below a threshold value or within a specified range. The system includes the amplifier and first through third capacitances. The amplifier is coupled between an input node and an output node that operates during first and second phases of operation. The first capacitance is coupled across the amplifier and between the input node and the output node during the first and second phases of operation. The second capacitance is coupled to the input node during the first phase of operation. The third capacitance is coupled to one of the input and output nodes during one or both of the first and second phases of operation.

The utility model discloses an ear canal embedded hearing aid, which relates to the technical field of medical instruments, and comprises a bearing assembly, the bearing assembly comprises a first packaging shell, a second packaging shell and a filter screen, a signal processing piece and a lithium battery are respectively arranged in the first packaging shell, and the second packaging shell is provided with a second packaging shell. The signal processing piece comprises a signal amplifier, a filter and a central processing unit, and a micro air pump, a control switch, a potentiometer and a microphone are installed on the right side of the first packaging shell. The beneficial effects of the utility model are that through the arrangement of the miniature air pump, the air delivery pipe and the expansion anti-skid assembly, when the ear canals of different users have large differences or need to be worn stably, the miniature air pump can be controlled to work, so that air enters the hollow rubber ring through the air delivery pipe and the delivery pipe, and the hollow rubber ring is gradually expanded to be in contact with the ear wall; therefore, the wearing stability of the bearing assembly is ensured, and the sound definition after conversion of the receiver is ensured.

A power amplifier includes a 3-dB coupler which splits a first signal into a second signal and a third signal lagging behind the second signal by 90°, a carrier amplifier, a peak amplifier, and a hybrid coupler. The carrier amplifier amplifies the second signal and outputs a fourth signal when the first-signal power level is a first level or higher. The peak amplifier amplifies the third signal and outputs a fifth signal when the first-signal power level is a second level or higher, which is higher than the first level. The hybrid coupler includes a first transmission line receiving the fourth signal at its first terminal, and a second transmission line receiving the fifth signal at its first terminal and being open at its second terminal. The first transmission line outputs, from its second terminal, an amplified first signal obtained by combining the fourth and fifth signals.

Methods and devices to improve nonlinearity performance of low noise amplifiers (LNAs) are disclosed. The described methods and devices reduce the capacitive loading of the LNA amplifying devices on the bypass path of the LNAs when operating in the bypass mode. This is performed by decoupling the active devices from ground to put the amplifying devices in a floating state, thus minimizing the impact of the gate-source capacitances of the amplifying devices on the overall linear performance of the LNA operating in the bypass mode.

The invention is suitable for the technical field of communication, and particularly relates to a method for detecting mismatched harmonic waves of a power amplifier. The method comprises the steps that a first power detection unit is connected with a coupler through a control unit, the standing-wave ratio of a to-be-detected power amplifier chip is adjusted to be 1: 1 through a tuner, and the power of an input signal of a vector signal generator is adjusted till the target power of the to-be-detected power amplifier chip is reached; the second power detection unit is connected with the coupler through the control unit, the output standing-wave ratio of the to-be-detected power amplifier chip is adjusted to a preset specific value through the tuner, and when the tuner modulates phases at intervals of preset degrees, the harmonic power of the to-be-detected power amplifier chip in each phase is recorded through the second power detection unit. Compared with the prior art, the method can accurately test and evaluate the harmonic wave of the to-be-tested power amplifier chip under the mismatched standing wave condition, thereby evaluating the harmonic wave index of the to-be-tested power amplifier chip.

The invention discloses a porcelain insulator nondestructive testing device and method based on chirp modulation photoacoustic spectroscopy. The device comprises a signal generator, a signal processing module and a signal processing module, the laser is connected with the signal generator; the power amplifier is connected with the laser; the laser collimator is connected with the power amplifier; and the signal collector collects the sound wave signals, converts the sound wave signals into electric signals, transmits the electric signals to the computer through a cable for data processing, obtains a spectrogram of the sound wave signals, and judges whether defects exist in the porcelain insulator or not according to the spectrogram. According to the porcelain insulator nondestructive testing device adopting chirp modulation and photoacoustic spectroscopy, characteristic frequency scanning is achieved through chirp modulation, a porcelain insulator acoustic signal spectrogram is obtained through the solid photoacoustic effect, non-power-cut nondestructive testing of porcelain insulators can be achieved, and the detection efficiency of porcelain insulator defects is greatly improved.

The invention discloses a multi-modal stimulation regulation and control system combining interactive feedback and AI self-adaption. The system comprises an AI main control and synchronization module which generates a unified rhythm time sequence; the acoustic stimulation output module outputs a rhythm acoustic signal; the visual LED stimulation module outputs rhythm visual signals; the game / animation interaction module provides an interaction task synchronized with the acousto-optic rhythm; the sensing acquisition and feedback module is used for acquiring multi-modal physiological and behavior data in real time; the amplifier output module drives the execution module or equipment; the power management module realizes voltage stabilization and low power consumption switching; the behavior habit forming mechanism module binds a stimulation signal and an interaction task; and the human-assisted management interface module supports remote parameter setting and real-time monitoring. The interactive feedback and AI self-adaptive multi-mode stimulation regulation and control system is combined, microsecond-level synchronization and multi-source closed-loop self-adaption of sound and light and animation can be achieved, a guidance scheme for personalized customization of treatment and behavioral habit cultivation can be achieved, and the efficiency, accuracy and effectiveness of system regulation and control are remarkably improved.

Apparatus and methods for reconfigurable power amplifiers are disclosed. In certain embodiments, a mobile device includes a transceiver configured to generate a first radio frequency signal of a first frequency band and a second radio frequency signal of a second frequency band, and a front-end system including a push-pull power amplifier configured to selectively amplify one of the first radio frequency signal or the second radio frequency signal based on a band control signal. The push-pull power amplifier includes an input balun, an output balun, and a pair of amplifiers coupled between the input balun and the output balun. The band control signal is operable to control an input capacitance of the pair of amplifiers.

The invention relates to the technical field of radio frequency integrated circuits, in particular to a harmonic suppression power amplifier combining a matching network and a feed network, which comprises a transistor, an input matching module, an output matching module, a stabilizing module and a bias module, the input matching module comprises a first parallel resonance unit, the first parallel resonance unit is used for second harmonic suppression, the output matching module comprises a series resonance unit and a second parallel resonance unit, the series resonance unit is used for resonating at a second harmonic frequency and performing low-impedance grounding on the second harmonic, and the second parallel resonance unit is used for resonating at a second harmonic frequency and performing low-impedance grounding on the second harmonic. The second parallel resonance unit is used for resonating at a third harmonic frequency and forms a high-impedance open circuit for the third harmonic, the output matching module is coupled to a drain electrode of the transistor, and the bias module comprises a grid bias sub-module and a drain bias sub-module. The grid bias sub-module is coupled to a connection node of the input matching module and the grid of the transistor, the drain bias sub-module is coupled to the output matching module, and the bias voltage of the transistor is jointly determined by the grid bias sub-module and the drain bias sub-module. The power amplifier has the effect of improving the efficiency level of the power amplifier while realizing harmonic suppression optimization.

A class D amplifier circuit receives an analog audio signal with a first reference voltage as its center level, and outputs an output pulse signal having a duty cycle that corresponds to the analog audio signal. A bias circuit generates a second reference voltage having a voltage level obtained as a division of the first reference voltage and the power supply voltage. A periodic voltage generating circuit of the class D amplifier circuit generates a periodic voltage having a triangle waveform or otherwise a sawtooth waveform having an amplitude that corresponds to the second reference voltage.

A mixer includes a mixing stage, and a first transistor and a second transistor coupled to the mixing stage. A gate of the first transistor is coupled to a first input of the mixer, and a gate of the second transistor is coupled to a second input of the mixer. The mixer also includes a first source resistor coupled to a source of the first transistor, and a second source resistor coupled to a source of the second transistor. The mixer further includes an amplifier having a first input coupled to the source of the first transistor, and a second input coupled to the source of the second transistor. The amplifier is configured to adjust at least one bias voltage of at least one of the first transistor and the second transistor based on a differential voltage between the first and second inputs of the amplifier.

The invention discloses a parallel constant-voltage digital audio power amplifier and a broadcasting system. Comprising a line input module, a line output module, a first analog-to-digital conversion circuit, a second analog-to-digital conversion circuit, a third analog-to-digital conversion circuit, a digital signal processor, a single-chip microcomputer, a digital-to-analog conversion circuit, an error comparator, a modulator, an integrating circuit, a pulse width modulation input half-bridge output stage, and a first carrier frequency selection and gain adjustment module. A second carrier frequency selection and gain adjustment module, a first LC filter, a high-frequency compensation network, a communication bus and a power switch. The technical problems that an existing multi-channel parallel digital constant-voltage power amplifier is only limited to power amplifier channels in the same power amplifier, the parallel connection mode only uses the first channel as a main power amplifier and only uses the other channels as slave power amplifiers, and certain limitation exists are solved.

The invention relates to the technical field of wireless communication, and provides a power amplifier, a power amplification module and a multi-mode multi-frequency power amplifier, the power amplifier comprises a first-stage low-frequency power amplifier, a second-stage low-frequency power amplifier, a harmonic suppression circuit, a first output matching circuit, a first filter circuit and a second filter circuit; the first-stage low-frequency power amplifier and the second-stage low-frequency power amplifier are used for amplifying low-frequency-band signals, the harmonic suppression circuit is used for suppressing harmonic waves output by the first-stage low-frequency power amplifier and the second-stage low-frequency power amplifier, and the output end of the first output matching circuit is used for outputting signals; and the first output end of the first filter circuit and the output end of the second filter circuit respectively provide filtered power supply voltage for the first-stage low-frequency power amplifier and the second-stage low-frequency power amplifier. According to the invention, the harmonic leakage of the multi-mode multi-frequency power amplifier can be optimized.

Digital pre-distorter (DPD) coefficients can be used to compensate for non-linearity of a power amplifier (PA). A system can receive a defined waveform from transmit hardware. The system can transmit an output waveform with a defined modulation from the PA. The system can capture samples of the output waveform. The system can submit the samples to a processing system temporarily connected to a transmitter system. The system can compute a PA model using the defined waveform and the samples. The system can determine a plurality of Digital Pre-Distorter (DPD) coefficients for a plurality of power levels, frequencies, and temperatures based on the PA model. The system can store the plurality of DPD coefficients to a memory of the transmitter system. Additionally, the system can add predistortions using the plurality of DPD coefficients to a plurality of input waveforms to correct for impairments introduced by the PA.

The invention relates to the technical field of audio driving, in particular to a driving circuit and method and electronic equipment. The method comprises the following steps: arranging two boosting units at the output end of the power amplifier, respectively receiving two paths of signals with opposite phases output by the power amplifier so as to realize that boosted signals output by the two boosting units are also signals with opposite phases, arranging one boosting unit to be connected with the positive electrode of the piezoelectric ceramic module, and arranging the other boosting unit to be connected with the negative electrode of the piezoelectric ceramic module; and the other boosting unit is connected with the negative electrode of the piezoelectric ceramic module, so that the driving voltage of the piezoelectric ceramic module is increased. The boost unit is simple in structure, occupies a small area of a circuit board, and can be effectively applied to miniaturized electronic equipment.

Embodiment of the disclosure relate to power splitter comprising a first separation block comprising an input and a first output, the first separation block being configured to receive an input signal via the input and forward the input signal. The power splitter further comprises a second output and a first non-linear impedance connected to the first separation block. The first non-linear impedance is configured to reflect a reflection signal of the input signal to the first output and forward a forward signal of the input signal to the second output, wherein a power ratio between the reflection signal and the forward signal is based on a configuration of the first non-linear impedance.

The invention discloses an enable signal control method and device and a storage medium. In the method, when it is detected that the current carrier-to-noise ratio of a satellite signal is out of a preset range, a second duty ratio is determined, and when an enable signal of the second duty ratio is used for controlling an amplifier, the carrier-to-noise ratio of the satellite signal is in the preset range. Meanwhile, when the second duty ratio is lower than the first duty ratio, the duty ratio of the enable signal is adjusted from the first duty ratio to the second duty ratio, and the amplifier is controlled based on the enable signal of the second duty ratio. The power consumption of the electronic equipment can be reduced while the performance benefit of the GNSS receiver is not influenced.

The invention discloses a low-noise and high-precision analog front-end circuit for biological signal acquisition. The low-noise and high-precision analog front-end circuit comprises a chopping capacitance coupling type instrument amplifier circuit, a switched capacitor type programmable gain amplifier circuit and a Sigma-Delta analog-to-digital converter modulator circuit. T-type capacitance feedback, chopping modulation and programmable technologies are introduced on the basis of an existing amplifier, and the low-noise and programmable gain functions of the pre-amplifier are achieved. Through the three-order one-bit quantized feed-forward chopping type Sigma-Delta modulator, the signal to noise ratio and the effective bit number of the signal are improved. Compared with the prior art, the analog front-end circuit not only has the capability of changing the gain multiple according to the bio-electricity signal, but also has the low-noise and high-precision signal processing effect, and the problems that a traditional analog front-end circuit is large in noise and low in signal processing precision are solved. In addition, the biological signal acquisition-oriented circuit provided by the invention can also be used in other analog front ends, such as an audio processor and the like, and is wide in application range.

A voltage generation circuit includes a voltage input terminal, a voltage output terminal, a first resistor having a first terminal electrically connected to the voltage input terminal, a second resistor having a third terminal electrically connected to the second terminal and a fourth terminal electrically connected to a ground potential, a first capacitor having a first capacitive terminal electrically connected to the voltage input terminal, a third resistor having a fifth terminal electrically connected to a second capacitive terminal, a fourth resistor having a seventh terminal electrically connected to a sixth terminal, and a first operational amplifier having a first inverting input terminal electrically connected to the sixth terminal, a first non-inverting input terminal electrically connected to the second terminal, and a first output terminal electrically connected to the voltage output terminal and an eighth terminal.

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.

The invention provides a low-noise amplifier and a radio frequency front-end module, and the low-noise amplifier comprises an input matching circuit, a first-stage power amplification circuit, an inter-stage matching circuit, a second-stage power amplification circuit and an output matching circuit. The inter-stage matching circuit comprises a first inductor, a second inductor and a first capacitor; the second-stage power amplification circuit is of a cascode structure; and the output matching circuit comprises a third inductor and a fourth inductor which are coupled with each other. According to the low-noise amplifier, the high-frequency gain, the in-band gain flatness, the isolation degree, the stability and the output matching bandwidth of the low-noise amplifier can be improved.

The utility model provides a kind of electrostatic discharge protection circuit and low noise amplification module, the electrostatic discharge protection circuit is applied to low noise amplification circuit, the low noise amplification circuit includes input matching circuit and the low noise amplifier of the output end being connected to the input matching circuit;The electrostatic discharge protection circuit includes inductance and resistance;The first end of the inductance is used to connect to the signal input end of low noise amplifier;The first end of the resistance is connected to the second end of the inductance, and the second end of the resistance is grounded.The electrostatic discharge protection circuit in the utility model is connected to the input end of low noise amplifier, and the noise coefficient of low noise amplifier will not be deteriorated, and the performance of low noise amplifier will not be affected, and the input stability of low noise amplifier will not be affected simultaneously.

A device and method for representing the foam porosity state of foamed lightweight soil with self-adjusting beams, and relates to the technical field of sound absorption coefficients measurement; the device includes a standing wave tube, a plurality of polyvinylidene fluoride piezoelectric films, a sensor, an exciter, a push-pull handle, an adjustable telescopic tube, a foamed lightweight soil detection material, a charge amplifier, a data memory, a data adapter, a signal generator, an adaptive power amplifier board, and a PC computer; the device of the invention has low cost, long service life, high measurement accuracy, relatively simple production process, and can be applied to different scenarios.

Aspects of this disclosure relate to a cancelling interference at an output of a power amplifier. An interference sensing circuit in a signal path between the power amplifier and an antenna can generate an interfering power signal. An interference cancellation loop can receive the interfering power signal and provide a cancellation signal to a transmit signal path that includes the power amplifier to thereby suppress interference at the output of the power amplifier. In certain embodiments, the interference cancellation loop includes an amplifier and a phase shifter. Related systems and methods are disclosed.

A method for harmonic trapping in a matching network of a power amplifier includes determining primary inductance and secondary inductance of a differential transformer of the matching network, based on a signal operating frequency of the power amplifier. An inductance value for an L-C filter is determined based on the secondary inductance and a harmonic frequency of a local oscillator (LO) signal. A capacitance value for the L-C filter is determined based on the inductance value and the harmonic frequency of the LO signal. The L-C filter is provided on an electric connection between a direct current (DC) bias voltage source and a secondary inductor of the differential transformer. The L-C filter is configured with the determined inductance value and the determined capacitance value.

An electronic device may include a transmitter coupled to an antenna over a signal path that runs through a front end module. The front end module may include a power amplifier disposed on the signal path. The front end module may include first, second, and / or third signal attenuators disposed on the signal path between an input of the amplifier and the transmitter. The front end module may include a voltage sensor that measures a bias voltage of the amplifier, a temperature that measures a temperature of the amplifier, and / or an impedance sensor that measures an impedance of the antenna. The first signal attenuator may be adjusted based on the measured bias voltage, the second signal attenuator may be adjusted based on the measured temperature, and the third signal attenuator may be adjusted based on the measured impedance to mitigate changes in the amplifier as operating conditions change over time.

Methods and systems for NN-based digital pre-distortion for digital envelope tracking power amplifiers. A computer-implemented method includes receiving a measure of a digital envelope at a digital pre-distortion module having a neural network (NN)-based digital pre-distortion structure for digital envelope tracking (DET), receiving a transmit signal at the digital pre-distortion module, inputting the measure of the digital envelope and the transmit signal into the NN-based digital pre-distortion structure to produce a pre-distorted transmit signal, adjusting nonlinearity compensation of a power amplifier based on the measure of the digital envelope, and using the adjusted nonlinearity compensation of the power amplifier to produce an output signal.

The invention provides a special digital interphone with recording and broadcasting functions for a railway, which is characterized in that an emergency recording key is pressed down, a master control MCU controls an audio channel management module to communicate a microphone to a recording module and starts the recording module to record, a playback key is pressed down, the master control MCU controls the audio channel management module to communicate the recording module to an audio power amplifier, and the audio power amplifier is started to play the sound. The main control MCU is used for controlling the recording module to output recorded audio to the loudspeaker for playing through the audio power amplifier, and controlling the audio channel management module to communicate the recording module to the radio frequency transceiving and modulation-demodulation module by pressing the emergency broadcast key; and controlling the recording module to output the recorded audio to the radio frequency transceiving and modulation-demodulation module for modulation, and starting radio frequency periodic automatic emission, so as to realize emergency broadcast emission. According to the invention, the limitation that a traditional interphone depends on manual real-time broadcasting is solved, the dangerous case response speed is obviously improved, and the reliability of emergency communication is improved.