3403 results about "Audio power amplifier" patented technology

An example apparatus includes: class D amplifier circuitry having a first input, a second input, a third input, and an output, the first input of the class D amplifier circuitry coupled to the output of the class D amplifier circuitry; and class AB amplifier circuitry having a first input, a second input, a third input, and an output, the first input of the class AB amplifier circuitry coupled to the first input of the class D amplifier circuitry and the output of the class D amplifier circuitry, the second and third inputs of the class AB amplifier circuitry coupled to the second and third inputs of the class D amplifier circuitry, and the output of the class AB amplifier circuitry.

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.

Various aspects provide a transceiver and a communication device including the transceiver. In an example, the transceiver includes an amplifier circuit including an amplifier stage with an adjustable degeneration component, the amplifier stage configured to amplify a received input signal with an adjustable gain, an adjustable feedback component coupled to the amplifier stage; and a controller coupled to the amplifier stage and to the adjustable feedback component and configured to adjust the adjustable feedback component based on an adjustment of the adjustable degeneration component.

The utility model discloses an acousto-optic coupling three-dimensional flame area temperature field monitoring system, which comprises a computer, a power amplifier, a relay, a loudspeaker, a microphone and a signal analyzer which are sequentially connected, and further comprises a three-dimensional rack, a light field camera and a blackbody furnace, a plurality of groups of loudspeakers and microphones are arranged, and each group of loudspeakers and microphones are located at the same position on the three-dimensional rack; the signal input end of the light field camera is respectively connected with the three-dimensional flame and the blackbody furnace in the three-dimensional rack, and the signal output end of the light field camera is connected with the signal input end of the computer; the blackbody furnace is used for the light field camera to calibrate the relationship between the gray level of the two-dimensional layered flame original brightness image and the radiation intensity; measurement targets of the system are gas temperature and three-dimensional flame temperature in a three-dimensional to-be-measured area which is surrounded by a three-dimensional rack and contains three-dimensional flame, the overall temperature of a gas medium in a three-dimensional space is measured by using a non-contact sound velocity method temperature measurement principle, and a more comprehensive contribution is made to temperature monitoring of a key area of a hearth.

Disclosed in the present invention are a radio frequency front-end module with input clipping protection, and an electronic device. The radio frequency front-end module comprises at least one transmission path, which comprises at least one stage of a power amplifier circuit, and an output matching circuit. Each stage of amplifier circuit comprises at least one clipping circuit and a biasing circuit thereof, and an input matching circuit and a power amplifier, wherein the clipping circuit, the input matching circuit, the power amplifier and the output matching circuit are sequentially connected in series; and the clipping circuit is used for performing clipping processing on an input signal power and then outputting a signal having a relatively small power, and when the input power of the transmission path is greater than a set threshold value, the clipping circuit enables a clipping function, such that the power amplifier is protected by means of reducing the input power.

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.

Apparatus and methods for load modulated power amplifiers are provided. In certain embodiments, a load modulated power amplifier system includes a power amplifier that receives a radio frequency signal at an input and provides an amplified radio frequency signal at an output, and a controllable load impedance coupled to the output of the power amplifier. The controllable load impedance receives an envelope signal that changes in relation to an envelope of the radio frequency signal, and the envelope signal is operable to control an impedance of the controllable load impedance to modulate a load at the output of the power amplifier.

A radio-frequency (RF) circuit including: a multi-tone generation circuit configured to generate a multi-tone signal including a plurality of tones; a predistortion circuit configured to predistort the multi-tone signal or a modulation signal and output a predistortion signal; a power amplifier configured to amplify the predistortion signal and output an output signal; and a predistortion modeling circuit configured to model a predistortion model corresponding to the predistortion circuit based on the predistortion signal corresponding to the multi-tone signal and the output signal.

The invention is a portable micromagnetic field generator device comprising a battery, a circuit board with a microcontroller, a memory and a current amplifier. The memory functions to store information, such as audio information, for the generation of specific pulsed magnetic field frequencies of pairs of such frequencies. The MCU uses the stored information to form a variable microcurrent, which is amplified via a current amplifier. The amplified current is used by a coil assembly to generate a variable micromagnetic field. The device is kept in close proximity to a user's body for the micromagnetic field to impart its therapeutic effects. The device also includes a display device and several buttons so that users may select the type of micromagnetic field they wish to use, as well as stop, start and pause the micromagnetic field generation.

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.

Embodiments disclosed herein relate to impedance matching for outputting wide-band signals in radio frequency applications. In an example, a circuit including a low-noise amplifier (LNA) sub-circuit and a tuning sub-circuit is provided. The LNA sub-circuit is configured to couple to an antenna and includes a transistor that includes a gate, a source, and a drain, a first inductor that includes a first terminal configured to couple to the antenna and includes a second terminal, a second inductor that includes a first terminal coupled to the first terminal of the first inductor and includes a second terminal coupled to the gate of the transistor, and a third inductor that includes a first terminal coupled to the source of the transistor and includes a second terminal. The tuning sub-circuit is coupled to the source of the transistor.

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.

The invention belongs to the technical field of signal processing, and particularly discloses a deep learning driven power amplifier predistortion method, which comprises the following steps: constructing a signal matrix of a target signal sequence, the target signal sequence being obtained by preprocessing an original time signal sequence collected from a signal source; sequentially inputting the signal matrix into a PDTRANS predistortion model and a power amplifier, and obtaining an output signal sequence of the power amplifier; determining a loss function value based on the output signal sequence and the target signal sequence, and adjusting hyper-parameters of a PDTRANS pre-distortion model based on the loss function value; the steps of obtaining the output signal sequence of the power amplifier and adjusting the hyper-parameters of the PDTRANS predistortion model are repeated until the loss function is minimized, and the trained PDTRANS predistortion model matched with the power amplifier is obtained; and performing pre-distortion compensation on the power amplifier based on the trained PDTRANS pre-distortion model. According to the invention, accurate pre-distortion modeling of the power amplifier is realized.

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.

Low noise amplifiers (LNAs) are disclosed herein. In certain embodiments, an LNA includes an input balun configured to convert a single-ended radio frequency (RF) receive signal to a differential RF receive signal, an amplifier chain configured to amplify the differential RF receive signal to generate a differential amplified RF receive signal, and an output balun configured to convert the differential amplified RF receive signal into a single-ended amplified RF receive signal. The LNA's amplifier chain is operable in multiple gain modes, and includes a first differential amplification stage, a second differential amplification stage, and a third differential amplification stage.

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 discloses an audio parameter adjusting circuit and method, a control device, a storage medium, a computer program product and an audible device, and relates to the technical field of electronic equipment.The audio parameter adjusting circuit comprises a power amplifier, an impedance detection circuit and a main control circuit, and the power amplifier end of the power amplifier is electrically connected with a loudspeaker; the impedance detector is used for detecting the impedance of the loudspeaker and outputting an impedance detection signal; the main control circuit controls the power amplifier to output a sweep frequency signal to the loudspeaker so as to drive the loudspeaker to work; and determining the current resonant frequency of the loudspeaker according to the impedance detection signal, and determining a target sound effect parameter corresponding to the current resonant frequency according to a mapping relationship between the resonant frequency and the target sound effect parameter, so as to adjust the sound effect parameter of the loudspeaker to the target sound effect parameter corresponding to the current resonant frequency, and enable the loudspeaker to work in a target state. The invention aims to improve the problem of performance reduction caused by aging of the loudspeaker, improve the sound effect of the loudspeaker by adjusting the sound effect parameters, and improve the user experience.

The embodiment of the invention provides a power amplifier, a radio frequency module and electronic equipment. The power amplifier comprises a signal input end, a signal output end and a plurality of tube cores which are connected in parallel; the tube core comprises electrode finger strips extending along a first direction, and the electrode finger strips comprise a grid electrode finger strip, a source electrode finger strip and a drain electrode finger strip; in the second direction, the signal input end and the signal output end are located on the two sides of the multiple tube cores respectively, and the second direction is perpendicular to the first direction. The extension direction of the electrode finger strips is perpendicular to the signal input / output direction, so that the performance of the electrode finger strips can be optimized to the maximum extent and the requirement of high power can be met under the limited layout area, and the flexible possibility is created for the circuit architecture design.

Systems and methods for amplifying signals propagated along a span of cable that imposes a loss tilt, and such that the loss tilt is canceled so as to provide unity gain, by modulating amplification as a function of frequency of an amplifier adjacent the span.

The present application relates to the technical field of terminals. Disclosed are a method for acquiring position information of a device, and a device and a system. A more economical, simpler, and easier-to-implement solution for acquiring position information of a terminal device that has been powered off after being lost is provided, so as to help a user quickly recover the lost terminal device. In the present application, on the basis of existing hardware of a terminal device, by means of improving software (e.g., pin control logic), a normal power supply to and the enabling of power-off recovery related modules, such as a Bluetooth chip, an ultra wide band radio (UWB) chip and an audio amplifier, are implemented after the terminal device is lost and has been powered off, so that the power-off recovery related modules can normally operate to help the user quickly recover the terminal device, thereby improving the user experience.

Systems and apparatuses are disclosed that include an RF generator configured to generate RF signals having a wavelength. Amplifiers are configured to receive and amplify the RF signals from the RF generator and are separated from each other by a separation distance in a range between about 0.2 times the wavelength and about 10.0 times the wavelength. A power management system is configured to control one or more of the amplifiers based on information received that is associated with the RF signals.

The invention discloses a method, a device and a system for acquiring position information of a device, relates to the technical field of terminals, and can provide a more economical, simple and easy-to-implement scheme for acquiring the position information of a terminal device which is shut down after being lost so as to help a user to quickly find the lost terminal device. On the basis of existing hardware of the terminal equipment, normal power supply and enabling of relevant modules, such as a Bluetooth chip, an ultra wide band (UWB) chip and an audio amplifier, for the shutdown after the terminal equipment is lost and shut down are realized by improving software (such as pin control logic), so that the terminal equipment can work normally, and the power consumption of the terminal equipment is reduced. A user is helped to quickly find the terminal equipment, and the user experience is improved.