An audio signal amplifying device processes an input signal to provide an output signal for a balanced headphone. The device includes a signal detection circuit, a voltage supply circuit, and an amplifying circuit. The signal detection circuit detects the variation in the input signal to generate a detection result. The voltage supply circuit outputs one of multiple voltages as a supply voltage according to the detection result; when the detection result indicates the amplitude of the input signal satisfying a first condition, the supply voltage is a first voltage; when the detection result indicates the amplitude of the input signal satisfying a second condition, the supply voltage is a second voltage lower than the first voltage; and the amplitude satisfying the first condition is greater than the amplitude satisfying the second condition. The amplifying circuit generates the output signal according to the input signal based on the supply voltage.

An electronic device includes a network monitor configured to acquire network environment information related to a radio frequency (RF) transmission signal; a transceiver configured to generate an envelope signal of the RF transmission signal; a transmission (Tx) module including a power amplifier for receiving the RF transmission signal from the transceiver and amplifying the RF transmission signal; and an envelope tracking (ET) modulator configured to receive the envelope signal from the transceiver and to provide a bias of a power amplifier to correspond to the envelope signal, wherein the ET modulator determines a magnitude of the bias of the power amplifier based on the network environment information acquired by the network monitor.

Disclosed are a power amplifier, comprising a main power amplifier unit, an auxiliary power amplifier unit, an envelope acquisition unit and a power control unit, wherein input ends of both the main power amplifier unit and an input end of the auxiliary power amplifier unit are connected to an electrical signal, and output ends of the two are coupled to each other; the power control unit comprises a first power control assembly and/or a second power control assembly, at least one main power amplifier unit is connected to the electrical signal through the first power control assembly, and a control end of the first power control assembly is connected to the envelope acquisition unit; and at least one auxiliary power amplifier unit is connected to the electrical signal through the second power control assembly, and a control end of the second power control assembly is connected to the envelope acquisition unit.

Window-based envelope tracking in a multi-antenna transmission circuit is provided. The multi-antenna transmission circuit includes a power amplifier circuit that amplifies multiple radio frequency (RF) signals concurrently based on a modulated voltage, an envelope tracking integrated circuit (ETIC) that generates the modulated voltage based on a modulated target voltage, and a transceiver circuit that generates the RF signals and the modulated target voltage. The RF signals may be modulated across a wide modulation bandwidth, but the ETIC may have a lower bandwidth limit. Such bandwidth disparity can cause a ripple(s) in the modulated voltage and, consequently, lead to distortions in the RF signals. Herein, the transceiver circuit is configured to perform window-based envelope tracking to thereby determine and add a compensation term(s) in the modulated target voltage. As a result, it is possible to suppress the ripple(s) and prevent distortions in the RF signals across the wide modulation bandwidth.

Apparatus and methods for power amplifier distortion networks are disclosed. In one aspect, there is provided a power amplifier system including a power amplifier configured to amplify a radio frequency input signal. The power amplifier including an input configured to receive the radio frequency input signal and an output configured to generate an amplified radio frequency signal. The power amplifier system further includes a distortion network electrically coupled to either the input or the output of the power amplifier. The distortion network including a plurality of channelized resistors. The channelized resistors connected in series to either an input or an output of the power amplifier.

An electronic device may include wireless circuitry with a processor that generates baseband signals, an upconversion circuit that upconverts the baseband signals to radio-frequency signals, a power amplifier, an antenna, and a transmit filter with a frequency dependent filter response coupled between the output of the power amplifier and the antenna. To help mitigate the frequency dependent filter response, the wireless circuitry may further include predistortion circuitry having an amplifier load response estimator that implements a baseband model of the filter response, an amplifier non-linearity estimator that models the non-linear behavior of the amplifier, and a control signal generator for adjusting the power amplifier based on the output of the amplifier load response estimator and the amplifier non-linearity estimator.

Envelope tracking systems with modeling for power amplifier supply voltage filtering are provided herein. In certain embodiments, an envelope tracking system includes a supply voltage filter, a power amplifier that receives a power amplifier supply voltage through the supply voltage filter, and an envelope tracker that generates the power amplifier supply voltage. The power amplifier provides amplification to a radio frequency (RF) signal that is generated based on digital signal data, and the envelope tracker generates the power amplifier supply voltage based on an envelope signal corresponding to an envelope of the RF signal. The envelope tracking system further includes digital modeling circuitry that models the supply voltage filter and operates to digitally compensate the digital signal data for effects of the supply voltage filter, such as distortion.

A power management circuit operable with group delay is provided. In embodiments disclosed herein, the power management circuit includes a voltage processing circuit configured to receive a first time-variant target voltage having a first group delay relative to a time-variant target voltage and a second time-variant target voltage having a second group delay relative to the time-variant target voltage. Accordingly, the voltage processing circuit generates a windowed time-variant target voltage higher than or equal to a highest one of the first time-variant target voltage and the second time-variant target voltage in a group delay tolerance window(s) defined by the first group delay and the second group delay. As a result, the power management circuit can generate a time-variant voltage based on the windowed time-variant target voltage to help a power amplifier to avoid amplitude clipping when amplifying an analog signal.

A tracker module is provide that includes an integrated circuit on a main surface of a module laminate, and at least one capacitor included in a switched-capacitor circuit disposed on the other main surface of the module laminate. The switched-capacitor circuit generates, based on an input voltage, a plurality of discrete voltages. The integrated circuit includes at least one switch included in the switched-capacitor circuit, and at least one switch included in a supply modulator that selectively outputs, based on an envelope signal, at least one of the plurality of discrete voltages. The at least one capacitor overlaps the integrated circuit in a plan view of the module laminate.

The representative embodiments discussed in the present disclosure relate to techniques in which the operating characteristics (e.g., gain and/or efficiency) of a power amplifier in a transmitter may be regulated according to an operation mode of the transmitter. More specifically, in some embodiments, different LUTs may be employed for each mode of operation to suitably adjust the supply voltage to the power amplifier and modulate its operating characteristics based on power input to the power amplifier. Further, in some embodiments, a method to calibrate a LUT for ULCA, an operation mode of the transmitter, may be employed to populate a LUT that may be used to suitably adjust the supply voltage during ULCA.