The invention relates to a device for linearising a power amplifier by employing digital predistortion, comprising: a digital predistortion module, configured to infer a polar domain predistortion to be applied to a signal, and comprising a first neural network and a second neural network respectively configured to correct amplitude and phase distortion produced by the amplifier; an optimisation module of each of said neural networks configured to implement meta-learning, using: a meta-initialisation providing a prior initialisation of the initial weights of each of said neural networks; a meta-matching of the initial weights into optimal weights of each of said neural networks.

An amplitude and phase control device includes a signal dividing unit to divide a transmission signal into first and second signals and output the first and second signals to a Doherty amplifier, an error calculating unit to acquire, from the Doherty amplifier, a synthesized signal of first and second signals amplified by the Doherty amplifier, multiply the synthesized signal by a reciprocal of a gain of the Doherty amplifier, and calculate an error between a synthesized signal after being multiplied by the reciprocal and the transmission signal, and a controlling unit to control an amplitude of each of the first signal and the second signal output from the signal dividing unit depending on the error calculated by the error calculating unit, and control a phase difference between the first signal output from the signal dividing unit and the second signal output from the signal dividing unit depending on the error.

A peak current limiter for an audio system comprising at least two audio amplifiers is described. The peak current limiter comprises at least two audio inputs; at least two audio outputs, each audio output being coupled to a respective one of the at least two audio inputs and configured to be coupled to a respective one of the at least two audio amplifiers. The peak current limiter is configured to receive an audio signal on each of the respective audio inputs. The peak current limiter determines a current value required by each of at least two audio amplifiers. An audio characteristic of at least one of the received audio signals is modified to limit the total current supplied to the at least two amplifiers below a predefined maximum current value.

An amplifier (300) comprising: a first signal path comprising first amplifier circuitry (105A) configured to receive a first signal (RF1) with a frequency and a variable phase and amplitude at the frequency; a second signal path comprising second amplifier circuitry (105B) configured to receive a second signal (RF2) with the frequency, wherein at least one of the relative phase and amplitude of the second signal is fixed at the frequency; combiner circuitry (106) configured to combine an output of the first amplifier circuitry and the second amplifier circuitry.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive a configuration indicating one or more directions for applying directional digital pre-distortion (DPD) to mitigate interference in a direction to another UE. The UE may transmit a communication to a wireless node based at least in part on applying the directional DPD according to the configuration. Numerous other aspects are described.

Various implementations include a common mode voltage controller for a self-boosting push pull amplifier. In some implementations, input signal are processed by: calculating, based upon the input signal, a maximum duty cycle to achieve a target differential in an output of the self-boosting push pull amplifier; calculating, based on the input signal, a set of control parameters associated with adjusting a common mode voltage of the output; and generating, based on the input signal, a pair of signals configured to adjust the common mode voltage of the output, wherein the pair of signals include a gain adjustment and offset based on the maximum duty cycle and the set of control parameters, and wherein the pair of signals are configured to maintain the target differential in the output of the self-boosting push pull amplifier as the common mode voltage is adjusted to a different operating point.

Various implementations include a common mode voltage controller for a self-boosting push pull amplifier. In some implementations, input signal are processed by: calculating, based upon the input signal, a maximum duty cycle to achieve a target differential in an output of the self-boosting push pull amplifier; calculating, based on the input signal, a set of control parameters associated with adjusting a common mode voltage of the output; and generating, based on the input signal, a pair of signals configured to adjust the common mode voltage of the output, wherein the pair of signals include a gain adjustment and offset based on the maximum duty cycle and the set of control parameters, and wherein the pair of signals are configured to maintain the target differential in the output of the self-boosting push pull amplifier as the common mode voltage is adjusted to a different operating point.

The embodiments described herein include amplifiers configured for use in radio frequency (RF) applications. In accordance with these embodiments, the amplifiers are implemented to generate a shaped envelope signal, and to apply the shaped envelope signal to transistor gate(s) of the amplifier to provide gate bias modulation. So configured, the shaped envelope signal may facilitate high linearity in the amplifier.

A device includes an amplifier having a first path and a second path and a first variable attenuator connected to the first path. The device includes a controller coupled to the first variable attenuator. The controller is configured to determine a magnitude of an input signal to the amplifier. When the magnitude of the input signal is below a threshold, the controller is configured to set an attenuation of the first variable attenuator to a first attenuation value. When the magnitude of the input signal is above the threshold, the controller is configured to set the attenuation of the first variable attenuator to a second attenuation value. The second attenuation value is less than the first attenuation value.

A multichannel transmission system which includes a calibration functionality that allows precise calibration of the frequency conversion chains and of the multiport amplifier of the system to be performed without interruption of service. The proposed calibration makes it possible to correct the defects over the entire frequency band of the system.