A power amplifier output stage includes a first output array group having a first plurality of semiconductor devices, and a first loading adjustment module coupled to the first output array group. The first loading adjustment module is configured to adjust a loading of the first output array group to produce a first power dissipation value associated with the first output array group. The power amplifier output stage further includes a second output array group having a second plurality of semiconductor devices, and a second source loading adjustment module coupled to a second input of the second output array. The second source loading adjustment module is configured to adjust a source loading of the second output array group to produce a second power dissipation value associated with the second output array group, the first power dissipation value being different from the second power dissipation value.

An amplifier includes an input matching network; at least one transistor; an input lead coupled to the at least one transistor; a ground terminal coupled to the transistor; an output lead coupled to the at least one transistor; an output matching circuit coupled to the output lead and to the at least one transistor; and a baseband impedance enhancement circuit having at least one reactive element coupled to the input matching network. The baseband impedance enhancement circuit is configured to reduce resonances of a baseband termination.

An in-band extraction unit is configured to extract an in-band from an output signal. An out-band extraction unit is configured to extract at least one pair of out-bands including a low frequency side out-band and a high frequency side out-band from the output signal. An ADC is configured to convert the extracted in-band and out-bands to digital signals. A signal processing unit is configured to process information included in the digital signals converted by the analog to digital converter and adjust an operation of predistorting an input baseband digital signal to generate the output signal.

A power amplifier comprising: a first amplifier; a second amplifier, wherein the first and second amplifiers are arranged in parallel; an analogue pre-distortion network; a first coupler; and a second coupler, wherein the first coupler is configured to receive an input signal, direct said input signal to the first amplifier, and direct a first pre-distortion signal to the analogue pre-distortion network, wherein the first pre-distortion signal comprises a first distortion component generated at the input of the first amplifier, and the analogue pre-distortion network is configured to receive the first pre-distortion signal and manipulate its amplitude and/or phase to obtain a manipulated first pre-distortion signal, and the second coupler is configured to direct the manipulated first pre-distortion signal to the second amplifier.

A digital pre-distortion method for a multiband signal, an electronic device and a non-transitory computer-readable storage medium are disclosed. The digital pre-distortion method may include: determining a possible power amplifier distortion according to configuration of a signal issued by a cell; selecting a basis function of pre-distortion according to the possible power amplifier distortion; solving, according to a pre-collected reference multiband signal and a corresponding feedback signal, the selected basis function to obtain a pre-distortion parameter; and processing an input multiband signal according to the selected basis function and the pre-distortion parameter to generate a pre-distortion signal.

A method comprises obtaining a transmission signal to be power-amplified in a power amplifier (361) prior to transmission; separating the transmission signal into two or more polyphase components of the transmission signal; feeding one or more polyphase components of the transmission signal comprised in the two or more polyphase components to each of two or more parallel predistortion circuits (320,321,322); selecting a dedicated predistortion model and dedicated predistortion coefficients for each of the two or more parallel predistortion circuits (320,321,322); performing non-linear memory-based modeling on the transmission signal according to the selected dedicated predistortion models and coefficients using the one or more polyphase components; and combining output signals of the two or more parallel predistortion circuits (320,321,322) to form a predistorted transmission signal (y[n]) to be applied to the power amplifier (361).

An apparatus includes a radio-frequency (RF) circuit, which includes a power amplifier coupled to receive an RF input signal and to provide an RF output signal in response to a modified bias signal. The RF circuit further includes a bias path circuit coupled to modify a bias signal as a function of a characteristic of an input signal to generate the modified bias signal. The bias path circuit provides the modified bias signal to the power amplifier.

A predistortion circuit for a wireless transmitter includes a signal input configured to receive a baseband signal. Further, the predistortion circuit includes a predistorter configured to generate a predistorted baseband signal using the baseband signal and a select of one of a first predistorter configuration and a second predistorter configuration.

An exemplary FET includes a substrate and multiple vertically stacked layer groups with each layer group having a quantum well semiconductive layer and a nonconductive layer adjacent the first quantum well semiconductive layer. Conductive source and drain electrodes in conductive contact with the semiconductive layers. A 3-dimensional ridge of the stacked layer groups is defined between spaced apart first and second trenches which are between the source and drain electrodes. A continuous conductive side gate is disposed on the sides and top of the ridge for inducing a field into the semiconductive layers. A gate electrode is disposed in conductive contact with the conductive side gate.

A predistortion system for linearizing the output of a power amplifier includes a first signal representative of an RF modulated signal and a feedback signal representative of nonlinear characteristics of a power amplifier. The system also includes a predistortion controller, comprising at least one lookup table, adapted to receive the first signal and the feedback signal and to generate a correction factor for correcting the nonlinear characteristics of the power amplifier and combining logic which combines the RF modulated signal with a signal corresponding to the correction factor and supplies it to the power amplifier to linearize the output of the power amplifier.