Aspects of the disclosure relate to a radio frequency phase shifter. An example includes an amplification stage to produce an amplified voltage, the amplification stage having a first amplifier with a first input coupled to a first output of a hybrid coupler and a second amplifier with a complementary second input coupled to a complementary second output of the hybrid coupler. A vector modulation stage coupled to the amplification stage receives the amplified voltage and produces a modulated vector, the vector modulation stage has an in-phase section and a quadrature section to control the phase of the modulated vector in response to a phase control signal. A varactor coupled across the first input and the second input of the amplification stage adjusts the capacitance between the first input and the second input in response to a capacitance control signal.

A radio frequency (RF) communication assembly includes an RF communication circuit and a compensator apparatus. The compensator apparatus receives an input including an I-component of a pre-compensated signal, a Q-component of the pre-compensated signal, and encoded operating conditions of the RF communication circuit. The RF communication circuit includes RF circuit components causing signal impairments. The compensator apparatus perform neural network computing on the input, and the RF communication assembly generates a compensated output signal that compensates for at least a portion of the signal impairments.

A wireless communications system includes a pre-distortion actuator configured to receive a carrier-modulated signal and convert the carrier-modulated signal into an output signal. The system includes one or more antennas configured to receive the output signal and transmit the output signal, one or more power amplifiers electrically coupled between the pre-distortion actuator and the one or more antennas and a receiver configured to receive the output signal over-the-air and generate feedback based on the output signal. The pre-distortion actuator is configured to generate the output signal by applying a correction to the carrier-modulated signal that cancels out nonlinearities associated with the one or more antennas and/or the one or more power amplifiers. The pre-distortion actuator is configured based on the feedback.

Pre-distorted transmitters operable over a wide range of frequencies including a plurality of predetermined frequency bands are provided. The transmitters include a programmable digital up-converter and a programmable digital down-converter, an ADC, a DAC, a power amplifier and at least one analog filter arranged along a transmit signal path and a feedback signal path.

Various examples are directed to systems and methods for digital predistortion (DPD). A linear digital predistortion (DPD) circuit may be programmed to generate a pre-distorted signal linear component based at least in part on a complex baseband signal. A nonlinear DPD circuit may be programmed to generate a pre-distorted signal nonlinear component based at least in part on the complex baseband signal. A mixer circuit programmed to generate a pre-distorted signal based at least in part on the pre-distorted signal linear component and the pre-distorted signal nonlinear component.

The present invention discloses a power amplification apparatus having a digital pre-distortion mechanism that includes a digital pre-distortion circuit and a power amplifier. The digital pre-distortion circuit receives an original digital signal having an original real part and an original imaginary part. When a first one and a second one of the original real part and the original imaginary part are a low state voltage level and a high state voltage level, the digital pre-distortion circuit outputs a first and a second voltage levels equivalent to the low state voltage level as a first pre-distortion part and directly outputs the second one of the original real part and the original imaginary part as a second pre-distortion part to generate an input signal having an input real part and an input imaginary part each corresponding to one of the first pre-distortion part and the second pre-distortion part. The power amplifier receives the input signal to perform power amplification to generate an output signal.

The present invention discloses a power amplification apparatus having a digital pre-distortion mechanism that includes a digital pre-distortion circuit and a power amplifier. The digital pre-distortion circuit receives an original digital signal having an original real part and an original imaginary part. When a first one and a second one of the original real part and the original imaginary part are a low state voltage level and a high state voltage level, the digital pre-distortion circuit outputs a first and a second voltage levels equivalent to the low state voltage level as a first pre-distortion part and directly outputs the second one of the original real part and the original imaginary part as a second pre-distortion part to generate an input signal having an input real part and an input imaginary part each corresponding to one of the first pre-distortion part and the second pre-distortion part. The power amplifier receives the input signal to perform power amplification to generate an output signal.

A wireless communications system includes a pre-distortion actuator configured to receive a carrier-modulated signal and convert the carrier-modulated signal into an output signal. The system includes one or more antennas configured to receive the output signal and transmit the output signal, one or more power amplifiers electrically coupled between the pre-distortion actuator and the one or more antennas and a receiver configured to receive the output signal over-the-air and generate feedback based on the output signal. The pre-distortion actuator is configured to generate the output signal by applying a correction to the carrier-modulated signal that cancels out nonlinearities associated with the one or more antennas and/or the one or more power amplifiers. The pre-distortion actuator is configured based on the feedback.

A novel and useful linear, efficient, smart wideband CMOS hybrid power amplifier that combined an analog linear amplification path and a digital power amplification (DPA) path. PA path control logic analyzes the input I and Q signals and determines which amplification paths to steer the input I and Q signals to. The analog linear amplification path comprises digital to analog converters for both I and Q paths and one or more analog linear power amplifiers. The digital power amplification path comprises I and Q up-sampling circuits and I and Q RF DAC circuits (e.g., digital PA circuits). In operation, the PA path control logic compares the I and Q signals to thresholds (which may or may not be different) and based on the comparisons, selects one or more paths for the input I and Q signals. Whether the signals from the analog and digital amplification paths are to be combined or selected (i.e. switched), the PA path control circuit is operative to generate select (switch) control signals which are applied to summer/selector elements which generate the output of the hybrid PA.

A predistortion processing apparatus: an auxiliary feedback module, configured to: extract a nonlinear distortion signal from an analog signal, and input an obtained feedback signal corresponding to the nonlinear distortion signal into an auxiliary model coefficient training module; the auxiliary model coefficient training module, configured to: train an auxiliary coefficient according to the feedback signal and a predistortion signal, and transmit a first auxiliary coefficient obtained through training to a predistortion processing module; a radio frequency signal feedback module, configured to extract a fundamental wave feedback signal; a predistortion model coefficient training module, configured to: train a predistortion coefficient according to the predistortion signal and the fundamental wave feedback signal, and transmit an obtained predistortion coefficient to the predistortion processing module; the predistortion processing module, configured to: perform predistortion processing on an input intermediate frequency signal by performing nonlinear modeling according to the first auxiliary coefficient and the predistortion coefficient.