Broadband feedforward power amplifiers are disclosed herein. In certain embodiments, a broadband feedforward power amplifier includes a power amplifier electrically connected between a radio frequency (RF) input and an RF output, and a feedforward compensation circuit including a first amplifier electrically connected in parallel with the power amplifier, a load impedance, and a second amplifier electrically connected between the radio frequency input and the load impedance. The feedforward compensation circuit generates a compensation signal based on sensing an output of the first amplifier and an output of the second amplifier, and provides the compensation signal to the radio frequency output to thereby compensate the power amplifier for non-linearity.

A method of a wireless transmitter is disclosed. The method is for mitigation of distortion caused by non-linear hardware components of the transmitter, wherein mitigation of distortion comprises mitigating at least one intermodulation component, wherein the transmitter is configured to process an input signal having an input signal spectrum, and wherein the transmitter comprises two or more signal branches, each signal branch comprising a respective non-linear hardware component. The method comprises modifying the input signal for a first one of the signal branches by applying a first phase shift to a first part of the input signal spectrum, wherein the first phase shift has a first sign and a first absolute value, and applying a second phase shift to a second part of the input signal spectrum. The second phase shift has a second sign which is opposite to the first sign, and a second absolute value which is equal to the first absolute value. The first and second parts are non-overlapping. The method also comprises modifying the input signal for a second one of the signal branches by applying the first phase shift to the second part of the input signal spectrum, and applying the second phase shift to the first part of the input signal spectrum. The method further comprises feeding the modified input signals to respective ones of the signal branches. Corresponding apparatus, wireless transmitter, communication device, and computer program product are also disclosed.

Envelope tracking systems for power amplifiers are provided herein. In certain embodiments, an envelope tracker is provided for a power amplifier that amplifies an RF signal. The envelope tracker includes a multi-level switching circuit having an output that provides an output current that changes in relation to an envelope signal indicating an envelope of the RF signal when the envelope tracker is operating in an envelope tracking mode. The multi-level switching circuit includes a multi-level supply (MLS) modulator that receives multiple regulated voltages of different voltage levels, and an MLS control circuit that controls the selection of the MLS modulator over time based on the envelope signal. When transitioning the MLS modulator from selection of one regulated voltage level to another regulated voltage level, the MLS control circuit provides a soft transition to gradually switch the regulated voltage levels.

A receiver circuit includes an analog-to-digital converter (ADC), a decision feedback equalizer (DFE), a slicer, and a timing error detector (TED). The DFE is coupled to the ADC, and includes a first tap and a second tap. The slicer is coupled to the DFE. The TED is coupled to the slicer. The TED is configured to initialize timing of a sampling clock provided to the ADC while initializing the second tap of the DFE and holding the first tap of the DFE at a constant value.

A compensator system includes a control loop with a gain modifier coupled to an antenna. A control unit is configured to adjustably control the gain of a Tx signal being provided to the antenna by the gain modifier. The control unit receives feedback from a first detector connected to the output of the gain modifier that allows the first control unit to ensure the gain modifier is providing the appropriate amount of gain. A signal level can be provided to the control unit to set the desired output level from gain modifier and the signal level can be determined adjacent a transceiver that is separated from the gain modifier by a length of cable.

Envelope tracking systems for power amplifiers are provided herein. In certain embodiments, an envelope tracker is provided for a power amplifier that amplifies an RF signal. The envelope tracker includes a multi-level switching circuit having an output that provides an output current that changes in relation to an envelope signal indicating an envelope of the RF signal when the envelope tracker is operating in an envelope tracking mode. The multi-level switching circuit includes a multi-level supply (MLS) modulator that receives multiple regulated voltages of different voltage levels, and an MLS control circuit that controls the selection of the MLS modulator over time based on the envelope signal. When transitioning the MLS modulator from selection of one regulated voltage level to another regulated voltage level, the MLS control circuit provides a soft transition to gradually switch the regulated voltage levels.

A receiver circuit includes an analog-to-digital converter (ADC), a decision feedback equalizer (DFE), a slicer, and a timing error detector (TED). The DFE is coupled to the ADC, and includes a first tap and a second tap. The slicer is coupled to the DFE. The TED is coupled to the slicer. The TED is configured to initialize timing of a sampling clock provided to the ADC while initializing the second tap of the DFE and holding the first tap of the DFE at a constant value.

A method and system for digital feed-forward linearization. The system includes a main transmit path and an auxiliary transmit path. The main transmit path includes circuitries configured to process a transmit signal for transmission. The main transmit path includes a power amplifier (PA) for amplifying the transmit signal. The auxiliary transmit path includes circuitries configured to generate, in a digital domain, a distortion error signal corresponding to a distortion introduced to the transmit signal due to a non-linear characteristics of the PA in the main transmit path and convert the distortion error signal to an analog distortion error signal. The analog distortion error signal is combined with an output of the PA in the main transmit path. The auxiliary transmit path comprises a PA model circuit that mimics the behavior of the PA to generate a distorted transmit signal in a digital domain.

The present disclosure relates to a 5G communication system or a 6G communication system for supporting higher data rates beyond a 4G communication system such as long term evolution (LTE). A method performed by a first entity transmitting data in a wireless communication system is provided. The method includes detecting a nonlinearity of a transmission power of a signal transmitted from the first entity is changed, transmitting, to a second entity, a nonlinearity state indicator corresponding to the changed nonlinearity, and transmitting, to the second entity, data according to the nonlinearity state indicator.

Envelope tracking systems for power amplifiers are provided herein. In certain embodiments, an envelope tracker is provided for a power amplifier that amplifies an RF signal. The envelope tracker includes a multi-level switching circuit having an output that provides an output current that changes in relation to an envelope signal indicating an envelope of the RF signal when the envelope tracker is operating in an envelope tracking mode. The multi-level switching circuit includes a multi-level supply (MLS) modulator that receives multiple regulated voltages of different voltage levels, and an MLS control circuit that controls the selection of the MLS modulator over time based on the envelope signal. When transitioning the MLS modulator from selection of one regulated voltage level to another regulated voltage level, the MLS control circuit provides a soft transition to gradually switch the regulated voltage levels.