A power amplifier circuit including a plurality of analog power amplifiers configured to generate a output power for an output signal; at least one processor configured to: select a highest output power signal; determine an input signal power of a modulated signal; determine an output signal power based on the input signal power; compare the output signal power and the highest output power; and disable a subset of the plurality of analog power amplifiers based on the comparison, wherein a remainder of the plurality of analog power amplifiers are configured to generate the output signal power.

A tracker circuit is provided that includes a switched-capacitor circuit configured to generate a plurality of discrete voltages and a supply modulator configured to selectively output at least one discrete voltage of the plurality of discrete voltages to a power amplifier. The switched-capacitor circuit generates the plurality of discrete voltages based on a difference between a first input voltage and a second input voltage that is variable and that is lower than the first input voltage.

In one example, an apparatus includes: an operational amplifier (opamp) to amplify a difference between a reference voltage and a feedback voltage and output a bias signal based on the difference; a replica device coupled to the opamp, the replica device having a gate terminal to receive the bias signal; and an output stage coupled to the replica device and to output a regulated voltage, the output stage having a pass device and a plurality of feedback devices coupled to the pass device. A selected number of the plurality of feedback devices can be enabled based at least in part on an output power level of a power amplifier that is to receive the regulated voltage.

A tracker module is provided that includes a module laminate, and an integrated circuit disposed at the module laminate. The integrated circuit includes at least one switch included in a pre-regulator circuit; at least one switch included in a switched-capacitor circuit; at least one switch included in an output switching circuit; and a digital control circuit. In plan view of the module laminate, at least one of the at least one switch included in the output switching circuit; or the digital control circuit is disposed between the at least one switch included in the pre-regulator circuit and the at least one switch included in the switched-capacitor circuit.

Methods and apparatus for amplifying a signal via an amplification circuit are described. An example amplification circuit generally includes an amplifier including an inverting input configured to receive a signal for wireless transmission. The amplification circuit also includes an impedance coupled between the inverting input and an output of the amplifier. The amplification circuit further includes a resistive element including (i) a first terminal coupled to the inverting input and (ii) a second terminal coupled to a reference potential node for the amplification circuit.

In some embodiments, a power supply system for a power amplifier can include a voltage converter implemented generate a first voltage at an output node, and an envelope following circuit implemented to generate and combine a second voltage with the first voltage to provide a combined output voltage for the power amplifier. The combined output voltage can have a waveform that follows one or more peaks of an envelope of a radio-frequency signal above the first voltage.

A system and method which includes receiving an input signal having an envelope and generating an envelope detection signal corresponding to the envelope. A bias current provided to an amplifier circuit is adjusted based upon the envelope detection signal, the amplifier circuit including an amplifier and a transformer. The transformer is configured to establish a magnetically coupled feedback loop from an output of the amplifier to an input of the amplifier. An output signal is provided, by the amplifier circuit, in response to the input signal.

Control and calibration for load modulation power amplifiers are disclosed. In certain embodiments, envelope shaping for a modulated power amplifier incorporates shifting of the envelope shaping table response characteristic with a signal power target (for instance, an average power target). Thus, as a voltage level of a power amplifier supply voltage changes for APT for a given power range, a replicated but shifted envelope shaping table response characteristic can be used for load modulation.

Envelope shaping tables calibrated for Isogain can provide a response characteristic that achieves a constant gain of the power amplifier. Although calibrating the load modulated power amplifier in this manner can provide low gain distortion (AM/AM), an Isogain calibration can result in phase distortion (AM/PM). To compensate for this phase distortion, in certain embodiments herein the envelope shaping table is smoothed at least at a lower end of the power range relative to an envelope shaping table calibrated for Isogain. By providing smoothing in this manner, spectral regrowth can be reduced.

Wireless communication circuitry for use in an electronic device may comprise: a power amplifier configured to amplify (RF) signals in a first frequency band of a first radio access technology (RAT) in a first communication mode and to amplify RF signals in a second frequency band of a second RAT in a second communication mode and a switch including a first input node configured to be connectable to receive an envelope tracking power supply signal, a second input node configured to be connectable to receive an average power tracking (APT) power supply signal, and an output node connected to the PA. The switch may be configured to switchably connect one of the first input node and the second input node to the output node in response to a switching control signal.