The representative embodiments discussed in the present disclosure relate to techniques in which the operating characteristics (e.g., power consumption) of a power amplifier in a transceiver may be regulated according to an operation mode of the transceiver. More specifically, in some embodiments, different LUTs may be employed for each mode of operation to suitably adjust the supply voltage (e.g., bias voltage) and/or quiescent current input to the power amplifier based on an input signal and a margin by which transmission standards are met. Further, in some embodiments, a method to calibrate a LUT for average power tracking and/or envelope tracking in a transceiver mode of operation may be employed to populate a LUT that may be used to suitably adjust the power and/or current consumption of the power amplifier.

A low modulation bandwidth (LMB) envelope tracking (ET) circuit is provided. The LMB ET circuit is configured to generate an ET modulated voltage at an output node based on a modulated target voltage for amplifying an LMB radio frequency (RF) signal. More specifically, the LMB ET circuit includes an amplifier configured to generate a modulated amplifier voltage based on the modulated target voltage and an offset circuit configured to raise the modulated amplifier voltage by a modulated offset voltage at the output node. The offset circuit is configured to generate the modulated offset voltage based on a modulated target offset voltage that is proportional to the modulated target voltage. As a result, it may be possible to maintain the ET modulated voltage at a defined voltage level for a defined duration such that the LMB RF signal can be amplified to a defined power level.

Disclosed is a high-power and high-frequency DC-DC converter block for the envelope tracking technique including a step-down power circuit whose output constitutes the output of the DC-DC converter block, the step-down power circuit including at least one HEMT depletion-mode transistor, the DC-DC converter block further including a gate driving circuit of the at least one HEMT depletion-mode transistor of the step-down power circuit. The driving circuit has HEMT depletion-mode transistors configured to drive the gate of the at least one HEMT depletion-mode transistor of the step-down power circuit, and the step-down power circuit is powered by two positive and non-zero power supply voltages, namely a first power supply voltage and a second power supply voltage, the first power supply voltage being greater than the second power supply voltage.

Embodiments of the disclosure generally relate to a method and device for improving the efficiency of a power amplifier. The apparatus comprising: a harmonic generator, configured to generate one or more harmonic according to an output signal of a power amplifier; a harmonic feedback device, configured to inject the harmonic generated by the harmonic generator to an input terminal of the power amplifier; and a harmonic eliminator, configured to eliminate the harmonic in the output signal of the power amplifier. According to embodiments of the disclosure, the efficiency of power amplifier can be improved without degrading the linearity.

Aspects of this disclosure relate to a switching circuit with enhanced linearity. The switching circuit can include a switch and an envelope generator. The switch can receive an input signal, provide an output signal, and receive an envelope signal corresponding to an envelope of the input signal. The envelope generator can generate the envelope signal so as to cause intermodulation distortion in the output signal to be reduced to cause linearity of the switch to be improved.

An electronic device may include wireless communications circuitry, control circuitry, and sensor circuitry. The wireless communications circuitry may include amplifier circuitry that amplifies radio-frequency signals using on a bias voltage to generate amplified radio-frequency signals transmitted over an antenna. Power supply circuitry may generate the bias voltage based on an envelope mapping setting and an envelope signal associated with the radio-frequency signals. The sensor circuitry may generate sensor data that characterizes the performance of the wireless communications circuitry and provide the sensor data to the control circuitry. The control circuitry may use the provided sensor data to generate control signals for the power supply circuitry. The control signals may adjust the envelope mapping setting of the power supply circuitry.

The present invention breaks up the frequency bands which can be filtered by a simple low-loss band-pass or low pass filter. The second harmonic frequency is reduced by use of a non-linear clipper element which controls the driving waveform symmetry and can reduce the harmonics by as much as 5-15 db which makes the filter much simpler and allows the amplifier to remain wide-band. The output waveform from the amplifier is symmetrical or nearly symmetrical.

Provided is a power amplification module that includes: a first power amplifier that amplifies a first signal and outputs a second signal; and a first noise removing circuit that is inputted with a first voltage supplied from a DC-DC converter, removes noise from the first voltage in order to generate a second voltage, and outputs the second voltage as a power supply voltage of the first power amplifier.

Apparatus and methods for power amplifiers with positive envelope feedback are provided herein. In certain implementations, a power amplifier system includes a power amplification stage that amplifies a radio frequency signal, at least one envelope detector that generates one or more detection signals indicating an output signal envelope of the power amplification stage, and a wideband feedback circuit that provides positive envelope feedback to a bias of the power amplification stage based on the one or more detection signals. The power amplifier system further includes a supply modulator that controls a voltage level of a supply voltage of the power amplification stage based on the one or more detection signals such that the supply voltage is modulated with the output signal envelope through positive envelope feedback.

An envelope tracking (ET) power management circuit is provided. The ET power management circuit includes a number of tracker circuits each configured to operate based on a respective input voltage. In various operation scenarios, one or more selected tracker circuits may be configured to provide ET modulated voltages to a number of amplifier circuits. In examples discussed herein, each of the selected tracker circuits is configured to draw the respective input voltage from a single voltage circuit (e.g., an inductor-based buck-boost circuit) in the ET power management circuit. By utilizing the single voltage circuit to power the selected tracker circuits, as opposed to employing multiple voltage circuits, it is possible to reduce the footprint of the ET power management circuit, thus helping to reduce cost and power consumption of the ET power management circuit.