The present disclosure provides a device and a method for adjusting envelope signals for use by an envelope tracking (ET) enabled power amplifier. The device comprises: a controller configured to calculate a difference between a first amplitude of a first envelope signal received at a first time instance and second amplitude of a second envelope signal received at a second time instance; compare the difference with a predetermined threshold; and adjust an output envelope signal corresponding to the first envelope signal in response to determining that the difference is greater than or equal to the predetermined threshold, such that the output envelope signal is adjusted step-by-step from the second envelope signal to the first envelope signal with each amplitude step being less than or equal to a predetermined amplitude step.

Radio frequency systems and methods adjust power amplifier operation based on power amplifier operating mode or power level to achieve a tradeoff between improved linearity at lower power levels and improved out of band noise performance and coexistence at higher power levels.

A circuit includes a single-ended amplifier having first and second transistors and an amplifier output. The first transistor has a first control input and first and second current terminals. The second transistor has a second control input and third and fourth current terminals. The first and third current terminals are coupled to an adaptively regulated voltage terminal. The circuit also includes a chopper circuit coupled to the amplifier output and to the first and second transistors. A voltage tracking circuit has a voltage tracking circuit input and a voltage tracking circuit output. The voltage tracking circuit input is coupled to the amplifier output, and the voltage tracking circuit output is coupled to the adaptively regulated voltage terminal. The voltage tracking circuit is configured to adaptively vary a voltage on the regulated voltage terminal based on the amplifier output.

The present disclosure relates to devices and methods for detecting and preventing occurrence of a saturation state in a power amplifier. A power amplifier module can include a power amplifier including a cascode transistor pair. The cascode transistor pair can include a first transistor and a second transistor. The power amplifier module can include a current comparator configured to compare a first base current of the first transistor and a second base current of the second transistor to obtain a comparison value. The power amplifier module can include a saturation controller configured to supply a reference signal to an impedance matching network based on the comparison value. The impedance matching network can be configured to modify a load impedance of a load line in electrical communication with the power amplifier based at least in part on the reference signal.

The present disclosure relates to circuitry comprising: amplifier circuitry configured to receive a variable supply voltage, wherein the supply voltage varies according to an output signal of the amplifier circuitry; monitoring circuitry configured to monitor one or more parameters of an output signal of the amplifier circuitry; and processing circuitry configured to receive an indication of the voltage of the variable supply voltage and an indication of the monitored parameters from the monitoring circuitry and to apply a correction to one or more of the monitored parameters to compensate for coupling between the variable supply voltage and the monitoring circuitry.

Described are concepts, circuits, systems and techniques directed toward N-phase control techniques useful in the design and control of supply generators configured for use in a wide variety of power management applications including, but not limited to mobile applications.

A semiconductor device is provided. The semiconductor device comprises an output terminal from which an output voltage is output, a switching converter configured to control the output voltage on the basis of a first reference voltage, a load capacitor configured to be charged with a voltage corresponding to the output voltage, a linear amplifier connected to one end of an alternating current (AC) coupling capacitor and configured to control a voltage of the AC coupling capacitor on the basis of a second reference voltage, and a switching circuit configured to control a charging speed of the load capacitor and control a connection between the output terminal and one end and another end of the AC coupling capacitor.

Group delay determination in a communication circuit is disclosed. The communication circuit includes a power amplifier circuit that amplifies a radio frequency (RF) signal based on a modulated voltage and a power management integrated circuit (PMIC) that generates the modulated voltage. Herein, the PMIC includes a group delay determination circuit to determine a relative group delay between the modulated voltage and a modulated current, which is internal to the power amplifier circuit and unknown to the PMIC, solely based on signals known to the PMIC. The determined relative group delay can help to time align the modulated voltage with the modulated current at the power amplifier circuit to improve error vector magnitude (EVM) and/or adjacent channel leakage ratio (ACLR). Further, by determining the relative group delay based on known signals to the PMIC, it is possible to achieve good time alignment between the modulated voltage and the modulated current.

Circuit and method for intra-symbol voltage method are disclosed. In an embodiment, a transceiver circuit is configured to divide a voltage modulation interval(s) (e.g., a symbol duration) into multiple voltage modulation subintervals each corresponding to a respective one of multiple voltage targets. Accordingly, a power management integrated circuit (PMIC) can adapt a modulated voltage multiple times within the voltage modulation interval(s) based on multiple voltage targets, respectively. By adapting the modulated voltage within the voltage modulation interval(s), the modulated voltage can be timely adapted to closely track a time-variant power envelope of a radio frequency (RF) signal to thereby avoid potential distortion (e.g., amplitude clipping) during amplification of the RF signal.

Examples of the disclosure include an output stage circuit assembly for a power amplifier system, the output stage circuit assembly comprising a plurality of output stage amplifiers connected in parallel to each other, each output stage amplifier of the plurality of output stage amplifiers configured to amplify an input signal of the output stage circuit assembly when turned on, and a controller configured to determine a number of output stage amplifiers to be turned off based on at least one of a voltage supplying mode for the power amplifier system or a power management mode of a device in which the power amplifier system is embedded, and to control the plurality of output stage amplifiers to be turned on or off according to the determined number of output stage amplifiers to be turned off.