Apparatus and methods for envelope tracking calibration are provided. In one embodiment, a method of calibrating an envelope tracker having an envelope shaping table generated at a desired gain compression of a power amplifier is provided. The method includes generating a supply voltage for the power amplifier using the envelope tracker, operating the supply voltage of the power amplifier at a first voltage level associated with substantially no gain compression of the power amplifier, and measuring an output power of the power amplifier at the first voltage level. The method further includes decreasing a voltage level of the supply voltage one or more times and measuring the output power at each voltage level, determining a second voltage level of the power amplifier associated with a gain compression equal to about that of the desired gain compression, and calibrating the envelope tracker based on the determination.

Apparatus and methods for envelope tracking calibration

An open loop envelope tracking system calibration technique and circuitry are proposed. A radio frequency power amplifier receives a modulated signal. An envelope tracker power converter generates a modulated power amplifier supply voltage for the radio frequency power amplifier based on a control signal derived from the modulated signal. A first output power and a second output power of the radio frequency power amplifier are measured when the control signal is respectively delayed by a first delay period and a second delay period. A sensitivity of the output power of the radio frequency power amplifier is near a maximum near the first delay period and the second delay period. The first delay period and/or the second delay period are adjusted until the first output power substantially equals the second output power. The first delay period and the second delay period are used to obtain a calibrated fine tuning delay offset.

Group delay calibration method for power amplifier envelope tracking

Embodiments disclosed in the detailed description relate to a pseudo-envelope follower power management system used to manage the power delivered to a linear RF power amplifier.

Pseudo-envelope following power management system

Configuration-feedback circuitry and transceiver circuitry are disclosed. The configuration-feedback circuitry regulates an output power from a radio frequency power amplifier based on a difference between a target output power from the radio frequency power amplifier and a measured output power from the radio frequency power amplifier. The transceiver circuitry regulates a modulated power supply voltage, which is used by the radio frequency power amplifier to provide power for amplification, based on the difference between the target output power from the radio frequency power amplifier and the measured output power from the radio frequency power amplifier.

Power loop control based envelope tracking

A direct current (DC)-DC converter, which includes a parallel amplifier, a radio frequency (RF) trap, and a switching supply, is disclosed. The switching supply includes switching circuitry and a first inductive element. The parallel amplifier has a feedback input and a parallel amplifier output. The switching circuitry has a switching circuitry output. The first inductive element is coupled between the switching circuitry output and the feedback input. The RF trap is coupled between the parallel amplifier output and a ground.

Noise reduction for envelope tracking

A power amplifier unit having a power amplifier which can be used efficiently without causing any trouble in operation. A control section (11) makes a decision based on an estimated output power level whether the power amplifier is in a first period performing low power output operation or in a second period performing high power output operation. During the first period, a DC/DC converter (2) is brought into active state and a power supply voltage Vdd2 is supplied as the operating power supply voltage of an HPA (1). During the second period, activation/inactivation of the DC/DC converter (2) and on/off of a switch (3) are controlled based on a power supply voltage level VM detected by an operating power supply voltage detecting circuit (13) and one of the power supply voltage Vdd2 or a power supply voltage Vdd3 is supplied as the operating power supply voltage.

Makoto Mitsubishi Denki Kabushiki Kaisha Baba

Papers

Power amplifier unit, communication terminal and control method of power amplifier unit