Apparatus and methods for envelope tracking systems with automatic mode selection are
provided herein. In certain configurations, a power amplifier system includes a power …

Wireless communications devices include two essential components—a transmitter and a
receiver. In mobile wireless communications devices, such as cellular handsets, the trans …

Apparatus and methods for wideband envelope tracking systems are disclosed herein. In
certain implementations, an envelope tracker includes a DC-to-DC converter, a current …

Configuration-feedback circuitry and transceiver circuitry are disclosed. The configuration-
feedback circuitry regulates an output power from a radio frequency power amplifier based …

This disclosure relates to radio frequency (RF) power con verters and methods of operating
the same. In one embodi ment, an RF power converter includes an RF switching con verter …

A switch mode power supply converter and a parallel amplifier are disclosed. The switch
mode power supply converter is coupled to a modulated power supply output and the …

(57) ABSTRACT A radio frequency (RF) system includes an RF power ampli fier (PA), which
uses an envelope tracking power supply voltage to provide an RF transmit signal, which has …

(57) ABSTRACT A system and method for performing sample rate conversion and creating
fractional delays to a signal is disclosed. The system comprises a filter, a look up table for …

Apparatus and methods for envelope tracking systems with automatic mode selection are
provided herein. In certain configurations, a power amplifier system includes a power …

Fast envelope tracking systems are provided herein. In certain embodiments, an envelope
tracking system for a power amplifier includes a switching regulator and a differ ential error …