Abstract: An apparatus for generating a plurality of power supply signals for a plurality of power amplifiers configured to amplify radio frequency transmit signals includes a first power supply circuit configured to generate a first power supply signal and a different second power supply signal. The first power supply circuit is configured to provide the first power supply signal to a first output path and the second power supply signal to a second output path. Further, the apparatus includes a second power supply circuit configured to generate a third power supply signal. Still further, the apparatus includes a switching circuit configured to couple the second power supply circuit to the first output path in a first operating mode to provide a first combined power supply signal at an output of the first output path based on the first power supply signal and the third power supply signal.

Abstract: An apparatus for generating a plurality of power supply signals for a plurality of power amplifiers configured to amplify radio frequency transmit signals includes a first power supply circuit configured to generate a first power supply signal and a different second power supply signal. The first power supply circuit is configured to provide the first power supply signal to a first output path and the second power supply signal to a second output path. Further, the apparatus includes a second power supply circuit configured to generate a third power supply signal. Still further, the apparatus includes a switching circuit configured to couple the second power supply circuit to the first output path in a first operating mode to provide a first combined power supply signal at an output of the first output path based on the first power supply signal and the third power supply signal.

Abstract: An apparatus for generating a plurality of power supply signals for a plurality of power amplifiers configured to amplify radio frequency transmit signals includes a first power supply circuit configured to generate a first power supply signal and a different second power supply signal. The first power supply circuit is configured to provide the first power supply signal to a first output path and the second power supply signal to a second output path. Further, the apparatus includes a second power supply circuit configured to generate a third power supply signal. Still further, the apparatus includes a switching circuit configured to couple the second power supply circuit to the first output path in a first operating mode to provide a first combined power supply signal at an output of the first output path based on the first power supply signal and the third power supply signal.

Abstract: A method of calibrating an envelope tracking system for a supply voltage for a power amplifier module within a radio frequency (RF) transmitter module of a wireless communication unit. The method includes, within at least one signal processing module of the wireless communication unit, applying a training signal having an envelope that varies with time to an input of the RF transmitter module, receiving at least an indication of instantaneous output signal values for the power amplifier module in response to the training signal, calculating instantaneous gain values based at least partly on the received output power values, and adjusting a mapping function between an instantaneous envelope of a waveform signal to be amplified by the power amplifier module and the power amplifier module supply voltage to achieve a constant power amplifier module gain.

Abstract: A method of calibrating an envelope tracking system for a supply voltage for a power amplifier module within a radio frequency (RF) transmitter module of a wireless communication unit. The method includes, within at least one signal processing module of the wireless communication unit: applying training signal having time-variant envelope to input of the RF transmitter module; receiving indication of instantaneous output signal value(s) for the power amplifier module in response to the training signal; and adjusting timing alignment between envelope tracking path of the envelope tracking system and transmit path of the RF transmitter module to align envelope tracking power amplifier module supply voltage to instantaneous envelope(s) of a waveform signal to be amplified by the power amplifier module, based at least partly on the received indication of the instantaneous output signal value(s) for the power amplifier module in response to the training signal.

Abstract: A method of calibrating an envelope tracking system for a supply voltage for a power amplifier module within a radio frequency (RF) transmitter module of a wireless communication unit. The method includes, within at least one signal processing module of the wireless communication unit: applying training signal having time-variant envelope to input of the RF transmitter module; receiving indication of instantaneous output signal value(s) for the power amplifier module in response to the training signal; and adjusting timing alignment between envelope tracking path of the envelope tracking system and transmit path of the RF transmitter module to align envelope tracking power amplifier module supply voltage to instantaneous envelope(s) of a waveform signal to be amplified by the power amplifier module, based at least partly on the received indication of the instantaneous output signal value(s) for the power amplifier module in response to the training signal.

Abstract: A method of calibrating an envelope tracking system for a supply voltage for a power amplifier module within a radio frequency (RF) transmitter module of a wireless communication unit. The method includes, within at least one signal processing module of the wireless communication unit, applying a training signal having an envelope that varies with time to an input of the RF transmitter module, receiving at least an indication of instantaneous output signal values for the power amplifier module in response to the training signal, calculating instantaneous gain values based at least partly on the received output power values, and adjusting a mapping function between an instantaneous envelope of a waveform signal to be amplified by the power amplifier module and the power amplifier module supply voltage to achieve a constant power amplifier module gain.

Abstract: An electronic circuit includes a first signal line that extends along a first direction, a spark gap device that has a first conductive trace and a second conductive trace, the first conductive trace being connected to the first signal line. The first and second conductive traces are spaced apart to define a spark gap, the first and second conductive traces being aligned along the first direction to direct an electrostatic discharge along the first direction from the first signal line through the spark gap to a ground reference electrically coupled to the second conductive trace. A second signal line is connected to the first conductive trace or to the first signal line in a vicinity of the first conductive trace, the second signal line extending along a second direction at an angle relative to the first direction.