Controlling a power amplifier based on transmitter output emissions
AssigneeBroadcom Corporation
InventorsYing Xia, Sriraman Dakshinamurthy, Robert Lorenz
Life of this patent
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Abstract
Methods and systems for controlling the supply voltage provided to a power amplifier (PA) in a radio frequency (RF) transmitter based on measured output spectrum emissions are provided. In an embodiment, the PA supply voltage is adjusted such that spectrum emission limits are satisfied with predetermined margins. In another embodiment, the predetermined margins are reduced to lower power consumption of the PA.
Claims19
A method for controlling a power amplifier (PA) in a radio frequency (RF) transmitter, comprising:
- performing spectrum emission measurements at an output of the RF transmitter;
- comparing at least two of the spectrum emission measurements to each other;
- and
- controlling the PA based at least in part on the comparison of the at least two of the spectrum emission measurements, wherein controlling the PA comprises adjusting a timing between a supply voltage of the PA and an input signal of the PA.
A. radio frequency (RF) transmitter, comprising:
- a digital module configured to generate baseband in-phase (I) and quadrature-phase (Q) signals of a desired output waveform;
- a filtering and up-conversion module configured to generate a RF signal from the baseband I and Q signals;
- a power amplifier (PA) configured to power amplify the RF signal to generate an output signal of the RF transmitter;
- and
- a feedback path comprising:
- a RF receiver configured to receive the output signal of the Rh transmitter and to generate feedback I and Q signals;
- and
- a spectrum measurement module configured to generate spectrum emission measurements of the output signal based at least in part on the feedback I and Q signals,
- wherein the digital module is further configured to compare at least two of the spectrum emission measurements to each other and to control a timing between a supply voltage of the PA and the Rh signal based at least in part on the comparison of the at least two of the spectrum emission measurements.
A method for controlling a power amplifier (PA) in a radio frequency (RF) transmitter, comprising:
- performing a first spectrum emission measurement and a second spectrum emission measurement based on an output of the PA;
- comparing the first spectrum emission measurement and the second spectrum emission measurement;
- and
- adjusting a timing difference between an application time of a supply voltage to the PA and an application time of an input signal to the PA based at least in part on the comparison of the first and second spectrum emission measurements.
Dependencies are inferred from the claim text.