| US 7,555,275 B2 | ||
| Systems, methods and devices for dual closed loop modulation controller for nonlinear RF amplifier | ||
| David R Lang, Phoenix, Ariz. (US) | ||
| Assigned to ViaSat, Inc., Carlsbad, Calif. (US) | ||
| Filed on Apr. 14, 2006, as Appl. No. 11/279,857. | ||
| Prior Publication US 2007/0243838 A1, Oct. 18, 2007 | ||
| Int. Cl. H04B 1/06 (2006.01) | ||
| U.S. Cl. 455—260 [455/127.2; 455/234.1; 455/340; 375/345] | 12 Claims |
| 1. An RF envelope amplitude control system, the system comprising:
an RF amplifier configured to receive an RF input signal and to output an RF output signal, wherein said RF amplifier is associated
with a feedback device that is configured to create a first feedback signal representing the power in said RF output signal;
a transmit waveform generator configured to generate a reference waveform signal;
an adaptive table waveform generator configured to compare said reference waveform signal and said first feedback signal and
to create a second feedback signal based on the distortion between said reference waveform signal and said first feedback
signal; and
a loop filter configured to combine said reference waveform signal, said first feedback signal, and said second feedback signal
to form an amplifier control signal, wherein said amplifier control signal is provided to said RF amplifier to adjust said
RF output signal to reduce nonlinearity in said RF output signal with reference to a specified RF envelope.
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