Fiber-optic node with forward data content driven power consumption

Abstract

Methods and systems for modulating an amplifier power supply to efficiently attain amplified RF output power with much lower power dissipation than existing amplifiers.

1 . A device having a processor for generating a signal output from a digital to analog converter (DAC), the digital signal having a first component to be amplified by an amplifier, and a second component for modulating a bias point of the amplifier, where the second component is based on the first component. 
     
     
         2 . The device of  claim 1  including a third component of the digital signal capable of use to pre-distort the first component prior to digital to analog conversion and amplification. 
     
     
         3 . The device of  claim 2  where the third component is based on the first component and a signal envelope of the first component. 
     
     
         4 . The device of  claim 1  where the first component and the second component have an associated delay between them. 
     
     
         5 . The device of  claim 1  where pre-distortion information is transmitted to the amplifier with said digital signal, the pre-distortion information based on said signal and an envelope of said signal. 
     
     
         6 . A method for modulating a bias point of the amplifier, the method comprising:
 receiving a first signal and a second signal   amplifying said first signal by an amplifier such that the amplified signal modulates the bias of the amplifier to reduce the power usage of the amplifier.   
     
     
         7 . The method of  claim 6  where the first signal includes a first component to be amplified by the amplifier and a second component for modulating a bias point of the amplifier, where the second component is based on the first component. 
     
     
         8 . The method of  claim 7  where the first signal includes a third component of the signal for pre-distorting the first component prior to amplification. 
     
     
         9 . The method of  claim 8  where the third signal is based on a signal envelope of the first signal. 
     
     
         10 . The method of  claim 6  where the first component and the second component have an associated delay between them. 
     
     
         11 . The method of  claim 6 , further comprising transmitting pre-distortion information to the amplifier with said signal, the pre-distortion information based on said signal and an envelope of said signal. 
     
     
         12 . A system within a CATV network for reducing a power usage of an amplifier, said system comprising:
 (a) a processor that receives data to be converted to a first signal;   (b) the amplifier that amplifies said first signal; and   (c) a signal analyzer for analyzing the signal to determine a second signal for modulating a bias point of the amplifier.   
     
     
         13 . The system of  claim 12  where the amplifier includes a power supply modulated by said second signal. 
     
     
         14 . The system of  claim 12  where said processor adds pre-distortion information to said first signal for said amplifier along with said first signal. 
     
     
         15 . The system of  claim 14  where the pre-distortion information is based on said signal and an envelope of said signal. 
     
     
         16 . The system of  claim 12  including a transmitter that transmits an amplified said first signal to a second amplifier along with said second signal 
     
     
         17 . The system of  claim 16  where the second signal is added to the output of said amplifier. 
     
     
         18 . The system of  claim 12  where said amplifier includes a plurality of transistors, each driven by a respective D/A converter that respectively converts a pre-distorted component of said first signal. 
     
     
         19 . The system of  claim 12  where said first signal is provided to said amplifier at a delay relative to said second signal. 
     
     
         20 . The system of  claim 12  further comprising:
 a power supply providing bias to the amplifier with an inductor connected to a fixed voltage, 
 a capacitor connected to the amplifier power supply to generate a variable voltage, wherein the variable voltage is controlled by a signal derived from the envelope of a signal output from the amplifier. 
 
     
     
         21 . A system within a CATV network, said system comprising:
 (a) a processor that generates a first signal and a second signal each including a first component to be amplified, said first signal including a first predistortion component and said second signal including a second predistortion component; and   (b) an amplifier comprising a first transistor and a second transistor that each simultaneously amplifies a respective one of the first signal and the second signal such that the first predistortion component and the second predistortion component jointly modulates the bias of the amplifier.   
     
     
         22 . The system of  claim 21  where the first predistortion component and the second predistortion component that jointly modulate the bias of the amplifier cancel each other at the output of the amplifier. 
     
     
         23 . The system of  claim 21  where the predistortion components carry a component that reduces amplifier distortion without cancellation of each other at the output of the amplifier.