Method and system for linearizing an amplifier using transistor-level dynamic feedback

Abstract

The present disclosure describes a method and system for linearizing an amplifier using transistor-level dynamic feedback. The method and system enables nonlinear amplifiers to exhibit linear performance using one or more of gain control elements and phase shifters in the feedback path. The disclosed method and system may also allow an amplifier to act as a pre-distorter or a frequency/gain programmable amplifier.

What is claimed is: 
     
         1 . A method for performing amplification of an input signal using dynamic feedback comprising:
 receiving an input signal, wherein the input signal is applied to an input of an amplifier;   receiving an output signal, wherein the output signal is obtained from an output of an amplifier;   applying one or more control voltages to one or more gain control elements for adjusting the magnitude of a feedback signal,   wherein the one or more gain control elements are contained in one or more feedback paths coupled to an output and an input of the amplifier for conveying the feedback signal from an output signal of the amplifier to the input of the amplifier;   limiting the feedback signal to have a maximum operating frequency whose wavelength is equal to or less than the one or more feedback paths' physical length; and   using values for the one or more control voltages for implementing a programmable variable gain amplifier.   
     
     
         2 . A method for performing amplification of an input signal using dynamic feedback comprising:
 receiving an input signal, wherein the input signal is applied to an input of an amplifier;   receiving an output signal, wherein the output signal is obtained from an output of an amplifier;   applying a first set of one or more control voltages to one or more gain control elements for adjusting the magnitude of a feedback signal,   wherein the one or more gain control elements are contained in one or more feedback paths coupled to an output and an input of the amplifier for conveying the feedback signal from an output signal of the amplifier to the input of the amplifier;   limiting the feedback signal to have a maximum operating frequency whose wavelength is equal to or less than the one or more feedback paths' physical length; and   applying a second set of one or more control voltages to one or more phase shifters for adjusting the phase of a feedback signal, wherein the one or more phase shifters are contained in one or more feedback paths,   wherein applying the second set of one or more control voltages to one or more phase shifters allows for adjusting the phase of a feedback signal for applying predistortion to the input signal.   
     
     
         3 . A method for performing amplification of an input signal using dynamic feedback comprising:
 receiving an input signal, wherein the input signal is applied to an input of an amplifier;   receiving an output signal, wherein the output signal is obtained from an output of an amplifier;   applying a first set of one or more control voltages to one or more gain control elements for adjusting the magnitude of a feedback signal,   wherein the one or more gain control elements are contained in one or more feedback paths coupled to an output and an input of the amplifier for conveying the feedback signal from an output signal of the amplifier to the input of the amplifier;   limiting the feedback signal to have a maximum operating frequency whose wavelength is equal to or less than the one or more feedback paths' physical length; and   applying a second set of one or more control voltages to one or more phase shifters for adjusting the phase of a feedback signal, wherein the one or more phase shifters are contained in one or more feedback paths,   wherein applying the second set of one or more control voltages to one or more phase shifters allows for adjusting the phase of a feedback signal for implementing an amplifier with a specific gain at a particular frequency.