SWITCHABLE MULTI-OUTPUT LOW-NOISE AMPLIFIER WITH DISTORTION CANCELLATION

摘要

A low-noise amplifier is provided that includes an input amplifier stage coupled to a plurality of independently switchable output amplifier stages. The input amplifier stage is operative to amplify an input communications signal, and it provides both an amplified communications signal and a feedforward signal. The amplified communications signal and the feedforward signal both include a distortion component. Each of the switchable output stages is operative to provide an output that combines the feedforward signal with the amplified communications signal in such as way that the distortion components of the signals at least partially cancel one another. In some embodiments, the switching of the output amplifier stages is performed by circuitry that also serves to improve reverse isolation of the separate output amplifier stages.

主权项

1. An amplifier comprising:
an input amplifier stage operative to amplify an input communication signal and to provide an amplified communication signal and an input feedforward signal, wherein the input amplifier stage generates a first distortion component in the amplified communication signal and a second distortion component in the input feedforward signal; and a plurality of switchable output amplifier stages, wherein each of the switchable output stages is operative to amplify the input feedforward signal to create an amplified feedforward signal and to combine the amplified feedforward signal with the amplified communication signal so as to at least partially cancel the first and second distortion components on an output conductor.