초록 ▼

A linear power amplifier includes a driver stage, employing an active feedforward-type predistorter, connected in cascade with a final power stage. The active feedforward-type predistorter has an amplifier with a predistorter connecting between its input and output. This driver stage has opposite ga

A linear power amplifier includes a driver stage, employing an active feedforward-type predistorter, connected in cascade with a final power stage. The active feedforward-type predistorter has an amplifier with a predistorter connecting between its input and output. This driver stage has opposite gain and phase characteristics to that of the final power stage and is used to predistort an input signal. When combined with the final power stage, the nonlinear gain and phase of the power stage are compensated and linearized by the driver stage, resulting in a linear power amplifier with low distortion amplification and high efficiency operation.

대표청구항 ▼

1. A linearized amplifier comprising:an RF input node; an RF output node; a power amplifier having an input and an output, and having a gain characteristic which decreases with the increase in input power applied to said input of said power amplifier, and having a phase characteristic which increase

1. A linearized amplifier comprising:an RF input node; an RF output node; a power amplifier having an input and an output, and having a gain characteristic which decreases with the increase in input power applied to said input of said power amplifier, and having a phase characteristic which increases with input power applied to said input of said power amplifier; and an active feedforward-type predistorter having an input and an output, acting as a driver amplifier which amplifies a signal applied to said RF input node, having a gain characteristic which increases with input power applied to said input of said active feedforward-type predistorter for compensating the decrease in gain of said power amplifier, and having a phase characteristic which decreases with the increase in input power applied to said input of said active feedforward-type predistorter for compensating the increase in phase of said power amplifier; wherein said output of said power amplifier is coupled to said RF output node, said input of said active feedforward-type predistorter is coupled to said RF input node, and said output of said active feedforward-type predistorter is coupled to said input of said power amplifier.