Predistorter
First Claim
1. A predistorter arrangement for linearising an amplifier, the predistorter arrangement comprising an input signal path for receiving an input signal which is required to be amplified, a distortion path in which the input signal from the input signal path is processed to generate a distortion signal comprising at least one distortion component which is a third order or higher order component of the input signal, a combiner for combining the distortion signal with the input signal in the input signal path to produce a predistorted input signal which is supplied to the amplifier input, and an error corrector in which the amplifier output signal is compared with the distortion signal from the distortation path to produce error correction signals for controlling the generation of at least one distortion component in the distortion path, wherein, for each distortion component for which an error correction signal is produced, the error corrector compares the distortion component individually with the amplifier output signal to produce the error correction signal for controlling the generation of that distortion component.
5 Assignments
0 Petitions
Accused Products
Abstract
A predistorter arrangement for linearising an amplifier. The predistorter arrangement is designed to compensate for IMD distortion in an amplifier using multiple order polynomial approximation techniques. The predistorter arrangement also includes feedback circuitry for controlling the operation of the predistorter.
-
Citations
15 Claims
- 1. A predistorter arrangement for linearising an amplifier, the predistorter arrangement comprising an input signal path for receiving an input signal which is required to be amplified, a distortion path in which the input signal from the input signal path is processed to generate a distortion signal comprising at least one distortion component which is a third order or higher order component of the input signal, a combiner for combining the distortion signal with the input signal in the input signal path to produce a predistorted input signal which is supplied to the amplifier input, and an error corrector in which the amplifier output signal is compared with the distortion signal from the distortation path to produce error correction signals for controlling the generation of at least one distortion component in the distortion path, wherein, for each distortion component for which an error correction signal is produced, the error corrector compares the distortion component individually with the amplifier output signal to produce the error correction signal for controlling the generation of that distortion component.
-
15. A method for linearising an amplifier, including a distortion step in which an input signal which is required to be amplified is processed to generate a distortion signal comprising at least one distortion component which is a third order or higher component of the input signal, a combining step in which the distortion signal is combined with the input signal to produce a predistorted input signal which is supplied to the amplifier input, and an error correction step in which the amplifier output signal is compared with the distortion signal to produce error correction signals which control the generation of at least one distortion component in the distortion step, wherein for each distortion component for which an error correction signal is produced, the error correction step comprises comparing the distortion component individually with the amplifier output signal to produce an error correction signal for controlling the generation of that distortion component.
Specification