Feed-forward correction loop with adaptive predistortion injection for linearization of RF power amplifier
US5760646A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 23, 1996 |
| Grant date | Jun 2, 1998 |
| Priority date | — |
| Expiry date | Jul 23, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2201/3233
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A linearization scheme for an RF power amplifier combines an adaptive predistortion modulator with a feedforward error correction loop, which cancels noise imparted by predistortion modulation to the amplified signal, and minimizes distortion in the RF amplifier's output to a level that allows the use of a low cost auxiliary RF error amplifier in the feed-forward loop. The predistortion correction mechanism produces a predistortion signal based upon the input signal and is adaptively adjusted by an error signal extracted from the output of the a main RF power amplifier. The input signal is supplied to a work function generator unit and to a subtraction unit, which is also coupled to receive a fractional portion of the amplifier output signal and outputs the RF error component. The RF error component is coupled to a predistortion function generator, which is driven by the work function generator unit. The predistortion modulator uses the output of the predistortion function generator to predistort the input signal by a compensation characteristic equal and opposite to the distortion expected at the output of the main RF amplifier. When subjected to the transfer function of the RF am…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.