Feedforward predistortion linearizer
US4987378A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 28, 1989 |
| Grant date | Jan 22, 1991 |
| Priority date | — |
| Expiry date | Nov 28, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/198
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A feedforward predistortion equalizer includes a first loop with a signal divider for dividing signals into first and second portions, and a distortion generator for distorting the second signal. The first loop is completed by a signal combiner which combines the undistorted first signal and the distorted second signal. The phase and amplitude of the signals in the loop are controlled so that the linear or carrier signal component is cancelled, leaving at the output of the first combiner only the distortion component of the distorted signal. A second loop includes phase and amplitude controls for combining the pure distortion and undistorted signals to produce the desired predistorted signals. In a particular embodiment, the phase and amplitude controls of the first loop are automatically adjusted for a null.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.