Predistortion circuit for a power amplifier
US4465980A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1982 |
| Grant date | Aug 14, 1984 |
| Priority date | — |
| Expiry date | Sep 23, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F1/3241
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A predistortion circuit for a radio frequency power amplifier which has gain and phase shift characteristics that are non-linear as a function of power level of an RF input signal. The circuit includes a dual gate FET, with a drain coupled to the power amplifier. A modulated RF input signal is applied to an inductive matching network which is coupled to the signal gate of the FET. A modulating envelope detected version of the input signal is applied to a video amplifier which is coupled to the FET control gate. The signal applied to the control gate varies the gain of the FET as a function of input signal to compensate for the non-linear gain characteristic of the power amplifier and in conjunction with the matching network causes a phase change of the signal through the predistortion circuit to compensate for the non-linear phase characteristic of the power amplifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.