Radio transmitter with power amplifier linearizer
US5722056A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 19, 1995 |
| Grant date | Feb 24, 1998 |
| Priority date | — |
| Expiry date | Jul 19, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/57
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
This invention relates to a radio transmitter having a power amplifier and a linearizer arrangement, for example Cartesian feedback, for compensating for non-linearity in the power amplifier. A training signal is applied to the amplifier (36) and the linearizer arrangement is adjusted during a training mode of operation. In one embodiment, a look-up table (23) is provided for storing predetermined operating condition adjustment parameters. According to an operating condition input (e.g. frequency, temperature) control means (21) select operating condition adjustment parameters during the training mode and adjust the training signal to compensate for loop gain variations during the training mode. Automatic gain control (26) may be provided in the amplifier loop for activation during at least a portion of the training mode of operation to maintain constant closed loop gain.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.