Amplifier and driver system with multichannel operation
US5990750A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 16, 1998 |
| Grant date | Nov 23, 1999 |
| Priority date | — |
| Expiry date | Mar 16, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F1/3241
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An RF amplifier includes a FET output stage and a driver. The FET is subject to long-term degradation in multiple-carrier use if its average gate current often exceeds a predetermined value. The random superposition of signal peaks of the multicarrier signal may cause such peaks to occur. The driver stage is selected to provide a range of four dB or less between the single-signal 1 dB compression point and the hard compression point, as measured by driver input signal level. This prevents application of excessive input signal to the output stage in a multicarrier situation, and prevents degradation of the FETs of the output stage. In one embodiment, a predistortion equalizer or linearizer is placed before the driver stage, to tend to linearize the characteristic of the driver and output stage combination at signal levels below those at which the driver is limited.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.