Automatic gain control circuit for controlling multiple variable gain amplifier stages while estimating received signal power
US6107878A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 6, 1998 |
| Grant date | Aug 22, 2000 |
| Priority date | — |
| Expiry date | Aug 6, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/109
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The present invention is a novel and improved AGC circuit which is generically configurable to accommodate a variety of AGC amplifier configurations to enhance IP3 performance and reduce required amplifier current, while providing a received power estimate which remains valid regardless of how the gain or attenuation is distributed among the various amplifiers. A generic control circuit maintains this power estimate in a single overall gain amplification value by distributing gain to at least two amplifier stages in response to that value. By programming or hard coding a few key parameters, a generic control circuit can control a wide variety of amplifier configurations. Among the configurations supported are switched LNA, switched variable gain LNA, variable gain, and a decoupled IF and UHF variable gain LNA configuration. The invention is extendable to include multi-stage amplifier configurations. Although the preferred embodiment includes two stages, one for UHF and one for IF, three or more stages can easily be adapted. Various filtering schemes can be applied to the power estimate to tailor the temporal dynamics of gain switching. For example, a low pass filter can be applied …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.