Programmable gain amplifier (PGA) with AGC in receiver section
US6862438B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 3, 2002 |
| Grant date | Mar 1, 2005 |
| Priority date | — |
| Expiry date | Aug 13, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/406
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for dynamically controlling a programmable gain amplifier (PGA) to provide a plurality of gain steps thereby providing automatic gain control (AGC) in a receiver intermediate frequency (IF) stage comprising a succession of operational amplifiers wherein at least one is for providing fine gain control and wherein the gain of each fine gain amplifier is controlled by the resistance ratios of a plurality of selectively biased MOSFETs. In one embodiment of the invention, three coarse amplifiers are provided, each having a gain of either 0 dB or 12 dB based on the value of a two-state signal provided to each amplifier gain control input. A single fine gain amplifier has a gain of 0 dB, 3 dB, 6 dB or 9 dB based on the binary value of the two-bit signal provided to the amplifier. The combination of three coarse gain amplifiers and one fine gain amplifier provides for a total gain of 45 dB in 3 dB steps in the described embodiment of the invention. The output of the gain control circuitry also is fed into an inverter. The inverter output may be used as a received signal strength indicator for a desired signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.