Apparatus and method for reducing nonlinear distortion in an automatic gain control system
US6718165B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 27, 2000 |
| Grant date | Apr 6, 2004 |
| Priority date | — |
| Expiry date | Mar 2, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/0475
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A mobile communication system having an AGC (Automatic Gain Control) function includes an apparatus for adaptively controlling an output level of a local oscillator to reduce nonlinear distortion which may occur when a high-power RF signal is received or when it is necessary to transmit a high-power transmission signal. When a high-power RF signal is applied to a first stage in a receiving stage, the apparatus prevents the signal input to a reception AGC loop from being distorted by decreasing an output level of the local oscillator, which is provided to a down-converter. Further, when the output signal of a transmission stage has a high power level, the apparatus decreases the output level of a transmission AGC amplifier and instead increases the output level of the local oscillator, which is input to an up-converter located in an IF stage, so that it is possible to obtain a nonlinear distortion-reduced signal while obtaining the same output level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.