Method and apparatus for reducing distortion in an output signal of an amplifier
US5491454A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 31, 1994 |
| Grant date | Feb 13, 1996 |
| Priority date | — |
| Expiry date | Oct 31, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2201/3212
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A feed forward amplifier network (100) employs a method (300) and apparatus for reducing distortion contained in an output signal (142) of an amplifier circuit (101). A modulator (118, 120) modulates (303) an input signal (141) of the amplifier circuit (101) with a reference modulation. The amplifier circuit (101) amplifies (305) the modulated signal, introducing nonlinear distortion in the process. A modulation determination circuit (107, 109, 115) determines (307) the reference modulation in the amplified signal and provides the determined modulation to an adjustment circuit (105). The adjustment circuit (131,133, 135) adjusts (309) a characteristic of the determined modulation in response to a control signal (153,155) and combines (137, 311) the adjusted modulation with the amplified signal (142) at the output of the amplifier circuit (101) to produce a corrected signal (151). A residual modulation detection circuit (139, 125, 127, 129) demodulates (313) the corrected signal (151) to recover any residual modulation remaining in the corrected signal (151) and adjusts (317) the control signal (153, 155) to reduce the recovered residual modulation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.