Feed forward amplifier
US5477187A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 22, 1994 |
| Grant date | Dec 19, 1995 |
| Priority date | — |
| Expiry date | Apr 22, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2201/3212
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In a feed forward amplifier, an RF amplifier is supplied with an input RF signal at an input terminal for amplifying the same; a distortion extraction loop supplied with the input RF signal and further with the output RF signal from the RF amplifier is for extracting non-linear distortion components formed in the output RF signal as a result of amplification in the RF amplifier; a variable phase shifter is provided in the distortion extraction loop for varying a phase of the input RF signal; a variable attenuator is provided in the distortion extraction loop for attenuating an amplitude of the input RF signal that has been supplied to the distortion extraction loop; and a distortion extraction circuit is provided in the distortion extraction loop for producing a distortion output signal that includes non-linear components; further, a control circuit is supplied with the input signal and with the distortion output signal for extracting a main signal component contained in the distortion output signal. The control circuit controls the variable phase shifter and the variable attenuator such that a ratio of the main signal component level with respect to the input RF signal level is de…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.