Feedforward amplifier network with swept pilot tone for reducing distortion generated by a power amplifier
US5923214A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 17, 1997 |
| Grant date | Jul 13, 1999 |
| Priority date | — |
| Expiry date | Dec 17, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F1/3235
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A feedforward amplifier network (42) generates a fixed offset frequency swept pilot tone (46) over at least the same frequency band as an input signal (40). The fixed offset frequency swept pilot tone (46) is a function of a variable frequency reference signal (52) and a fixed pilot tone clock signal (54). A mixer arrangement (66 and 70), as opposed to a phase lock loop arrangement, helps ensure that the fixed frequency offset can be generated over the swept range. In addition, the feedforward amplifier network (42) incorporates a delay (58) which is added to the variable frequency reference signal (52) and used by a pilot tone detector (57) so that the pilot tone generator (44) and pilot tone detector (57) are in synchronization over narrow bands to accommodate pilot tone detection in the presence of code division multiple access channels that are relatively close together.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.