Method and apparatus for linear amplification of a radio frequency signal
US6449465B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 1999 |
| Grant date | Sep 10, 2002 |
| Priority date | — |
| Expiry date | Dec 20, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/102
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method and apparatus is provided that amplitude modulates a modulated radio frequency (RF) signal (411) by modulating the supply voltage of a power amplifier (410). The method and apparatus further provides an impedance modulator (412) that reduces output signal (415) errors in response to an error signal generated by a feedback circuit (416) that includes a quadrature modulator (506), a limiter (520), a comparator (502), and a quadrature downconverter (510). Intermodulation distortion generated in the feedback circuit (416) by delay mismatches between amplitude and phase feedback paths, and non-linear effects of AM/PM conversion in a limiter (520), are suppressed by placing limiter (520) and quadrature downconverter (510) in a forward path of the overall amplifier loop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.