Power amplifying apparatus and radio communications apparatus using same
US6900693B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 6, 2003 |
| Grant date | May 31, 2005 |
| Priority date | — |
| Expiry date | Jul 15, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B2001/0441
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
By extracting a portion of RF signals from an input side of a multistage RF amplifier with a detector, and converting extracted signals into envelope signals, low-frequency second-harmonic distortion components are efficiently extracted. Then, the extracted low-frequency second-harmonic distortion components are amplified with a low-frequency amplifier, and phase adjusted with a phase shifter, after which they are injected into a gate or base bias of the final stage of the multistage RF amplifier. As a result, the low-frequency second-harmonic distortion components are converted into third-harmonic distortion due to the non-linearity of transistors, and the third-harmonic distortion thus obtained cancels out the third-harmonic distortion originally present in the multistage RF amplifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.