High efficiency power amplifier circuit with wide dynamic backoff range
US6157253A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 3, 1999 |
| Grant date | Dec 5, 2000 |
| Priority date | — |
| Expiry date | Sep 3, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/21142
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A radio frequency signal (FIG. 2, 205) is sampled and the sample is conveyed to a video detector (220). The detected envelope amplitude is sent to an envelope tracking circuit (280), a comparator (230), and an envelope tracking and gate biasing circuit (240). Based on the instantaneous value of the envelope amplitude, the comparator (230) selects one of the available supply voltages (340) via switch drivers (270). The selected one of the available supply voltages (340) is adjusted by the envelope tracking circuit (280) and the resulting voltage output (282) is supplied to the drains of the power amplifiers (390), thus enabling operation near saturation. As the instantaneous value of the envelope amplitude increases, the comparator (230) selects higher supply voltages (340) which increases the voltage conveyed to the power amplifiers (390), thereby increasing their power output. In order to maintain constant gain performance, the envelope tracking and gate biasing circuit (240) modifies the gate bias inversely with the changes the drain voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.