RF transmitter with compensation of differential path delay
US7970362B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 26, 2006 |
| Grant date | Jun 28, 2011 |
| Priority date | — |
| Expiry date | Jun 20, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/99
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A transmitter has a power amplifier (40) to amplify an input signal having amplitude modulation, a supply voltage controller (10) to control a supply voltage of the power amplifier (40) according to the envelope, a sensor (R1) for sensing a modulation of a current drawn by the power amplifier (40), a delay detector (20) for detecting a delay of the controlled supply voltage relative to the sensed current, and a delay adjuster (30) for compensating the relative delay according to the detected delay. By sensing a current drawn, the delay detected can include any delay contributed by the power amplifier (40) up to that point, and yet avoid the more complex circuitry needed to derive the delay from an output of the power amplifier. Thus the distortion and out of band emissions caused by differential delays can be reduced more effectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.