Digitally controlled bias circuit for amplifiers
US6496073B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 26, 2001 |
| Grant date | Dec 17, 2002 |
| Priority date | — |
| Expiry date | Mar 26, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F1/306
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Power gain and quiescent current of a radio frequency (RF) transistor is controlled by a current draw-away circuit that diverts (“draws away”) a portion of the reference current from a reference transistor residing in an RF transistor bias circuit. When in the “off” state, the current draw-away circuit is not conductive. When in the “on” state, a transistor residing in the current draw-away circuit is conducting and draws a draw-away current, IDRAW, through a resistor. The magnitude of IDRAW is determined by the resistor. Other embodiments include a variable resistance that varies IDRAW, a variable current source (or variable voltage source) that varies IDRAW by adjusting the current (or voltage) applied to the control input of the transistor residing in the current draw-away circuit, and two or more current draw-away circuits individually controlled such that one or any combination of the current draw-away circuits varies IDRAW.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.