Linearization bias circuit for BJT amplifiers
US6426677B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 14, 2001 |
| Grant date | Jul 30, 2002 |
| Priority date | — |
| Expiry date | Sep 14, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/456
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A linearization bias circuit for an RF BJT amplifier including a reference circuit, a current device and a transconductance amplifier. The linearization bias circuit controls the operating point of the BJT amplifier based on signal level of an input RF signal. The current device provides a constant reference current to the reference circuit, where the constant reference current has a level that is based on a desired collector current of the BJT amplifier. The reference circuit applies a predetermined relationship between DC and AC scale factors of collector current of the BJT amplifier. The transconductance amplifier asserts its output to maintain the constant reference current into the reference terminal of the reference circuit, and in doing so controls the base terminal of the BJT amplifier to modify its operating point to substantially maintain constant transconductance in the presence of varying input voltage amplitudes of the input RF signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.