Configurable, variable gain LNA for multi-band RF receiver
US7486135B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 29, 2007 |
| Grant date | Feb 3, 2009 |
| Priority date | — |
| Expiry date | Sep 4, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/7209
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A configurable LNA architecture for a multi-band RF receiver front end comprises a bank of LNAs, each optimized to a different frequency band, wherein each LNA has a configurable topology. Each LNA comprises a plurality of amplifier stages, each stage including an RF transistor having a different width. The transistor widths in adjacent amplifier stages may be binary weighted, or may be sized to achieve a constant gain step. By selectively enabling and disabling RF transistors, the effective transistor width of the LNA can be controlled with a fine granularity. A DAC generates a bias voltage with a small quantization step, additionally providing a fine granularity of gain control. The LNAs are protected by overvoltage protection circuits which shield transistors from a supply voltage in excess of their breakdown voltage. A source degeneration inductor presents a real resistance at inputs of the LNAs, without introducing thermal noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.