Differential intermediate frequency (IF) amplifier with narrow band noise dithering for driving high speed analog-to-digital conversion and communication applications
US6515542B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 2001 |
| Grant date | Feb 4, 2003 |
| Priority date | — |
| Expiry date | May 16, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/45475
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An amplifier circuit includes a first operational amplifier having an inverting input and a non-inverting input. The non-inverting input receives an input signal, and the inverting input is connected to a noise generating system. The amplifier circuit further includes a second operational amplifier having an inverting input and a non-inverting input. The non-inverting input of the second operational amplifier receives an input signal, and the inverting input is connected to a noise generating system. A differential in/out operational amplifier, in the amplifier circuit, has an inverting input connected to an output of the second operational amplifier and a non-inverting input connected to an output of the first operational amplifier. The noise generating system injects a narrow band noise into a differential amplifier with no insertion loss and mismatching along the signal path. The narrow band noise is obtained by amplifying thermal noise of an amplifier. The amplified thermal noise is bandwidth limited. The bandwidth limited amplified thermal noise is filtered by a low pass a filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.