Measuring jitter of high-speed data channels
US6661836B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 17, 1999 |
| Grant date | Dec 9, 2003 |
| Priority date | — |
| Expiry date | Oct 17, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L1/24
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A jitter measurement technique utilizing a high-bandwidth undersampling voltage measurement instrument is presented. A trigger is derived from the a signal having a repetitive signal pattern. The signal is compared with a threshold at a plurality of times relative to the trigger during multiple repetitions of the signal pattern to produce measurement samples indicative of signal level relative to the threshold. The measurement samples are used to determine the probability of signal edge states as a function of time for the multiple repetitions. The probability of signal edge states are used to determine an edge probability density as a function of time. A histogram of signal state transition times can be prepared from the edge probability density. Mean deviation of edge transitions of the signal can be estimates, and standard deviation of edge transitions of the signal can be estimated to give the root-mean-square (rms) jitter of the signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.