Eye expander for PAM4 signal linearization
US12334932B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 28, 2022 |
| Grant date | Jun 17, 2025 |
| Priority date | — |
| Expiry date | Jan 28, 2042 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/4917
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An eye expander that increases the transmitter linearity of Pulse-Amplitude Modulation 4-Level (PAM4) signals having an inner eye and two outer eyes. In embodiments, the eye expander includes a semi-linear gain stage that increases the eye height of the outer eyes. In some of those embodiments, the semi-linear gain stage includes a semi-linear gain input transistor having a base or gate coupled to an input terminal and a collector or drain coupled to an output terminal, a semi-linear gain resistor coupled to the emitter or source of the semi-linear gain input transistor, and semi-linear gain transistor-resistor pairs that selectively connect the emitter or source of the semi-linear gain input transistor to ground. In some embodiments, the eye expander includes a limiting gain stage that reduces the eye height of the inner eye and a linear gain stage that increases the eye height of the inner and outer eyes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.