Many things change in the transition from good old baseband, logic-emulating non-return-to-zero (NRZ) signaling to 4-level pulse-amplitude modulation (PAM4): We get three eye diagrams instead of one, ...

Fig.1: NRZ signal (top) and eye diagram (bottom). Pulse amplitude modulation builds upon this concept by encoding data across multiple voltage levels. PAM4 uses four levels. A PAM4 signal can appear ...

Optical modulation amplitude (OMA) indicates the strength of the modulation power. For legacy NRZ systems, eye-mask tests place polygons below, within, and above the NRZ eye diagram and verify ...

Modulation analysis on both optical andelectrical signals is also moving out of the lab and into production,where components need verification. The N4392A can let you viewconstellation diagrams and ...