Industry's most-integrated bit error ratio tester (BERT) for PAM-4 and NRZ features new adjustable equalizer

Keysight Technologies, Inc. (NYSE:KEYS) has announced innovative enhancements for the M8040A high-performance bit error ratio tester (BERT) solution for testing PAM-4 and NRZ devices that operate up to 64 GBaud, the company said.

Engineers in validation labs and R&D who characterize receivers on the physical layer for emerging 400G data center interconnects will benefit from simplified test setups and repeatable and accurate results.

Today´s data center infrastructure is continuously optimized to address bandwidth capacity growth, power, reach and service differentiation. Higher transmission rates, more transmission lanes, and new multi-level data formats, such as PAM-4, address the increased transmission bandwidth demand for the next-generation data center interconnects.

The latest revisions of IEEE 802.3bs and OIF CEI-56G implementation agreements define PAM-4 and NRZ interfaces for electrical chip-to-chip, chip-to-module, backplane connections and optical interfaces for up to 400 Gb/s bandwidth. R&D and validation labs that need to characterize receivers for data center interconnects with PAM-4 or NRZ data rates up to 64 GBaud are facing new test challenges, such as tighter timing margins, channel loss, non-linearity, level interference and crosstalk effects–making test efficiency and accuracy essential.

Overcoming channel loss in electrical interfaces, such as chip-to-chip, chip-to-module interfaces and backplanes, is a big challenge with higher symbol rates. Pre-distortion techniques, such as de-emphasis, are used in the transmitter and equalization in the receiver to help re-open closed eyes caused by inter-symbol interference.

Keysight Technologies is a technology company that helps its engineering, enterprise and service provider customers optimize networks and bring electronic products to market faster and at a lower cost. Keysight´s solutions go where the electronic signal goes, from design simulation, to prototype validation, to manufacturing test, to optimization in networks and cloud environments.