Keysight's M8040A BER test system

Keysight introduced an AXIe modular 64 GBaud BERT for 400G testing

  • Keysight Technologies announced improvements to the modular BERT M8040A (BERT for Bit Error Ratio Tester) solution for testing applications using PAM-4 and NRZ encodings at speeds up to 64 GBaud.
  • This AXIe ( (AdvancedTCA Extensions for Instrumentation and Test ) test solution is intended for validation and R & D laboratories to characterize the physical layer receivers used for 400G transmissions.

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 test challenges, such as tighter timing margins, channel loss, non-linearity, level interference and crosstalk effects.

Overcoming channel loss in electrical interfaces, such as chip-to-chip, chip-to-module interfaces and backplanes, is a 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.

The M8040A is the latest member of the modular AXIe based M8000 series of BER test solutions and is a highly integrated BERT that supports PAM-4 signals up to 64 Gbaud and NRZ signals up to 64 Gbit/s.

The pattern generator module provides built-in de-emphasis, jitter injection and an optional second channel. It is possible to select PAM-4 and NRZ by software in the user interface, eliminating the need for external combiners, cabling and deskew to provide PAM-4 signals. For best signal quality, remote heads reduce the distance to the device under test. The analyzer module provides true PAM-4 error analysis in real-time for long PRBS and QPRBS patterns allowing proofing even low-bit error ratios and symbol error ratios with the required confidence.

The error analyzer now supports symbol rates up to 64 Gbaud for NRZ signals and built-in adjustable equalization. Users can control the M8040A from a graphical and remote-control interface.

The price of a M8040A BERT starts at $323,000 for a 32 GBaud PAM-4 BERT with one channel, including the M8070A software. The analyzer provides new options for built-in equalization and support of data rates up to 64Gb/s NRZ. Both options are upgradable and available now for ordering.