Anritsu boosts signal level quality with all-in-one 400GbE measurements
Anritsu has released a 64Gbaud PAM4 pulse pattern generator (PPG) and 32Gbaud PAM4 error detector (ED), to deliver the PAM4 BERT, which supports 400GbE testing when these modules are installed in the Anritsu Signal Quality Analyzer-R MP1900A series for next-generation broadband communication systems.
Data traffic volumes are expected to increase due to the expansion of next-generation 5G mobile communications and cloud services. To manage this demand, infrastructure operators, e.g. data centres, are investigating the improvements to speed in PAM4 and multi-lane communications systems. Now 400GbE speeds are being deployed using either the 26.5625Gbaud PAM4 x eight lanes or 53.125Gbaud PAM4 x four lanes methods.
To meet this demand, Anritsu has developed the released 64Gbaud PAM4 PPG with what it claims is best-in-class signal level quality, and the 32Gbaud PAM4 ED with “excellent Rx sensitivity performance” to support evaluation of equipment and devices for high-speed, large-capacity transmissions.
When using the PAM4 method to encode data as four amplitude levels, the gap between signal levels is one-third compared to the NRZ method, which reduces the unit time per symbol at higher baud rates. This emphasises the importance of signal quality in achieving high-speed transmissions. The degraded signal quality caused by crosstalk and noise resulting from use of multiple lanes and high-density circuit design increases the need for evaluation of minimum Rx sensitivity using stress-test signals, points out Anritsu.
The Signal Quality Analyzer-R MP1900A is a BERT for the over 400G market and supports generation of high-speed signals as well as analysis of signal performance.
The PPG for PAM4 signals up to 64Gbaud and is believed to have the world’s best Tr/Tf (20 to 80 per cent) time of 8.5 pico seconds (typical) and intrinsic jitter of 170 farad seconds (typical). The multi-channel function can be expanded up to four channels, and the integrated emphasis function corrects signals degraded by transmission path loss. The 32Gbaud PAM4 ED module has a high sensitivity performance of 23mV (typical) and supports the installation of a clock recovery function required for Rx sensitivity evaluation, as well as PAM4 symbol error measurements.
The true performance of 400GbE optical modules and devices can now be tested within an adequate margin, satisfying the specifications, says Anritsu, to avoid difficulties in achieving an accurate evaluation due to inadequate signal quality. The multi-channel expandability helps cut measurement times using simultaneous measurement of multiple lanes, while the jitter and noise addition functions configure an all-in-one test for evaluating Rx sensitivity to improve development and testing efficiency.
