A new era of data center infrastructure enabling cloud computing, big data and analytics is driving the development of new high-speed data transfer standards such as 100-Gb Ethernet and 32-Gb Fibre Channel. The higher speeds create new testing challenges for optical and electrical component designers. More stringent requirements for component characterization necessitate faster rise/fall times. Optical transceivers and transmitter optical subassemblies (TOSAs) require high drive voltages that standard pattern-generator outputs cannot supply.
To address the issue, Agilent has created remotely mountable pattern-generator heads for use with its N4960A BERTs (bit error ratio testers). The new pattern-generator heads (N4951B Option H32 and Option H17) feature improved rise and fall times of 12 ps to give ASIC designers the headroom necessary for signal fidelity at the test pin.
In addition, these options integrate higher voltage output drivers into the pattern generator. This feature allows designers of optical transceivers to directly drive VCSELs, TOSAs and laser modulators for higher-data-rate applications such as 100-Gb Ethernet and OIF-CEI-28G, without the need for external driver amplifiers, associated interconnecting cables and power supplies.
As part of the N4960A BERT family, the pattern generators are configured as remote heads connected to the BERT controller with a cable. This configuration allows the pattern generator to be located close to the device under test, minimizing the length of the signal cable, which helps minimize signal degradation.