Over 25-GHz Bandwidth Testing Station Using a 0.3-mm-Pitch LGA Interface for a 50-Gbaud × 16-Channel CPO Transceiver

We report a design and characteristics of an electrical pluggable interface and a testing station for a 50- Gbaud x 16-channel CPO transceiver using a 0.3-mm-pitch LGA interface. This testing station has a 3-dB bandwidth of 27.1 GHz at the longest differential transmission line, which is sufficient for 50-Gbaud signal transmission. We also build an optical link employing a 53-Gbaud x 8-channel optical transceiver on the testing station to evaluate signal transmission characteristics. When operating the optical link by 53-Gbaud NRZ signals, a measured jitter margin at BER of 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">–12</sup>is as wide as 0.25 U.I. without any CDR and feed-forward equalizer.