Testing station using a 0.3-mm-pitch LGA interface for a 25-Gbaud x 16-channel CPO transceiver

We report the designs and characteristics of electrical pluggable interface using a 0.3-mm-pitch LGA for a 25-Gbaud x 16-channel CPO transceiver and a testing station using the electrical pluggable interface. The testing station has a TEC-integrated temperature control unit attached to the bottom of test board. Differential transmission lines for the test board were designed with the aid of electromagnetic simulations. By adopting an electrical loopback module, the differential transmission lines and the electrical pluggable interface were evaluated. As a result, the testing station has sufficient characteristics for 25-Gbaud NRZ and PAM4 link tests. We also report the integrated electrical pluggable interface to accommodate 8 transceivers, to be oriented for a small CPO daughter board of 100 mm X 100 mm.