Signal Integrity Analysis of High-speed PCIe Channel with Board-to-Board Interconnect for High-Performance Server

In this paper, we analyzed high-speed peripheral component interconnect express (PCIe) channel with board-to-board (B2B) interconnect considering signal integrity for high-performance server. The physical length of the PCIe channel with different B2B interconnects, corresponding to cable type and connector type, is designed. Each component of the PCIe channel including the interposer, package, PCB, cable, and connector is modeled by a 3D electromagnetic (3D-EM) solver and commercial reference. The electrical characteristics of cable-type and connector-type PCIe channels are analyzed in the frequency and time domains. As a result, the cable-type PCIe channel shows higher eye height and width than the connector-type at 32 Gbps due to the small loss despite the high impedance discontinuity and the stub effect of the connector.