Charactterization of Mulit-Bit Differential Channels: A Modified Modal Scattering Parameter Approach

摘要

High speed inter-chip interconnects have reached and exceeded the multi-gigabit per second benchmark using differential signaling. Multi-bit differential signaling (MBDS) has been proposed as a solution to the 2n per n bit pin requirement of classical differential channels. MBDS does not currently have a modal characterization similar to the common and differential mode analysis developed for differential signaling that would allow a description of MBDS channel behavior. This thesis introduces a modal characterization of MBDS links via the development of modal scattering parameters that allow the analysis of the communications channel. Simulation results are presented in conjunction with data collected from a fabricated printed circuit board designed for MBDS links. Multiple printed circuit board layouts are be presented for analysis and design comparison. It is shown that the performance of MBDS links can be severely impacted by unoptimized PCB layout.