Mitigating Crosstalk in High-Speed Digital Interconnect Systems Using High-impedance Surface with Embedded Metal Protrusions

In server systems, the moat or slot is added in the system’s reference plane to suppress Delta-I noise and ground bounce noise. Furthermore, moats in servers aid in distinguishing voltage power and ground planes. However, when a single-ended signal line crosses a slot or moat, parasitic modes, also known as parallel-plate modes (pp-mode), arise due to the discontinuity in the return path in the stripline. This mode results in crosstalk interference at both the near and far ends. Therefore, the proposed solution in this paper is to use a high-impedance surface to suppress the propagation of the parallelplate mode, thereby reducing crosstalk interference. The high-impedance surface operates in the frequency domain at 12.4-14.6 GHz, and this structure achieves a 32% reduction in peak-to-peak crosstalk interference in the time domain.