UWB Far-End Crosstalk Mitigation With “LL” Shaped Defected Tabbed Routing Structures

This article investigates a novel approach to mitigate far-end crosstalk (FEXT) in high density interconnects featuring distinctive “LL” shaped defected tabbed routing structures. The integration of “LL” shaped defected patterns and trapezoidal tabs are specifically engineered to concurrently increase capacitive coupling and decrease inductive coupling, mitigating FEXT to a greater extent. The proposed methodology is comprehensively analyzed utilizing the generated equivalent circuit model. Moreover, the capacitance and inductance matrices of coupled line, tabbed routing, and the proposed structures are extracted from full wave simulations and analyzed with numerical equations to ensure an accurate evaluation of FEXT. To validate the efficacy of the proposed designs, the structure prototypes are implemented with FR-4 printed circuit board. The <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i>-parameters performance and eye diagrams are measured and compared. The measurement results demonstrate that the proposed structure effectively enhances FEXT behavior while ensuring robust high-speed signal propagation along the transmission paths. Specifically, FEXT is reduced by 15 dB within the frequency range of 1–18 GHz, and the maximum reduction of 55 dB at 10.6 GHz. The proposed structure exhibits superior FEXT behavior improvement within a wide frequency range, indicating significant potential for practical wideband high-speed applications.