Optimization of the stub-alternated and serpentine microstrip structures to minimize far-end crosstalk

Crosstalk is a signal integrity effect that negatively impacts high-speed digital designs, especially those with dense routing. Several techniques have been proposed to reduce crosstalk. One of them consists of using innovative microstrip structures, such as the stub-alternated and the serpentine structures, which are intended to reduce far-end crosstalk. However, these structures also present a negative effect on return loss and near-end crosstalk. In this paper, these two structures are optimized for far-end crosstalk reduction while minimizing their negative impact on reflections and near-end crosstalk. A genetic algorithm complemented with the Nelder-Mead method is employed for direct optimization, using highly accurate EM simulations in Sonnet driven from Python.