Enhanced passive equalizer using the open stub compensation technique

In this paper, we propose an open-stub compensation technique for passive equalizers used in high-speed digital communication systems. By simply lumping an open-stub to the conventional RL-type passive equalizer, the frequency-dependent channel loss from the long transmission path can be compensated, the frequency response of the channel becomes more flat and the bandwidth is wider. Compared proposed passive equalizer with typical RL passive equalizers, the simulation result shows this technique can improve 1 GHz in the flat region of S₂₁ on a 60 cm long differential pair. This technique is successfully demonstrated the improvement of electrical performance about 57.4% on time domain.