Reflection Enhanced Compensation of Lossy Traces for Best Eye-Diagram Improvement Using High-Impedance Mismatch

As the signal rates increase toward the multigigabit range, the lossy effect of typical transmission lines on the signal quality of printed circuit boards has become a more and more significant issue. This paper introduces the concept of reflection gain resulted from the high-impedance mismatch to improve the eye diagram at the receiving end by inserting the inductance or high-impedance line between the signal trace and matched termination. A systematic design methodology is also proposed here to tell how to resolve the optimal high-impedance elements for the finest compensation efficiency. Moreover, with the optimal inductance, a design formula based on the circuit theory is derived accordingly to estimate the approximate length of high-impedance line and after that, the ultimate performance of this compensation method is also evaluated. Eventually, some experiments are implemented to validate the design technique.