Study of Effects of Differential via on Signal Integrity

If characteristic impedance along a transmission line mismatch on a printed circuit board, high-speed signal has serious signal integrity problems. When signal path of a differential pair jumps layers, mismatched impedance between differential via and differential line will affect the signal integrity. The models of a coupled transmission line and via are presented in this paper. Impedance matching of the coupled transmission line and differential via for differential signals is studied. The effects of differential via dimensions on differential signals is simulated and analyzed.