Analysis Of Via Resonance In Multi-Layer Printed Circuit Board

Via resonance effects which are caused by via stub and surrounding shorting vias are investigated in this paper by numerical simulation and theoretical calculation from a via-trace model on multilayer printed circuit boards. It is discovered that via stub can significantly worsen electric performance of the via transition and stub resonance can be eliminated by shortening via stub. For the case of a signal via surrounded by shorting vias, the vertical signal current flowing on the central signal via can excites resonant mode of circular waveguide resonator, which also generate via resonance.