Using via fences for crosstalk reduction in PCB circuits

Crosstalk is one of the major signal integrity con- cerns at high-speed and high-frequency electronic circuits. Via fences or in another term guard traces are increasingly used to alleviate this problem as dense interconnect layouts emerge. In this paper, first the effect of loading of a via fence on signal transmission in a microstrip line is investigated through para- metric studies. Subsequently, a via fence structure is designed and optimized to reduce coupling between two adjacent traces. Additionally, experimental results, while compared with fullwave simulations, are presented to demonstrate crosstalk reduction. Index Terms— Via fence, guard trace, crosstalk, coupled PCB microstrip, signal integrity.