Vias play a critical role in the high frequency electrical behavior of packages and printed circuit boards. Although measured data and electromagnetic solvers can be used to study via electrical properties, a clearer description of the underlying physics would make engineering judgment concerning vias more effective. This paper introduces a simple experiment and corresponding textbook solution for radial TEM waves which demonstrates the physics of vias. Extensions of this experiment show how the underlying physical model can be used to explain the behavior of differential vias, ground vias, and via antipads.

This paper presents a method for testing jitter tolerance of SerDes receivers using the timing misalignment between the jittered bit clock and the recovered clock. To estimate the jitter tolerance, the method first injects random jitter into the serial bit stream and measures the jitter transfer function of the CDR in the SerDes receiver. The paper derives an equation for estimating BER accurately using the jitter transfer function of SerDes CDRs. The method is much faster than the conventional BERTS method. The accuracy and test speed of the method are verified by 2.5 Gbps-SerDes experiments.