Signal integrity analysis of a super speed pair of a USB 3.0 connector with test Jig

In this paper, we compare and analyze the signal integrity of a USB 3.0 connector depending on its pin assignment. Four pins of the connector are grouped and assigned as a differential signal pair at the center and the others as a reference. The reference can either be power and ground. Therefore, a test jig should be designed with consideration how to properly connect a power pin to the measurement reference of the test jig to evaluate the electrical performance of the connector without affecting high frequency performance of the connector. For three cases of different power pin to test jig connection, we analyze and compare their S-parameter and Z-parameter based on 3D electromagnetic simulation up to 10 GHz; for the first case, the power pin and ground pin are tied to the reference plane of the test jig by a decoupling capacitor. For the second case, the power pin is directly tied to the reference plane, and for the last case, the power pin is floated untied to the reference plane. The second case shows the most similar electrical performance to the first case.