At high signal frequencies (i.e. in the GHz range), a connector must be considered as part of an electromagnetic transmission line. At these frequencies, the impedance characteristics of the connector stemming from the distributed inductance and capacitance of pins and the associated wiring, must be carefully controlled; insertion losses must be minimized and undesirable coupling between non-neighboring pins giving rise to crosstalk must be avoided to achieve optimal signal transmission. This paper reviews fundamental issues associated with the performance optimization of multi-conductor connector structures for high speed signal transmission. The paper complements an earlier publication that reviewed the major factors affecting electrical contact resistance at high frequencies [1].

At frequencies in the GHz range, an electrical connector must be considered as part of an electromagnetic transmission line. This paper reviews the effect of signal frequency on constriction resistance, interfacial capacitance and contact inductance at an electrical interface in a high speed connector. The deleterious effects of contact degradation at pin-receptacle junctions on transmitted signal integrity, are addressed. For frequencies in the GHz range, an electrical interface becomes capacitively coupled if contact resistance increases sufficiently. Contact deterioration may also lead to the generation of parasitic third-order harmonics that contribute to loss of signal integrity.