An electrical connector is provided that includes a connector housing supporting a plurality of electrical contacts. The electrical contacts are edge-coupled along a column direction, and spaced apart along a row direction so as to define a space that is defined by adjacent electrical contacts along the row direction. The electrical connector includes at least one rib disposed in the space. The rib has a dielectric constant greater than air such that the dielectric constant of the space is increased with respect to a substantially identical space that is filled only with air. The increased dielectric constant reduces the impedance of the electrical connector.