The key innovation that enables high signal density at higher speeds is the addition of internal shielding. In the UHM Connector vertical and horizontal shields are placed between each column and row in order to isolate each signal contact. For differential signals this allows the designer to utilize either row differential or column differential formats as shown here. This shielding is designed to control the differential impedance as close as possible to 100 Ohms which is demonstrated here in the TDR profile of a UHM socket mated to a standard CompactPCI® header.