A microelectronic structure includes a first row of contacts (14) and a second row of contacts (24) offset from the first row, so that the first and second rows cooperatively define pairs of contacts. These pairs of contacts include first pairs (30a) and second pairs (30b) arranged in alternating sequence in the row direction. The first pairs are provided with low connectors (32a), whereas the second pairs are provided with high connectors (32b). The high connectors and low connectors have sections vertically offset from one another to reduce mutual impedance between adjacent connectors.