A semiconductor chip (101) with bond pads (110) on a substrate (103) with rows and columns of regularly pitched metal contact pads (131). A zone comprises a first pair (131a, 131b) and a parallel second pair (131c, 131d) of contact pads, and a single contact pad (131e) for ground potential; staggered pairs of stitch pads (133) connected to respective pairs of adjacent contact pads by parallel and equal-length traces (132a, 132b, etc.). Parallel and equal-length bonding wires (120a, 120b, etc.) connect bond pad pairs to stitch pad pairs, forming differential pairs of parallel and equal-length conductor lines. Two differential pairs in parallel and symmetrical position form a transmitter/receiver cell for conducting high-frequency signals.