US Patent 7535963 Data processing circuit with a driver and a receiver

A data processing circuit has four signal conductors between a driver and a receiver, and first and second, mutually conducting shield planes. First and second signal conductors form a symmetrical stack in a column between the first and the second plane. Third and fourth signal conductors are arranged substantially midway between the first and the second plane, on mutually opposite sides of the stack. The first, second, third and fourth signal conductors have respective widths so that respective transmission line impedances of transmission lines between each particular one of the first, second, third and fourth conductors and the first and second planes are substantially mutually equal.