| 摘要 |
A backplane has through holes for conductors to project through the backplane in arrays corresponding to respective circuit boards arranged along the front side of the backplane. The through holes include ground holes for receiving ground conductors in connection with a ground plane, and signal holes for receiving signal conductors free of connections with the ground plane. In accordance with a principal feature, the backplane is free of circuitry configured to interconnect signal conductors in the signal holes. This avoids problems associated with circuit density within the structure of a backplane. In accordance with another principal feature, each signal hole is wide enough to provide clearance for a respective signal conductor to extend fully through the signal hole free of contact with the backplane. The clearance contains air that serves as a dielectric to increase the impedance between adjacent signal holes, and thereby to reduce crosstalk and other problems associated with close proximity between signal holes. Additional through holes provide additional impedance at locations between adjacent conductor through holes. Such additional through holes for impedance control can be included in the circuit boards as well as the backplane. |
