Abstract: A modem shelf is described in which internal dividers separate the interior of the shelf into individually isolated Faraday cages that effectively suppress EMI generated by circuit cards mounted within the shelf and isolate the circuit cards from EMI originating outside the shelf and from cards mounted within the shelf. The shelf enables high-speed data communications over a twisted pair network of about 10 Mbps or more. The top and bottom of the shelf are made of relatively thin sheet material, which maximizes the vertical dimension of the circuit cards mounted in the shelf and thus the area on which circuitry can be placed.

Abstract: A backplane assembly of electronic equipment includes a plurality of coaxial connectors which are engaged by complementary coaxial connectors on a removable circuit card as it is inserted into the equipment. Precise alignment of the coaxial connectors is facilitated by mounting each coaxial connector on the backplane in a resilient bushing which permits limited movement of the connector. The coaxial connectors are arranged in pairs, the connectors of each pair also passing through shaped holes in a grounding and retaining component having spring fingers around its periphery biassed against a ground conductor on the backplane. This component provides for electrical grounding of and shielding around the coaxial connectors, and prevents rotation of each coaxial connector about its own axis.