EMI/RFI ENVIRONMENTAL BACKSHELLS

Electromagnetic interference (EMI) and radio frequency interference (RFI) generate interference. When strong external noise fields exist, the conductors of a cable act as antennas and pick up the radiated signals. The reception of this interference results in inaccurate or interrupted data transmission. An effective shield prevents the reception of undesired signals as well as confining extraneous signals generated within the cable itself. Emi/rfi backshells enclose the cable in a tightly woven metal braid comprised of wire strands which is then terminated at one or both ends of the cable to ground potential. The termination and grounding of the shield is accomplished by using a suitable connector backshell. A variety of backshell configurations are available for termination of cable shielding. Environmental backshells protect the wiring side of the connector from dust, dirt, moisture and fluids. Almost all recent military specification cylindrical connectors are designed so that when the wires are inserted through the grommet, and assuming all holes in the grommet contain either a wire or a sealing plug, the connector will be environmentally sealed once the backshell or strain relief is secured.