Methodology for EMC cable design

EMC cable design is perhaps the most important task in system EMC design. Large complex electronic system is composed from many LRU (line replaceable units-electronic boxes). Each LRU is connected with one or more cables to other LRU. From intrasystem point of view, the crosstalk problems in multi-wire cable is of main concern. From intersystem point of view, external cables are effective antenna farm for radiated emission and radiated susceptibility (immunity). In addition to EMC aspects there are other design constraints like weight flexibility and cost which are sometimes with contradiction with EMC design. Dynamic cables that are connected to gimbals should by flexible, while space and airborne should be lightweight. This paper establish the methodology of designing cable EMC from ICD (interface control drawing) to full cable and harness design. Some cable design technique is presented. The emphasis here is on defense systems but some approaches can be adapted to commercial systems.