Performance study of cable harnesses

Analytical and experimental study of the performance of coaxial cables in different frequency ranges has been carried out and is the subject of the paper. Various computer models have been developed to predict the effects due to the inductive and capacitive coupling in parallel cables under different circumstances. To validate the computer models developed, experiments were carried out in a range of frequencies for several braided coaxial cables. Cable harnesses are important because they are the longest parts of a system and usually major contributors to EMC related problems. However, the design of cable harnesses is an after thought in the design of the whole system. Design of cable harnesses is normally a manual process and does not involve EMC study of individual cables. EMC problems are addressed when the whole system design has been completed by which time the remedy for these problems becomes more difficult. The ability to predict performance of cables at the early design stage would lead to better overall design of the system, and minimise EMC related problems. A research programme was set up to investigate the possibility of computerising the process of designing cable harnesses. As a result, an expert system for cable harness design (CHD) has been developed. This system has two main components: design rule checker and performance predictor. The former is for qualitative analysis of cable harness design; the latter for evaluation of electrical and mechanical performances of cable harnesses