Post design EMI encounters and remedies in indigenously developed systems

Prediction of the EMI performance theoretically, and implementation of the EMC design practices may not assure the total electromagnetic compatibility of the system in the final compliance testing. The post design EMI encounters may be few but may poses severe costs as well as time consuming. Analyzing and trouble shooting EMI sources are very difficult and EMC fixes may see practical difficulties in terms of space constraints, immediate availability and cost. Practical experience in the EMI-EMC performance evaluation can be helpful in coming out from these sort of problems. In airborne systems weight is the important criteria. One have to consider in terms of flexibility and weight before implementing EMC Fixes. Usage of shielded cables should be minimized to reduce the weight and the coupling of noise should be eliminated. In these areas prediction of common mode noise and differential mode noise becomes tough and eliminating at the source is desirable. The conducted noise can become radiated and vice versa. In this paper the authors mainly expressed their views about controlling the post designed EMI problems with fundamental EMI mitigation techniques.