Non-invasive Identification of a Degraded Passive Filter Component

The development of modern technology makes the use of low-pass filters increasingly necessary to protect sensitive equipment from the impact of high-frequency noise. However, filters are often exposed to harsh operating conditions that can cause a significant influence on the condition of the filter components themselves. Affecting any element of the filter will result in a change in the performance of the filter as a whole. Therefore, it is possible to determine the nature of changes that occurred in a damaged filter from the changes in its performance. This paper presents an application of the previously proposed method for identifying the culprit filter component using a simple combination of measurements and simulations. A simple filter, in which one component was changed to mimic its degradation, was selected as a case study. Measurements in common mode were made to estimate the magnitude of that effect in terms of insertion loss (IL). Monte Carlo simulations with variable component values were performed to fit the IL of the damaged filter and identify the culprit component. It is shown that the proposed approach can be used as a tool for finding the possible cause of changes due to filter damage.