Educational Demo’s for Showing the Influence of (im)proper Installation and Grounding of Filters

The need of implementing low-pass filters to protect sensitive equipment from high-frequency noise, and reverse, increases as technology develops. However, for efficient filter operation, it is important to ensure its proper installation, with a focus on ensuring a secure and stable ground connection. This paper presents setups for educational purposes as part of electrical engineering courses, in order to demonstrate how the performance of a passive filter depends on the quality of its grounding. The designed units are used to measure the filter's insertion loss in various modes: normal mode, differential mode and common mode. Analytical methods describing the operation of the filter and simulation of its performance using LTSpice XVII have been performed to explain the processes more clearly, and to explain the concept of impedance mismatch and modes for filters.