Electromagnetic Wave Propagation Through Closed Metal Systems

Abstract

A Faraday cage is an enclosure that shields electromagnetic fields from entering or exiting the cage. While metals with high electrical conductivity are expected to effectively demonstrate the operation of a Faraday cage, preliminary observations of a sealed cast iron cylinder allowing the transmission of Bluetooth signals between a smartphone and wireless earbuds across it suggested the need for further research into electromagnetic wave propagation through closed metal systems. This research utilized Bluetooth connectivity tests through sealed metal cylinders made of cast iron, aluminum, and stainless steel to analyze the working of Faraday cages, explore related material properties, and isolate possible reasons for the conflict in expected behavior when electromagnetic transmission is detected through such cages. The research methods included conducting Bluetooth connectivity tests with different cylinder orientations and analyzing the strength of the transmitted and received Bluetooth signal. The key findings of this study suggest that material properties, spatial orientation, and the strength of the electromagnetic source influence the transmission of electromagnetic waves through sealed metal cylinders. The implications of these findings suggest potential exceptions to a common electromagnetic phenomenon and provide insights for future research.