Investigating the EMI Shielding Effectiveness of Sustainable Biochar-Based Composites for 5G and 6G Mid-Band Applications

Biochar and biochar-based materials find multiple uses in environmental applications that are expanding nowadays in the field of electronics and electrical engineering. With the rapid growth of technology in everyday, various electronic devices and systems emit electromagnetic waves causing interferences. For example, new vehicles have an increasing number of electronic systems which in return expands the requirements for EMI shielding solutions to minimize the emitted fields that could affect circuits in the vehicle. Thus, studying EMC and especially the critical field of proper EMI shielding to avoid interference problems is more than ever imperative. In this study, biochar-based materials with high electromagnetic shielding effectiveness are introduced as new and emerging use cases in modern telecommunications systems. Biochar was extracted from the pruning of the olive tree and was next mixed with carbon black, and the polytetrafluoroethylene as binder. Test samples have been characterized regarding their EMI shielding efficiency in the frequency range of 1-18 GHz, covering the spectrum applications in the 5 G and 6 G Mid-Band according to ASTM D4935-18 standard methodology. Results revealed that the proposed biochar presents shielding capabilities that reach almost 46 dB, especially in higher frequencies of the experiment. Our methodology demonstrated the feasibility of using biochar as a substrate to create composites with high shielding efficiency and evaluate the performance using a fast and easy-to-use laboratory approach.