Sustainable X-Band Microwave Absorber Using Tea Waste and Recycled Carbon Composites

This paper introduces an innovative eco-friendly flat microwave absorber designed for X-band applications, utilizing plant waste and recycled materials, thereby contributing to a circular economy. The composite material is composed of 75 % used tea powder and 25 % carbon sourced from discarded batteries. The electromagnetic (EM) absorption performance of the proposed composite has been characterized, revealing enhanced absorption capabilities, averaging around 26.2 % for a thickness of 5 mm, compared to a 100 % tea waste configuration across the X-band frequency range. Furthermore, the results indicate that EM absorption improves with increasing frequency. The environmental advantages of this composite, including waste reduction and a minimal carbon footprint, position it as an attractive alternative to conventional RF absorbers. This sustainable solution shows promise for applications in EM interference shielding and microwave energy harvesting.