A cost effective solution for development of broadband radar absorbing material using electronic waste

Electronic-waste items like disassembled mobile and computer printed circuit boards (PCBs) have been processed in a high energy planetary ball-mill for 10 h, to investigate the dielectric, magnetic and radar absorbing properties. The main goal of present paper is to achieve wide bandwidth for <−10 dB reflection loss at minimum cost in the frequency range of 8.2 to 12.4 GHz. The frequency dependent complex permittivity and permeability values of electronic waste composite material have been measured using transmission/reflection approach, and are used for computation of reflection loss with varying absorber layer thickness ranging from 1.0 to 3.5 mm. A single layer absorber is fabricated with optimal coating thickness of 2.5 mm (i.e., thickness value for reflection loss <−10 dB). The measured reflection loss value has been found to −27.98 dB at 9.3 GHz with absorber layer thickness of 2.5 mm, which may ascribe to proper impedance matching and large dielectric loss. Moreover, broadest bandwidth (for <−10 dB reflection loss) covering the maximum frequency range of X-band has been noticed as 3.9 GHz. Results demonstrate the enormous potential of the electronic waste composite material to act as highly efficient, cost effective, and broadband radar wave absorber for various practical electromagnetic applications.