Double elliptical resonator based quadruple band metamaterial absorber for EMI shielding applications in microwave regime

Abstract

A quadruple band wide angle polarization insensitivity metamaterial absorber based on double elliptical resonator structure for electromagnetic interference (EMI) shielding applications in microwave regime has been considered in this paper. The proposed metamaterial absorber (MA) unit cell comprises of a top metallic resonating patch and a ground copper, both of which are separated by an inexpensive FR-4 substrate with a thickness of 0.0185λ and an electrical size of 0.138λ, at lowest resonance frequency. The proposed MA demonstrates the peak absorption of 97 %, 99.9 %, 99.9 % and 99.6 % at 3.46 GHz, 6.44 GHz, 7.89 GHz and 12.44 GHz, respectively for transverse-electric (TE) mode at normal incidence. The quadruple band absorption mechanism has been understood by the analysis of electromagnetic field with surface current distribution. In addition, the designed MA also exhibits near unity absorption for a polarization and oblique incident angle up to 60° for TE mode. The proposed MA offers greater than 35 dB shielding effectiveness in all bands under both simulated and measured environment. The designed MA has been fabricated and measured to validate the simulation results. The agreement between the measured and simulated results allow for EMI shielding applications in microwave regime.

Keywords

• Double elliptical
• EMI shielding
• Quad-band
• Metamaterial absorber