A broadband metamaterial absorber design using characteristic modes analysis

In this paper, a broadband metamaterial absorber with a fractional bandwidth of 126.88% was presented. The characteristic mode theory was used to guide the design of the absorber. According to the analysis of characteristic mode and characteristic current, the resistance value of resistive films can be determined. The different modal information obtained through parameter changes can also better guide the design of the absorber. To study its operation mechanism, the equivalent impedance and surface current distribution of the proposed absorber have been analyzed. The final simulation and measurement results show that the proposed absorber has a wide absorbing bandwidth which is from 3.21 to 14.35 GHz, and the absorptivity is greater than 90%, covering the S, C, X, and Ku bands. In addition, for TE and TM polarization, it can achieve an absorptivity of more than 85% at 45° oblique incident and has good angular stability. Hence, the absorber has great potential applications in the field of electromagnetic stealth technology and Radar Cross Section reduction.