Metamaterials absorber for multiple frequency points within 1 GHz

Designing high efficiency microwave absorbers with frequencies in 1 GHz is still a huge challenge in practical applications. We design and present a novel microwave metamaterials absorber at six frequency points of 160, 442, 530, 723, 765 and 965 MHz with absorptances up to 90%, which is insensitive to polarization, viable at wide incidence angle and relatively simple in structure. We demonstrate the absorption characteristics of the absorber and explain the mechanism by means of equivalent impedance theory, surface current and energy distribution. The experimental results verify the correctness of the simulation and provide valuable reference for the design of broad-band microwave absorber in lower frequency band. (paper)