A tri-band microwave perfect metamaterial absorber

A tri-band metamaterial absorber is presented that shows high absorption and double negative characteristics (DNG) at microwave frequency. The proposed absorber structure is developed by the square shape resonators with circular ring in the middle of the square resonators. The finite integration technique based computer simulation technology microwave studio has been utilized to numerical analyses and design purposes. An Agilent N5227A vector network analyzer is used to measure the transmittance (S-21) and the measured are well suited on the simulated results. This design illustrates 4.71 GHz wide bandwidth and applicable for tri (C-, X-, and Ku-) band applications. The effective medium ration is 5.83 and the absorption are respectively, 82%, 67%, and 93%. Finally, the effects of the resonators and inner circle on the DNG is also investigated in this paper.