IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, vol.16, pp.1060-1063, 2017 (Journal Indexed in SCI)
In this study, almost monochromatic tuning of absorption strength, i.e., tuning the absorption peak level at almost the same frequency, is presented by using an angle-dependent closed-ring resonator (AD-CRR)-type narrowband absorber structure in S-band. With this aim, first an ordinary planar closed-ring resonator (CRR) structure having a ground plane is designed, and then the structure is folded inward by a rotation angle a from a = 0. (i.e., a planar CRR) to a = 60. along the center line, which is parallel to the incident electric field. Both simulation and experimental results agree with the fact that the rotation angle a provides the freedom of tuning the absorption strength of the absorber structure almost monochromatically.