A five-band metamaterial absorber (MMA) based on a simple planar structure is proposed. It utilizes different areas of a single unit cell to match impedance, and produces different absorptive frequencies. Numerical calculation shows that the MMA has five
A five-band metamaterial absorber (MMA) based on a simple planar structure is proposed. It utilizes different areas of a single unit cell to match impedance, and produces different absorptive frequencies. Numerical calculation shows that the MMA has five different absorption peaks at 3.78 GHz, 7.66 GHz, 10.9 GHz, 14.5 GHz and 16.7 GHz, and their absorption rates reach 95.5%, 98.6%, 95.7%, 96.6% and 99.8%, respectively. The proposed structure is polarization insensitive for transverse electric (TE) and transverse magnetic (TM) incident waves. Also, the absorptive characteristics over large incident angles are examined. In addition, we analyze the absorption mechanism by the surface current density and power flow density distributions. This simple structure provides a way to design multi-band MMA, and also saves the cost of fabrication.
We demonstrate that ultra-thin porous alumina membrane (PAM) is suitable for controlling of both size and site of Ge nanodots on Si substrates. Ge nanodots are grown on Si substrates with PAM as a template at different temperatures with molecular beam epi
A dual-frequency laser Doppler velocimeter implemented by a dual-polarization fiber grating laser is proposed, with the two laser frequencies produced by the two orthogonally polarized laser outputs of the fiber grating laser. The reflected laser outputs