Development of A Symmetric Metamaterial Absorber with Bandwidth Improvements for 5G Millimeter-Wave Applications

This study presents the development of a one-layer symmetrical Metamaterial Absorber (MMA) for millimeter-wave (mm-wave) applications. The target is to enhance the narrow band behavior and to achieve ultra-wideband with high absorptivity rates. The design is based on octagonal shaped cut rings and octagonal patches printed on grounded rigid substrate. A novel unit cell is developed and enhanced with the use of lumped elements technique to obtain ultra-wideband absorbers with high absorptivity rates. It is implemented on Rogers RT5880 with dielectric relative permittivity
$\varepsilon_{\mathrm{r}}=2.2$
, dielectric loss tangent of
$\text{tan} \delta=0.0009$
, thermal conductivity of 0.2 W/m. K and with a 1.575 mm thickness. The characteristics of the MMA are examined in term of different resistive values, geometries, and angle of incidence. The obtained results show great enhancements in both the −10 dB bandwidth and in the absorptivity rates. The narrow bandwidth of the symmetrical design is enhanced by a factor of about 200 with average absorptivity of about 98% over the whole bandwidth. The current design is a very suitable for applications in the mm-wave.