Absorption Properties in Millimeter-Wave of Radio Wave Absorber with Porous Carbon Material

Abstract

As a new broadband-wave absorber material in millimeter waves, the thin rubber sheet containing a porous carbon material “PHYTOPOROUS” made from plant-based ingredients were prepared. We investigated the complex permittivity ε_r*and the reflection loss Γ measured by free-space method using dielectric lenses and incident angle dependence of the reflection loss measured by free-space arch method. The rubber sheet containing PHYTOPOROUS made from soybean hulls showed the reflection loss of more than −20 dB with a bandwidth of 18 GHz at centered frequency of 90 GHz.