Magnetic medium based metamaterial for broadband microwave absorption and multiband transmission characteristics

Abstract

Abstract To fulfill the criteria of antenna system for broadband microwave-absorbing materials, magnetic medium is introduced into the metamaterial-structure design process, which can produce artificially required transmission properties in microwave region. Through the optimization design of metasurface, dielectric and magnetic medium, the composite meta-structure can effectively provide microwave absorption characteristic at low frequency and microwave transmission characteristic at high frequency. According to the design, the magnetic medium based metamaterial is fabricated and the electromagnetic characteristics are studied. The experimental results show that the absorptivity of the proposed metamaterial structure is higher than 85% at 2.5–9 GHz and the transmissivity is higher than 71% at 15.5–18.8 GHz, 19.6–20.5 GHz and 36–39 GHz. The bandwidth of absorptivity more than 90% reaches 6.5 GHz, which is significantly better than the traditional metamaterial without magnetic medium. Moreover, the electromagnetic characteristics of the composite material are consistent under different microwave polarizations.