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

¹ Beijing Institute of Technology - Beijing, 100081, China
² Science and Technology on Electromagnetic Scattering Laboratory - Beijing 100854, China
³ Navigation and Control Technology Institution of NORINCO - Beijing, 100089, China

^(a) textyangzhihui@126.com (corresponding author)

Received: 10 June 2021
Accepted: 24 August 2021

Abstract

To fulfill the antenna system criteria for broadband microwave-absorbing materials, herein, a magnetic medium is introduced into the metamaterial structure design process, which can produce the artificially required transmission properties in the microwave region. The composite meta-structure can effectively provide microwave absorption at low frequency and microwave transmission at high frequency by optimising the design of the metasurface, dielectric and magnetic medium. The magnetic-medium–based metamaterial is fabricated in accordance with the design, and its electromagnetic characteristics are investigated. Experimental results show that the absorptivity of the proposed metamaterial structure is higher than 85% at 2.4–9.8 GHz, and that the transmissivity is higher than 71% at 15.5–18.8 GHz, 19.6–20.5 GHz, and 36–39 GHz. The absorptivity bandwidth exceeding 90% reaches 6.0 GHz, which is significantly higher than the traditional metamaterial without a magnetic medium. Moreover, the electromagnetic characteristics of the composite material are consistent under varying microwave polarisations.