Ultra-Wideband and Wide-Angle Microwave Metamaterial Absorber

• Main Authors: Xavier Begaud, Anne Claire Lepage, Stefan Varault, Michel Soiron, André Barka
• Format: Article
• Language: English
• Published: MDPI AG 2018-10-01
• Series: Materials
• Subjects: electromagnetic wave absorbers based on multilayer structures; metasurface; ultra-wideband microwave absorber; metamaterial absorber; frequency selective surface; wide-angle metamaterial absorber; wide-angle impedance matching layers; self-complementary structures; anti-phase metasurface
• Online Access: http://www.mdpi.com/1996-1944/11/10/2045

In order to extend the performance of radar absorbing materials, it is necessary to design new structures with wideband properties and large angles of incidence which are also as thin as possible. The objective of this work, realized within the framework of the SAFAS project (self-complementary surface with low signature) is, then, the development of an ultra-wideband microwave absorber of low thickness. The design of such material requires a multilayered structure composed with dielectric layers, metasurfaces, and wide-angle impedance matching layers. This solution has been realized with on-the-shelf materials, and measured to validate the concept. At normal incidence, the bandwidth ratio, defined for a magnitude of the reflection coefficient below −10 dB, is 4.7:1 for an absorber with a total thickness of 11.5 mm, which corresponds to λ/7 at the lowest operating frequency. For an incidence of 60°, this bandwidth ratio is reduced to 3.8:1, but the device remains ultra-wideband.