A novel three-dimensional broadband angular stable polarization insensitive microwave metamaterial absorber

Abstract This paper proposes a novel three-dimensional, angle stable, polarization-insensitive, thin, low-profile microwave absorber. The designed absorber consists of a planar array of slotted split ring structures with split cross bars connected with resistors at the top. The four side walls consist of slotted circular rings making a criss-cross mesh structure with a metallic copper plate as ground. The angular stability in Transverse Magnetic mode, with polarization-independent was enhanced by inserting the criss-crossed array between the top surface and the ground. The absorber has a broad bandwidth of 3.74 GHz, from 2.42 to 6.16 GHz, with more than 90% absorption. The dimension of a unit cell is 0.16λ o × 0.16λ o × 0.104λ o , as the height of the absorber is less which is only 0.104 times the free space wavelength therefore the proposed absorber is thin. The designed absorber has insensitivity to polarization angles and angular stability behaviour till 30° for Transverse Electric (TE) and Transverse Magnetic (TM) both polarization modes till 60°. The proposed structure is fabricated and on comparison provides promising results with the simulated structure.