Fig. 3
Absorption results from 1 to 30 GHz for the proposed ultra-wideband perfect metamaterial absorber with different parameters. a Absorption results of the PMA with different Ra values. b Absorption results of the PMA with different Rb values. c Absorption results of the PMA with different lengths of P. d Absorption results of the PMA with different lengths of s. e Absorption results of the PMA with different thicknesses of d1. f Absorption results of the PMA with different thicknesses of d2