Design of Artificial Metamaterial Absorber Based on Stacking Method

Table 3

Performances of the absorbers. Here, is defined as the minimum working wavelength, and is defined as the total operating wavelength. is the wave number and d is the total thickness.

Reference	Number of layers	Operation bandwidth (GHz) (absorption>90%)	Thickness ()	Period of unit cell ()	Dimension ()	Structure shape
30	20	7.8-14.7	0.28	0.54	1.54	Pyramidal
31	30	3.93-6.05, 11.64-14.55	0.26	1.16	3.20	Cone
32	20	7-18	0.16	1.44	1.64	Multisized pyramidal
This work	7	14.4-14.8 15.4-20.6	0.29	0.64	0.64	Cone with notched structure