Dual-Band Electromagnetic Absorber based on a Frequency Selective Surface

Electromagnetic absorbers based on frequency selective surfaces (FSS) find important applications in various microwave systems. However, the design of highly efficient and at the same time robust and easy-to-implement FSS electromagnetic absorbers presents many challenges. This paper describes the design of a dual-band FSS electromagnetic absorber at Ka band. The design was carried out by a finite element method implemented on a computer for numerical simulation of the FSS cells. The unit cell combines two different kinds of resonant elements that contribute to dual absorption bands. The designed cells exhibit peaks of electromagnetic absorption at 32.3 and 37.9 GHz, with −10 dB bandwidths of 128 and 95 MHz in the two frequency bands, respectively. The proposed absorber shows an absorption coefficient of 0. 99 in the two frequency bands for normal incidence. The specific frequencies of the absorption bands can be changed by scaling the sizes of the unit cells.