Water Based Frequency Selective Surface Acting as an Absorber

Absorbers are used for selective enclosure screening and stealth technology. This paper proposes a cost-effective frequency selective surface (FSS) that functions as a narrow-band absorber, utilizing spherical water resonators within the unit cell as absorbing elements. A strong and sharp absorption resonance is achieved at 3.38 GHz for a unit cell size of 15×15mm2. The surface demonstrates stability with respect to polarization, incidence angles up to 60°, and temperatures between 5° C and 45° C. Its operation is evaluated through simulations, with field images provided to offer insight into its performance.