This paper aims at designing a thin low profile frequency-selective surface (FSS)-based absorber without an air gap in the frequency range of 6.1–12.5 GHz. A resistive FSS-based impedance surface of 11 Ω/square is designed on a two-layered FR4 substrate backed by a metallic plate. The return loss exhibited by the absorber is below −10 dB in the operating frequency range, yielding more than 90% absorption. The absorber shows an angular stability upto 50° for both TE and TM polarizations. The absorber is polarization insensitive due to its fourfold symmetric structure. Parametric studies of different impedance surfaces have been conducted. Finally, an equivalent circuit model is proposed which is used for deriving various circuit parameters. © 2021, Springer Nature Singapore Pte Ltd.