Multifunctional complementary frequency selective surfaces for wireless applications

The paper presents the development of multifunctional frequency selective surfaces (M-FSSs) by using multilayer complementary structures and discusses their possible application in C-band wireless communication systems. The fundamental complementary FSS geometry (M-FSS_1) offers reflector–transmitter (R–T) behaviour that ranges from 1 to–10 GHz. The introduction of a corrugated metallic plate to M-FSS_1 (M-FSS_2) changes the characteristics to reflector–absorber (R–A) over a specified frequency range. This improved (M-FSS_2) geometry provides absorptivity at three frequencies that are greater than 85%. The equivalent circuit model (ECM) of the proposed M-FSS structures is also created to extract their lumped parameters. The proposed M-FSSs can be used to enhance antenna gain, reduce mutual coupling, and achieve RCS reduction, offering a compact and low-cost solution for integrated electromagnetic control in modern wireless systems.