Multifunctional Active Frequency Selective Surface with Switchable Modes of Absorption, Transmission and Reflection

In this paper, a multifunctional active frequency selective surface (AFSS) with compound modes of absorption, transmission and reflection is presented. The proposed structure consists of three parts including a switchable transmission/lossy layer, an air spacer and a switchable transmission/reflection layer from top to down. PIN diodes are employed in the two switchable layers to realize the switching function and resistors are used to introduce ohmic losses in the top switchable transmission/lossy layer. Due to the separated bias networks in the two switchable layers, the PIN diodes for different polarizations can be controlled independently. Compared to other multifunctional designs previously reported, the proposed structure simultaneously integrates three different operating modes of absorption, transmission and reflection, and meanwhile, dual-polarized and wideband characteristics are also achieved.