A 1-bit Broadband Reconfigurable Electromagnetic Surface With Switchable Modes of Reflection and Tunable Absorption

Abstract

In this communication, a broadband reconfigurable electromagnetic surface (REMS) with two switchable modes, reflective and tunable absorptive, is designed, simulated, and measured. The proposed structure is derived from a dipole antenna with a broadband characteristic. To further expand the bandwidth and maintain the element’s stability under oblique incidence, two pairs of slots are introduced. A p-i-n diode, located between the dipole’s two arms, facilitates 1-bit phase resolution, while the variable resistance of the p-i-n diode in its on-state enables the tunable absorption mode of the REMS. Based on this design, a $16\times 16$ (256 elements) REMS was fabricated for validation. Measurement results revealed a 3-dB gain bandwidth of 56.4% featuring a beam-scanning capability covering ±60° for the reflective mode. Additionally, a tunable radar cross section reduction (RCSR) capacity ranging from 0 to −10 dB can be realized over 68.8% bandwidth for monostatic RCSR, and remains above 62% RCSR bandwidth under 15° and 30° oblique incidence. The proposed multifunctional REMS features additional adjustable absorbing capability over a wide bandwidth, demonstrating significant potential for applications in radar stealth and deception techniques.