Radar cross-section reduction using digital programmable metamaterials

Abstract

This paper presents radar cross-section reduction using a digital programmable metamaterials (MTM). The proposed structure is composed of agile unit cells with two different behaviors that can be controlled using an external command system, such as PIN installed in every unit cell. When the diode states are swapped, two types of unit cells are produced. The ON-state is for the absorber type with an absorption rate of 96%, and 180-phase of reflection, and the OFF-state is for the reflector type MTM unit cell with zero-phase reflection. A field-programmable gate array (FPGA) is used to supply binary codes (0/1) to control the diode states (ON/OFF) of the MTM unit cell, and the structure becomes completely coded. By combining these two types in the same structure, we were able to obtain a MTM supercell that can switch between five prototypes (sequences) in which the unit cells are symmetrical, and each prototype has its own working frequency.