Optically Controlled Digital Metasurface for Radar Cross-Section Reduction

Abstract

We propose the design of a digital coding metasurface controlled by optical light to dynamically manipulate the electromagnetic wave (EM) in real-time to reduce the radar cross-section (RCS). The PIN diode is integrated into the digital metasurface that alters the EM performance of the metasurface without changing its physical properties. The photodiode module turns the optical light intensity into a bias voltage and tunes the unit cell’s states (0 or 1) in a non-contact way. The proposed digital coding metasurface is 1-bit coding composed of “0” and “1” unit cell elements corresponding to 0 and 180-degree phase responses respectively. These arrangements of various coding sequences applied to the metasurface that alter the EM wave and produces a beam splitting and RCS reduction patterns. The design and simulation of the proposed unit cell element and digitally coded metasurface array is carried out using CST MWS. In the simulation the amplitude and 180-degree phase response at 7.6 GHz (C- Band) has been observed for the unit cell element and analyzed the RCS reduction of 22.5 dBm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , 12.5 dBm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and 9.8 dBm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> for different digital coding sequences of the metasurface array. This RCS reduction finds a very promising application in stealth and military technology.