Broadband RCS reduction for electrically-large open-ended cavity using random coding metasurfaces

Abstract

A scattered radar signal by an electrically-large open-ended cavity involves information of the target. Therefore, controlling the Radar cross section (RCS) of the cavity is significant for target stealth. Coding metasurfaces have promised great possibilities for full control of the electromagnetic waves, especially for reducing RCS by random coding metasurfaces. Here, we report an approach to realize broadband RCS reduction of electrically-large openended cavities through loading random coding metasurfaces on the inner side walls. The RCS reduction is caused by suppressing the strong backscattering of corner reflectors inside the cavities, which is further attributed to the diffuse reflection performance of the random coding metasurfaces. Both simulation and measurement show a decrease of cavities RCS, which is a broadband (X-band), polarization-independent, high performance (10 dB) RCS reduction. The proposed method may create new opportunities to improve microwave stealth features of cavities working in high temperatures, which could provide crucial benefits in many practical uses, such as engine nozzles.

Li‐Ion Doping as a Strategy to Modulate the Electrical‐Double‐Layer for Improved Memory and Learning Behavior of Synapse Transistor Based on Fully Aqueous‐Solution‐Processed In2O3/AlLiO Film

“…As shown in Figure 1e, all the thin films show high transparency in the wavelength of visible light visible (250–800 nm). Figure 1f shows the energy band gap ( E g ) value calculated by the optical transmittance versus wavelength [Equation ()] [ 18 ] where α is the optical absorption coefficient, h is Plank's constant, and v is frequency of light, respectively.…”

“…It is observed that with the Li doing content increasing, the transfer curve shifts toward the negative voltage direction. The mobility (μ) and subthreshold swing ( SS ) are calculated from the following equation [ 20 ] where W is channel width, L is the channel length, and C i is the specific capacitance of the AlLiO film at 20 Hz (about 450 nF cm −2 ). The electrical performances are calculated and summarized in Table 1 .…”

An efficient parameter-retrieval-based surrogate-assisted optimization of on-platform honeycomb absorbing structures

“…shape, edge, and surface of an object to minimize reflections back to the radar, is one of the scattering methods [3]. Nonabsorptive metasurfaces (MSs) offer another approach by eliminating scattering between elements through equivalent amplitude and out-of-phase scattered waves [4][5][6][7][8]. On the other hand, radar absorbing materials are employed to absorb electromagnetic (EM) energy and convert it into heat, thereby reducing the RCS.…”

An Ultra-Thin Wideband Reflection Reduction Metasurface Based on Polarization Conversion

“…Different from absorbing metamaterials based on amplitude regulation, coding metamaterials, which are based on phase regulation, can redirect scattered energy into nonmirror direction, hence suppressing the strong specular reflection [14]. Since magnetic materials are not required, the reflection reduction metasurface is promising for the application in high temperature environment [15]. An all-dielectric heat-resisting metasurface composed of patterned aluminum nitride ceramics has been designed to achieve specular reflection reduction, which cannot meet the mechanical requirements in practice [16].…”