A coding metasurface antenna array with low radar cross section

Abstract

An aperiodic metasurface antenna array with low radar cross section (RCS) is designed. The upper patches of the two antenna elements have the same shape and are placed at an orthogonal position, which can effectively reduce the workload of simulating the reflection characteristics of the patch. As antenna elements, they have identical operational band and polarization mode, and as metasurfaces, they can form an effective phase difference of 180° ± 37°. The RCS of the array is reduced mainly by phase cancellation under the <i>x</i> polarization and by absorption under the <i>y</i> polarization. According to the coding metamaterial theory, the two elements can be coded aperiodically by using the programming software. Regarding element A and element B as “0” and “1”, respectively, the coding matrix can be solved by a genetic algorithm. Element A and element B are arranged according to positions “0” and “1” to obtain a proposed array. The scattering field of proposed array is diffusive, and the peak RCS is effectively reduced. In order to highlight the characteristics of the proposed array, the chessboard-type array is designed for comparison. The simulation results show that the radiation performance of proposed array is good. Comparing with the metal board of the same size, the 6 dB reduction bandwidth of the monostatic RCS is 4.8－7.4 GHz (relative bandwidth is 42.6%) under the <i>x</i> polarization and 4.6－7.8 GHz (relative bandwidth is 51.6%) under the <i>y</i> polarization. Comparing with the chessboard type array, the scattering energy distribution of the designed antenna array is very uniform and the peak RCS in space reduces obviously. When a 4.8 GHz electromagnetic wave is incident with different incident angles and polarization modes, the scattering field is diffusive. Compared with other similar arrays, the proposed array has advantages of simple design process and even scattering field. The experimental results are in good agreement with the simulation results. This work makes full use of the scattering characteristics of the antenna element itself to solve the problem that the array antenna possesses both good radiation characteristics and low scattering characteristics at the same time, and improves the design process of the antenna patch. This design method has certain universality and reference significance for designing the low RCS antenna array.

Dual Circularly Polarized Fabry-Perot Antenna with Metamaterial-based Corner Reflector for High Gain and High Aperture Efficiency

“…近年来, 超材料由于其独特的电磁特性引起了学者广泛关注 [3,4] . 在微波领域, 超材料被广泛应用于提高天线性能 [5] , 例如提高天线增益 [6][7] 、减小雷达散射截面 [8] 、滤波 [9] 、极化转换 [10] . 其中, 将超材料结构放置在馈源之上形成 Fabry-Perot (F-P)天线 [11] , 因其具有高增益、低剖面、馈电网络简单的优点而被广泛研究 [12] .…”

Design of Low-RCS Broadband High-Gain Antennas Based on Transmission Array Metasurface

“…Since Metasurface was proposed as a two-dimensional form of metamaterial, more and more examples have proved that the polarization, phase, amplitude and other characteristics of electromagnetic(EM) waves can be effectively regulated by designing the structure and arrangement of metasurface elements [ 1 , 2 , 3 ]. With the development of metasurface, using metasurface to design antennas has become a hotspot of research in recent years, which provides a new idea for the designing method of high-gain antennas [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ]. For example, frequency selective surface (FSS) has been used to design high-gain antennas.…”