Broadband RCS reduction for both microstrip array and Fabry‐Perot antenna based on the quasi‐ AMC superstrate

Abstract

This article presents a new type of quasi‐AMC superstrate (QAMCS), which can achieve wideband RCS reduction (RCSR) for both the microstrip array and Fabry‐Perot (FP) antenna. The proposed QAMCS comprises of two‐layer metallic patterns with a thin air gap. The top‐layer consists of two types of frequency selective surfaces (FSSs) in a checkerboard layout, and the wideband RCSR is realized based on the phase cancelation principle. The bottom‐layer consists of the slotted FSS, to reflect out‐of‐band signal while allowing the in‐band signal to pass through with a low insertion loss. Besides, the reflection phase of the proposed QAMCS is about −180° around higher frequencies. Therefore, it can be regarded as a partially reflecting surface (PRS) to construct the FP antenna with a highgain and low‐RCS. The simulation and measurement results show that the bandwidth of 10‐dB RCSR is more than 76% (7.2‐16.1 GHz). The 10‐dB impedance bandwidth of the array antenna is ranging from 16.6 to 18.6 GHz. For the FP antenna, its aperture efficiency is 31.5% and the peak gain is 17.5 dBi at 20 GHz.

Wideband monostatic and bistatic radar cross‐section reductions using polarization conversion metasurface

“…However, the in-band RCS was not reduced at oblique incidence. In Refs., [6][7][8][9][10] artificial magnetic conductor (AMC) structures were used, remarkable RCS reductions were achieved by arranging two or more units. In addition to polarization regulation of EM waves, polarization conversion metasurface (PCM) can be used for RCS reduction by arranging the array and its mirror array.…”

“…18,19 Up to now, there are still a lot of space to improve conversion bandwidth and efficiency of PCM. Moreover, many research 6,8,9,12,14,[16][17][18]20 mainly focus on monostatic RCS under normal incidence, those are lacking analyses and evaluations for bistatic RCS or oblique incidence. In the actual application, EM waves cannot only vertically impinge when radar detects target objects.…”