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

摘要

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 inband 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.