Reducing the radar cross section while maintaining the performance of a coplanar waveguide-fed antenna with an absorptive metasurface

Abstract

The paper presents, for the first time, an analysis of the optimum arrangement of a coplanar waveguide-fed monopole antenna and a metasurface absorber (MSA), aiming to reduce the antenna’s in-band radar cross section (RCS) without perturbing its radiation properties. The proposed arrangement will show that the efficiency of the antenna, of great interest in many applications (such as the internet of things), can be preserved, contrary to results of previous papers focused on combining these structures. Moreover, the final structure will be easily embeddable (with an optimum number of unit-cells) as well as conformable. A proper analysis of the losses and currents on the structure will be provided for a better understanding of the interaction phenomena that arise. Good agreement between simulation and measurement results can be observed, corroborating the proper performance of the structure. Furthermore, bistatic reductionis obtained as well as monostatic RCS reduction, due to the angular stability of the employed MSA. Finally, it will be shown that the introduction of loaded resistors will be preferable to the use of a lossy dielectric to improve the RCS reduction whilst maintaining the antenna performance.