Design of frequency selective surface using proximity mode coupling and its applications to Ku band RCS reduction

This article proposes a novel approach to design a frequency selective surface (FSS) based on proximity coupling modes. Two closely placed modes given by two different structures are merged to achieve the coupled modes to improve the operation bandwidth (BW). This method reduces the radar cross section (RCS) of the patch antenna without deteriorating the radiation characteristics like gain, directivity, and radiation efficiency. A FSS unit cell of dimension 8 × 8 mm is made into a 3 × 2 array and is placed in the same layer around the microstrip patch antenna for RCS reduction in single layer. The simulated and measured results show the RCSR of 17 dB with a BW of 5.2 GHz in radar Ku band.