Ultra-wideband A-Sandwich Radome wall with Multilayer FSS

In this article, an Ultra-wideband Radome wall with a multi-layered Frequency Selective Surface (FSS) structure for aircraft applications is proposed. A-sandwich structure is constructed with as the core layer and Syntactic foam applied as a skin layer for the radome. The proposed design has two core layers of along with multiple FSS layers providing a bandwidth of 14.25 GHz, starting from 7.75 GHz to 22 GHz, and a centre frequency of 14.87 GHz with sharp roll-off characteristics. The top and bottom layers of FSS have a cylindrical patch at the centre, whereas the middle layer has octagonal rings along the perimeter, reducing the inter-element spacing, which helps in angular stability and creates a coupling effect. The FSS structures provide stability for wide-angle incidence up to 30 degrees with low profile dimensions. Further, the dimensions of a design are in harmony for both TE and TM polarisation modes, showing stable results in the X and Ku bands.