In this paper, the design of a novel polarisation rotating frequency selective surface (FSS) radome is presented based on substrate integrated waveguide (SIW) technology. The proposed radome consists of an FSS core with Y‐shaped slots on either side of the substrate and surrounded by metallic vias. The primary function of the core is to select the linear polarisation from the impinging electromagnetic (EM) wave and to rotate the wave into 90° clockwise direction in the X‐band regime. The radome structure shows a relative bandwidth of 13.2% from 9.2 GHz to 10.5 GHz with impedance matching better than −10 dB and the insertion loss (IL) better than 0.5 dB. The proposed structure shows very stable resonance performance with sharp band edge characteristics compared to the existing FSS radomes. Also, the conformal analysis of the proposed structure has been carried out to study its behaviour for real‐time radome applications. Finally, to prove the efficacy of the proposed structure, a prototype has fabricated and measured its performance in a free space measurement setup. A good agreement is observed between the experimental and simulated results. Furthermore, the conversion of E‐field pattern to H‐field pattern and vice‐versa is proved from the experimental verification.

The spectacular development of frequency selective surfaces (FSS) as a spatial filter, absorbers and reflectors made them feasible for the aerospace and defence applications. The intervention of substrate integrated waveguide (SIW) technology into FSS results in the improvement of unit cell structures and better performance by isolating them from inter-element interference. Such FSS structures with SIW cavities upholds the FSS properties and improves their selectivity and performance. Considering the diversity in applications of introducing SIW cavity technology into FSS, the aim of this paper is to furnish a study on the glimpse of EM design techniques to analyze this type of structures. Design topologies of narrowing bandwidth, dual resonance, the design of FSS with sharp sideband edges and frequency selective polarization rotating structures are presented. Further, a novel design for improving the bandwidth of reflective FSS is discussed based on SIW technology. Fabrication techniques pertaining to this type of structures are presented in brief.