Application of Metallic Strip Gratings for Enhancement of Electromagnetic Performance of A-sandwich Radome

Enhancement of the electromagnetic (EM) performance characteristics of A-sandwich radome wall over X-band using metallic strip gratings is presented in this work. Equivalent transmission line method in conjunction with equivalent circuit model (ECM) is used for modeling the A-sandwich radome panel with metallic strip gratings and the computation of radome performance parameters. Metallic strip grating embedded in the mid-plane of the core and those in the skin-core interface are the configurations considered in the present work. For a given thickness of metallic strip grating, its width and pitch are optimized at different angles of incidence such that the new radome wall configuration offers superior EM performance over the entire X-band as compared to the conventional A-sandwich wall. The EM analysis shows that the superior EM performance of A-sandwich with metallic strip gratings makes it suitable for the design of normal incidence and streamlined airborne radomes.Defence Science Journal, 2013, 63(5), pp.508-514, DOI:http://dx.doi.org/10.14429/dsj.63.245

Optimal Design of Multilayered Radar Absorbing Structures (RAS) using Swarm Intelligence based Algorithm

The steady progress in the fields of material science and processing technologies has made multi-layered radar absorbing structures (RAS) an attractive option w.r.t. stealth technologies. They possess the ability to reduce radar cross-section with minimum thickness and is therefore most preferred in airborne applications. As far as their electromagnetic performance is concerned, the sequence of material layers and thickness profile plays a pivotal role. Optimization of these two factors becomes complex in case of availability of large number of potential materials. Commonly used EM simulation software can be employed for the optimization of thickness profile. However, selection of suitable material layer sequence is out of their scope. In this context, a particle swarm optimization (PSO) based algorithm is presented for sequencing of material layers and optimization of thickness profile of multi-layered RAS configurations. The fitness function has been appropriately formulated to achieve maximum power absorption over broad band of frequencies and wide range of incident angles. Further, the efficacy of the algorithm has been demonstrated using a suitable case study

Broadbanding techniques for radomes

This SpringerBrief details various techniques employed for enhancing the transmission efficiency of radomes by modifying the radome wall configurations. These broadbanding techniques are based on inclusion of metallic wire-grids/meshes in the radomewalls, inclusion of metallic strip-gratings in the radome layers, inclusion of FSS based structures in between the radome layers and the use of inhomogeneous dielectric structures as radome wall. The volume provides detailed chapter-wise explanation of the design aspects and discusses the performance analysis of the modified radome wall configurations. It will be of interest to researchers, academicians and students working in the field of radomes.