Research Projects

This project is intended to showcase the design and implementation of metasurface radomes for broadband and multiband airborne radar systems. A radome acts as a cover or housing for the antenna/array to protect it from environmental conditions (rain, fog, wind, etc.) without causing significant deterioration in the radiation characteristics. It is essential to achieve high transmission efficiency, low weight, and an aerodynamically compatible configuration in the radome design. Traditional radomes have various structural forms, the common ones including single-layer half-wavelength monolithic radome walls, A-sandwich, B-sandwich, C-sandwich, and multilayer configurations. However, they face limitations due to narrowband transmission capabilities and limited angular performance. When the antenna beam passes through the radome wall, its radiation pattern is affected by increased side-lobe levels, enhanced cross-polarization, the appearance of undesired flash lobes, boresight error, and blind spots within the scan volume. These impairments limit radar range and reduce beam-scanning angles in monopulse tracking and detection applications. To overcome the aforementioned drawbacks of conventional radomes, conformal frequency-selective surface (FSS) radomes will be investigated in this research. FSS structures exhibit a wide flat transmission window within their passband region and sharp roll-off characteristics outside the band. This feature can be utilized to achieve high electromagnetic (EM) performance in the FSS-based radome. Additionally, the stopband properties of FSS structures can help realize the low observable (stealth) feature of airborne radomes by reducing their spectral signature outside the operational bands. This technique is crucial for making military and defence aircraft less detectable by ground-based radar. Unlike monolithic dielectric or sandwich radomes, metamaterial-inspired FSS radomes offer reduced mutual coupling between radiating array elements. Carefully designed metasurface unit cells maintain stable transmission characteristics over a wide range of incident angles, thereby lowering reflection from the inner surface of the radome wall. The project will demonstrate various metasurface radomes conformal to different airborne geometries, ensuring high transmission efficiency within the operational bands and low radar cross section (RCS) outside them. The research will address the challenges in designing multifunctional metasurface radomes for bistatic radar detection, including phase-gradient metasurface and dynamically reconfigurable metasurface for beam-steerable radiation. In the final stage, a novel wideband antenna will be designed to realise an integrated antenna–radome–radar system.