Tunable metamaterials for the slotted waveguide antenna stiffened structure – RMIT University
Dr Kelvin Nicholson was awarded his PhD degree in 2014. The Slotted Waveguide Antennas Stiffened Structure (SWASS) concept is a conformal load bearing antenna structure designed by a joint DSTO and Air Force Research Laboratory team. In SWASS, the top-hat cross-section stiffeners commonly used to reinforce thin aircraft skins double as microwave waveguides and can therefore be integrated into airframes with little weight and drag penalties compared to conventional protruding aircraft antennas. This work has investigated electromagnetic metamaterials as one approach to overcome the structural impact of the slot and the required orientation of the stiffeners.
Dr Nicholson’s work was directly related to DMTC Project 2.3 – Technology Development for Multifunctional Composite Structures. This project investigated vehicle structures that incorporate functional systems such as antennas. By integrating structure and functionality, and simultaneously optimising both, there is tremendous potential to substantially enhance vehicle capability. Significant gains are expected by better integration of existing structures, materials and systems. However, potential transformative gains could be made by the integration of new advanced materials such as metamaterials. Dr Nicholson’s research investigated electronically tunable metamaterials for the slotted waveguide antenna stiffened structure concept. The research revealed a novel method to reduce the physical size of the antenna while also achieving electronic beam steering. This enables the integration of antennas into load bearing structures to achieve enhanced aircraft performance.
Dr Nicholson joined DSTO in 2006 as part of the Advanced Composites Technology group within the Aerospace Division. As part of this group, Dr Nicholson is involved in the development of microwave Doppler tomography imaging techniques for the assessment of damaged and repaired composite structures. Dr Nicholson hopes to apply his knowledge of metamaterials to the development of new repair techniques for advanced composite structures typically found on next generation military platforms. Dr Nicholson also plans to pursue an overseas research posting with DSTO support.