Research Projects

Non-destructive quality assessment of agricultural produce is a critical challenge in precision agriculture, where internal defects such as bruises, rot, and structural inconsistencies in fruits like apples often remain undetected until they significantly impact quality and marketability. Traditional inspection methods are destructive or limited to surface analysis, necessitating the development of innovative technologies for reliable internal defect detection. This project aims to address this challenge by developing and applying Frequency-Diverse Microwave Imaging (FDMI) using metasurface antennas. Microwave imaging, combined with frequency diversity, offers a powerful one-shot solution for mapping the dielectric properties of materials. Metasurface antennas enable the generation of highly spatially diverse, frequency-dependent radiation patterns combined with advanced reconstruction algorithms and can provide high-resolution dielectric contrast maps of defects inside the fruits. The project focuses on developing a fast, single-shot microwave imaging system. Firstly, the project focuses on designing and developing metasurface-enabled antennas capable of generating sparse radiation patterns with frequency diversity over a wide bandwidth necessary for high-resolution defect detection. Next, the designed metasurface antenna with higher measurement modes will be integrated with a receiving antenna to capture scattered electromagnetic radiation effectively. Finally, advanced image reconstruction algorithms, such as compressed sensing and inverse scattering, will be designed and implemented to translate the complex microwave data into interpretable dielectric maps capable of accurately identifying internal defects. The FDMI system will be validated through experimental studies on apples with known defects, assessing its ability to detect variations in size, location, and severity of internal damage. The research is expected to deliver a non-invasive imaging system capable of detecting subtle defects with high resolution and accuracy.