Design and application of microstrip antenna for different soil structures for mine detection

Today, landmines continue to pose a serious threat, primarily affecting civilians, with approximately 600 people either killed or maimed each month. These devices remain lethal long after military operations have ceased, resulting in prolonged humanitarian crises. Landmines are typically categorized into two main types: anti-personnel mines and anti-tank mines. Anti-personnel mines are designed to restrict the movement of individuals on foot and serve to prevent passage through specific areas, while anti-tank mines are intended to disable or destroy armored vehicles. Over time, with advances in technology, anti-tank and anti-personnel landmines have been designed to be undetectable. Consequently, numerous methods and sensors have been developed to detect these low-metal-content mines, which are now extremely difficult to identify. These sensors, sensitive to metallic and plastic components, include material and chemical analysis tools, thermal imaging devices, and ground-penetrating radar systems. However, only a few of these sensors perform satisfactorily under certain conditions, and most fail to deliver the desired level of detection. The main reasons are the vast variety of mine types and the environmental conditions where mines are placed. Therefore, factors such as climate, soil type, and vegetation must be identified and considered during sensor design. In response to these challenges, this doctoral study prioritizes mine detection based on environmental conditions and investigates the influence of soil type on detection accuracy. To evaluate the effect of soil in the presence and absence of mines, a microwave antenna setup operating in the 1–13 GHz range was developed. The transmitting and receiving antennas used in the setup were designed and fabricated with a resonance frequency of 9 GHz. Using the transmitted and received signals, the presence or absence of mines in four different soil types was examined with the developed experimental setup. For the experiments, passive epoxy-based cylindrical dummy mines measuring 20 x 4.5 cm were prepared to simulate real landmines. Clay, sandy, salty, and red soil samples collected from various terrains were used. A Vector Network Analyzer (VNA) was employed to take measurements. The experimental setup was designed to evaluate how soil affects mine detection. Data were collected using a radiating antenna at distances of 2, 5, and 10 cm from the soil surface distances determined based on near- and far-field criteria. In all trials, the mine was positioned 15 cm below the soil surface. The electrical measurements obtained during the experiments included S11 and S21 scattering parameters and their corresponding frequency values. The results demonstrated measurable differences between the presence and absence of mines, indicating successful detection. It was also found that the detectability varied with different soil types. The first chapter of the thesis provides a literature review summarizing previous studies related to the research objective. The second chapter explains the materials and methods used. The third chapter presents the research findings and includes a discussion on the experimental setup and methodology. The final chapter evaluates the results and provides suggestions for further work. The findings show that mines can be detected and that soil type affects detection performance. The presented results assess the impact of four selected soil types on mine detection under different environmental conditions. Future studies may incorporate additional factors and methods. Based on these results, a detection model could be developed and transformed into a practical device. Furthermore, artificial intelligence algorithms could be employed to explore the influence of other potential variables. Keywords: Dielectric, Landmine, Microstrip Antenna, Soil