Analysis of Resistor-Loaded Bow-Tie Antennas for Ground Penetrating Radar Applications

Sammanfattning: Ground penetrating radar (GPR) systems are increasinglybeing used for the detection and location of buried objectswithin the upper regions of the earth's surface. Numericalsimulation of such systems plays an important role in thedevelopment of GPR hardware and signal processingtechniques. This thesis is about analyzing resistor-loaded bow-tieantennas for GPR applications using the finite difference timedomain (FDTD) technique. First, the antenna is optimized to getbroadband properties and signal detection with low clutterlevel using a parametric study. In this study, it is describedhow the flare angle, length, and lump resistors of the antennashould be selected for the best performance. Moreover, theposition of transmitting and receiving antennas with respect toeach other and ground surface is also analyzed. Next, a realistic GPR simulation is performed on theoptimized antenna by including ground losses, dispersion,surface roughness and natural clutter like rocks and twigs. Theeffect of different ground conditions on target detection ispresented. Also the ability to detect metal and plastic pipesis investigated while describing the target signatures andtarget polarization characteristics.