Numerical Design and Experimental Validation of a Plastic 3D-Printed Waveguide Antenna for Shallow Object Microwave Imaging

摘要

Microwave imaging of shallow buried objects has been demonstrated with holographicradar for landmine detection, civil engineering and cultural heritage. A keycomponent of this system is the antenna based on a truncated cylindrical waveguidewith two feeds. This paper investigates for the first time a manufacturing technologybased on the 3D printing of a volumetric cylindrical plastic antenna. The investigationof this manufacturing technology was motivated by the reduction in the antennasize and customization of the electromagnetic characteristics to the radio frequencyelectronics mounted on the robotic scanning system. The antenna that was designedusing a simulator and filled with polylactic acid plastic material (relative dielectricpermittivity Ɛr = 2.5) is compared to the metal antenna, both operating at around2 GHz. The goal was to replicate the characteristics of the void core antenna to beable to provide the same quality/information of the microwave images of shallowburied objects. Finally, we compared the scan results of dielectric and metal targetsboth in the air and in natural soil. From the observation of some of the characteristicsof the images, such as dynamics, morphology of the target, signal-to-noise ratio,and operating distance, we demonstrate that 3D printing for volumetric cylindricalwaveguide antenna could be used to obtain compact and easily adaptable antennasfor different applications in remote sensing.