Simplified two‐dimensional microwave imaging scheme using metamaterial‐loaded Vivaldi antenna

Abstract

AbstractIn this paper, a highly efficient, low‐cost scheme for two‐dimensional microwave imaging is proposed. To this end, the AZIM (anisotropic zero index metamaterial) cell‐loaded Vivaldi antenna is designed and tested as effective electromagnetic radiation beam source required in the microwave imaging scheme. The designed antenna is first individually tested in the anechoic chamber, and its directivity along with the radiation pattern is obtained. The measurement setup for the imaging here involves a vector network analyzer, the AZIM cell‐loaded ultra‐wideband Vivaldi antenna, and other associated microwave components. The potential of the designed antenna for the microwave imaging is tested by first obtaining the two‐dimensional reflectivity images of metallic samples of different shapes placed in front of the antenna, using the proposed scheme. In the next step, these sets of samples are hidden behind wooden blocks of different thicknesses and the reflectivity image of the test media is reconstructed by using the proposed scheme. Finally, the reflectivity images of various dielectric samples (Teflon, Plexiglas, permanent magnet moving coil) along with the copper sheet placed on a piece of cardboard are reconstructed by using the proposed setup. The images obtained for each case are plotted and compared with the actual objects, and a close match is observed which shows the applicability of the proposed scheme for through‐wall imaging and the detection of concealed objects.