Design of UWB Antipodal Vivaldi Antenna with Parasitic patch for Microwave Head Imaging System

This study presents a high gain and miniaturized antipodal Vivaldi antenna with a metallic resonator for biomedical tissue characterization in the field of microwave imaging applications. The proposed approach involves the design and fabrication of an Antipodal Vivaldi antenna with staircase shaped metal patch and diamond shaped metal patch on a cost-effective FR4 substrate. The novelty of this antenna lies in producing a better reflection coefficient and minimizing side lobe level. This is achieved by proper positioning of a metallic patch in the aperture. The antenna is simulated and investigated using HFSS simulation software and good pulse handling capability is observed from time domain response. The proposed antenna is fabricated with the dimension of 48mmx21mm loaded with a metal patch. The measured results are compared with the conventional antenna. The final design exhibits a high gain of 10.46 dB for an antenna with a step parasitic patch and 10.12 dB for a diamond shaped parasitic patch. The measured and simulated values of S11 are almost similar in magnitude and phase.