Design of a Fractal Based Wideband Antipodal Vivaldi Antenna with Improved Radiation Characteristics for Biomedical Applications

In this communication, a novel fractal inspired antipodal Vivaldi antenna surrounded by dielectric cover is designed for biomedical applications. A step wise techniques has been used to modify the designed Vivaldi antenna's performance. First, a reference antenna is designed which is a conventional antipodal Vivaldi antenna (CAVA). Then a triangular shaped dielectric lens has been added. Finally, a Koch fractal shape dielectric cover is added to the antenna for enhancement of the directivity. The presence of this surrounding dielectric lens produces stronger radiation which enhances the gain and directivity of the antenna. The antenna is optimized using CST which shows S11 below -10 dB from 4.2 GHz to 45 GHz band which is applicable for medical imaging applications. The dimension of the proposed antenna is 155×66×1.524 mm
³
. Results show that S
₁₁
characteristics and other parameters are in good agreement with the simulation counterpart.