A Wideband Vivaldi Antenna with Fractal Dielectric Lens for Imaging Applications

In this communication a novel fractal inspired antipodal Vivaldi antenna is proposed for wideband applications. A step by step procedure has been employed to design and optimize the performance of the proposed antenna. First, a conventional antipodal Vivaldi antenna (CAVA) is designed as a reference antenna and then a Koch fractal shaped dielectric lens has been added an extension of the antenna substrate. The presence of fractal dielectric lens produces stronger radiation in the end fire direction and also enhances the gain and directivity of the antenna. The optimized antenna is fabricated and tested showing S11 below -10 dB from 4.2 GHz to 42 GHz band. The dimension of the proposed antenna is 129×66×1.524 mm
³
. Results show that S11 characteristics and other parameters are in good agreement with the simulation counterpart.