Investigation and improvement of the phase-center characteristics of VIVALDI's antenna for UWB applications

In this article, the phase center of antipodal Vivaldi antennas is investigated, because the phase center location of antennas is an important parameter for pulse transmission/reception. A comparison between these models is presented and our model is proposed to reduce their drawbacks by some techniques to show the effect of these techniques or benefits of them by numerical simulations and experimental results. Vivaldi antenna is celebrated for its benefits such as low profile, easy fabrication, high gain, end-fire radiation pattern. In this article, the phase center behavior in antipodal Vivaldi antenna is shown and a novel implementation of a perpendicular lens and planner aperture are presented on an antipodal antenna for modification of the Phase-Center characteristic in single. We have presented a novel technique for amending pattern and gain parameters to achieve linear phase center in the wide bandwidth. In this new method, we have combined the aperture method with Vivaldi antenna. The final antenna shows good performance in 2-18 GHz with VSWR less than 2 and the gain of the antenna is enhanced more than 1-2 dBi in comparison with conventional Vivaldi antenna. The antenna is fabricated on roger 4003 and the experimental result confirms the simulations. (c) 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1275-1281, 2016