The design and simulation of a compact Vivaldi Shaped Partially Dielectric Loaded (VS-PDL) TEM Horn antenna for UWB applications

Ultra wide band (UWB) antennas are of huge demand and Vivaldi antennas as well as the TEM Horn antennas are good candidates for UWB applications as they both have relatively simple geometry and high gain over a wide bandwidth. The aim of this study was to design such an antenna that achieves the maximum antenna gain over a bandwidth between 1 GHz to 10 GHz while minimizing the size of the antenna. The idea was to make use of combined respective advantages of Vivaldi antennas and TEM Horn antennas to achieve the desired goals by shaping the TEM Horn antenna to look like a Vivaldi antenna. The antenna structure was modified by partially dielectric loading it in the center to increase the gain and bandwidth. It was placed in a surrounding box made of PEC material to reduce the undesired side lobes to obtain a more directive radiation pattern. The simulations were performed by using the CST STUDIO SUITE Electromagnetic (EM) Simulation software. The results showed that the Vivaldi Shaped Partially Dielectric Loaded (VS-PDL) TEM horn antenna with 5 cm aperture depth had the best gain values over the desired bandwidth. This antenna is considered as compact enough for applications like hand-held impulsive Ground Penetrating Radar (GPR) and Electromagnetic Compatibility (EMC) measurement systems due to its reduced size and shielded metallic box structure.