International Science and Technology Journal

The Yagi-Uda antenna is a popular design for high gain in directional antennas. Antennas represent challenging to design due to high gain sensitivity. It is conventionally used for high gain and directionality applications, often inserting additional directors lead to increase the gain. The aim of this paper is to optimize and improve its gain and bandwidth by changing director lengths and optimizing spacing between directors. In this paper, to optimize this gain, four elements of directors and spacing between them have been considered. Adding number of directors can increase gain. However too many elements can raise losses and decrease efficiency. Spacing between directors is crucial for overall performance. The length and diameter of directors also affect gain. By adding more uniform and non-uniform directors, the maximum gain reached. Simulation and testing were applied on the model using MATLAB simulation tool. A significant improvements were obtained in gain and bandwidth compared to the original design, making Yagi-Uda antenna more suitable for applications in field of wireless communication or radar systems. Keywords: Yagi-Uda antenna, active Element antenna gain, Antenna directors.