A Note of Poynting Flow of Power of Sketch Mapping for a YAGI-UDA Antenna Above a Flat Ground

Abstract

Because of their simple geometry, Yagi-Uda antennas have been widely used in various fields. There are a variety of techniques to analyze the near field of antennas. To examine how electromagnetic wave energy propagates around antennas, we calculated Poynting power flow. The strength of Poynting power flow is expressed by the number of arrows. In this paper, we calculated Poynting's vectors for a three-element Yagi-Uda antenna using parameters of maximum gain and maximum F/B ratio, when placed on a flat ground (wet and dry ground) and also on a perfect conductor plate. As a result, it is found that the rotating power flow can be observed in the case of specific height and above the feeding element due to the effects of reflected wave.