Research Article published by Journal of Interdisciplinary Sciences Volume 1, Issue 1; November 2017
A Yagi-Uda Antenna, commonly known simply as a Yagi antenna or Yagi, is a directional antenna system consisting of an array of dipole and additional closely coupled parasitic elements (usually a reflector and one or more directors) (Dubey and Zafar, 2014). The second dipole in the Yagi-Uda array is the only driven element with applied input/output source feed, all the others interact by mutual coupling since receive and radiate electromagnetic energy, they act as parasitic elements by the induced current Dubey and Zafar (2014). It is assumed that an antenna is a passive Reciprocal device, then may be used either for transmission or for reception of the electromagnetic energy this well applies to Yagi-Uda also (Dubey and Zafar, 2014). These antennas are directional along the axis perpendicular to the dipole in the plane of the elements, from the reflector toward the driven element and the director(s). A Yagi-Uda Antenna is a widely used Antenna design due to its high forward gain capability, low cost and ease to construction (Balanis, 2011).
It is commonly used as a roof top television receiver. Basically as antenna is a real system that matches or coupled the energy to the free space. One element is energized directly by a