# Design and Development of a Wideband Planar Yagi Antenna Using Tightly Coupled Directive Element
)1 Department of Electrical Engineering, King Saud University, Riyadh 11421, Saudi Arabia; [EMAIL_ADDRESS] (M.A.A. ); [EMAIL_ADDRESS] (K.J. )1 Department of Electrical Engineering, King Saud University, Riyadh 11421, Saudi Arabia; [EMAIL_ADDRESS] (M.A.A. ); [EMAIL_ADDRESS] (K.J. )1 Department of Electrical Engineering, King Saud University, Riyadh 11421, Saudi Arabia; [EMAIL_ADDRESS] (M.A.A. ); [EMAIL_ADDRESS] (K.J. )1 Department of Electrical Engineering, King Saud University, Riyadh 11421, Saudi Arabia; [EMAIL_ADDRESS] (K.J. )1 Department of Electrical Engineering, King Saud University, Riyadh 11421, Saudi Arabia; [EMAIL_ADDRESS] (M.A.A. ); [EMAIL_ADDRESS] (K.J. )1 Department of Electrical Engineering, King Saud University, Riyadh 11421, Saudi Arabia; [EMAIL_ADDRESS] (K.J. )1 Department of Electrical Engineering, King Saud University, Riyadh 11421, Saudi Arabia; [EMAIL_ADDRESS] (M.A.A. ); [EMAIL_ADDRESS] (K.J. )1 Department of Electrical Engineering, King Saud University, Riyadh 11421, Saudi Arabia; [EMAIL_ADDRESS] (K.J. )1 Department of Electrical Engineering, King Saud University, Riyadh 11421, Saudi Arabia; [EMAIL_ADDRESS] (K.J. )1 Department of Electrical Engineering, King Saud University, Riyadh 11421, Saudi Arabia; [EMAIL_ADDRESS] (M.A.A. ); [EMAIL_ADDRESS] (K.J. )1 Department of Electrical Engineering, King Saud University, Riyadh 11421, Saudi Arabia; m.  
a narrow bandwidth (<10%) [17; 18]. Research efforts on improving the performance of typical Yagi antennas by exploiting their fundamental design principles have been presented in the literature. As a result, a new antenna structure called quasi-Yagi was proposed to improve the conventional Yagi antenna performance [19]. This antenna was first introduced by [PERSON] in 1991. However, one critical limitation of the Quasi-Yagi antenna is its lower gain compared to the classic Yagi antennas. Several techniques for simultaneously enhancing the bandwidth and gain of microstrip Yagi antennas have been proposed in the literature [20; 21; 22; 23; 24; 25]. The printed Yagi antenna consists of a dipole antenna acting as a feed, which is called driven element. The directive elements are printed toward the end-fire direction to enhance the gain of the antenna by directing the electromagnetic energy toward a specific direction. The front-to-back ratio and gain over a broad bandwidth or multiple bands can be improved by increasing the number of directive elements. However, this technique increases the overall size of the antenna. For example, a printed Yagi antenna comprising two different types of feeding networks (i.e., loop and dipole types) has been proposed in [26]. This antenna exhibits a fractional bandwidth of 23% and 16% with a gain of 4.7 and 3.65 dBi, respectively. However, the gain enhancement achieved by increasing the number of directive elements is limited as the multiple incorporated directive elements introduce a phase shift at the center frequency of operation in a particular band. Such degradation in antenna performance is not suitable for broadband applications [27]. A broadband Yagi antenna comprising modified bowtie driven dipole is presented in [28]. The presented antenna is very compact with an excellent fractional bandwidth of 42%. However, the maximum gain value is about 4 dBi as it has employed only one directive element to maintain the antenna's compactness. In [29] a magnetic dipole quasi-Yagi antenna based on a dielectric resonator (DR) is presented. The gain of DR based Yagi antenna is found greater than the traditional ones. However, because of DR high quality factor property, the fraction bandwidth is limited to 3% only. A compact planar Moxon-Yagi composite antenna is presented in [30]. This hybrid antenna operate over dual bands with fractional bandwidth and gain values of 3.2% and 5 dBi, respectively. Similarly, a compact printed Yagi antenna based on half bow-tie monopole element, two director strips and finite ground plane is presented in [31].