A Quasi Yagi Antenna Backed by a Metal Reflector

A quasi Yagi antenna is presented that provides off-axis radiation when backed by a metal reflector. The off-axis radiation pattern is achieved by an increase in the substrate thickness beneath the antenna elements. At 2.4 GHz the antenna demonstrated a bandwidth of 190 MHz, beam tilt towards the end fire direction (thetas = 42^deg) , maximum gain of 4.5 dB, and a radiation efficiency of 87%. The results of a study on bandwidth, gain and radiation pattern versus substrate thickness are presented herein. To the best of the authors´ knowledge previous realization of this antenna over a ground plane has not been investigated.