A wideband quasi-Yagi antenna using symmetrical slots on the ground plane

A wideband quasi-Yagi antenna with symmetrical rectangular slots in the ground plane is studied. The feeding structure of the antenna is simplified, consisting of a microstrip transmission line and a short strip. The driver and director arms are designed as half on both sides of the substrate to improve pattern stability. The antenna's bandwidth is improved by symmetrically adding rectangular slots to the ground. The antenna works between 3 and 7.7 GHz with a gain that varies between 4.7 to 7.4 dBi, a bandwidth of 87.8%, and an efficiency of more than 90%. The antenna has a very compact size of 0.42?(L )x 0.42?(L) (?(L) is the wavelength for the lowest operating frequency). The simula-tion and measurement results are in good agreement. The antenna has highly stable end-fire radiation within its operating frequency and can be used for wideband wireless communication systems.