A Simple dual-band quasi-Yagi antenna with defected ground structures

Abstract

In this article, a dual-band compact quasi-Yagi antenna with defected ground structure (DGS) is proposed. The proposed antenna has a simple feeding mechanism consists of a microstrip and transmission line. Half of the driver and director elements are printed on the opposite side of the substrate to ensure good coupling between the antenna elements and achieve a stable radiation pattern. The ground plane is modified with one rectangular slot below the microstrip line to form dual-band operation. Also rectangular slots placed on the sides of the ground plane to improve the matching. The proposed antenna works at f1 = 3.35 and f2 = 6.15 GHz, respectively. The antenna efficiency is above 88% at f1 and 78% at f2 with bandwidths of 11.8% and 9.7%, respectively. The realized gain is around 4.3 dBi at both frequency range with an end-fire radiation characteristics. An excellent agreement is observed between the simulation and measurement results. The proposed antenna is suitable for dual-band operations in wireless communications systems.