Research on a novel Yagi-Uda antenna fed by balanced microstrip line

Slots A novel printed Yagi-Uda antenna fed by balanced microstrip line is proposed. All the active dipole, reflector and director are printed on the same side of a dielectric substrate. The feeding line printed on the same side with the dipole is directly connected to one of active dipole's branches, while the other feeding line is printed on the other side and connected to another branch through a via-hole. The simulation software CST MICROWAVE STUDIO® is utilized to optimize the structural parameters. Both simulated and experimental results show that the operating bandwidth is 1.8GHz~2.4GHz with reflection coefficient less than -10dB (relative bandwidth 28.6%). Antenna gain in the band can achieve 5~6dBi, which well matches the simulated results. Moreover, the antenna size is only 78mm×40mm (0.47λ×0.24λ). All the excellent performance of the proposed antenna can meet the requirements of WLAN systems.