Design of microstrip Yagi-Uda antenna array for 4.5 GHz band fixed wireless access in 5G

Fixed wireless is a part of wireless local area network (WLAN) infrastructure which connects two fixed locations, like, tower to building or building to building by radio link or by other wireless link. In fifth generation (5G) for fixed wireless access (FWA) one of the attractive bands is 4.5 GHz band. The designs of a microstrip Yagi-Uda antenna and a 4-element Yagi-Uda array for the application to 5G FWA at 4.5 GHz band are reported here. The experimentally investigated impedance and radiation properties of Yagi-Uda antenna and a 4-element array of it are reported. The antenna has 10 dB return loss bandwidth of 580 MHz which is 12.8% of the centre frequency and the array has bandwidth of 520 MHz which is 11.7% at the centre frequency. The Yagi-Uda antenna array beam is tilted by 46 degrees from the broadside direction. The measured maximum gains of the Yagi-Uda antenna and the 4-element array are 7.2 and 16.5 dBi, respectively. The cross-polarization levels lower by about 20 dB than the main lobes are observed. The Yagi-Uda array has high front-to-back ratio of better than 25 dB. The measured results are compared with the simulated results.