Fig.5: Final designed antenna array
Return loss from the designed single patch antenna substrate, 2-way Wilkinson power divider, 4-way Wilkinson power divider and in the end, final designed 4-element array antenna illustrated from figure (6) to figure (9). 3D radiation pattern of final array antenna is shown in figure (8). Gain, Directivity and Gain-Phase proportion is inhibited in figure (9). All the results were obtained by ADS (2017) software.
Using 4-element array antenna caused an increase in return loss to -35db from 23db for a single element. (Fig 6).