Optimum substrate size for radiation pattern of an H-plane coupled linear microstrip patch antenna array

Radiation characteristics of an H-plane coupled linear microstrip phased array antenna on a finite grounded dielectric substrate with high dielectric constant are investigated. When the H-plane coupled microstrip antenna arrays has an optimum substrate size with the minimum mutual coupling, the broadside gain is significantly improved and the effect of the mutual coupling on radiation patterns is minimized. The excellent radiation performances such as higher main beam gain over the entire scanning range and very low SLL less than -10 dB in the scanning range from -35° to 45° are obtained from the measured results of a 5-element H-plane coupled linear microstrip patch antenna array.