“…However, employing waveguide horn antennas is a common way of realizing Monopulse antennas, but it suffers from large size and difficulty in instruction. The challenge of solving this problem led to applying planar structure antennas such as Microstrip and substrate integrated waveguide (SIW) antennas in designing Monopulse radar [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12]. Circularly polarized (CP) antennas have unique features such as the ability to reduce polarization mismatch resulting from the multipath interference of wave propagation and also the ability to cross the ionosphere has been considered by many researchers in various applications [4], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22].…”