Figure 4 (a), (b) and (c) shows the Smith chart plots of impedance locus versus frequency for the
proposed microstrip slot antennas 1, 2 and 3 (MSSA 1, MSSA 2 and MSSA 3). The presence of two
loops on the Smith chart shows dual band characteristics. Hence, the design parameters of the antenna
lead to good impedance matching between the input and the load in S and C band frequency range.