The pair of narrow slots of MSSA 1 as shown in figure 1 resonates at two frequencies; at 3.51 GHz
with return loss (RL = – 14.10 dB) and at 4.52 GHz (RL = – 17.14 dB) signifying dual band nature is
depicted in figure 2. An impedance bandwidth of 230 MHz (5.8 %) and 140 MHz (3.9 %) are obtained
at these two independent resonant frequencies with a moderate gain of 5.6 dB and 4.3 dB. MSSA 2
also resonates at two frequencies; at 3.81 GHz with return loss (RL = – 16.58 dB) and 5.16 GHz (RL =
– 15.21 dB) as shown in figure 2 with achievable impedance bandwidth of 280 MHz (7.5 %) and 170
MHz (4.6 %) and a moderate gain of 3.7 dB and 4.9 dB. Due to the pair of wide slots printed on
MSSA 2, the impedance bandwidth is increased to 280 MHz compared to impedance bandwidth of
MSSA 1. As shown in figure 1 (c), when one horizontal and vertical slots are printed, the MSSA 3
resonates at two lower frequencies compared to MSSA 1 and MSSA 2; i.e., at is 2.22 GHz with return
loss (RL = – 24.98 dB) and 3.68 GHz (RL = – 19.89 dB) with achievable impedance bandwidth of 195
MHz (4.9 %) and 260 MHz (5.6 %) with a peak gain of 5.75 dB and 7.58 dB.