3. Results and Discussion
Fig. 2 shows the photograph of the fabricated prototype
of the proposed 9-shaped monopole antenna for
2.45 GHz (WLAN) and 5.2 GHz (RFID) applications.
Fig. 3 shows the comparison of the simulated return loss
(|S11|) and the measured return loss. The return loss measurement
was done using the Rohde and Schwarz ZVA24
vector network analyzer. From the graph, it is quite clear
that there is reasonably good agreement between the measured
and the simulated return losses. The first simulated
resonance frequency (f1) occurs at 2.54 GHz at the return
loss value of -15.02 dB with the percentage bandwidth of
29.35 (2.18 GHz to 2.93 GHz). The second simulated
resonance frequency (f2) occurs at 5.13 GHz at the return
loss value of -24.87 dB with the percentage bandwidth of
34.20 (4.46 GHz to 6.30 GHz). Similarly the first resonance
(f1) occurs at 2.46 GHz having a measured returnbandwidth in the tabular form