III. SIMULATION AND EXPERIMENTAL RESULTS
A. Return Loss Fig. 2 shows the comparison between the simulated and measured return loss (S11) of the proposed monopole antenna. The differences between the simulation and experiment results is mainly due to the accuracy of the simulation model and the errors introduced by soldering the chip inductor, which has a small size of only 1.12×0.66 mm2, to the antenna element. During the simulation process, to simplify the simulation model, the inductor was simulated by assigning RLC boundary conditions to a rectangular of size 0.5×0.65mm2 in Ansoft HFSS, which is a simplified consideration. However, from both simulated and measured results, it can be observed that the proposed monopole antenna clearly exhibits two operational bands (S11 < -10dB) at 2 and 5GHz band. The experimental results show that the proposed antenna has a -10dB return loss over 2.55-2.65GHz and 5.1-5.3GHz.