Multiband Operation and Performance Enhancement of the PIFA Antenna by Using Particle Swarm Optimization and Overlapping Method

Table 3

PIFA characteristics.

HFSS			CST
Resonant frequency (GHz)	Reflection coefficient (dB)	Bandwidth (%)	Resonant frequency (GHz)	Reflection coefficient (dB)	Bandwidth (%)
2.21	−24.21	18.55	2.14	−35.81	18.69
2.89	−36.25	30.10	3.18	−28.16	21.38
5.58	−21.03	23.11	5.95	−26.83	22.68