282373.fig.003a
(a)
282373.fig.003b
(b)
282373.fig.003c
(c)
282373.fig.003d
(d)
Figure 3: Parametric analyses of the effect of capacitive ground plane on the return loss of the PIFA. (a) Period effect (  mm, , and  mm), (b) radiating patch height effect (  mm, , and  mm), (c) substrate permittivity effect (  mm,  mm, and  mm), and (d) substrate thickness effect (  mm, , and  mm). The of the conventional PIFA with a solid ground plane is also given in (a).