An UWB planar inverted-F antenna for wireless applications

The planar inverted-F antenna (PIFA) is widely used in mobile and portable radio systems due to its excellent features. However, it is not yet employed as an ultra wide band antenna because it was considered a narrowband antenna. This paper introduces an ultra wideband planar inverted-F antenna based on three techniques, which are (a) changes in the widths of feed and shorting plates, (b) addition of an inverted-L shaped parasitic element and (c) addition of a rectangular parasitic element. It is shown that ultra wideband PIFAs with fractional bandwidth of more than 100 % is achieved covering from 3.4 GHz to 10.7 GHz. Simulated and measured results are provided to verify the conclusion.