This paper presents a planar inverted-F antenna (PIFA) for ultra-wide band (UWB) communication, which is printed on a dielectric substrate of FR4-epoxy with 4.4 relative permittivity (ɛr), 2 mm thickness. This antenna is designed to be used in a 2.9–10.7 GHz frequency band, and a very wide bandwidth is realized by the addition of a parasitic element and a J-shaped slot to the PIFA. The effects of varying the parameters of the antenna on the performance have been investigated.