Multi-band planar inverted-F (PIFA) antennas and systems with improved isolation

Exemplary embodiments are provided of multi-band Planar Inverted-F antennas and antenna systems including the same. In an exemplary embodiment, a Planar Inverted-F antenna (PIFA) generally includes a planar radiator having a slot and a lower surface spaced apart from the upper radiating patch element. First and second shorting elements electrically connect the planar radiator to the lower surface. The PIFA also includes a feeding element electrically connected between the upper radiating patch element and the lower surface. The PIFA may be mounted on a ground plane that is larger than the lower surface of the PIFA.