Ultra-wideband planar inverted-F antennas with cut-etched ground plane

Improved bandwidth property of the planar inverted-F antenna (PIFA) is presented by using a cut-etcheded ground plane. A demonstration PIFA exhibits more than 100% bandwidth with resonance covering all wireless local area network frequencies and 2-6 GHz mobile broadband wireless access applications. It is shown that such an ultra-wideband PIFA will achieve nearly omnidirectional radiation pattern at 2.4/2.5 GHz, and mainly backward radiation at 3.8 GHz and 5.1-5.8 GHz.