Planar multi-band monopole antenna with L-shaped parasitic strip for WiMAX application

A multi-band design of a planar inverted L-shaped monopole antenna with an L-shaped parasitic strip for the WiMAX system is proposed. With the use of L-shaped monopole and parasitic strips, multi-resonant modes close to the 2.6/3.5/5.5 GHz bands are excited to meet the specifications of the WiMAX system (IEEE 802.16e). Also, obtained impedance bandwidth across the operating bands can reach about 270/1000/1250 MHz for the 2.6/3.5/5.5 GHz bands, respectively. With a nearly omnidirectional pattern in the xy-plane, measured peak gains and radiation efficiencies are about 3.7/3.1/4.8 dBi and 68/80/84% at the 2.6/3.5/ 5.5 GHz operating bands, respectively.