Wideband dual-frequency double inverted-L CPW-fed monopole antenna for WLAN application

A novel and simple wideband dual-frequency design of a coplanar waveguide (CPW)-fed monopole antenna is proposed. The antenna comprises a planar patch element with a sided L-shaped slit to become a double inverted-L monopole and is capable of generating two separate resonant modes with good impedance matching conditions. Prototypes of the proposed antenna have been constructed and studied experimentally. The measured results show good agreement with the numerical prediction, and good dual-frequency operations with -10 dB impedance bandwidths of 7.3% and 35.1% at the resonant frequencies of 2.48 and 5.22 GHz, respectively, which cover the 2.4/5.2/5.8 GHz WLAN operating bands. Also, good monopole-like radiation patterns and antenna gains over the operating bands have been obtained.