A Compact UWB Antenna with Sharp Dual Band-Notched Characteristics for Lower and Upper WLAN Band

A compact dual band-notched Ultra-Wideband antenna with sharp band-notched characteristics and controllable notched bandwidths is presented. The antenna consists of a spade-shaped microstrip-fed Ultra-Wideband planar monopole antenna and two sets of band-notched structures. The band-notched structures are employed to generate the desired lower and upper rejection bands with good frequency selectivity and sufficient rejection bandwidths. Moreover, the bandwidth of the lower and upper rejection bands can be independently adjusted by changing the size of the band-notched structures. Finally, a UWB antenna is successfully designed with the dual notched bands for the lower WLAN band (5.15-5.35 GHz) and upper WLAN band (5.725-5.825 GHz). A good impedance match is obtained in 3.1-10.6 GHz frequency range (||<-10 dB), except the lower and upper WLAN band (|| >-5 dB). The ratios of the notched bandwidths between -5 dB and -10 dB in the two stop bands are greater than 0.73.