Band-notched UWB antennas: Recent trends and development

Since the approval and allocation of the frequency range of 3.1-10.6 GHz, ultrawideband (UWB) technology has become one of the most promising technologies for the high-data-rate wireless communications. Compact UWB antenna, as an essential part of the UWB system, has become the main subject of recent researches. Several techniques have been reported in the literature showing desirable characteristics. However, with an increase in the number of wireless communication devices, there is a problem of a possible electromagnetic interference, as over the allocated spectrum of the UWB system, some narrow band of other communication standards exist. In this paper, we summarize the main recent applied techniques used to suppress electromagnetic interferences with such narrow bands. Three notched bands relative to WiMAX, WLAN and for downlink X-band satellite communication systems are achieved by incorporating a stick of semicircular half-wavelength and open-ended quarter-wavelength straight slots etched in the radiating patch. Dual notched-bands can also achieved by incorporating two Γ-shaped slits and Ω-shaped parasitic structure in the radiating patch. Another technique, applied to suppress interference, consisted of two short-circuited folded Stepped Impedance Resonators (SIRs) embedded in the ground plane. The last presented band-notching technique consists of incorporating slots in both radiating patch and ground plane. The studies and discuss are followed by experimental and simulated reported results such as the coefficient reflexion over the allocated spectrum of the UWB system, the impedance bandwidth, radiation patterns and the antenna dimensions.