Design of UWB Planar Band-Notched Antenna Using Parasitic Elements

A method is described to reject certain bands within the passband of an ultrawideband (UWB) planar antenna using parasitic elements. In the presented design, the antenna is created by a planar monopole and a ground plane both of half circle shape, whereas parasitic elements are in the form of printed strips. Four examples of UWB antenna design are shown. The first design is without parasitic, while the remaining ones are with parasitics to reject a single narrow band, a wide band or three narrow bands. The results of simulation and measurements show that all these antenna designs exhibit a 10-dB return loss bandwidth from 3 GHz to 11 GHz excluding the rejected bands. More than 10 dB gain drop is recorded in the suppressed bands. The time domain transmission test between two identical antennas without the parasitic strips shows an almost distortionless pulse performance.