Improved band-notch technique for ultra-wideband antenna

This study describes a compact ultra-wideband (UWB) antenna that exhibits desirable band-notch and gain characteristics. The antenna consists of a rectangular aperture etched on a printed circuit board´s ground plane that is excited by a taper shaped patch. The antenna´s broadband matching impedance is enhanced by inserting periodic open-end stubs (POES) on the inside edge of the rectangular aperture. A band-notch function to eliminate the WLAN interfering signals between 5 and 6´GHz is created on the proposed antenna using three different techniques. It is shown that the frequency of the band-notch characteristic can be tuned by varying the parameters of the notching structure. The antenna was fabricated and its performance measured to validate its feasibility and the band-notch techniques. A compact aperture area of 12´23´mm² is realised which exhibits an excellent voltage standing wave ratio (VSWR) performance and stable radiation patterns over the UWB spectrum.