Bandwidth enhancement of single notch planar UWB antenna with single step feed line

A compact single notch microstrip-fed monopole ultra-wideband (UWB) antenna with bandwidth (BW) enhancement is proposed. To improve the impedance BW, a rectangular slot is etched in the bottom edges of a rectangular radiating patch and the feed line is modified in staircase manner with single step junction. As a result, the antenna achieves a wide operational impedance BW ranging from 3.25 to 40 GHz for return loss (RL) > 10 dB. Also, a band rejection with center frequency at 5.5 GHz is introduced to avoid the interference caused by WLAN system. The rejected band, inherent in the antenna characteristics, is created by etching a thin rectangular slot in the patch. The proposed antenna dimensions are 35×30×1.6 mm³ was built using FR-4 substrate. In comparison to other antenna designs devoted to enhance the impedance BW for future UWB applications, this antenna has simple structure suitable for fabrication and integration. RL, peak realized gain, radiation efficiency, surface current distribution, and the effect of varying geometric parameters of the antenna on the notch band are studied using high frequency structure simulator (HFSS).