Compact concentric ring shaped antenna for ultra wide band applications

A novel antenna for compact size, simple structure suitable for low cost fabrication is proposed for UWB application. A compact ring shaped monopole antenna is designed to cover the entire ultra wide bandwidth which has straight forward printed circuit board integration. The dimensions of the antenna are 16mm x 12mm x 0.787mm. More specifically, the impedance matching of the antenna is improved by employment of the tapered microstrip feed line. The measurement and simulation results show that the proposed antenna achieves good impedance bandwidth from 6.5 GHz to 25 GHz which covers the entire UWB. The antenna also has a gain approximately 2.5dBi from 6 GHz to 22 GHz. Compared to the existing UWB antennas, the presented modified structure has the smallest size, the widest bandwidth and better return loss characteristics.