A Wideband Sleeve Monopole Antenna

A wideband sleeve monopole antenna is presented. In this design, a cylindrical sleeve is introduced to enhance the impedance bandwidth. For reducing the weight of the antenna, a hollow metal tube is employed as the main radiator. Moreover, another four rectangular stubs are introduced for impedance matching. It is shown that the proposed sleeve monopole antenna achieves an impedance bandwidth of 141.2% (1.16-6.74GHz) for voltage standing wave ratio (VSWR) ≤ 2, and the antenna has symmetrical radiation patterns over the operating frequency band. Therefore, it is suitable for the applications of wide wireless communication.