Extremely wideband printed monopole antenna with dual rejection bands

摘要

An extremely wideband (EWB) microstrip antenna is presented that is designed with band rejection characteristics at C and WLAN bands. This is achieved by embedding inside the inverted triangular shaped patch a pair of L-shaped slits that have been rotated by ±90° so that they are horizontal and downward facing, and topping the patch with an arrow-shaped strip. The feedline to the patch also needs to be backed with a trapezoid shaped ground-plane. The center frequency of the notched bands can be easily controlled by altering the parameters of the slits and arrow-shaped strip. The low-profile antenna essentially radiates omni-directionally and has a measured impedance bandwidth of 18.9 GHz (2.9–21.8 GHz) with a VSWR ≤ 2, except at the two rejection bands. The antenna has an average gain > 3 dBi.