A miniaturized elliptic-card UWB antenna with WLAN band rejection for wireless communications

An elliptic-card ultra-wideband (UWB) (3-11 GHz) planar antenna is designed and miniaturized. It consists of an elliptic radiating element and a rectangular ground plane. A novel feeding mechanism is proposed to feed the antenna by using a microstrip line on the other side of the substrate and connecting the line to the elliptic element by a via. The structure of the antenna is miniaturized by optimizing its elliptic profile and the required ground plane to obtain only 22 x 40 mm dimension. The antenna is then modified to possess band rejection at the wireless local area network (5.1-5.8 GHz) band by adding two slits within the elliptic element. Critical antenna characteristics are verified by measurements including the antenna transfer function. Housing effects on the antenna performance are also studied. The satisfactory overall performance with such a simple structure and small size makes this antenna a viable candidate for UWB wireless communications applications.