A compact CPW-fed hexagonal 5 GHz/6 GHz band-notched antenna with an U-shaped slot for ultrawideband communication systems

A planar ultrawideband (UWB) antenna with an U-shaped slot for a 5/6 GHz band notched characteristics is presented. The antenna is a planar structure and has a compact area of 25×25 mm
²
, which covers the frequency band from 3.1 GHz to 10.6 GHz (VSWR ≤2). The antenna has an elliptical slot cut in the ground plane and a hexagonal patch is printed within that. A 50-Ω coplanar waveguide (CPW) transmission line is used to feed the printed hexagonal metal patch. By removing a U-shaped slot from the hexagonal patch, band rejected property in the WLAN band is obtained. The compact antenna has the promising performance including broadband impedance matching, consistent radiation pattern and stable gain. An equivalent circuit model of the proposed antenna is presented to explore the band-notch function of the UWB antenna.