Compact Ultrawideband Monopole Antenna With an Inverted-L-Shaped Coupled Strip

Abstract

We present a compact, ultrawideband, and planar monopole antenna that is composed of a C-shaped radiator and an inverted-L-shaped coupled strip extending from the ground plane. A wideband impedance bandwidth is achieved; the monopole antenna itself operates over a higher frequency range, while an increased electrical length due to the combination of the radiating element with the L-shaped strip operates over a lower frequency range. Furthermore, a coupling effect between both structures improves the impedance matching. The impedance bandwidth measured from 2.3 to 10.8 GHz includes the WiMAX (2.30-2.39, 2.50-2.69, 3.4-3.8, and 5.72-5.85 GHz), WLAN (2.4-2.48 and 5.15-5.875 GHz), S-DMB (2.605-2.655 GHz), and UWB (3.1-10.6 GHz) bands.