A dual band-notched ultra-wideband monopole antenna with spiral-slots and folded SIR-DGS as notch band structures

Abstract

In this paper, an ultra-wideband (UWB) planar monopole antenna with impedance bandwidth from 2.83 to 11.56 GHz and dual band-notched characteristics is presented. The antenna consists of a small rectangular ground plane, a bat-shaped radiating patch, anda 50-Ω microstrip line. The notched bands are realized by introducing two different types of structures. The half-wavelength spiral-slots are etched on the radiating patch to obtain a notched band in 5.15 5.925 GHz for WLAN, HIPERLAN, and DSRC systems. Based on the single band-notched UWB antenna, the second notched band is realized by etching a folded stepped impedance resonator as defected ground structure on the ground plane for WiMAX and C-band communication systems. The notched frequencies can be adjusted by altering the length of resonant cells. Surface current distributions and equivalent circuit are used to illustrate the notched mechanism. The performance of this antenna both by simulation and by experiment indicates that the proposed antenna is suitable and a good candidate for UWB applications.