Dual-Band Dual-Polarization Printed Monopole Antenna For Wlan Applications

In this paper, a printed monopole antenna with dual-band and dual-polarization characteristics for WLAN applications is presented. The proposed antenna consists of circular shaped patch antenna fed with a trapezoidal line; two pairs of narrow width arc-shaped slots are placed close to the patch boundary to generate the circular polarization. Good impedance matching is realized for two frequency bands, the first one spreads from 2.34 GHz to 3.68 GHz with a fractional bandwidth of 33.11% the second spreads from 4.83 GHz to 6.49 $\mathbf{G H z}$ with a fractional bandwidth of $\mathbf{3 0. 5 1 \%}$; these frequency bands correspond to WLAN application ranges. An axial ratio less than 1dB over the two frequency bands is achieved. For the 2.45 GHz band the polarization is right circular because the axial ratio is negative and it is right circular for the 5.8 GHz band indicating an interesting dual polarization behavior. Simulation results are provided by using the full wave software package CST microwave studio.