A Compact Tri-Band Antenna for WLAN and WiMAX Applications

A compact tri-band antenna is proposed in this paper. The tri-band operation and bandwidth enhancement are achieved through the introduction of curved branches to a coplanar waveguide(CPW) fed monopole and L-shaped slots into the ground plane. Simulation results show that the lower band (2.32 - 2.58 GHz) of the proposed antenna covers the 2.4 GHz WLAN band, the middle band (3.38 - 3.81 GHz) covers the 3.5 GHz WiMAX band, and the upper band (4.39 - 6.93 GHz) covers the 5.2/5.8 GHz WLAN and 5.5 GHz WiMAX bands. Furthermore, the antenna is rather compact, with a size of only 0.21 ×0.28 × 0.01 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\lambda_{0}^{3}$</tex>, where <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\lambda_{0}$</tex> is the freespace wavelength at the central frequency of the lower band.