In this paper a CPW-fed slot antenna for wideband application was designed and simulated. In order to examine the performances of this antenna a prototype was designed at frequency 2.4 GHz and simulated with various width of slot antenna in both sides for input impedances matching and simulated by IE3D software package of Zeland. The simulation result of bandwidth is 1.65 GHz (2.1{3.75 GHz) which covers the standard frequency of IEEE 802.11 b/g (2.4{2.4835 GHz) and Wimax (2.3{3.6 GHz). With these performances the proposed antenna can be used in wideband applications.

The narrow slot loop antenna and linear slot antenna fed by microstrip line are designed for dual frequency at 2.44 GHz and 5.25 GHz on the standard of IEEE 802.11b/g (2.4{2.4835 GHz) IEEE 802.11j/a (5.15{5.35 GHz) and IEEE 802.16d (5.7{5.9 GHz). These structures are easy to adjust the length of slot antenna for dual frequency band. It can control the higher frequency band around 4.9 GHz to 5.8 GHz by linear slot antenna. Adjusting some parameters of narrow slot loop antenna will influence on the resonance frequency and bandwidth. By using IE3D software [1] the characteristics of antenna are investigated and analyzed including instance input impedance return loss and far field radiation patterns.