Gain enhancement of a CPW - Fed horse shoe shaped slot antenna with defected ground structures for WiMax/WLAN applications

In this paper we present, design and analysis of a coplanar waveguide (CPW) fed slot antenna for broadband applications. The technique of Defected Ground Structure (DGS) is used to enhance the gain of proposed antenna. The antenna size is compact with dimension of 30 × 43 × 1.6 mm³, built over low cost FR4-epoxy substrate with relative permittivity of ε_r = 4.4. The antenna covers Wireless Local Area Network (WLAN) applications including WLAN IEEE 802.11 g/a (5.15 GHz - 5.35 GHz and 5.725 GHz - 5.825 GHz) band and Worldwide Interoperability for Microwave Access (WiMAX) applications at 2.5 GHz - 2.69 GHz, 3.4 - 3.69 GHz, and 5.25 GHz - 5.85 GHz bands ; HIPERLAN/1/2 (5.150 GHz) and upper Ultra Wide Band (UWB) applications, at 3 GHz - 6 GHz Prototype of the proposed antenna is fabricated and measured for its performance evaluation. The experimental results show that impedance bandwidth (S₁₁<; -10 dB) of antenna is 85.135%. The performance of proposed antenna (with DGS) is compared to conventional slot antenna (without DGS) in terms of reflection coefficient, radiation characteristics and gain.