Design of a practical dual-band planar monopole antenna for WLAN and WiMAX applications

The design of a microstrip based compact dual band Monopole Antenna for Wireless Local Area Network (WLAN) and WiMAX (Wi-Fi) applications is presented. The antenna consists of two symmetric twisted arms fed by a 50 Ω microstrip line. The basic design and the numerical simulation of the proposed antenna are carried out using a full wave electromagnetic simulator, the CST Microwave Studio. Various design parameters are optimized for a better performance, and a detailed parametric analysis is also carried out in order to study the effects of various parameters. The antenna is designed to operate at two resonating frequencies corresponding to the ISM bands of 2.4 GHz and 5.2 GHz, respectively. The antenna is fabricated after freezing its design with an optimized size of 28×23 mm², and its return loss is measured with the help of a network analyser. The measured data match reasonably well with the simulated values. The proposed antenna is seen to have very low return loss (S11< −15 dB) at both the operating frequencies, and a good radiation characteristics.