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 28x23 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.