A novel polarization diversity antenna for WLAN applications

Due to the advantage of mobility, there are many applications in wireless local area networks (WLAN) in the 2.4 GHz ISM band. For these applications, multipath effects are the common reception problems in dynamic, complex electromagnetic environments. In order to reduce signal fading caused by multipath effects, diversity techniques are usually required for the antenna system at the receiving site. For this reason, a modified printed strip monopole antenna having a polarization diversity with a hybrid feed system is proposed in this paper. From experimental results, it is shown that the impedance bandwidth for the proposed antenna can reach over 17%, and the antenna length is only 17 mm (~0.14 λ₀, where λ₀ is the free-space wavelength of the center operating frequency). Owing to its compactness in antenna length, the proposed antenna can be integrated into a restricted area of 30 mm×50 mm as a part of a WLAN PCMCIA card