A compact shorted rectangular‐ring slot antenna fed by a CPW for circularly polarized wave operations in the WLAN 2.4 GHz band

Abstract

Abstract A compact shorted rectangular‐ring slot antenna fed by a coplanar waveguide is presented for circular polarization operations. This proposed antenna has only 40 mm square size in the applications of WLAN 2.4 GHz band. It seems the most compact size while referenced to other shorted ring slot antennas in recent articles. The reduced size is over 30% will save much cost and antenna can apply to portable devices. Simulated and measured data are matched in the reflection coefficient, axial ratio (AR), radiation patterns, and gain. Its measured center frequency and impedance bandwidth are 2.38 GHz and 15.1%, respectively. Also, the frequency of minimum axial‐ratio and axial‐ratio bandwidth are 2.43 GHz and 4.1%, respectively. From the bandwidths of view, both impedance and AR bandwidths can cover the 2.4 GHz band's applications. The radiation patterns are broadside radiations. Forward radiation belongs to right hand circular polarization and backward one is left hand circular polarization, respectively. Also, antenna gain is about 3 dBic in the operating band of WLAN 2.4 GHz band. The antenna performances and compact size of the proposed antenna are easy to be applied in the consumer products. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2229–2232, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24524