High‐isolation 2.4/5.2/5.8 GHz WLAN MIMO antenna array for laptop computer application

An isolation technique for two small-size triband wireless wide area network (WLAN) multiple-input multiple-output (MIMO) laptop computer antennas covering the 2.4/5.2/5.8 GHz bands is presented. The proposed WLAN MIMO antennas have measured isolation of better than −21 dB in the 2.4 GHz band and −32 dB in the 5.2/5.8 GHz bands in this study. In addition to enhanced isolation achieved, good antenna efficiencies of better than about 70 and 90%, respectively, in the 2.4 GHz and 5.2/5.8 GHz bands are obtained for the two antennas. The WLAN MIMO antenna array having a planar structure of size 9 × 55 mm2 is to be mounted at the top edge of the supporting metal plate of the laptop display. The two antennas can be fabricated at low cost on a thin FR4 substrate and are of a simple structure comprising a driven strip and a shorted strip, which provides two wide operating bands to cover the 2.4 and 5.2/5.8 GHz bands. Between the two antennas, there is an isolation element formed by a protruded ground plane and a spiral open slot embedded therein. The isolation element leads to enhanced isolation between the antennas in the 2.4/5.2/5.8 GHz WLAN bands and good antenna efficiencies for the antennas as well. Details of the isolation technique for the WLAN MIMO antennas are described, and the obtained results are presented and discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:382–387, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27279