On the isolation of two LTE700/2300/2500 antennas in the laptop computer

A simple technique for achieving enhanced isolation between two long-term evolution (LTE)700/2300/2500 antennas for the multiple-input multiple-output operation in the laptop computer is presented.The two antennas are mounted along the top edge of the supporting metal plate, which is generally disposed on the inner surface of the upper cover of the laptop computer. Improved isolation (measured S21 better than −30 dB in the LTE700 band and −26 dB in the LTE2300/2500 bands) between the two antennas is easily achieved by adjusting the supporting metal plate to have a length of about 110 mm in the longitudinal direction (orthogonal to the lateral direction or the top-edge direction of the supporting metal plate). Because the length is close to a quarter wavelength of a frequency in the LTE700 band, the excited surface currents in the supporting metal plate will become stronger in the longitudinal direction, which hence causes weaker surface currents flowing along the top edge of the supporting metal plate. This behavior leads to enhanced isolation between the antennas mounted along the top edge of the supporting metal plate. Details of the proposed isolation technique are described, and the obtained results are presented and discussed. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1370–1375, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27555