Compact MIMO antenna for Bluetooth, WiMAX, WLAN, and UWB applications

This paper presents a compact multiple-input-multiple-output (MIMO) antenna for wireless portable device applications. It entirely covers the Bluetooth (2.4-2.484 GHz), Worldwide Interoperability for Microwave Access (WiMAX) (3.4-3.69 GHz), Wireless Local Area Network (WLAN) (5.15-5.825 GHz), and ultra-wideband (UWB) (3.1-10.6 GHz) operating bands. This antenna consists of two planar polygon printed monopole(PM) antennas, a rectangular slot and a triangular trim on the antenna element to lower down the low-cutoff frequency for improving the impedance matching, and a stepped ground stub to improve the isolation. Two rounded corners are simultaneously used on the ground for the impedance matching at medium-high frequency. The results of simulation and measurement prove that the -10 dB bandwidth of this antenna is from 2.4 to 11 GHz, and the isolation is less than -15 dB in the entire band, which can satisfy the actual requirements according to most literatures. The envelope correlation coefficient is less than 0.02. The size of this antenna array is 40 x 36 mm(2). (c) 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:783-787, 2016