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 × 36 mm2. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:783–787, 2016