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A quad-element LTE MIMO antenna on a finite ground plane for femtocell base stations

Abstract A quad-element multiple-input–multiple-output (MIMO) antenna for compact long term evolution (LTE) base stations is proposed. While most of the literature on LTE base station antennas concerns only the upper frequency bands (1710−2690 MHz), this work not only focuses on the wideband performance enhancement of LTE700/850/900 (698−960 MHz), but it also employs four-unit antenna elements, which are the maximum number to date for compact base stations aiming at LTE700/850/900. A pentagonal conductor wall is established on the ground plane; accordingly, not only does isolation improve, but the electromagnetic interference (EMI) between the antenna and other electronic components is reduced. Although the design space exhibits a highly truncated ground plane, we design a top-loading meandered monopole with dual sleeves attached to each side of the radiating body, optimizing the characteristics of impedance bandwidth and radiation efficiency concurrently. The experimental results show that the impedance characteristics, radiation performances, and signal correlation are highly desired for femtocell base stations.