Design of a four-element multiple-input-multiple-output antenna for compact long-term evolution small-cell base stations

作者：Chen Yen Sheng^*; Chang Cheng Pang

来源：IET Microwaves Antennas & Propagation, 2016, 10(4): 385-392.

DOI：10.1049/iet-map.2015.0540

This study presents a multiple-input-multiple-output (MIMO) antenna for compact small-cell base stations operating in the long-term evolution (LTE) standard. This MIMO antenna comprises four unit antenna elements, targeted at the frequency band of LTE700/850/900 (698-960 MHz). In comparison with the state-of-the-art MIMO antennas covering these frequency bands, the proposed design enables the maximum number of antenna elements, yet it occupies a compact volume of only pi x 80(2) x 50 mm(3) (pi x 0.18(2) x 0.11 lambda(3)), which is the most miniature electrical configuration to date. The unit antenna element consists of a monopole antenna with a sleeve attached to each side, fed by a coaxial cable. Since the spacing between antenna elements is so small (0.24 lambda), this work uses four miniature and wideband defected ground structures (DGSs) to reduce the mutual coupling; moreover, although the DGSs adversely alter the impedance matching of unit element, the authors applied multi-objective fractional factorial design to achieve isolation enhancement and bandwidth preservation simultaneously. Accordingly, the optimised MIMO antenna shows desired -10 dB impedance bandwidth and sufficient isolation in the targeted frequency band. In addition, the radiation patterns, antenna efficiency, and the signal correlation coefficients are measured and evaluated.

• 出版日期2016-3-19