Measurement of compact MIMO antennas with 0.3 \lambda$ spacing under different polarization and coupling

Abstract

Channel performance of a compact dual-port MIMO antenna system with element spacing of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.3\ \lambda$</tex> in 2.4 GHz is measured and analyzed, in line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios under different polarization and mutual coupling. Results show that the channel capacity of the antenna with electromagnetic band gap (EBG) with lower mutual coupling is greater than that of the antenna without EBG with higher mutual coupling. Especially when the antenna with EBG is placed horizontally in the through-the-wall NLOS scenario, its channel capacity is the largest, which is 97.34% of the independent and identically distributed (i.i.d.) Rayleigh channel capacity. In addition, in the scenario of through-the-wall, for the antennas with same coupling, the channel capacity of the horizontally polarized antenna is larger than that of the vertically polarized one, and the correlation coefficient and condition number are reduced. In conclusion, the performance of the MIMO system is closely related to the coupling, polarization and propagation environment of the antenna and their interactions.