New compact dual polarised dipole antenna for MIMO communications

Abstract

A dual-polarisation dipole antenna is investigated, intended for use as one of three collocated orthogonal antennas in a polarisation-diversity Multiple-Input Multiple-Output (MIMO) communication system. The antenna actually consists of two overlaid dipoles, one electric and the other magnetic, such that their radiation patterns are nominally identical but they are cross-polarised and hence only interact minimally. Using Finite Difference Time Domain (FDTD) and HFSS simulations, it was found that the antenna performed broadly as expected, although the engineering to create a physical realisation would be challenging. In principle, however, a system using two of the triplicated antennas could, in a richly scattering environment, achieve a six-fold increase in channel capacity for the same bandwidth as a traditional line-of-sight link. Furthermore the channel capacity of the antennas has been investigated using various power azimuth spectrums.