Analyzed is the topology of a 3-element linear array antenna with vertically polarized isotropic antenna elements. The focus has been on point-to-point (PtP) multiple-input multiple-output (MIMO) communication over pure line-of-sight (LOS) channels. An empirical equation is presented for the mid-element's relative position achieving near-optimal 3 × 3 MIMO capacity. The position is a function of the transmit and the receive antennas separation distance and the wavelength of the transmit signal. The capacity gains of aperiodic over uniform array antenna configurations are presented, which at some distances can be a factor 2.5.