Designing planar MIMO antennas using a novel canonical dual port antenna

In this paper we present a canonical two element antenna that can be replicated to form planar MIMO antennas. The design of the canonical element uses folded slots for the radiating elements but includes a coupling element to create field cancellation and enhance isolation. By properly using the coupling element the canonical element can be packed together with high densities of up to 10 elements per square wavelength. To validate the idea, a 16-port printed MIMO antenna is presented. The 16-port antenna has dimensions 1.17λ₀×0.69λ₀ mm² and operates at 2.6GHz. Although the individual antennas are densely packed, all combinations of mutual couplings between ports exhibit better than 15 dB isolation. The antennas are printed on FR-4 printed-circuit-boards. The proposed antennas are investigated by simulation and measurement.