Tripolarized MIMO Antenna Using a Compact Single-Layer Microstrip Patch

A colocated tripolarized MIMO antenna realized by a multimode single-layer patch structure is presented, including two orthogonal patch-like patterns of mode TM
₁₁
and one monopole-like pattern of mode TM
₀₂
. In order to make the modes resonate at the same frequency, some vias are added. This tripolarized antenna works at 3.5 GHz, with a total height of 3.0 mm and radius of 25 mm. Good agreements are achieved between the measured and simulated S-parameters and radiation patterns.