Compact Co-Polarized Decoupled Microstrip Patch Array Antenna Based on TM02/TM03 Modes Cancellation

In this communication, two compact co-polarized decoupled microstrip patch array antennas (MPAAs) based on TM02/TM03 modes cancellation are proposed. It is only necessary to introduce shorting pins and etch slots on the patch antenna to precisely adjust the frequency and impedance of TM02 and TM03 modes to make them consistent, which can significantly reduce the strong coupling between the tightly spaced patch antennas. In addition, the L-shaped open-stub coupling feeding is used to eliminate the parasitic inductance caused by the shorting pins to achieve better impedance matching. Finally, the proposed two-/eight-port MPAAs are fabricated and measured. The simulation and measurement results show that the coupling of adjacent ports is decreased lower than −30 dB within the impedance matching bandwidth (3.42–3.58 GHz), while the edge-to-edge spacing is only
$0.023 \lambda _{0}$
between the antenna elements. With the advantages of simple design, significant decoupling effect, and good radiation performance, the proposed decoupling scheme has broad application prospects in the fifth-generation (5G) array antennas.