Wideband Decoupling Design for Slotted Dielectric Patch Antenna

A novel wideband decoupling design for slotted dielectric patch (DP) antenna (DPA) is proposed. Thanks to the multimode characteristic of the DPA, the TM
₁₀
mode and antiphase TM
₂₀
mode are excited simultaneously. The air tunnels are employed to incorporate TM
₁₀
and antiphase TM
₂₀
modes for expanding the antenna bandwidth. Since the two modes are the TM modes, introducing strong inductive coupling between the two DPAs, the decoupling of the two modes can be achieved simultaneously by introducing the capacitive coupling of the two pairs of metal strips on the nonradiating edges. As a result, the neutralization of the two kinds of couplings improves wideband isolation without using the conventional large isolating structures. At the same time, it should be highlighted that the radiation pattern can be stabilized during the decoupling process. For demonstration, 1 × 2 wideband decoupled slotted DPAs are implemented and measured. The measurement shows an impedance bandwidth of 17.9% (4.93–5.9 GHz) with an enhanced port-to-port isolation of over 21.0 dB. A good agreement between the simulated and measured results is obtained to validate the proposed wideband decoupling method.