Self-Decoupled MIMO Circularly Polarized Dielectric Resonator Antenna Array Using Higher-Order Mode

In this paper, a self-decoupled circularly polarized (CP) multiple-input multiple-output (MIMO) dielectric resonator antenna (DRA) array is implemented using the higher-order mode. Specifically, the orthogonal TE
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(x) and TE
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(y) modes are excited in the active DRA by a crossed slot to generate a CP field, while the TE
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(x/y) modes are excited in the adjacent passive DRA due to the near-field coupling of the active DRA. In this case, the energy cannot get to the receiving port of the passive DRA through the slot because the field intensity of TE
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(x/y) modes is rather weak there. As a result, a high isolation level of 47.1 dB is achieved without requiring any additional decoupling structure.