Simple Structure E-Plane Decoupled Millimeter Wave Antenna Based on Current Cancellation Model

A simple structure E-plane decoupled millimeter wave (mmW) multiple-input multiple-output (MIMO) antenna based on current cancellation model is proposed in this communication. First, a coupling model of E-plane MIMO antenna is established by analyzing the coupling current. Then, a high-isolation two-element E-plane MIMO antenna loaded with decoupling branch Bar-L is designed by current cancellation method. Finally, a high-isolation four-element E-plane MIMO antenna is designed, fabricated, and measured to verify the applicability of the decoupling method in large arrays. The measured results show that the antenna achieves
$\vert \text{S}_{\mathbf {11}}\,\,\vert < -10$
dB in band of 25.5–26.5 GHz, and the measured isolation of adjacent ports in this band is greater than 35 dB, which effectively improves the isolation without deteriorating other performance. The proposed antenna with a simple structure is suitable for mmW MIMO systems requiring high isolation.