Design of a flexible millimeter-wave MIMO antenna for 5G applications

To address the issues of limited communication capacity, poor interference immunity, and inefficient use of space in ship communications, a flexible millimeter-wave multiple-input multiple-output (MIMO) antenna for 5G communication was developed.

The antenna features an orthogonal arrangement of elements on a flexible polyethylene terephthalate (PET) substrate, with a compact size of 68 mm×68 mm×0.12 mm, effectively addressing the limitations of conventional rigid antennas. Each antenna element employs a circular monopole structure with an arc-truncated ground plane to optimize the coplanar waveguide (CPW) feed configuration. The orthogonal arrangement effectively suppresses mutual coupling while covering the key frequency bands for 5G millimeter-wave applications. The prototype was fabricated using screen-printed copper conductive paste, ensuring cost-effective manufacturing and excellent flexibility. Mechanical stability was verified through bending tests, with stable performance maintained at curvature radii of R≥20 mm.

Simulation and test results showed that the antenna operated in the frequency band of 26−32 GHz, with an isolation level below −36 dB, an envelope correlation coefficient below 0.00015, and a diversity gain exceeding 9.999 dB.

The proposed antenna leverages the high bandwidth characteristics of the millimeter-wave frequency band and the multi-stream transmission capability of MIMO technology, thereby significantly enhancing communication performance. Its flexible structure enables adaptable deployment in complex maritime environments, optimizing signal coverage and spatial efficiency. It provides an efficient and reliable solution for shipboard communication systems.