Capacity Enhancement Analysis and Implementation of a 3D Array Based on Miniaturized Dipole Antennas

TL;DR

This paper explores the design and implementation of a 3D array using miniaturized dipole antennas to improve MIMO system capacity by reducing inter-element correlation and optimizing element efficiency.

Contribution

It introduces a novel 3D array structure with miniaturized antennas and modified lower elements, enhancing capacity and efficiency in practical MIMO applications.

Findings

Achieved 16% higher capacity than 2D arrays at 20 dB SNR.

Demonstrated improved DoF and element efficiency through structural modifications.

Validated scalability and performance improvements via theoretical analysis and 3GPP scenario simulations.

Abstract

Theoretically, the three-dimensional (3D) array architecture provides a higher communication degree of freedom (DoF) compared to the planar arrays, allowing for greater capacity potential in multiple-input multiple-output (MIMO) systems. However, in practical implementations, the upper elements of 3D arrays significantly degrade the performance of the lower elements, leading to increased inter-element correlation and reduced array efficiency. As a result, the expected enhancement in MIMO performance is often suboptimal. To address this issue, this work employs a miniaturized antenna element to reduce the inter-element correlation and thus enhance the DoF of the 3D array. Moreover, to mitigate the efficiency degradation of the lower elements caused by the upper ones, the structures of lower elements are modified to achieve wideband impedance matching. The influence of upper element profile distribution on DoF and element efficiency is investigated, and the scalability of the proposed 3D array is theoretically analyzed. Finally, the MIMO performance of the proposed 3D array is evaluated under 3GPP scenarios, demonstrating a 16% higher capacity than conventional 2D arrays under the same SNR of 20 dB and a physical aperture area of 6.26 {\lambda}02. These results indicate that 3D arrays of appropriately arranged miniaturized elements offer a promising approach to enhancing MIMO system performance.