Decoupling and Matching Strategies for Compact Antenna Arrays

TL;DR

This paper introduces and compares three innovative strategies for decoupling and impedance matching in compact antenna arrays, highlighting the potential of a networkless approach as a promising alternative.

Contribution

It proposes three novel joint decoupling and impedance matching methods for antenna arrays, including a networkless technique, with analytical and simulation evaluations.

Findings

Networkless decoupling and matching (NDM) shows promising results.

The three methods are analytically and numerically compared.

NDM offers a simplified alternative to traditional network-based approaches.

Abstract

Antenna arrays have been used in various applications and have become an important tool to achieve high spectral efficiency in wireless communications. Its use brings to the communications system an increase in performance in terms of capacity and reliability. Recently one of the main communications architectures that makes use of antenna arrays is the Multiple-Input Multiple-Output (MIMO) technology. MIMO technology has been applied in antenna arrays composed of elements in the order of tens to hundreds. In this way, it is necessary to use the structure of compact antennas that offer all the necessary robustness to the applied project. In this context, it is important to revisit the concepts of mutual coupling and impedance matching among antenna elements in an array. This paper proposes and evaluates three strategies of joint decoupling and impedance matching networks(DMN) for antenna arrays. The first method called DMN with Lumped Elements (DMN-LE) performs the decoupling and impedance matching steps with capacitors and inductors. The second method is called the Ring Hybrid (DMN-RH). It is utilizes a microstrip line in the ring form. With this approach is achieved first the decoupling followed by impedance matching steps. The third method is called Networkless Decoupling and Matching (NDM). It brings a concept of decoupling without the presence of a network itself. A comparison of the methods is performed both analytically and via computer simulations. We conclude that the third method, networkless one, is an interesting new alternative approach.