The Causal Nexus Between Different Feed Networks and Defected Ground Structures in Multi-Port MIMO Antennas

Area of Science:

• Electromagnetics and Wireless Communication
• Antenna Theory and Design
• Metamaterials and Metasurfaces

Background:

• Compact Multiple-Input Multiple-Output (MIMO) antennas are crucial for high data rates in wireless systems.
• Antenna isolation remains a significant challenge in miniaturized MIMO electronics.
• Defected Ground Structures (DGS) offer a cost-effective solution for improving antenna performance, but their interaction with feed mechanisms is under-explored.

Purpose of the Study:

• To comprehensively review antenna designs, feeding strategies, and DGS architectures.
• To establish the relationship between feed networks and DGS performance in MIMO antennas.
• To provide guidelines for selecting optimal feed networks for DGS-integrated MIMO antennas.

Main Methods:

• Literature review of antenna design, feeding strategies, and DGS.
• Modeling, simulation, fabrication, and experimental measurement of MIMO antennas with SCSRR-based DGS.
• Comparative analysis of four feed methods: coaxial probe, microstrip line, proximity coupled, and aperture coupled.

Main Results:

• Coaxial probe feed achieved isolation between 16.5 dB and 46 dB.
• Aperture-coupled and proximity-coupled feeds enhanced bandwidth by 38.7% and 15.6%, respectively.
• Performance metrics including ECC, DG, CCL, and MEG were evaluated for each feed method.

Conclusions:

• The choice of feed network significantly impacts the isolation and bandwidth of DGS-integrated MIMO antennas.
• Coaxial probe feed is recommended for superior isolation.
• Aperture and proximity-coupled feeds are suitable for bandwidth enhancement, guiding future MIMO antenna designs.