A Compact Ultra-Thin 4 × 4 Multiple-Input Multiple-Output Antenna

Area of Science:

• Electrical Engineering
• Antenna Theory
• Wireless Communications

Background:

• The demand for compact and efficient antenna systems in fifth-generation (5G) mobile devices is rapidly increasing.
• Existing antenna designs often face challenges with miniaturization, isolation, and performance in the 5G n78 band (3.4-3.6 GHz).

Purpose of the Study:

• To develop and validate a compact, ultra-thin, tightly arranged 4x4 multiple-input multiple-output (MIMO) antenna pair for 5G mobile handsets.
• To enhance port impedance matching and mitigate magnetic coupling in a highly integrated antenna system.

Main Methods:

• Designed a 4x4 MIMO antenna pair with radiating elements measuring 8.5 × 4.2 mm².
• Integrated a T-shaped open-ended slot in the grounding plane to improve matching and reduce coupling.
• Achieved a minimized total volume of 145 × 75 × 5 mm³ with elements placed at a 1 mm distance.
• Fabricated and tested a prototype, comparing simulated and measured results.

Main Results:

• The antenna pair precisely resonated at 3.5 GHz within the 5G n78 band.
• Attained measured isolation performance superior to 17 dB.
• Demonstrated remarkable consistency between simulated and measured performance curves.
• Evaluated MIMO performance using metrics like Envelope Correlation Efficiency (ECC), Diversity Gain (DG), Total Active Reflection Coefficient (TARC), and Multiplexing Efficiency (ME).

Conclusions:

• The developed ultra-thin 4x4 MIMO antenna pair is suitable for 5G mobile handsets due to its compact size and effective performance.
• The T-shaped slot effectively improved impedance matching and reduced mutual coupling.
• The design meets the stringent requirements for high-performance 5G communication systems.