A Dual-Band Flexible MIMO Array Antenna for Sub-6 GHz 5G Communications.

Area of Science:

• Electrical Engineering
• Electromagnetics
• Antenna Theory

Background:

• Existing antennas for Sub-6 GHz 5G often lack flexibility and compactness.
• Rigid and bulky designs limit applications in wearable and on-body communication systems.
• Challenges in achieving high gain, isolation, and miniaturization simultaneously persist.

Purpose of the Study:

• To develop a novel dual-band flexible antenna array for Sub-6 GHz applications.
• To enhance antenna performance in terms of gain, bandwidth, and isolation.
• To create a compact and flexible MIMO configuration suitable for wearable devices.

Main Methods:

• Design of a single-element monopole antenna with a modified rectangular radiator and L-strips.
• Extension to a four-element, two-port MIMO configuration using a 1x2 array.
• Incorporation of a defected ground structure (DGS) for improved isolation.
• Fabrication on a flexible polyimide substrate and performance validation through measurements.

Main Results:

• Achieved dual-band operation in the 3.6-3.8 GHz and 5.65-5.95 GHz bands.
• Obtained high gains of 5.2 dBi and 7.7 dBi.
• Demonstrated superior isolation (>22 dB) and excellent MIMO diversity metrics (ECC < 0.05, DG > 9.99).
• Confirmed low Specific Absorption Rate (SAR) values suitable for on-body applications.
• Overall compact dimensions of 57 × 50 × 0.1 mm³.

Conclusions:

• The proposed flexible dual-band MIMO antenna offers a superior alternative for compact, high-performance Sub-6 GHz 5G applications.
• The design effectively addresses size, bandwidth, isolation, and safety concerns in wearable antenna systems.
• Validated performance confirms its suitability for next-generation mobile communication devices.