Two closely spaced microstrip patches with high isolation for full-duplex/MIMO applications

• Published in: PloS one Vol. 18; no. 10; p. e0290980
• Main Authors: Tran, Huy-Hung, Nguyen, Tung The-Lam, Nguyen Thi, Thuy
• Format: Journal Article
• Language: English
• Published: San Francisco Public Library of Science 09.10.2023; Public Library of Science (PLoS)
• Subjects: Antennas; Antennas (Electronics); Communications systems; Correlation coefficient; Correlation coefficients; Design; Engineering and Technology; Innovations; MIMO communication; MIMO communications; Mutual coupling; Patch antennas; Physical Sciences; Radiation; Transceivers; Wireless communications; Vietnam
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0290980

This paper shows an effective method to significantly enhance the isolation of a closely spaced two-port patch antenna, which can be deployed for full-duplex transceivers as well as multiple-input-multiple-output (MIMO) systems. Two rectangular microstrip patches are arranged in the E-plane configuration. To achieve high isolation, a grounded stub is positioned between the radiating patches. For validation of the proposed concept, an antenna prototype is fabricated for measurements. The measured data demonstrates that the port-to-port mutual coupling can be suppressed to -50 dB, which is useful in self-interference cancellation for full-duplex communication systems. Compared with the coupled design, the isolation is significantly enhanced by 43 dB with an inter-element spacing of 0.034[lambda].sub.c, where [lambda].sub.c is a free-space wavelength at the center operating frequency. Regarding MIMO metrics, the antenna also shows good MIMO diversity performance based on an envelope correlation coefficient and a diversity gain.