A Low-Profile Quad Element High Isolation MIMO Antenna for Enhanced Mobile Broadband Applications

AbstractA novel quad-element bio-inspired virus-shaped Multiple Input-Multiple Output (MIMO) antenna with significantly improved isolation is proposed. Each radiator is based on a modified hybrid fractal antenna with a 50 Ω feed and incorporates a chamfered defective ground structure (DGS). To enhance the impedance bandwidth and radiation characteristics of the antenna, an elliptical slot and the DGS are employed. The placement of radiating elements in an orthogonal configuration is a key aspect of achieving the proposed MIMO configuration. In many MIMO designs, one of the primary challenges is achieving adequate isolation between antenna ports. However, in this design, we address this issue effectively by incorporating a swastik-shaped decoupling plane, which significantly enhances the isolation characteristics. The 4-port MIMO antenna is constructed on a Rogers RO3003 substrate and boasts compact dimensions of 57 × 57 × 0.787 mm³. The fabricated antenna has undergone experimental validation, confirming that it covers a substantial operational bandwidth of 41.57 GHz, ranging from 2.54 to 44.1 GHz, has a fractional bandwidth of 178%, and maintains isolation levels of less than −23 dB across its entire frequency range. The antenna design has achieved optimal MIMO performance, characterized by an Envelope Correlation Coefficient (ECC) value of ≤0.05, high multiplexing efficiency, minimal Channel Capacity Loss (CCL), and omnidirectional radiation properties. Hence, this design stands as an epitome for constructing super-wideband MIMO designs. The design metrics show the potential of the proposed antenna to operate with Enhanced Mobile Broadband (eMBB) which forms an integral part of 5G applications.KEYWORDS: Channel capacity lossEnhanced mobile broadband (eMBB)Envelope correlation coefficientIsolationMultiple input multiple output (MIMO)Super widebandSwastik-shaped decoupling plane ACKNOWLEDGEMENTSThe authors wish to express their gratitude for the assistance provided by the “Science and Engineering Research Board (SERB),” Department of Science and Technology (DST), Government of India, as part of project No. ECR/2017/003341. They also extend their appreciation to the CARE Department of IIT Delhi for granting access to the measurement facility.DISCLOSURE STATEMENTNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was supported by the Science and Engineering Research Board.Notes on contributorsM AyyappanM Ayyappan (Graduate Student Member) received the bachelor of technology (BTech) degree in electronics and communication engineering from Cochin University of Science and Technology, Kerala, India in 2014, and the master of technology (MTech) degree in VLSI and embedded systems from Cochin University of Science and Technology, Kerala, India in 2016. He is currently pursuing the PhD degree in electronics and communication engineering at the National Institute of Technology, Goa, India. His research interests include super wideband antennas, multiple-input multiple-output antennas and dielectric resonator antennas.Abhijeet GaonkarAbhijeet Gaonkar received the bachelor of engineering (BE) degree in electronics and telecommunication engineering from Goa University, Goa, India in 2012, and the master of engineering (ME) degree in industrial automation and radio frequency engineering from Goa University, Goa, India in 2015. He is currently pursuing the PhD degree in electronics and communication engineering at the National Institute of Technology, Goa, India. His research interests include wideband antennas, RF circuits and dielectric resonator antennas for wireless communications. Email: abhijeet@nitgoa.ac.inPragati PatelPragati Patel (senior member, IEEE) received the BTech. degree from the Dr. K. N. Modi Institute of Engineering and Technology, Modinagar, Ghaziabad, India, the MTech degree from the Ambedkar Institute of Advanced Communication Technologies and Research (formerly Ambedkar Institute of Technology), Delhi, and the PhD degree from the Indian Institute of Technology Bombay, Mumbai, India. In 2016, she joined the Department of Electronics and Communication Engineering, National Institute of Technology Goa, India, as an assistant professor. She has authored or co-authored over 40 research articles in international peer-reviewed journals and conferences. Her current research interests include dielectric resonators, microstrip patch antennas, and MIC. She received the MHRD Fellowship during her PhD degree and also the Early Career Fellowship from the Department of Science and Technology, Government of India, for pursuing research in the field of DRA. She was a recipient of the Young Scientist Award at URSI AT-RASC 2015. She is actively involved in IEEE activities as a secretary for educational activities of IEEE Bombay Section. Email: pragati@nitgoa.ac.inHemant KumarHemant Kumar (S’16–M’18–SM’21 IEEE, M’20 IETE) received his BTech (with honors) degree in electronics and communication engineering from Kurukshetra University and a PhD in electrical engineering from the Indian Institute of Technology Bombay. Currently, he is working as an assistant professor at NIT Tiruchirappalli. His research interests include broadband antennas, microstrip antennas and arrays, passive microwave circuits, monopulse tracking, microwave imaging, and machine learning in antennas and microwaves. He is also serving as a reviewer in several national/international journals including IEEE Access, IET Microwave Antennas & Propagation, IETE, etc. He has published many research articles in refereed journals and refereed conference proceedings and also filed one patent and copyright. Email: hemant@nitt.edu