4-Port MIMO antenna with novel isolator conducting structure for sub-1 GHz/sub-6 GHz and RF-energy harvesting applications

Abstract

A 4-port MIMO antenna with a novel isolator structure for sub-1GHz/sub-6GHz and RF-energy harvesting applications is presented in this research. The proposed antenna is investigated systematically at 2.6 GHz design frequency with four distinct stages: STEP-1, STEP-2, STEP-3 and STEP-4 and an optimal design (STEP-4: $0.5\lambda \times 0.7\lambda \times 0.014\lambda$ mm³) is chosen for further study. A unique isolation structure was developed between two identical elements separated by $0.077\lambda$, resulting an improved isolation of greater than 14 dB at 0.9 GHz and greater than 18 dB at 2.6 GHz is obtained. The suggested antenna resonates at 900 MHz-simulated & measured and 2.6 GHz-simulated & 2.8 GHz-measured with simulated fractional bandwidth/resonating band of 24.6%/0.778–1 GHz & 20.7%/2.4–2.94 GHz and a measured fractional bandwidth/resonating band of 17.8%/0.83–0.99 GHz & 21%/2.41–3 GHz at lower and upper resonating frequencies respectively. A peak gain of 1.5 dB at 900 MHz and 4.2 dB at 2.8 GHz has been obtained. The SAR values of less than 0.5 and 1.6 W/kg and radiation efficiencies of 74.7% and 90% at 900 MHz and 2.8 GHz were obtained, respectively. The suggested antenna's MIMO performance is simulated using electromagnetic tool HFSS in terms of ECC, DG, TARC, MEG and CCL, and the obtained results are experimentally verified. Further, the proposed antenna is tested for harvesting applications wherein 9.5 mW of harvested power, 76.45% power conversion efficiency (PCE), 4V harvested voltage, current 2.4mA and 12.46 mW Friis equation output at 915 MHz and 26.98 mW of harvested power, 69.5% power conversion efficiency, 5V harvested voltage, current 5.4 mA and 38.8 mW Friis equation output at 2.5 GHz are recorded.

Keywords:

• RF-energy harvester
• 1 GHz/sub-6GHz
• LTE
• SAR
• PCE

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Kallollu Narayaswamy Nagesh

Dr. Nagesh Kallollu Narayanaswamy is working as a Professor and Head of the Department of Electronics & Communication Engineering, at Nagarjuna College of Engineering & Technology, Bengaluru, India. He completed his Ph.D. from Jawaharlal Nehru Technological University Anantapur (JNTUA) Anantapur- A.P, India in 2016. In 2007 he received his M.Tech. Degree in Digital electronics and communication from Nitte Mahalinga Adyanthaya Memorial Institute of Technology (NMAMIT) Mangalore, VTU, Karnataka, India. Completed B.E. in Electronics and Communication Engineering from Siddganga Institute of Technology (SIT) -Tumkur. VTU, Karnataka, India in 2005. He is a member of IEEE, a Life Member of IETE, and various other societies such as Antennas wave and Propagation society, etc. He has 15 years of teaching experience with UG and PG students. He has authored or co-authored more than 35 research papers in international journal/conference proceedings. His research interests include Wireless communication, Communication system, IoT, and Antennas. He is a reviewer of many international journal/conference proceedings.

Penmatsa Krishna Kanth Varma

Mr. Penmatsa Krishna Kanth Varma has completed his B.Tech from GVP College of Engineering, Visakhapatnam, affiliated to JNTU, AP, India in the year 2004. He has done his M.Tech from K.L College of Engineering, Vijayawada, AP, India, affiliated to ANU Guntur in the year 2006. He is currently working as Assistant Professor in ECE Department, S.R.K.R. Engineering College, Bhimavaram, Andhra Pradesh, India and has 12 years of teaching experience. He is currently Pursuing his PhD in Nagarjuna College of Engineering and Technology, Bengaluru, Affiliated to VTU, Karnataka, India. He has authored or co-authored more than 10 research papers in international journals and conference proceedings. His research interests include MIMO Antenna Design, Antenna array optimization techniques, Fractal antenna design.

Brijesh Kumar

Dr. Brijesh Kumar (Member, IEEE) received the Ph.D. degree from the Indian Institute of Technology (IIT) Roorkee, India, in 2014. He has more than 175 reputed international, national journals and conference publications. His research interests include VLSI design and technology, organic material-based novel devices and circuits, and solid-state devices and circuits. He is currently working as a Professor with the Department of Information Technology, Indira Gandhi Delhi Technical University for Women, Delhi, India, since April 2022. Before joining, IGDTUW, he was working as a Professor and Registrar of Madan Mohan Malaviya University of Technology (MMMUT) Gorakhpur, Uttar Pradesh, India (Technical University of UP Government) up to April 25, 2022. He has more than 23 years of experience in the field of Academics, Research and Administration. He has received various awards and certificates of appreciation for his dedicated academic and research activities. He is currently working on novel structures of OTFT, organic solar cells, OLED displays, VLSI systems and circuits, organic electronic devices and circuits, the IoT Drone, and AI. He has published one book entitled Organic Thin-Film Transistor Applications: Materials to Circuits (CRC Press of Taylor and Francis, U.K.). His name has been listed in Marquis Who's Who in the World, USA. He is a Life Member of the Indian Society for Technical Education (ISTE) and the International Association of Engineers (IAENG). He is a Reviewer of many international journals with reputed banners, including IEEE, IET, Elsevier, Springer, and Taylor & Francis publishers.

Rakesh Kumar Singh

Dr. Rakesh Kumar Singh received his M.Tech. (Electronics Engineering) and PhD (Electronics and Communication) degree from Sam Higginbottom University of Agriculture, Technology and sciences during 2013 and 2018 respectively. He has completedhis B.Sc. and M.Sc. degree from University of Allahabad in 1999 and 2003 respectively. Currently, he is working as Professor in the department of electronics and communication engineering at SIET, Prayagraj Uttar Pradesh, affiliated from AKTU. He has teaching and research experience of about 16 years. Dr. Rakesh Kumar Singh has published 1 patent, 1 edited book and more than 14 papers in International Journals and Conferences and supervised more than three M.Tech. and PhD thesis. His research interest includes modelling and simulation of VLSI devices, RF and microwave devices and its applications.

Brijesh Mishra

Dr. Brijesh Mishra received his M. Tech. (Electronics Engineering) and PhD (RF & Microwaves) degrees from the University of Allahabad in 2012 and 2018, respectively. Dr. Brijesh Mishra worked as an Assistant Professor in the Department of Electronics and Communication Engineering at Shambhunath Institute of Engineering and Technology (SIET) during 2012–2013 and again from 2017–2018, and as an Assistant Professor (NPIU-MHRD) in the Department of Electronics and Communication Engineering at Madan Mohan Malaviya University of Technology during 2018–2021. He is currently working as an Associate Professor and HoD in the Department of Electronics and Communication Engineering at Shambhunath Institute of Engineering and Technology (SIET). He has published 3 patents, 2 edited books and more than 45 research papers in journals of international repute, international conferences and book chapters. Dr. Brijesh Mishra has successfully completed two projects funded by the NPIU & the World Bank. He is the recipient of awards like Excellence in Performance and Outstanding Contributions. He has served as potential reviewer of more than 20 SCI & Scopus indexed journals, Organising Track Chair and Organising Secretary for the IEEE Conference (ICE3-2020), Springer Conference (ICVMWT-2021) and Taylor & Francis Conference (ICISSI-2022) respectively. He is a member of IEEE, ISTE, IE(I), IETE, IAENG and IFERP. His research interests include modelling, simulation and fabrication of RF and microwave devices, as well as their applications.

Dinesh Kumar Singh

Dr. Dinesh Kumar Singh received the B. Tech. degree in electrical and electronics engineering from GLA Institute of technology and management Mathura, Uttar Pradesh, India, in 2012 and M. Tech. degree in power system engineering from school of engineering, Gautam buddha University, Greater Noida, Uttar Pradesh, India, in 2015. He received his PhD degree, from the electrical engineering department, Motilal Nehru National Institute Technology (MNNIT Allahabad), Prayagraj, Uttar Pradesh, India in the field of power system protection. His research interests are in power systems, power system protection and design of protection scheme for micro grid with penetration of renewables.