University of Oulu

M. Berg, J. Chen and A. Pärssinen, "Analysis of Vertical Loop Antenna and Its Wide and Flat Variant Performance in Wearable Use," in IEEE Access, vol. 6, pp. 22570-22577, 2018. doi: 10.1109/ACCESS.2018.2824542

Analysis of vertical loop antenna and its wide and flat variant performance in wearable use

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Author: Berg, Markus1; Chen, Jiangcheng1; Pärssinen, Aarno1
Organizations: 1Centre for Wireless Communications, Faculty of Information Technology and Electrical Engineering, University of Oulu, Finland
Format: article
Version: accepted version
Access: open
Online Access: PDF Full Text (PDF, 2.1 MB)
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Language: English
Published: Institute of Electrical and Electronics Engineers, 2018
Publish Date: 2018-05-04


This paper presents an analysis of the input impedance and radiation pattern behavior for a rectangular loop antenna when it is reshaped from a narrow square to wide and flat. The antenna operation is examined by 3D electromagnetic simulations. Parametric simulation results are shown to explain the effect of antenna dimensions on the impedance behavior. Based on the numerical results, an equivalent circuit is developed to model the impedance change due to reshaping the loop antenna. The main observations are that the decreased height and the increased width of the antenna increase the bandwidth potential of the inherently narrowband loop and increase its directivity. These characteristics together with a vertical loop orientation enable a high performance antenna for locations very close to conductive or lossy materials. Based on the presented impedance analysis, an optimized antenna prototype for a wearable use is manufactured and its performance is verified by measurements. Measured radiation efficiency for the antenna in contact with a human tissue phantom is -5.0 dB at 2 GHz and the obtainable bandwidth potential is > 10 %.

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Series: IEEE access
ISSN: 2169-3536
ISSN-E: 2169-3536
ISSN-L: 2169-3536
Volume: 6
Pages: 22570 - 22577
DOI: 10.1109/ACCESS.2018.2824542
Type of Publication: A1 Journal article – refereed
Field of Science: 213 Electronic, automation and communications engineering, electronics
Funding: This work was done in WERME research project financially supported by Hilla research program through Tekes – the Finnish Funding Agency for Innovation
Copyright information: © 2018 IEEE. Translations and content mining are permitted for academic research only. Personal use is also permitted, but republication/redistribution requires IEEE permission. See for more information.