Battery-free wireless light-sensing tag based on a long-range dual-port dual-polarized RFID platform

Wagih, M. , Weddell, A. and Beeby, S. (2022) Battery-free wireless light-sensing tag based on a long-range dual-port dual-polarized RFID platform. Sensors, 22(13), 4782. (doi: 10.3390/s22134782)

Abstract

Radio Frequency Identification (RFID) represents an emerging platform for passive RF-powered wireless sensing. Differential multi-port RFID systems are widely used to enable multiple independent measurands to be gathered, or to overcome channel variations. This paper presents a dual-port/dual-integrated circuit (IC) RFID sensing tag based on a shared aperture dual-polarized microstrip antenna. The tag can be loaded with different sensors where the Received Signal Strength Indicator (RSSI) of one IC is modulated using a sensor, and the other acts as a measurand-insensitive reference, for differential sensing. The 868 MHz tag maintains a minimum unloaded read-range of 14 m insensitive to deployment on metals or lossy objects, which represents the longest reported range of a multi-port RFID sensing tag. The tag is loaded with a light-dependent resistor (LDR) to demonstrate its functionality as a battery-less wireless RFID light sensor. Following detailed RF characterization of the LDR, it is shown that the impedance, and consequently the RSSI, of the sensing tag are modulated by changing the light intensity, whereas the reference port maintains a mostly unchanged response for a correlated channel. The proposed tag shows the potential for channel variations-tolerant differential RFID sensing platforms based on polarization-diversity antennas.

• Item Type: Articles
• Additional Information: This work was supported by the UK Engineering and Physical Sciences Research Council (EPSRC) under Grants EP/P010164/1.
• Keywords: Wireless sensor, light sensor, RFID sensor, LDR, light-dependent resistor, light sensing, light intensity, RF measurement, battery-less sensor, wireless sensor node, wireless sensor networks, antenna sensors, microstrip antenna, patch antenna, differential rfid, long-range RFID, multi-port RFID, shared-aperture antenna.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Wagih, Dr Mahmoud

Creator Roles

Wagih, M.: Conceptualization, Investigation, Methodology, Writing – original draft, Writing – review and editing

• Authors: Wagih, M., Weddell, A., and Beeby, S.
• College/School: College of Science and Engineering > School of Engineering > Systems Power and Energy
• Research Group: Communication Sensing and Imaging
• Journal Name: Sensors
• Publisher: MDPI
• ISSN: 1424-8220
• ISSN (Online): 1424-8220
• Published Online: 24 June 2022
• Copyright Holders: Copyright © 2022 by the authors
• First Published: First published in Sensors 22(13):4782
• Publisher Policy: Reproduced under a Creative Commons Licence