Chamath Divarathne

MIMO based chipless RFID system

Chipless RFID systems are perhaps the most eligible candidate for catering the demand of low-cost multiple item tagging in future. However, the absence of a microchip in chipless tags limits the processing capabilities hence the RFID reader has to improvise most of the processing. In the mean time researchers have focused on applying MIMO antenna technology and decoding techniques in chipped RFID systems to utilize its unique spatial multiplexing capability and high diversity gains. However, applying the same techniques in chipless RFID systems is still a challenge due to less processing power available at the tag. This paper proposes a novel MIMO based multi-resonator chipless RFID systems and its validity is verified using Matlab simulations.

UiO-66 MOF end-face-coated optical fiber in aqueous contaminant detection

Optical quality metal organic framework (MOF) thin films were integrated, for the first time, to the best of our knowledge, with structured optical fiber substrates to develop MOF-fiber sensors. The MOF-fiber structure, UiO-66 (Zr-based MOF is well known for its water stability), is a thin film that acts as an effective analyte collector. This provided a Fabry-Perot sensor in which concentrations of up to 15 mM Rhodamine-B were detected via wavelength shifts in the interference spectrum.

Advanced chipless RFID: MIMO-based imaging at 60 GHz-ML detection

The book proposes new approaches to chipless RFID tag encoding and tag detection that supersede their predecessors in signal processing, tag design, and reader architectures. The text is divided into two main sections: the first section introduces the fundamentals of electromagnetic (EM) imaging at mm-wave band to enhance the content capacity of Chipless RFID systems. The EM Imaging through Synthetic Aperture Radar (SAR) technique is used for data extraction. The second section presents a few smart tag detection techniques for existing chipless RFID systems. A Multiple-Input and Multiple-Output (MIMO) based tag detection technique improves the spectral efficiency and increases data bit capacity. The book concludes with a discussion of how the MIMO approach can be combined with the image based technique to introduce a complete solution with a fast imaging approach to chipless RFID systems. The book has the following salient features:

A feasible detection technique for chipless RFID systems based on likelihood

This paper investigates a scalable likelihood detection techniques for chipless RFID tag reading. Detection error rate (DER) of a 4-bit multi-resonator chipless tag reading is performed using proposed detection algorithm. The computation complexity of the proposed detection method is significantly less compared to the other reported maximum likelihood (ML) detection techniques hence it is a feasible reading technique especially under larger number of tag bits. Validity of the proposed detection technique was verified using Computer Simulation Technology (CST) and MATLAB simulations.