New Technique for Segmenting RFID Bandwidth for IoT Applications

Abstract

This article proposes a new technique to extend the use of the UHF RFID technology in IoT applications. The technique is based on segmenting the bandwidth of the UHF RFID into smaller segments with the use of band-pass filters and circulators. The number of band-pass filters ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${N}$ </tex-math></inline-formula> ) used are equal to the number of segments needed, while the number of circulators are equal to ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${N}$ </tex-math></inline-formula> -1). Subsequently, each of these bandwidth segments is assigned to a specific geographical location/area/zone within a given larger space where an antenna is located. Using the reader, identifying the frequency where the maximum RSSI is received will hence identify its preassigned location/area where tagged object is located. As a proof of concept, in this article the available used-reader band is divided into two segments using two filters and one circulator. The system analysis performed using CST simulations and signal flow graph derived equations. Verification of the technique was done experimentally and location of the tag between the two segments was clearly identified.