Design of Domino-Resonators for Enhanced Power and Data Transmission of 13.56 MHz RFID Sensors

Abstract

This paper presents a straightforward design algorithm to enhance power and data transmission for 13.56 MHz Radio Frequency Identification (RFID) sensor applications by using domino-resonators. In this algorithm, the transformed transponder impedance and modulation depth seen at the reader antenna are formulated and modeled under the presence of domino-resonators. To improve the accuracy, voltage-clamped mode of the tag Integrated Circuit (IC) is considered, which enables accurate calculation of the maximum readable distance, transferred power and equivalent tag IC impedance. For the sake of simplicity, a type-A ultralight tag IC is used and modeled, while all resonators and tag antenna dimensions are based on standard smart-card sized coils. The design algorithm is coded in MATLAB for a 5-coil RFID system, i.e. with three identical domino-resonators, and verified using LT-Spice simulations. For experimental validation, the designed 5-coil RFID system is implemented for enhancing the distance between a commercial 13.56 MHz RFID reader and ISO/IEC 14443A standard RFID tag IC.