Novel notch modulation algorithm for enhancing the chipless RFID tags coding capacity

The main objective of this contribution is to introduce a novel technique for increasing the coding capacity of the Frequency Coded (FC) chipless RFID system. The proposed scheme encodes 4 bits per single resonator exploiting the notch bandwidth and its corresponding frequency position. Hence, 72-bits could be achieved from 2 to 5 GHz preserving the operating frequency bandwidth. Furthermore, a Smart Singular Value Decomposition (SSVD) technique is utilized to estimate the notch bandwidth and ensure low probability of error. Consequently, high encoding efficiency and accurate detection could be achieved with simplified reader design. Likewise, a novel 4 × 5 cm² tag is designed to fit the requirements of the devised coding technique. Different tag configurations are manufactured and validated with measurements using Software Defined Radio (SDR) platform. The introduced coding methodology is conclusively validated using Electromagnetic (EM) simulations and real world testbed measurements.