Receiver Design of Passive UHF RFID Sensor Platform for Gas Identification

摘要

The concept of passive Radio Frequency Identification (RFID) sensor tag is introduced to remove the dependency of current RFID platforms on battery life. In this paper, a reader for passive RFID sensor tag is presented along with the processing unit. The RFID system is compliant to Electronics Product Code Generation 2 (EPC-Gen2) protocol in 902-928 MHz ISM band. Whereas the processing unit is implemented and analyzed in software and hardware platforms. The software platform uses MATLAB, whereas a High Level Synthesis (HLS) tool is used to implement the processing unit on a Zynq platform. Moreover, Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) based feature reduction approaches are analyzed in detail for efficient classification of gas data. It is found that 90% gases are identified using first three principal components, which is 7% more efficient than LDA. While in hardware, LDA requires 50% less Look-Up Tables than PCA. The RFID tag used for transmission is implemented in 0.13 μm CMOS process, with simulated average power consumption is 2.6 μW from 1.2 V supply. ThingMagic M6e embedded reader is used for RFID platform implementation. It shows an output power of 31.5 dBm which allows a read range of 9 meter.