A novel communication method for semi-passive RFID based sensors

Abstract

Abstract-This paper presents a novel communication method for semi-passive RFID based sensors. The new method uses a digitally reconfigurable UHF RFID tag antenna to modulate sensed information at an RFID tag on to the received signal strength indicator (RSSI) response perceived at an RFID reader. This technique is completely compatible with the existing class 1 generation 2 UHF air interface protocol thereby enabling the use of existing RFID reader infrastructure to decode the additional sensed information. The effect of read distance, environment and bit duration on the performance of the communication method is examined through measurements obtained from a prototype. Through experimental verification, it is demonstrated that error free transmission of sensor information can be achieved up to 3.5 meters in different environments with a bit duration of 500 ms. Prospective future research directions are also discussed.

Hybrid Inertial Microwave Reflectometry for mm-Scale Tracking in RFID Systems

“…Moreover, if required, a customized RFID chip complying with EPCGlobal Gen2 protocol and containing an inbuilt inertial sensor may also be considered in a final product, thereby further increasing battery life. References [62][63][64][65] discuss methods for taking data gathered from external sensors and relaying their information through EPCGlobal Gen2-compliant RF tags.…”

“…First, we consider the N independent magnitude data points given by: v = (v 1 , v 2 , ..., v N ) (65) with Rician distribution to estimate the amplitude of the signal V o . The joint Rician distribution can be written as…”

Wireless Capacitive Liquid-Level Detection Sensor Based on Zero-Power RFID-Sensing Architecture

“…Several other passive RFID-based sensors have been developed that can detect liquid within the container but lack the capability of providing continuous information of the liquid-level variation in real time [ 18 , 21 , 22 ]. Sensing systems based on semi-passive RFID technology have been the focus of many researchers [ 23 , 24 , 25 ], due to their higher read-range as compared to the passive RFID systems. Despite the fact they use signals from the reader to energize the chip, semi-passive RFID technology also requires an internal power source to drive the electronic circuits, making them unreliable, bulky, and costly.…”