Scientific Results

Low-Frequency RFID Signal and Power Transfer Circuitry for Capacitive and Resistive Mixed Sensor Array

Year: 2019

Authors: Demori M., Bau M., Dalola S., Ferrari M., Ferrari V.

Autors Affiliation: Univ Brescia, Dept Informat Engn, Via Branze 38, I-25123 Brescia, Italy; CNR, Natl Inst Opt, INO CNR, Via Branze 45, I-25123 Brescia, Italy

Abstract: This paper presents a contactless measurement system for a mixed array of resistive and capacitive sensors exploiting a low-frequency radio-frequency identification (RFID)-based approach. The system is composed of a reader unit which provides power to and exchanges measurement data with a battery-less sensor unit. The sensor unit is based on a transponder operating at 134.2 kHz and a microcontroller. The microcontroller sequentially measures the elements of the sensor array composed of n capacitive and m resistive sensors which share a common terminal. The adopted technique measures the charging time of a resistor-capacitor (RC) circuit, where the resistor or the capacitor can be either the sensing element or a reference component. With the proposed approach, the measured values of the resistive or capacitive elements of the sensor array are first-order independent from the supply voltage level. A prototype has been developed and experimentally tested with resistive elements in the range 400 k ohm-1.2 M ohm and capacitive elements in the range 200 pF-1.2 nF showing measurement resolution values of 1 k ohm and 5 pF, respectively. Operative distances up to 3 cm have been achieved, with readings taken faster than one element of the array per second.

Journal/Review: ELECTRONICS

Volume: 8 (6)      Pages from: 675-1  to: 675-15

KeyWords: low-frequency RFID; capacitive and resistive sensors; contactless interrogation; power transfer
DOI: 10.3390/electronics8060675

Citations: 5
data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2021-11-21
References taken from IsiWeb of Knowledge: (subscribers only)
Connecting to view paper tab on IsiWeb: Click here
Connecting to view citations from IsiWeb: Click here

This site uses cookies. If you decide to continue browsing we consider that you accept their use. For more information about cookies and how to delete them please read our Info Policy on cookies use.
Read more