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Table of Contents |
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Trends in the design of RFID tags and sensors
Prof. Smail Tedjini
Agenda
INTRODUCTION & HISTORICAL FACTS
BACKSCATTER SYSTEM : RFID
CONVENTIONAL RFID TAGS
TAG ANTENNA DESIGN
RFID CHIP CHOICE
RFID COMMUNICATION SIGNALS : REGULATIONS
TAG DESIGN & SELECTED EXAMPLES
AUGMENTED RFID TAGS
SENSING TAGS
HARMONIC COMMUNICATION
HARVESTING TAG
CHIPLESS RFID SOLUTIONS
CONCLUDING REMARKS
Highlights
RFID tags are based on ultra high frequency bands.
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measuring the displacement based on the change of phase
symbols and texts as RFID tags
Barcode tag: RFID+QR at the same time
New Directions in RFID Reader and Tag Design
Prof. Nicolas Bardot
Designing a RFID reader starts by buying a RFID module (100 euros in avg)
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Integrated circuits and architectures for Industrial IoT applications: communication aspects
Prof. Sergio Saponara
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The frequencies that cannot be used for free, are those who need a service provider and an infrastructure like in cellular communication. However Bluetooth in a free service.
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Amplitude Shift Keying (ASK)
pros: simple
cons: not power efficient, susceptible to attenuation
On-Off Keying
pros: simple, lower-power comsumption
cons: lack of synchronization
Frequency Shift Keying (FSK)
pros: less susceptible to noise (the envelope is constant)
cons: require larger bandwidth
Phase Shift Keying (PSK)
pros: less susceptible to noise, bandwidth efficient
cons: requires synchronization in frequency and phase → complicated transmitter and receiver
used by IEEE 802.15.4 and Zigbee
Quadrature Amplitude Modulation (QAM)
mix of phase and amplitude modulation
pros: bandwidth effiecient
cons: non constant envelope → complex scheme
Baud: transmitted symbol, 1 Baud may include multiple bits
→ The optimal solution depends on the application
Spread Spectrum:
Data sent using Spread Spectrum is intentionally spread over a wide frequency range, Since it appears as noise, the signal is difficult to detect and jam. Thanks to spread spectrum the communication is resistant to noise and interference thus increasing the probability that the signal will be received correctly. Moreover, it is unlike to have interference with other signals.
2 types of Spread Spectrum techniques are common in ISM bands: direct sequence spread spectrum (DSSS) and frequency hopping spread spectrum (FHSS).
Direct Sequence Spread Spectrum (DSSS)
each bit represented by multiple bits using spreading code
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the frequency of the radar does not depend on the technology fabrication but on the length
all analog parts of the design depend on the wavelength and not on the fabrication process
when multiple amplifiers are cascaded, the noise figure is mainly determined by the first amplifier
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