This document discusses the development of accessible radio-frequency analysis technology for chipless RFID tags. It describes generations of tag readers from expensive lab equipment to a cheaper designed system using a microcontroller and digital synthesis device. The system is able to separate and decode signals to extract information stored in the resonant frequencies of multi-resonant tag structures. Potential applications discussed include analyzing milk quality in rural areas and performing real-time materials characterization to screen mail for hazardous contents.
2. Generations of Tag Readers
for Chipless RFID tags
HP Network Analyzer (~$100k)
‘Read Anything’ Design
MOMA board
Current Design (~$150)
3. System Design
PIC Micrcontroller
ADC ADC
Digital Direct
Synthesis Device
I Q
Output Buffer
Amplifier
Dual Directional Coupler
Reference Probe
Active Probe
Magnitude Phase
Differential Magnitude and
Phase Detector
Low-Pass Filter
RS-232
Interface
To PC
Signal
Generation
Signal Separation
Receiver
4. Space Into Frequency
• Storing information in
physical structures
• Utilizing frequency
instead of time domain
• Multi-resonant planar
structures
• Chipless, low-cost RFID
tags
1 2 3
6. Materials Characterization
Milk-Quality
Analysis
(MLA)
• Interest in non-destructive
methods of analyzing
biological substances
• Measuring milk content in
rural India – critical step in
collection and distribution of
milk
• Instrument can provide
complex frequency spectrum
of milk: Fast + non-invasive
measurement method
Postal Mail Security
(USPS)
• Need for low-cost
instrumentation for analysis
of mail content: Detection of
hazardous material
• Need to detect varying
material types:
Paper, metal, plastic, wood…
• RF dielectric constant
analysis : Real-time
materials characterization
for wide variety of materials