Download - Development of a UHF Passive RFID System
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Development of a Development of a UHF Passive RFID System UHF Passive RFID System
LSCM Technology Transfer ForumLSCM Technology Transfer Forum
Science Park, Cyber PortScience Park, Cyber Port
Edward Kai-Ning Yung
City University of Hong Kong 25 August, 2010
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BudgetBudget
Innovation and Technology Fund, Hong Kong SAR GovernmentApril 2005 - March 2007 : $4,600,000
Industrial Sponsorship: $500,000
City University of Hong Kong: $920,000
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Industrial SponsorsIndustrial Sponsors
Surface Mount Technology Company Limited, Hong Kong
GoldTel Electronics Company Limited,Shenzhen
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AimsAims
Strengthen Hong Kong as the center of logistics management in the region
Demonstrate that Hong Kong is also a world-class center of technological innovation
Resurrect Hong Kong as a premium center of engineering supports
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RFID EraRFID Era
RFID has been identified by the national government as an area of intensive development
RFID has also been identified by the federal government of USA as an area of intensive development
RFID is the technology driver in the coming decades, similar to telephone, computer, network, and mobile phone in the last century
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From Strength to StrengthFrom Strength to Strength
Electronic article surveillance system for retail outlets: passive, 143.2kHz, 1-bit
Autotoll system, semi-active system, 2450MHz
Octopus system: passive, 13.56MHz
Container port & containers: active, 433MHz
Baggage handling system in the Hong Kong Airport: passive, 900MHz
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Hi-Tech in Hong KongHi-Tech in Hong Kong
Hong Kong is an ideal site for field-testing novel applications of new technologies, such as RFID
Although all technologies are imported, some of the home-grown RFID systems have been recognized as the pioneer and the world leader in their respective areas
Without a home-grown technology, it is very difficult to export our system and recover part of the cost of development
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ObjectivesObjectives
Tailor-make a new RFID system for libraries
Develop a RFID reader with unique features
Design the needed antennas and other critical components/devices
Devise value-added features for libraries
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Design from ScratchDesign from Scratch
Develop a new RFID system from scratch with in-house developed critical components innovative modules with discrete components some of the key circuits packaged in RFIC system integration implementation, and in-situ field testing
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RFID LibraryRFID Library Books and multi-media disks are relatively
homogeneous in nature and in size, it is easier to implement a RFID system, comparatively
These items are not very expensive, a few errors are tolerable
They are not very cheap; thus, the high cost of implementation is justified
New features developed for libraries could be applied in other areas of logistics management
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Edges in CompetitionEdges in Competition
Besides an import replacement, our design is affordable, efficient, reliable, robust, user-
friendly, and culturally independent environmental friendly physically and psychologically safe downward and laterally compatible
Most important of all, there are ample rooms left for modification; thus, it could easily be adopted in other applications
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UHF verses HFUHF verses HF
UHF and HF technologies are equally mature
High-gain resonant UHF antenna is feasible
Unlike UHF ones, HF RFID tag could only be used for gaining access
With a longer range of coverage, UHF RFID makes detection, trace-and-track, real-time location/search, surveillance, eavesdropping, and other processes possible. Compared with a HF system, it is a role-reversal
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Active verses PassiveActive verses Passive
Compared with an active one, the pros and cons ofa passive RFID system are:
its tags are smaller, lighter, and cheaper; they could be used indefinitely without change of battery
its reader is large and very expensive its range of coverage is relatively short its operation decrees a strong EM field and the
feedback signal is vulnerable to noises; thus, it allows little room for modification
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UHF RFID MandateUHF RFID Mandate
With a unique ID number, UHF passive RFID is the natural extension of the popular bar-code system; it has been adopted by the EPC of the United States:
A passive tag is required in every pallet to be shipped to the States
The requirement is later extended to every carton Eventually, a tag must be embedded in every
item to be sold in retail stores
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Market SurveyMarket Survey
The readers are very expensive
Most readers are very large, so are the antennas
The take-it-or-leave-it reader allows no room for alteration
Early tags could not meet the market demands; they are frequently upgraded
New reader must be bought for every upgrade
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Potential Health HazardPotential Health Hazard
Without license, the output power of a reader could be as high as 4W for a range of 8 meters
For detection, the reader must be turned on at all time; thus, operators working in a library are subject to prolonged exposure to a strong non-ionization radiation
With the proliferation of wireless gadgets, the public is annoyed by the sight of many antennas and psychological illnesses are resulted
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ObservationsObservations
Some of the FCC requirements may have been over-specified for applications in Hong Kong, such as the capacity of 200 tags and the speed of 30 tags/sec
Most readers use one antenna for transmitting a high power for energizing the tags and for picking up the feedback signals. To separate the out-going and the in-coming signals of >60dB in rating, an expensive isolator is needed
As the waves scattered from the tags are very difficult to predict, the signal picked up by one antenna is not reliable
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InterferencesInterferences
For convenience, most readers are put on-top of a desk or installed on the wall of an entrance; thus, it is vulnerable to intra-system and inter-system interferences
Interruption of services may arise from the fixed-wire connection in terms of surge currents and static charges
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RemedyRemedy
A reader is custom-designed to handle the less demanding capacity and the slower speed of detection
The paths of transmission and feedback are separated after the synchronization process
While one antenna is used for energizing the tags, multiple antennas are strategically installed around the tag-to-be-detected for picking up the scattered signals, collectively
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Critical ComponentsCritical Components
Expensive components such as the high power voltage-controlled oscillator are custom-designed in an application-specific RFIC
An efficient low-noise amplifier and other front-end components are packaged in another RFIC for installation near the pick-up antenna
Instead of putting all circuits in one RFIC, discrete components are used strategically such that later modifications are made possible
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New ConfigurationNew Configuration
The antenna is installed upside down
In this orientation, interferences from mobile phones and other wireless gadgets are reduced
The antenna is camouflaged as a decorative lighting for relieving the operator’s anxiety
The reader is turned on by a motion detector
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Interference ContainmentInterference Containment
High gain helical antenna with small side lobes is used to contain intra-system interference
Ferrite tiles are placed under the antenna to absorb the excessive electromagnetic waves
A middleware is included inside every reader for buffering the computer network in the library and our network of RFID readers
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Handheld ReaderHandheld Reader
A handheld reader is used to read tags missed by the array of fixed antennas
Communication between the principle reader and a handheld reader is established via a blue-tooth link
As the handheld reader provides no power of excitation, the required battery pack could be significantly reduced, and the resultant device is light in weight
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Value-added ServicesValue-added Services
Multiple-book check out system
Multiple-book return
Book sorter
Self service library
Smart book shelf/book bin
Compact book storage system