Report submitted in partial fulfilment of the requirement for the degree of
Bachelor of Technology
Electronics & Communication Engg.
Raj Kumar Goel Institute of Technology
ECE-B (VI SEM.)
Under the guidance of:
Mrs. Neetu goel
Dept. of ECE
I avail this opportunity to convey my sincere thanks to my
seminar guide Mr. NEETU GEOL for playing a vital role in making
the presentation on “RADIOFREQUENCY IDENTIFICATION”,
through his able guidance and encouragement. Her valuable
suggestions have helped me a lot in improving this presentation.
B.tech IIIrd year
ECE-B (VI SEM)
Roll No. : 1003331902
This is to certify that ANJANI KUMARI of Electronics &
Communication engineering (6th
Semester) has worked hard under my
guidance on the seminar topic “RADIOFREQUENCY
IDENTIFICATION” that was assigned to her.
She has been honest and determined throughout the seminar
Mrs. Neetu goel
Dept. Of ECE)
Name of Topics Page No
2. History of RFID………………………………………………………….8
3. The ABCs of RFID……………………………………………………….9
5. Classification of tags………………………………………………..13-15
Passive RFID tags
Semi-passive RFID tags
Active RFID tags
6. RFID system…………………………………………………………….16
7. System performance…………………………………………………….17
8. RFID today and tomorrow…………………………………………..18-26
Current use of RFID
RFID in the supply chain
Supply chain management
Security and access control
9. Applications for RFID……………………………………………….27-28
Radio-frequency identification (RFID) is a technology that uses communication
via radio waves to exchange data between a reader and an electronic tag
attached to an object, for the purpose of identification and tracking.
The main component of this technology is the transponder/tag, which in most
cases comprises of a chip and antenna mounted onto a substrate or an enclosure.
The chip consists of a processor, memory and radio transmitter. These
transponders communicate via radio frequency to a reader, which has its own
antennas. The readers can interface through wired or wireless medium to a main
computer. Transponders are also known as smart or radio tags. The memory
will vary, depending on the manufacturer, from just a few characters to
The two most common types of RFID technologies are Active and Passive.
Active RFID transponders are self powered and tend to be more expensive than
Passive. Having power on board allows the tag to have greater communication
distance and usually larger memory capacity. The most common application for
Active RFID is for highway tolls.
As for Passive RFID transponders, which are available with chips and without
chips, they have no internal power source therefore require external power to
operate. The transponder is powered by an electromagnetic signal that is
transmitted from a reader. The signal received will charge an internal capacitor
on the transponder, which in turn will then supply the power required to
communicate with the reader.
Whether we are talking about Active or Passive RFID, the features and benefits
are the same.
The following details some of the benefits:
Transponders can be read from a distance and from any orientation, thus
they do not require line of sight to be read.
Transponders have read and write capabilities, which allow for data to be
changed dynamically at any time.
Multiple transponders can be read at once and in bulk very quickly.
RF-Tags can easily be embedded into any non-metallic product. This
benefit allows the tag to work in harsh environments providing permanent
identification for the life of the product.
Today, most implementations involve passive technology. For this reason, this
document is based solely on passive RFID. There are different frequency bands
which passive technology operates within.
Low and High RFID operate on the inductive coupling principle. That is, the
energy is transferred from the reader to the tag through shared magnetic field.
The amount of transferred energy is proportional to the size of the transmitting
And receiving antennas as well as the tag ability to operate at the resonance
frequency. The resonant frequency is a state in which the impedance is at its
minimum, allowing for maximum current flow in the circuit. The resonance
frequency is a function of the inductance and capacitance of the tag circuit. The
quality of a resonant circuit is measured by Q factor. The higher the Q factor,
the higher the amount of energy transfer. Although higher energy transfer is
desirable, the higher Q factor results in reduced bandwidth.
Of all the various frequency bands RFID operates within, there isn't one that can
address all applications. In essence, there is no super RFID frequency band in
other words "one frequency does not fit all". For this reason, the next three
sections will review the most common passive RFID frequencies.
HISTORY OF RFID
The history of RFID can be directly related to a similar technology employed by
the Allies in World War 2 called IFF (Identification Friend or Foe). The
function of this technology was to identify whether an incoming plane was a
friend or foe by using coded radar signals. These signals would trigger the
aircrafts transponder, and a correct reply indicated a friendly military or civilian
aircraft. After the war, scientists and researchers began to explore the use of
RFID to store and relay information.
Radio Frequency Identification presented one major obstacle before it could
become a feasible technology; finding a suitable power source. It took roughly
thirty years for technology and research to produce internal power sources for
RFID tags and chips
THE ABC’s OF RFID
Understanding what RFID devices are and how they work is critical to an
analysis of the policy issues surrounding this technology. Generic references to
“RFID technology” may be applied incorrectly to a wide range of devices or
capabilities. For example, RFID by itself is not a location-tracking technology.
At sites where readers are installed, RFID may be used to track tagged objects,
but this static readability differs from technology such as global positioning
systems, or GPS, which uses a network of satellites to pinpoint the location of a
And RFID technology itself can be used for a variety of applications, from
contactless identification cards that can be scanned no farther than inches away
from a reader, to highway systems utilizing “active” RFID tags that can initiate
communication with a scanner 100 feet away.
A tag is any device or label that identifies the host to which it is attached. It
typically does not hinder the operation of the host or adversely affect its
The word transponder is derived from the words transmitter and responder. The
tag responds to a transmitted or communicated request for the data it carries.
The transponder memory may comprise of read-only (ROM), random access
(RAM), and non-volatile programmable memory for data storage depending on
the type and sophistication of the device. The ROM-based memory is used to
accommodate security data and the transponder operating system instructions
which in conjunction with the processor or processing logic deals with the
internal house-keeping, functions like response delay timing, data flow control
and supply switching. The RAM-based memory is used for temporary data
storage during transponder interrogation and response. The non-volatile
programmable memory may be of several types of which the electrically
erasable programmable read-only memory (EEPROM) is the most common. It
is used to store the transponder data and needs to be non-volatile to ensure that
the data is retained when the device is in its quiescent or power-saving sleep,
Data buffers are further components of memory used to temporarily hold the
incoming data following demodulation and outgoing data for modulation and
interface with the transponder antenna. The interface circuitry provides the
facility to direct and accommodate the interrogation field energy for powering
purposes in passive transponders and triggering of the transponder response.
The transponder antenna senses the interrogating field and serves as the means
for transmitting the transponder response for interrogation.
The reader/interrogators can differ considerably in complexity depending on the
type of tags being supported and functions to be fulfilled. The overall function
is to provide the means of communicating with the tag and facilitating data
transfer. Functions performed by readers include signal conditioning, parity
error checking and correction. Once the signal from a transponder has been
correctly received and decoded, algorithms can be applied to decide whether the
signal is a repeat transmission and may then instruct the transponder to stop
transmitting. This is known as Command Response Protocol and is used to
circumvent the problem of reading multiple tags in a short span of time. Using
interrogators in this way is also referred to as Hands Down Polling. A more
secure, but slower tag polling technique is called Hands up polling which
involves the interrogator looking for tags with specific identities and
interrogating them, in turn. A further approach uses multiple readers,
multiplexed into one interrogator but results in cost increase
CLASSIFICATION OF TAGS
PASSIVE RFID TAGS
Transponders (tags) of passive RFID system don’t have power supply. This is
why they are called passive. Passive tags are powered from electromagnetic
field generated by reader antenna. Reader antenna has to transmit enough power
to provide enough energy to tag so it could to transmit back data. Because of
this reading distance is very limited – up to several centimetres.
Well some of implementations may reach several meters. Passive tags are most
common used because they are cheap, can last indefinitely long as there is no
need for power supply, and they are small size what allows them easy to
integrate almost in every environment starting wrists, necklaces, cards, stickers.
Passive tags simply consist of single IC and antenna coil which is usually flat.
Passive tags are operating below 100MHz frequencies (most common
frequencies are 125 kHz – 134.2 kHz and 13.56 MHz) and main transfer energy
is carried by magnetic field. Magnetic field generated voltage in the coil which
is used as power supply also as data signal. There are also HF passive tags that
operate at 900MHz and 2.45GHz. These tags have dipole antenna (1/8 wave
length) construction. With these tags distance may reach more than 3 meters.
But high frequency tags require more expensive manufacturing processing with
more precise electronics, but they can support up to 2Mb/s data stream.
SEMI-PASSIVE RFID TAGS
Semi-Passive tags are more similar to passive transponders than active. These
tags are powered from battery or so called battery assisted tags, but radio
transmission depends on antena activity. As data processor had it own power, so
all received power can be used for transmitting back the signal which is stronger
than passive transducer. This allows to increase communication distance with
quit cheap solution.
Semi passive RFID tags augment the energy from reader antenna, but they are
not constantly beaming signals as active tags does. Semi-passive RFID tags use
a process to generate a tag response similar to that of passive tags. Semi-passive
tags differ from passive in that semi passive tags possess an internal battery for
the tag’s circuitry which allows the tag to complete other functions such as
monitoring of environmental conditions (temperature, shock) and which may
extend the tag signal range.
ACTIVE RFID TAGS
Active RFID tags may provide all advantages of RFID system because tags are
fully powered transmitters. They don’t have to be activated by antenna reader.
Active RFID topic may be very wide because there are many areas where an
how they can be used. In some cases tags may not need a reader antenna
because tags in some particular cases can be configured to interact with each
other. Active transponders can communicate in very long ranges up to several
hundred kilometres. Main disadvantages of active tags may be relatively big
size and production price compared to passive ones.
RFID uses radio-frequency (RF) transmissions of bit streams to communicate with,
identify, classify, and/or track objects. Each object has its own RFID tag (also
known as a transponder). The overall system employs a tag reader, a subsystem
that receives RF energy from each tag. The reader has embedded software that
manages the interrogation, decoding, and processing of the received tag
information; and it communicates with a storage system that houses a tag database
and other relevant information. Figure 1 shows a conceptual diagram of an RFID
Simplified representation of an RFID system.
Reading distance: The actual reading distance depends on the transponder type,
electromagnetic noise, transponder orientation, antenna type. In general, a
32mm glass transponder can be read with a stationary reader and gate antenna
from a distance of about 1m.Larger transponders can achieve ranges up to 2m
with handheld readers offering lower ranges up to 250mm.
Data accuracy: A 16-bit cyclic redundancy check algorithm is used to ensure
that only valid data is sent from the reader to its associated controller.
Antenna selection: Of the antenna types, the one giving larger read ranges is
selected. Electromagnetic noise affects the readout pattern.
Transponder orientation: For maximum range, the antenna orientation with
respect to the transponder must be optimized for maximum coupling. The
orientation in line with a ferrite antenna produces the largest read ranges from
2mm glass transponder.
Reading speed: Many applications require that that transponder must remain in
the reading range. Since a standard stationary reader completes one cycle in
abut 120ms, transponders must remain in the boundaries of a readout pattern for
at least that amount of time.
RFID Today and Tomorrow
The Workshop included a comprehensive discussion of RFID’s various current
and anticipated applications. Both private and public sector users of RFID
explained how they are applying this technology to improve their delivery of
goods and services. Privacy advocates also addressed the implications of these
initiatives, sounding a cautionary note about some of the emerging uses of
RFID and their consequences for consumer privacy.
Current Uses of RFID
Workshop participants described a number of RFID applications that consumers
may already be using. For example, some consumers are familiar with
employee identification cards that authenticate the pass-holder before permitting
A related use of RFID is for event access – to amusement parks, ski areas, and
concerts, where tagged bracelets or tickets are used.
Panellists also explained how RFID is being used in a variety of transportation
related contexts. Many automobile models already use RFID tags in keys to
authenticate the user, adding another layer of security to starting a car.
Another example, the “Speed pass,” allows drivers to purchase gas and
convenience store goods from ExxonMobil stations.
RFID is also transforming highway travel, with the advent of E-Z Pass in North-
eastern and Mid-Atlantic states and similar programs in other regions of the
country that allow drivers to pass through tolls without stopping to pay. An
active tag on the vehicle’s windshield lets a reader installed at the tollbooth
know that a tagged vehicle is passing through; information flows from the tag,
to the reader, and then to a centralized database, where the prepaid or checking
account associated with that vehicle is charged.
RFID in the Supply Chain
To the extent that the much-touted “RFID revolution” is underway, it is
occurring somewhat out of public sight – in warehouses, distribution centres,
and other stages of the supply chain.
Workshop participants discussed how RFID’s impact on the flow of goods
through distribution channels has implications not just for manufacturers,
suppliers, and retailers, but also for consumers.
Many panellists reported that as a result of more efficient distribution practices
generated by RFID use, consumers may find what they want on the store
shelves, when they want it, and perhaps at lower prices.
Workshop participants representing manufacturers and retailers described the
anticipated economic benefits of RFID. According to one panellist, the retail
industry suffers losses between $180 and $300 billion annually because of poor
supply chain visibility – the inability to track the location of products as they
make their way from manufacturer to retailer.
As a result, this panellist stated, retailers are not always able to keep high-
demand goods in stock, or they may have inventory that they can’t move.
Participants discussed how RFID may help prevent these lapses by improving
visibility at multiple stages of the supply chain. RFID readers can gather
information about the location of tagged goods as they make their way from the
manufacturer, to a warehouse or series of distribution centres, and to the final
destination, their store.
Also, as one workshop participant explained, RFID enhances the accuracy of
information currently obtained through bar code scanning, which is more
vulnerable to human error.
According to this panellist, access to more – and more accurate – information
about where products are in the distribution chain enables retailers to keep what
they need in stock and what they do not need off the shelf.
Workshop participants also touted the discipline that RFID imposes on the
supply chain by, for example, reducing “shrinkage,” or theft.
One panellist explained how RFID may lower costs by keeping shipping
volumes leaner and more accurate.
Other panellists described how RFID tags can be read much faster than bar
codes, citing tests indicating that RFID’s scanning capability can result in goods
moving through the supply chain ten times faster than they do when bar codes
According to another participant, RFID will facilitate quicker, more accurate
recalls by enabling the tracking of a product’s origin and its location in the
Further, this panellist asserted, RFID will enhance product freshness by
monitoring expiration dates of consumer goods, so retailers know when not to
offer items for sale.
RFID Use in the Public Sector
Panellists also discussed how RFID is being used or contemplated for use by
government entities to meet objectives similar to those their private-sector
counterparts hope to achieve. Workshop participants discussed a variety of
ongoing and proposed government RFID applications, from the U.S.
Department of Defence’s (“DOD”) October 2003 mandate Requiring its
suppliers to use RFID tags by January 2005 to local library systems deploying
this technology to track and trace their books. DOD’s initiative reportedly will
affect 43,000 military suppliers. And, according to panellists, public libraries in
California, Washington State, and elsewhere have implemented internal RFID
systems to facilitate patron usage and manage stock.
One Workshop panellist, representing the U.S. Food and Drug Administration
(“FDA”), highlighted that agency’s RFID initiative.
Although the FDA itself is not using this technology, it recently announced an
initiative to promote the use of RFID in the pharmaceutical supply chain by
For now, drug manufacturers will primarily tag “stock bottles” – those used by
pharmacists to fill individual prescriptions – but eventually consumers may be
purchasing packages labelled with RFID chips.
The core objective of this initiative is to fight drug counterfeiting by
establishing a reliable pedigree for each pharmaceutical.
The FDA believes that this goal can most effectively be accomplished by its
target date through the adoption of RFID, which offers distinct advantages over
other identification systems that require line-of-sight scanning and are not as
accurate or fast.
Another government entity turning to RFID is the U.S. Department of
Homeland Security (“DHS”). One program described by a DHS official at the
Workshop uses RFID for tracking and tracing travellers’ baggage.
Both individual airports
Will use RFID technology to identify and track passenger luggage, from check-
in to destination. Another DHS initiative addressed at the Workshop involves
the agency’s “US-VISIT” (U.S. Visitor and Immigrant Status Indicator
Technology) program. That initiative will test RFID at the country’s fifty
busiest border-crossing locations by using RFID to read biometric identifiers,
such as digital photographs and fingerprint scans, embedded in U.S. work visas
issued to foreign nationals.
It's no surprise that asset tracking is one of the most common uses of RFID.
Companies can put RFID tags on assets that are lost or stolen often, that are
underutilized or that are just hard to locate at the time they are needed. Just
about every type of RFID system is used for asset management. NYK Logistics,
a third-party logistics provider based in Secaucus, N.J., needed to track
containers at its Long Beach, Calif., distribution centre. It chose a real-time
locating system that uses active RFID beacons to locate container to within 10
RFID has been used in manufacturing plants for mo re than a decade. It's used
to track parts and work in process and to reduce defects, increase throughput
and manage the production of different versions of the same product.
Supply Chain Management
RFID technology has been used in closed loop supply chains or to automate
parts of the supply chain within a company's control for years.
As standards emerge, companies are increasingly turning to RFID to track
shipments among supply chain partners.
Retailers such as Best Buy, Metro, Target, Tesco and Wal-Mart are in the
forefront of RFID adoption. These retailers are currently focused on improving
supply chain efficiency and making sure product is on the shelf when customers
want to buy it.
RFID is all the rage in the supply chain world, but the technology is also
catching on as a convenient payment mechanism. One of the most popular uses
of RFID today is to pay for road tolls without stopping. These active systems
have caught on in many countries, and quick service restaurants are
experimenting with using the same active RFID tags to pay for meals at drive-
Security and Access Control
RFID has long been used as an electronic key to control who has access to
office buildings or areas within office buildings. The first access control
systems used low-frequency RFID tags. Recently, vendors have introduced
13.56 MHz systems that offer longer read range. The advantage of RFID is it is
convenient (an employee can hold up a badge to unlock a door, rather than
looking for a key or swiping a magnetic stripe card) and because there is no
contact between the card and reader, there is less wear and tear, and therefore
As RFID technology evolves and becomes less expensive and more robust, it's
likely that companies and RFID vendors will develop many new applications to
solve common and unique business problems.
Applications for RFID
Applications fall into two principal categories: short range applications in which
the reader and tag must be in close proximity (such as in access control), and
medium to long applications in which the distance may be greater (such as
reading across a distribution centre dock door). A sample of applications is
Access control for people: There are many areas in which
RFID tags are carried by people to allow them to gain access to facilities
o Secure access to work place
o Safety access to dangerous/secure equipment
o Access to a computer or vehicle
o Access to travel on trains/buses
o Access to leisure facilities
Access control for vehicles:
o Secure access on site
o Road tolling
o Instant payment for fuel
o Control of flexible manufacturing processes by recognizing items
being built on a production line (mass customization enabler)
o Libelling key components for later recycling
Logistics and distribution:
o Tracking parcels from shipment to end customer
o Tracking goods from manufacture to retail
o Supply chain management
o Stock taking
o Reducing loss through shrinkage
o Reverse logistics
o Product availability
o Plant & Equipment
o Fixed assets
o Tamper evidence
o Product authentication
RFID technology permits no line of sight reading.
Robustness and reliability under difficult environmental
These tags can be read through water, snow, concrete, bricks,
plastics, wood, and most non-metallic materials
Available in a wide variety of physical forms, shapes, sizes and
RFID tags can be read at very high speeds.
In most cases the response time is less than 100ms.
Difficulty in duplicating, offers a high degree of security.
RFID solutions cost much higher than the conventional barcodes. A large
fraction of its cost lies in the software infrastructure and the enterprise
application and integration
Lack of standardization.
Standardization has not been provided across many fronts, ranging from
the different data formats used to interoperatability between RFID readers
and tags from different vendors to interference between RFID products
from different manufacturers.
RFID will hurt privacy
RFID transponders are forever part of the product, and designed to
respond when a signal is received.
RFID tags will soon be tracking millions of consumer products worldwide.
Manufacturers will know the exact location of each product they make from the
time it is made until it is used and tossed in the recycle bin or trash can. The
crypto transponders will be well suited for future generation vehicle entry
The RFID tagging will take off when the cost of the tags drops to one percent of
the cost of the product it is applied to, and that date is somewhere near.
2005 is the date that researchers say when radio frequency tagging becomes
viable and until then, we must wait and see.