RFID – Radio Frequency Identification is An ADC
(Automated data collection).
It is a wireless non-contact radio system to transfer data
from a tag attached to an object.
RFID is a new generation of auto identification and data
collection technology which helps to automate business
processes and allows identification of large number of
tagged objects like books using radio waves.
RFID tag wirelessly sends bits of data, when it is
triggered by a reader.
A SAMPLE RFID TAG
A paper label
with RFID inside
or stamped ...
… and a chip
attached to it
… on a substrate
e.g. a plastic
HISTORY OF RFID
The concept of RFID is based on the barcode.
First barcode patents was in 1930s.
RFID technology was first used in world
war- II for identification, friend or foe (IFF)
systems, and has been available in one form
or another since 1970’s.
Mario cardullo’s device (1973) was first true
ancestor of modern RFID.
The first patent to be associated with the
abbreviation RFID was granted to Charles
RFID is being used to tie the physical world
with the virtual world. RFID in social media
first came to light in 2010 with Facebook's
RFID technology uses radio waves as the medium to
transfer the data from an electronic tag, called RFID
tag, through a reader for the purpose of identifying and
tracking the object.
RFID technology uses
I) RFID tag.
II) RFID reader.
IV) Middle ware.
V) Host computer.
RFID API software
Many types of RFID exists, but at the highest level based
on the type of tag and the power sources and their
powered infrastructure, we can divide RFID devices into
1). Active RFID.
2). Passive RFID.
An active rfid tag talks first, it beacons.
This tag does not depends on a reader to be
Active tag can be read at much greater ranges and
is equipped with a battery that can be used as a
partial or complete source of power .
Active tag transmits radio signals.
It has capability to perform independent
Active rfid tags may even be equipped with
autonomous networking; the tags autonomously
determine the best communication path.
Active rfid tag
RF and it beacons
Passive tag uses reader talk first.
Tags are muted until a signal is received from
Passive RFID tag functions without any battery;
these tags have a useful life of twenty years or
The tag is much less expensive to manufacture and
is smaller in size.
Passive RFID tag costs upto $0.25 to $10.
Power and data transmission occurs between
reader via antenna.
RFID, HOW FAST……
ISM band, dif fering
power levels and duty
Non-specif ic Short
Range Devices (SRD),
ISM band (Region 2);
increasing use in
differing pow er levels
and duty cycle
ISM band, dif fering
power levels and duty
Data Spe ed
Animal identific ation
and factory data
Popular frequency for
I.C. Cards (Smart
Å 10 cm
1 Š 100 m
Asset trackin g for U.S.
MH10.8.4 (RTI) ,
AIAG B-11 (Tir es)
A RFID reader transmits an encoded radio
signal to interrogate the tag.
RFID readers are two-way radio transmitterreceiver called interrogates or reader.
The reader sends a signal to the tag and read
The readers generally transmit their
observations to a computer system running
RFID software or RFID middleware.
Signaling between the reader and the tag is done in
several different incompatible ways, depending on the
frequent band used by the tag.
This signaling is of two types
2). Far- field.
Near field RFID is based on the principle of faraday’s
A reader passes a large alternating current through a
reading coil, resulting in an alternating current
through reading coil.
If you place a tag that incorporates a smaller coil in
this field, an alternating voltage will appear across it.
The current is proportional to the load applied to the
tag’s coil. This concept is load modulation.
RFID tags based on far-field emissions capture
electromagnetic waves propagating from a dipole
antenna attached to reader.
Unlike induction designs, information can’t be
transmitted back to the reader using load
By changing the antenna’s impedance
overtime, the tag can reflect back more or less of
incoming signal in a pattern that encodes the tag’s
Host controller is a computer that communicates with the
reader, it performs two main functions.
1). It is receiving data from the readers and performing
data processing such as filtering and collation .
2). It serves as a device monitor, making sure the reader
is functioning properly, securely and with up to date
Host controllers are connected to readers through
network technologies such as TCP/IP or sometimes
through serial connectivity.
APPLICATIONS OF RFID
Automated Vehicle Id
• Isolated systems
• Simple reads
• Slow growth
We proposed a rfid based employee tracking system
with the functionalities as
1). It tracks the employee location with in the campus.
2). It stores the data of an employee during his stay in
3). Graphical interface system.
4). Automatized attendance system can be embedded.