Radio Frequency Identification(RFID) - Engineering Seminar

Radio Frequency Identification(RFID)
RFID is an acronym for Radio Frequency Identification. RFID is one member in the family of Automatic Identification and Data Capture (AIDC) technologies and is a fast and reliable means of identifying just about any material object.
 Primarily, the two main components involved in a Radio Frequency Identification system are the Transponder and the Interrogator. Communication between the RFID reader and tags occurs wirelessly and generally does not require a line of sight between the devices.                             
An RFID reader typically contains a module (transmitter and receiver), a control unit and a coupling element. The reader has three main functions: energizing, demodulating and decoding. In addition, readers can be fitted with an additional interface that converts the radio waves returned from the RFID tag into a form that can then be passed on to another system, like a computer or any programmable logic controller. Anti-Collision algorithms permit the simultaneous reading of large numbers of tagged objects, while ensuring that each tag is read only once.

RFID is a sight less identification system. It is the combination of Radio Frequency and the Microchip technologies. RFID transmits the identity of an object as a unique serial number. This identity is stored in the tag chips and can be retrieved by the Readers. The components of RFID are

Tag, also called transponder is a small device which contains a microchip. The chip is used to store the data. The tag can be programmed with specific items of information, such as an ID or serial number or a user data. The tag identifies itself by transmitting signals to the Interrogator. 
There are two types of Tags namely,

  • Active Tag 
  • Passive Tag
  • Semi Passive Tag


  • Transmits signals from the microchip circuit through the power obtained from an internal battery
  • High Signal range
  • Used on large assets, such as cargo containers, rail cars, and large reusable containers 
  • Costlier and Larger in Size.


  • Contains no power source
  • Obtains power from the Interrogator
  • Low Signal range 
  • Cheaper and Smaller than active tags


  • Semi-passive RFID uses an internal power source to monitor environmental conditions, but requires RF energy transferred from the Interrogator similar to passive tags to power a tag response. 
  • 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 power source  for the tag's circuitry which allows the tag to complete other functions such as monitoring of environmental conditions and which may extend the tag signal range.

A Interrogator consists of one or more antennas that emit and receive radio waves. The microchip circuit present in the tags is powered by this signal. When the tags enters into the radio wave field, it transmits its unique information to the Interrogator by modulating the signal. The Interrogator converts the signal obtained from the tag as digital information and passes to the applications.


  • Employee Identification and Access Control
  • Airline baggage Identification
  • Wafer Identification during manufacturing process
  • Livestock Identification
  • Parts Identification
  • Identification and Tracking of Vehicles
  • Identification of  widgets through manufacturing process
  • Supply Chain Automation
  • Asset Tracking, and others.

In this new concept we use active rfid transponders in cell phone towers. By increasing the internal battery power of the transponders, we can increase the range of coverage of the transponder. So that we can ensure that all the areas are under this range. These transponders have data’s such as the map of that area, so that any incoming cars can download these data’s.

 In the modernized road system each and every speed limit boards are converted into rfid transponders, which means the data in the boards are transmitted as radio signals to a minimum range of 60 to 300m. Similarly for the road signals such as green, orange and red corresponding data’s are transmitted.  And in this modernized road each and every vehicle acts as an active rfid transponder, so that they can communicate with each other. We have categorized this in three ways
The categories are
1. Simple rfid in cars
2. Semi-automatic cars
3. Fully automatic cars

We use the basic rfid’s to store various information’s about the vehicle such as

  • Registration  number
  • Colour
  • Make and the Model of the vehicle

                                   By using this we can spot the target vehicle anywhere when required. This will be a more effective way to maintain the security system.

As in simple rfid, this also includes all the features. In addition to it these cars consists of a microcontrollers. These microcontrollers process the incoming signals and acts accordingly to take over the control of accelerator and brake. All these semi-automatic cars are clutchless cars.

When the car is approaching a signals range, the signal information is decoded and the microcontroller acts accordingly.  

  • If the signal data is ‘STOP’(i.e. red) the accelerator control is taken off and the brake is applied gradually.
  • If the signal data is ‘SEE’(i.e. orange) only the accelerator control is taken off.   
  • If the signal data is ‘GO’(i.e. green) the microcontroller will not interrupt.
  • These signal data will only be processed if and only if the vehicle is 100m away from the signal.

Every speed limit board transmit the data in it. These data’s are received by the vehicles and it is decoded and the microcontroller acts accordingly. 

  • If Speed Error MORE THAN null then ACCELERATOR UP 
  • If Speed Error LESS THAN null then ACCELERATOR DOWN
  • If Acceleration MORE THAN null then ACCELERATOR UP 
  • If Acceleration LESS THAN null then ACCELERATOR DOWN
  • If Speed Error MORE THAN null then BRAKE DOWN 
  • If Speed Error LESS THAN null then BRAKE UP 

In these vehicles we use both the type of transponders (i.e. active and passive). As usual an active transponder is placed in the front end of the vehicle and three other passive transponders are placed in the other three dimensions of the vehicle. 
Let us consider two moving vehicle s A and B.
  The vehicle A is moving before us with the constant speed limit, if the vehicle B tends to move close to A the active transponder which is in front of vehicle B receives more signal power compared to other passive transponders. Now the pre-programmed microcontroller takes off the control of the accelerator and gradually applies the brake until both the vehicles are separated with a pre-specified distance.    
Now the vehicle  A is coming back of vehicle  B. In this case the passive transponders in the back and sides will get more signal power than that of the active transponder in the front and so this less signal power at the front end was ignored and the microcontroller will not interrupt.

As in simple rfid and in semi-automatic cars this also includes all the features. But in this we include a computer with all advanced features such as GPS, large memory, RAM for high processing speed and many other applications included in it.
The  working of the fully automatic vehicles is shown in the following steps:
Step1:  Enter the vehicle and set the source and destination point in the computer.
Step2:  The computer will automatically download the map details and the traffic details 
from the nearest transponder. Displays various path to attain the destination with the time taken for each travel. The user can select the required  path from the display.
Step3:  Now the plan is set and the vehicle start moving to the destination.  
Step4:  It travels in the road as like the semi-automatic vehicles. In addition to that it uses 
GPS technique to position the vehicle exactly(i.e. to distinguish between curves, bends and others vehicles).
Step5:   If traffic in current lane is more than the nearby lanes, which can be found by the 
 transponders. Then the vehicle is moved to the lane with less traffic, which is done
 by the computer. 
Step6:   When the destination is reached the engine is turned off. 

Many IT decision makers have heard about, and took interesting it, but are still far from implementation. The opinion on the strategic importance of RFID is divided. The judgments seem to be influenced by RFID experience and perceived potential of the technology. Hope for improved customer service, reduction of errors and optimization of stock most attract CIOs to RFID. 
Companies expect their RFID budgets to rise over the next years, especially within the next 3 years. As expected, a higher perception of strategic importance correlates positively with a higher willingness to invest in the technology.
However, RFID is not a topic of high priority on companies’. The high-level concepts often associated with RFID in the media or in consulting, above all the “real time enterprise” or the “internet of things” have not yet found their way into companies’ RFID visions. On the other hand, virtually all participants state that the importance of RFID will rise significantly over the next years. The technology might well turn out to be a sleeping giant.

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