What is Rfid: Definition and 39 Discussions

Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects. An RFID system consists of a tiny radio transponder, a radio receiver and transmitter. When triggered by an electromagnetic interrogation pulse from a nearby RFID reader device, the tag transmits digital data, usually an identifying inventory number, back to the reader. This number can be used to track inventory goods.
There are two types of RFID tags:

Passive tags are powered by energy from the RFID reader's interrogating radio waves.
Active tags are powered by a battery and thus can be read at a greater range from the RFID reader, up to hundreds of meters.Unlike a barcode, the tag does not need to be within the line of sight of the reader, so it may be embedded in the tracked object. RFID is one method of automatic identification and data capture (AIDC).RFID tags are used in many industries. For example, an RFID tag attached to an automobile during production can be used to track its progress through the assembly line, RFID-tagged pharmaceuticals can be tracked through warehouses, and implanting RFID microchips in livestock and pets enables positive identification of animals. Tags can also be used in shops to expedite checkout, and to prevent theft by customers and employees.
Since RFID tags can be attached to physical money, clothing, and possessions, or implanted in animals and people, the possibility of reading personally-linked information without consent has raised serious privacy concerns. These concerns resulted in standard specifications development addressing privacy and security issues. ISO/IEC 18000 and ISO/IEC 29167 use on-chip cryptography methods for untraceability, tag and reader authentication, and over-the-air privacy. ISO/IEC 20248 specifies a digital signature data structure for RFID and barcodes providing data, source and read method authenticity. This work is done within ISO/IEC JTC 1/SC 31 Automatic identification and data capture techniques.
In 2014, the world RFID market was worth US$8.89 billion, up from US$7.77 billion in 2013 and US$6.96 billion in 2012. This figure includes tags, readers, and software/services for RFID cards, labels, fobs, and all other form factors. The market value is expected to rise from US$12.08 billion in 2020 to US$16.23 billion by 2029.

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  1. E

    I Antenna inductance calculation (RFID applications, inductive coupling)

    Inductance of antenna coils of different shapes can be estimated. Some examples are: A circular coil with single turn. N turn multilayer circular coil. Spiral coil. N turn squae loop coil. etc. For plannar design (spiral, rectangular, etc) I have used this reference (from pag. 9 onwards)...
  2. S

    Mesh hole size calculation for RFID signal blocking

    For a project I am currently facing a problem that I find difficult to solve. I am developing a shielding portal that uses a mesh to blocks UHF RFID signals. I would like to use aluminium mesh due to it being lightweight and its attenuation properties. The frequency of UHF RFID signals in the...
  3. K

    Does an RFID wallet contain any chemical addictives?

    Does RFID wallet or any other wallet that suggest to be protecting contain any chemical addictive or have a different composition of material so that they can protect against unauthorized card reading?
  4. Y

    Can a smartphone transmit/receive 125KHz?

    As part of my final project in my EE studies I was thinking if it is possible to read 125KHz RFID tags with a smartphone. I know it is possible with NFC (13.56MHz) and I was thinking about implementing a 125KHz reader. Is there any antenna in a regular smartphone that can deal with these low...
  5. O

    How RFID Tags Work: Detailed Explanation for Physics Students

    I'm afraid my Google-fu is failing me. Try as I might, I can only find very basic descriptions online of how RFID tags (specifically passive ones) work. I'd like to actually know what the microcontroller in the tag does, and how it creates a signal the reader can pick up and decode. For example...
  6. V

    Connecting a Sensor to an RFID Chip: A Mechanical Engineer's Guide

    Hi, I have an internet of things project and I am wondering how you would cheaply go about connecting a sensor to an RFD chip? I am a mechanical engineer by training so this is a bit of a learning curve, apologies if it is a really basic and obvious question. I have found this chip...
  7. V

    Is there an RFID chip that lets you add sensor input?

    Hi, I am working on a project where I will be building my own sensor and would like to have this in an RFID circuit. I am new to this so any info pointers would be much appreciated. Here is what I would like to do: The receiver would send a signal to energise the circuit. Using this energy, my...
  8. rushi121

    How can I detect whether driver is sitting in car or not?

    I want a device that can either stick on dashboard or like a key fob in driver pocket that will help to detect whether person is in car or not. Requirements: - Device must have a detector and siren. When detector detects that person is not in car should buzz siren. - Can be a device in car or...
  9. W

    Is there Something to RFID blockers?

    Hi all, After having had my credit card hacked for the 5th time in a few years, I am looking for ways of protecting my information. My best guess is that some have used some devices to read my card number from my wallet. I have seen some ads for RFID blockers, but I don't have the background to...
  10. 4

    Is this RFID antenna design possible?

    Hey everyone, Looking for someone in the know regarding RFID reader antenna design. Part of a project I'm working on requires a custom RFID transmitter antenna. If possible, I'd like to design the antenna as an integral part of a steel cylinder. I know there are on-metal tags, but is it...
  11. 4

    What is Embeddable In-Metal RFID and How Does It Work?

    I am new to RFID but relatively familiar with how it works and its limitations. However, I recently learned of an advancement in the tech known as embeddable in-metal RFID, which appears to be a newer evolution in the tech and a product offered by very few suppliers thus far. I believe this type...
  12. H Smith 94

    NFC/RFID devices -- How do they transmit data?

    Hi all, I am designing an NFC device but am still a little unsure about the principles behind NFC/RFID. From what I understand: A primary coil constantly emits a 'carrier frequency' magnetic field. This field induces an e.m.f. on a passive secondary coil which is in a secondary circuit. The...
  13. W

    Setting Off RFID Alarms: Causes & Solutions

    Hi, I am almost completely ignorant on any Physics beyond the high school level. Not proud of it, but it is a fact. But I am curious about this: While at a bookstore, I set off the RFID detector. I found out, by trial and error, that (something in) my wallet was setting it off, but not clear...
  14. AlexTommyP

    Is their a way to sniff an RFID signal?

    Hi all and thanks for reading, I'm working on a concept and am trying to establish if there is a way to sniff a signal between an RFID tag and it's reader. What I mean by this is - is there a way an ON (1) can be generated when the tag and the reader communicate? I don t need power from the...
  15. D

    Help in trying to build microcontroller powered Chess Board

    Hello all, as the title states I'm trying to build an arduino powered chess board. The chess pieces will have magnets on the bottom and each square of the board will be equipped with a reed switch for detecting the presence of the magnetic field produced by the magnet. I recently tried this out...
  16. D

    Challenge Connecting Multiple Smartphone Mic's Simply & Quickly

    Dear Readers, I'm facing a pretty interesting challenge, which is: "How to connect multiple smartphone mic's in the quickest and simplest way?" Here is a use case. I go into a meeting with a group of random (strangers) that all have smartphones, Android, iOS, Windows. Now I want to record this...
  17. H

    RFID and Block Diagram Questions, help please

    Questions are shown on the pictures. For the block diagram, I know (1) error signal (5) output (7) feedback signal What are the (2), (3), (4) and (6)? Besides, how to answer the RFID questions? Ans. 1. For example, mall card? Ans. 2. Ans. 3. Ans. 4. Ans. 5. Please help!
  18. S

    Designing an ASK Demodulator for RFID Tags

    Hi, I am designing an ASK demodulator for RFID Tags. I have attached the circuit diagram. This is the ckt from IEEE paper. If you look at the ckt, the first stage is the inverter kind of thing. I didn't get why second NMOS is used for Stage I. Similarly, the second stage is also inverter...
  19. S

    RFID rectifier Tag - Issues regarding PCE

    Hi, I am designing a RFID rectifier. I am referring a IEEE paper for this purpose. The paper has shown results for both 130nm and 350nm technologies. I have chosen 180nm technology. So, I expected results in between the above technologies. To my surprise, the results are weird -...
  20. M

    RFID tags for temperature and moisture

    Hi, I have been searching and looking for RFID tags that capture moisture and temperature but i didn't find specific things. Could anybody provide some references or models names please?
  21. M

    RFID induction question and frequency

    Well, passive RFID tags has to be inducted to work. When the induction reaches the tag, it powers itself and then the microcontroler sends a RF signal to the reader, with the product ID, rigth? What I want to know is: what type of induction does it use? How the induction radio frequency...
  22. B

    RFID Scanners: Can Metal Protect?

    Hi, All: Sorry if this is not the right forum. I was just reading that the information in one's wallet can be stolen using an RFID scanner. Also, metal , aluminum supposedly can be used to protect, i.e., I assume, block the signal from coming into the wallet. Is this all correct?
  23. C

    Can you make RFID scanner to detect any 3rd party tags despite countermeasures?

    suppose Team Red wants to make RFID tags that only their own "authorized" scanners can pick up, such as for tagging merchandise in Walmart. Meanwhile Team Blue wants to be able to find any Team Red tags on items or prove that they are not there. They don't need to extract any info from the tags...
  24. B

    RFID attendance marking, what infrastructure?

    RFID attendance marking, what infrastructure?? im trying to plan for an RFID system. 1)what resources and material and general infrastructure do i need? 2) i think i want it to connect it up to my Uni's intranet maybe wireless, so i'd only need to wire the power source? this good? 3)...
  25. C

    TI RFID Evaluation Kit - Why Can't Tags be Placed on Metal?

    Hi, I've been doing some work with a TI RFID evaluation kit and I noticed that when I place one of the tags onto metal, they don't work. These are passive tags that respond to a signal from an antenna after being charged through induction and I was just curious as to why they can't be...
  26. A

    Help Finding RFID Reader & Interfacing for Senior Project

    Hello. I am getting ready to start my senior year in college for EET. I had to come up with a senior project, design, and fabricate it. I have an idea of what I want to do but need help understanding it and what product is suffecient for my idea and cost effective for a college student...
  27. V

    Rfid tag antenna design for moisture sensor

    hi this is vebi , i want to design rfid tag antenna with moisture sensor can anybody suggest me how to design
  28. G

    RFID or better alternative?

    RFID or better alternative?? I want to be able to transmit and receive a signal from one device to another; the devices need to be very small and very inexpensive.. I'm hoping for it to work over quite a long distance; definitely more than just 10m.. also if a battery or energy source is...
  29. L

    Faraday cage problem with RFiD

    I'm working in a tracking solution based on RFiD, that consists on tags without any type of battery or power source. When the antenna generates the signal in the correct frequency, an induction process occur in the tag, generating a response to the antenna (containing the tag's id number)...
  30. R

    Is it possible to clone RFID cards with basic hardware?

    I'm a first year computing student and have just finished this years exams. I tend to get a little bored in my free times and so have looked towards a sort of project besides programming. I've seen RFID is staging a take over of wireless technology and seen in the news it's been implanted...
  31. V

    Designing RFID Reader: Looking for Suggestions & Help

    Hi to all, I am looking for suggestions and help I already have Rsk board (TRH031M reader for 13.56MHz rfid, ISO 14442A) i am planing to design or build a Rfid reader using RFID tags(ISO 14442A). I am looking at building the small transformer that links rfid reader. I need some...
  32. D

    Can a Master's Project in RFID Still Offer Unique and Valuable Contributions?

    I am thinking of some RFID applications, and the web seems to prove there is an endless supply of applications and problems already solved. Is there any hope to do a master's thesis/project in this field that would be worthwhile? If I come up with a good idea, its already done, and if I come...
  33. S

    Can You Extend the Range of a Proximity RFID Tag?

    Hey guys...not sure if this is possible but is there a way to extend the range of a proximity RFID Tag. I'm looking for a way to broadcast the tag information so i don't have to walk up to the reader with a proximity tag. I'm trying to find a way to open my apartment gate by driving up to it...
  34. C

    Is an RFID Warehouse Tag System the Solution for Efficient Inventory Tracking?

    I had this idea a while ago but having just finished reading an article about the recent increase in college-aged entrepreneurs, I was inspired. At present, I am a freshman math major at a small state college in Vermont. I plan to transfer into a competitive Economics/Mechanical Engineering...
  35. benzun_1999

    Designing a Small Location Detection System with RFID Tags

    hi, i need help... i am planing to design a small location detection system within a room using RFID tags or some resonace technique. Each object must have a unique identification code. I intend to place 4 detectors like Satellites to determine the exact position of the object... I need...
  36. B

    Maximum range (RFID) can function

    I need to know the maximum range in which a radio frequency identification device (RFID) can function. What is it limited by?
  37. I

    Buy RFID Readers & Tags | Testing Purposes

    Does anyone know where I can purchase an RFID reader and some RFID tags please? I'm doing my thesis on this technology and I need to buy some of these. Testing purposes.
  38. T

    RFID Antennas with ferrite Rod

    Hi, I have a question relating to RFID antennas... For inductively coupled RFID systems, the max. range is about 1.4 times the diameter of the sender antenna (for a loop antenna). In low frequency systems (125, 134 kHz) the antenna coil is often wounded around a ferrite rod, making the...
  39. T

    Magnetic Fields & RFID: Rolling to Detect

    Hi First, I´m new in this forum so I´m not sure if I´m posting in the right place. If I don´t...well, sorry. Then my question...I´ll try to explain. I´m playing with an inductively coupled RFID-reader and smart labels. Holding the smart label 90 degrees with respect to the antenna, the...