First Question...
1. What is RFID?
RFID is short for Radio Frequency Identification; this essentially works using Radio Waves.
Now, Radio Waves were first used by Guglielmo Marconi an Italian Inventor who proved the feasibility of radio communication by sending the first Radio Signal in 1895 (7).
It quickly caught on and the US Army used Wireless Radio Signals soon after in 1899 (8) and the Radio Wave technology just rapidly grew from there.
The very first INVENTION of RFID was by Charles Walton with his design in 1973, for a “Portable radio frequency emitting Identifier” which was awarded a Patent in 1983, becoming the first official RFID invention! (12) (Big Cheer!!)
We may still only be at the start of using this technology and I am sure there will be many more rapid new developments in the near future involving Radio Wave technology.
Lets get a bit of Background on RFID. The Electromagnetic Spectrum has various frequencies from the far left of the scale ‘Very Low Frequency’ all the way through to the far right of the scale ‘Extremely High frequency’, there are a total of 8 frequencies used on the Radio Wave Band.
from these 8, RFID uses 3 of them. Low Frequency LF, High Frequency HF, Ultra High Frequency UHF.
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| RFID With NO Batteries, Passive |
For the purposes of this Article I am NOT going to mention RFID Tags with Batteries or Active RFID, why? Well, the market demand is so big for Passive (no Battery in the tags) that from my experience most RFID sales will be of the Passive type.
Now for a brief explanation of the bands used for RFID, else you can really get lost in the Radio Wave Bands as they are Huge!!
Radio Bands are used in our Everyday life like WIFI, Bluetooth, Garage Doors, Cordless Phones, Cars, and of course RFID!! The everyday use of Radio Waves in our lives makes life so much easier else we wouldn’t be using them.
The Radio Spectrum is part of the Electromagnetic Spectrum with Frequencies from 30 Hertz to 300 GHz (1)
Low Frequency LF Band is Between 30KHz and 300KHz, however the RFID band is between 120KHz and 150KHz as this is all RFID can use for Low Frequency and is Unregulated. (1)
The High Frequency Band or HF operates at a Single Frequency of 13.56MHz pretty standard and because of this it makes it easy to integrate as it’s Globally excepted standard for NFC tags (Near Field Communication Tags) making them widely adopted and used in many applications Worldwide. This ISM Band Is adopted Worldwide. (5)
Now, for UHF, Ultra High Frequency RFID, This Operates between the Radio Bands 860 MHz to 960 MHz(3)(4) and it’s split for EUROPE and North America to the Following Bands 865–868 MHz (Europe) and then 902–928 MHz (North America) UHF
A full list of the “Regulatory status for using RFID in the EPC Gen2 (860 to 960 MHz) band of the UHF spectrum” can be found here Click this link. (9)
2. How Does RFID Work?
Too Start, you will have an RFID Tag and an RFID Reader.
Now, The RFID tag is usually Passive, which means it does not have a Battery, pretty cool hey!
This means the tag can sit for many years stored with information and can then be ‘woken up’ by the reader when the information from that tag is required. So how does this work then?
When a RFID reader is close and powered up it sends Radio Waves out, the power from the radio waves on the same frequency of the RFID Tag Lets say 13.56MHz reader to a 13.56MHz tag. The radio waves from the reader are then received by the RFID Tags Antenna, The radio waves then power up the RFID Tags chip and in turn send enough power to the chip to ‘Wake it up’ and send the information on that chip to the reader, Simple Hey!! (6)
3. Can I use any RFID Reader with any type of RFID Tag?
NO! Unfortunately not, as an example, If you have a LF Low Frequency RFID tag which you are using with your Access Control System and it is operating on 125KHz, and you have a pet Cat or Dog which also has a LF Low Frequency Microchip at 134.2KHz, then if you try to scan the Animal RFID Chip with the reader that you are using for Access Control then it probably won’t work as they are operating on a different frequency.
I say, ‘Probably’ won’t work as you can get readers that will work across the full RFID LF Low Frequency Band and will read the Access control chip and the Animal Chip. However Most readers won’t read them as there purpose or job is to read the RFID Tag that they are built to read, this also keeps the cost down on the production of the reader.
Also, a UHF RFID Reader will NOT work with any HF High Frequency or LF Low Frequency RFID Tags as UHF Radio Band is not anywhere near the HF or LF Radio Band on the Electromagnetic Spectrum, therefore the power emitted from the RFID Reader Antenna to the RFID Antenna on the RFID Tag will not be the same. Hence you have no chance of reading the Tag.
Hope this explains why you can’t use certain RFID Readers to read various types of RFID tags.
4. I want a RFID Tag that I can read at a Long Distance?
If you want to use RFID and you need a good Read distance from the RFID Reader to the RFID Tag, then you will have to consider which type to use. LF, HF or UHF.
OK, when I say I want a good read range, do I mean several miles/Kilometers,
Do you know the furthest Distance ever read of a Passive UHF RFID Tag? I would love to be able to answer this one, but I can’t sorry,
Also you have to consider the type of UHF Reader used. A HandHeld UHF RFID Reader will read significantly less distance then a Fixed UHF Reader with a separate Antenna. Why? This is because the Antenna on a UHF HandHeld RFID Reader is usually quite small, it’s the little square part that sticks out at the front of the reader. 
The benefit of using a Fixed UHF RFID Reader is you can usually attach several Antennas as well as significantly covering a much wider area than a HandHeld Reader, you can also obtain different types of RFID Antenna (10) that can be used to suit your application, small antennas, long antennas, thin antennas, there are so many that can be used and the choice has grown rapidly over the past few years, with many RFID Antenna Manufacturers in this Market.
5. How Much Does an RFID Tag Cost?
I personally get asked this by customers before we have even discussed the type of system required. Lets try and respond as best as I can:
RFID Tags costs vary greatly, if you want a HF High Frequency 13.56MHz RFID Tag or a NFC RFID Tag in label form then you may purchase them from approx. $0.20 as long as you are purchasing several thousand.
However if you need a rugged UHF Tag for a Harsh Environment that will last the test of time and endure a very Harsh environment and read at a long distance then you could pay $30+ for this tag.
However, Typically the cost of a RFID Tag in low volume for a Pilot Project will more than likely be approx. $1 each for HF or LF and $2 to $9 each for a UHF Tag, as most applications only require low volumes to get started.
6. OK, Now I know the approximate price of the RFID tag, What’s the cost of the RFID Reader?
Well, It really depends on what you go for. The prices below are a Guesstimate!
If you go for LF Low Frequency then you are going to pay approx. $150 per unit, could be much less depending on the functionality of the unit, however if you decide to go for a bit more functionality then upgrade to better than a Basic one! A Basic LF RFID Reader is an option at approx. $50
If you are wanting an HF High Frequency RFID Reader then again you should probably be looking at a reader with a SDK (Software Development Kit) priced at approx. $150. Again, a Basic HF RFID Reader is an option at approx. $50.
Another Option with HF is you can use your Mobile Phone for FREE to read and write to the tags. I can show you how this is done using the link in this article (11) . Therefore you won’t pay anything for a reader and you can purchase a handful of RFID tags for a few $ Dollars to get your project up and running.
For a UHF RFID Reader things can get expensive. But don’t despair there are other solutions! If you want a fixed UHF Reader then most come without a RFID Antenna so you will need to purchase this separately
A Fixed UHF RFID Reader will cost approx. $1,000 - $2,500 and a RFID Antenna Approx. $130 - $250 USD and don’t forget you may need Several antennas.
There are UHF HandHeld Units also, these are quite popular as they can be carried about and read a tag from Several Meters away, cost can vary again from approx. $1000 - $2000. An added benefit is you can see the UHF Scan on the HandHeld Screen when you scan a RFID Tag, which means the information is instantly available to you, you can be close to the UHF Tag and get all the information you need. Unlike the Fixed readers which would be connected to a computer.
There is another option for reading UHF Tags and that’s a UHF Desktop RFID Reader. While you won’t get the best read range as the Antenna is integrated into the desktop reader, the price is usually good enough to get started with a trial project, approx. cost is $200.
Read range from a UHF Desktop is approx. 10cm but can read up to 1 meter, really depends on type of UHF tag and size of the tags Antenna.
7. I want to start using RFID in my application which type of RFID Tag should I use?
Depending on the distance required, if it’s short range 1-10cm then LF or HF would be a good option. If it’s over 1 meter maybe up to 10 meters then UHF should be the preferred option.
Tag type: Paper Labels are much cheaper and HF and UHF are the most common RFID Paper Labels. LF tends to be more rugged like plastic, Epoxy, Silicone or even glass.
There is no easy answer to this question as there are so many applications and so many uses for RFID that it would require another article to at least get near an answer.
I would suggest contacting an RFID specialist manufacturer or systems integrator and asking them the best type of chip type and material that RFID Tag is made up of to find the most suitable RFID Tag for their application.
We are of course happy to help at AbleID, if you do have any questions then please ask we will try to help you find your solution. Please contact us using the form here http://www.ableid.com/contact.html
If you would like us to write an Article or answer any questions in this Article then please leave your comments below.
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