Here is how you can solve your doubts about RFID. I have provided with few FAQ’s. Hope it helps everyone!!
What is RFID?
Radio frequency identification, or RFID, is a term for technologies that use radio waves to automatically identify people or objects. It generally has two important components a TAG or a Transponder and a receiver. The tag is basically a has antenna to transmit the waves through an antenna .then the receiver decodes the received information.
How does an RFID system work?
An RFID system consists of a tag made up of a microchip with an antenna, and an interrogator or reader with an antenna. The reader sends out electromagnetic waves. The
tag antenna is tuned to receive these waves. A passive RFID tag draws power from the field created by the reader and uses it to power the microchip’s circuits. The chip then modulates the waves that the tag sends back to the reader, which converts the new waves into digital data. This digital data can be passed on to a computer which can use the data.
What is the difference between low-, high-, and ultra-high frequencies?
Just as your radio tunes in to different frequencies to hear different channels, RFID tags and readers have to be tuned to the same frequency to communicate. RFID systems use many different frequencies, but generally the most common
- Low-frequency -Around125 KHz
- High-frequency -13.56 MHz
- Ultra-high-frequency or UHF -860-960MHz
- Microwave -2.45 GHz
Every frequency has its own application so one needs to choose a right frequency for a desired application.
How do I know which frequency is right for my application?
Different frequencies have different characteristics that make them more useful for different applications
- low-frequency tags – they use low power and are good for scanning materials with high water content. They have also the capacity to penetrate into non-metallic products.
- High frequency tags- they perform better when used around metallic components. They have a maximum read range up to 3feet or 1metre
- Ultra high frequency tags- they use high power and they are highly directive, so they a need a path between the tag and the receiver. They have the capacity to transfer the data faster and safer
How much information can an RFID tag store?
It depends on the vendor and the application, but typically a tag carries no more than 2KB of data-enough to store some basic information about the item it is on. Companies are now looking at using a simple “license plate” tag that contains only a 96-bit serial number. The simple tags are cheaper to manufacture and are more useful for applications where the tag will be disposed of with the product packaging.
What’s the difference between passive and active tags?
Active RFID tags have a transmitter and their own power source typically a battery. The power source is used to run the microchip’s circuitry and to broadcast a signal to a reader .The passive tags have no battery. Instead, they draw power from the reader, which sends out electromagnetic waves that induce a current in the tag’s antenna. The passive tags can also be categorized into Semi-passive tags, which use a battery to run the chip’s circuitry, but communicate by drawing power from the reader.
Active and semi passive tags are useful for tracking high-value goods that need to be scanned over long ranges, such as railway cars on a track, but they cost more than passive tags, which means they can’t be used on low-cost items.
What are different types of RFID tags?
There are two types of RFID tags which can be broadly categorized into
1. Read only or “write once and read many” [WORM]
2. Read-write
With read-write chips, you can add information to the tag or write over existing information when the tag is within range of a reader. Read-write tags usually have a serial number that can’t be written over. Additional blocks of data can be used to store additional information about the items the tag is attached to Read-only microchips have information stored on them during the manufacturing process. The information on such chips can never be changed. WORM tags can have a serial number written to them once, and that information cannot be overwritten later.
What are some of the most common applications for RFID?
RFID is used for everything from tracking cows and pets to triggering equipment down oil wells. The most common applications are payment systems Mobil Speed pass and toll collection systems, for instance, access control and asset tracking. Increasingly, retail/CPG and pharma companies are looking to use RFID to track goods within their supply chain, to work in process and for other applications.
If you have a question which is not listed in this FAQ please add a comment…….
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