RFID: WHAT’S BEHIND THE TECHNOLOGY?
What is RFID?
The abbreviation “RFID” stands for radio frequency identification. The technology makes the clear identification of objects possible without touching them or seeing them through the use of radio technology. Thereby, the information will be transferred from a data storage medium, the transponder or the tag to an RFID scanner and vice versa. The term “transponder” is composed from the English words transmitter and responder.
Like a radio, an RFID system uses radio waves for communication. In principle, RFID applications have been equipped to use the same ISM frequency ranges as industrial, scientific and medical applications. Thus, the uninterrupted exchange of data is guaranteed and mutual interactions with other radio systems are avoided.
How does RFID work?
RFID systems use a variety of frequency ranges and can therefore be adjusted perfectly to the respective requirements. Three frequency ranges are used for passive applications: low frequency (LF), high frequency (HF) and ultra-high frequency (UHF).
In principle, an RFID systems consists of the following three components:
- an RFID scanner (reader)
- an RFID antenna
- a transponder
The RFID scanner generates a magnetic field and serves as the sending and receiving unit. The transponder’s antenna receives the electro-magnetic field generated by the scanner and stores it in its buffer. This activates the microchip contained in the transponder, which can receive commands from, and send commands to, the scanner through the antenna.
Depending on the respective frequency range, inductive and electromagnetic connections are used for RFID.
Near Field (inductive connections)
The field lines sent from the scanner generate energy through the antenna by means of induction in the transponder’s antenna coil and provide the transponder with power thereby.
Far Field (electro-magnetic connection)
A dipole antenna provides the chip with power and allows for exchanging data in far field systems.
What are the Advantages of RFID in Contrast with Other Systems?
Although RFID is more expensive than bar coding in comparison, there are a number of automated applications for acquiring data and identifying objects that prove themselves indispensable. RFID is not appropriate for completely replacing bar coding or other systems. Moreover, bar codes and RFID technology will exist in parallel in the future and used as appropriate to the application.
An Overview of the Advantages
Visual Inspection not required
The significant advantage of RFID systems is that visual inspection and contact are not required.
Robust System
Transponders can be read through a number of substances, such as: snow, fog, ice, paint, dirt and difficult construction properties. These are situations in which visual scanning technologies could not be used.
RFID System Speed
RFID transponders can also be scanned in difficult circumstances with noteworthy speed and will respond in less than 100 milliseconds in most cases.
Quick Communication
The read/write capabilities of an active RFID system is significantly faster than other systems, especially with interactive applications such as for tracking goods.
Bulk Scanning
Active as well as passive systems that work with HF and UHF frequencies can scan several transponders located in the field. This property can be called bulk scanning. In practical terms, this means that the individual data storage media do not have to be scanned, but rather all transponders can be scanned automatically by one scanning process.