Science Fiction or reality? The truth is, that RFID already captured our daily life in the last ten years.
Every modern car is already equipped with RFID used in it’s key to disable not allowed drive away.
All modern time- and attendance systems, most of the Ski passports and all tickets for World Championship 2006 are using RFID to insure their reliability.
All animals in worldwide zoos as well as most of farmhouse cows and pigs are tagged with an electronic button in their ears or below their skin. Who wonders, when the Spanish visitors of discothèques are willing to identify themselves proudly by having a RFID chip implemented to show that they are “Hype”.
Every day millions of RFID tags are flying around the world at the leg of pigeons or on luggage to be recognized at their destination. Nobody is talking about that...
The Transponder
The name Transponder is coming from the word combination: Trans-fer and Res-pond.
How does it work? Every modern airplane is equipped by a Transponder unit, which responds back to the ground radar system it’s own unique airplane-code, after being asked by the ground system. In this way it is identically recognized.
Transponder types
Two types of Transponder are used: Passive and active Transponders.
Passive Transponders do not have a power supply, they do get their required energy out of the high frequency field of the decoder by inductive way. There are two major benefits: Service free usage and small dimensions. Passiv transponder are made of an antenna and a Silicon chip. The antenna is used for interchanging data and aquiring power by induction. Because of small size and easy to use, the housings are very compact. Tagging people or environment is not a big deal. Common housings are small glass tubes, coins, plastic cards, key chains, wristbands, paper lables etc..
Thanks to the various possibilities to register persons or things by computer readable tags a large field of solutions are coming up. One of the big benefits of RFID technology is to read several transponders at same time. Bulg reading enables the registration of a complete pallet in seconds.
Active Transponders: In case of longer reading distances, the transponder needs more energy. Because of regulations the decoder energy can not be enlarged without limitation. The transponder need to have its own power to transmit it’s data, so it becomes to be active, what means he will be equipped with a battery.
Beside it’s unique number, which has been given to it while production, a Transponder also can be equipped with an own memory, to enable storing data at the product side.
Range of frequencies
Beside the way of being powered transponder also differs in the frequencies they are used. Three most used rages are: LF ( Low Frequency ), HF ( High Frequency ), UHF ( Ultra High Frequency ).
UHF - Ultra-High-Frequency: Most requested UHF Transponder systems in Germany are using 869MHz and are presently most used for retail and logistic applications. Main benefits are large reading range and fast data exchange. Disadvantage of UHF is the water incompatibility and a more complicated chip production.
LF - Low-Frequency. LF - Low-Frequency: LF Transponder are usually working at 125/134kHz. These transponders are not influenced by water or metal, what enables a very universal usage. Because of their low frequency the data transmission rate is also low. Antennas are larger and reading distance is short. Most used applications: time- and attendance, animal and tool recognition.
HF - High-Frequency. HF Transponder are working at 13,56 MHz. These transponders are often used as inlets in paper labels, because they do have only a view windings and can be produced very flat. The easy to use and easy to produce way makes these RFID labels to most used once worldwide in logistics. Because of being able to be recognized in a bulge, what means several hundreds at the same time makes them to be the most used transponders for boxes being placed on plates. These transponders do not like to be in direct contact of metal surfaces. Enabling them to be used on metal a separator made of ferrite will be placed in-between both materials.
