RFID

RFID stands for Radio Frequency IDentification. This technology enables data to be read from a tag by a special receiver using radio signals. It also enables data to be stored on the tag.

An RFID tag is an object that can be attached to or incorporated into a product, animal or person. Radio signals enable identification. There are many types and shapes of tags. Every object that can be penetrated by radio signals can contain a tag. Examples include a label, a key ring or a glass/plastic tube. The distance the tag can be read across varies from millimetres to a number of metres. Most RFID tags consist of two parts: the chip for storing and processing information and the antenna for sending and receiving radio signals.

There are three basic types of RFID tag: passive, active and semi-passive tags. Passive tags have no energy source of their own and are passive until they receive energy from outside. This energy is emitted by the RFID receiver. Active and semi-passive tags have their own energy sources, usually in the shape of a small battery.

*Passive tags:
Passive tags do not have their own energy source. The incoming radio signal from the RFID reader induces just enough power in the antenna to provide the chip with sufficient energy to start up and transmit a signal back.

Generally, the signal transmitted by passive RFID tags is, depending on factors such as the wavelength used and the tag's design, pretty weak. This limits the reading distance in practice from a number of centimetres to a few metres. The signal is also sensitive to external influences such as damp and the presence of metal objects or barriers. The reliability of passive tags is an important point of attention in every application.

*Active tags:
Active tags, in contrast to passive tags, do have their own energy source. The chip has sufficient energy to transmit a signal to the receiver. Communication between active tags and receivers is therefore often a lot more reliable than that of passive tags. Active tags can also transmit signals with more power. This enables them to function in more difficult surroundings, such as those with metal objects in them or where there is a lot of damp or water. The reading distance for active tags is a lot further than it is for passive tags. This distance can be up to several hundred metres. Active tags are bigger and more expensive than passive tags. This is because active tags contain a battery which, incidentally, has a limited lifespan.

There are special types of active tags which contain a sensor, for example, for measuring temperature. Such tags can, for example, measure the temperature of perishable goods during transport. There are also tags with sensors for measuring humidity or radiation.

*Semi-passive tags:
Just like active tags, semi-passive tags have their own energy source. The difference is that the battery in semi-passive tags is only used to provide the chip with energy and not to transmit a signal. The energy for transmitting signals originates with the RFID receiver as it does for passive tags.

*RFID Applications:
A problem facing the mass application of RFID is that there is no global standard yet for the use of RFID frequencies. The frequencies permitted in the US are different to those in Europe and Japan. There is also no standard type of tag that is as universally applicable as the barcode yet. As far as the passive tags are concerned, the EPC Gen 2 is an internationally accepted standard. This has greatly reduced the cost of this type of tag.

Dalosy focuses on the application of EPC Gen 2 tags in retail and supply chain applications. We hereby use hardware made by manufacturers such as Motorola and Microsoft software (BizTalk). Dalosy would be only too pleased to help you examine the options for the application of RFID in your business processes. We also offer support for the creation of comprehensive, functioning solutions.

If you need more information about RFID? Please contact us