RFID: basic characteristics

RFID is an abbreviation for Radio Frequency Identification. It is an Automatic Identification and Data Capture (AIDC) technology like optical character recognition, barcode, smart cards and, to some extent, the emerging biometric technologies (recognition of hand and face geometry, fingerprint, iris, retina, voice etc.).

All AIDC technologies transfer identification and/or collection of data into a computer system without the necessity of using a keyboard. They basically aim at eliminating errors in the identification process and speeding up the data collection activities.

RFID provides a means of obtaining information of an item without making direct contact and without a line of sight, which is the main advantage in comparison with other AIDC technologies.

RFID systems consist of two main components:

• The transponder (or tag) located in the object for identification
• The interrogator (or reader), which allows the data transfer to and from the transponder

The interrogator

The interrogator is the interface between the application software and the transponder. It consists of a radio frequency module, a control and communication module and an antenna.

Reading and writing distances can vary from a few millimetres to several metres depending on the technology used (active/passive, frequency, dimension of the antennas etc.)

The shape and size of a system consisting of an interrogator and antennas may considerably vary. Typical configurations include:

• Matchbox-sized modules to be integrated into portable terminals or hand-held scanners, or embedded along an automated production line
• Desktop reader slightly larger then a computer mouse
• Wall-mounted reader used in the access control
• Tunnel reader
• Reader with one or two large standing antennas used in access control or for electronic article surveillance

The transponder

The transponder represents the actual data carrier. It consists of an electronic chip and an antenna. In the case where a passive transponder is the interrogator which wirelessly supplies the energy, the active transponder contains its own power source (battery).

The transponders themselves may be embedded into differently shaped and sized casings. Among others you will find the transponders embedded into:

• Credit cards, keys, key rings, watches - for personal identification
• Miniature injectable glass housing, ceramic cylinders, ear tag, collar - for tracking animals
• Heavy duty plates - for identification of cars, trucks, containers or trains
• Paper or plastic self-adhesive labels - for parcel identification and logistics
• Different plastic housing used in automated industrial plants

Common features

Different technologies offer different features. As you will not necessarily find all of the features in a single technology, the role of a competent system integrator is to find the one that suits every specific case the best. Below you will find a list of features offered by the RFID technology-based systems.

• Reading distance ranging from a few millimetres to several metres
• Reading and writing of transponder data on the fly
• The possibility of adding or updating the information contained in the transponder at every reading point and the possibility of reading several transponders at the same time
• Reading and writing operations through mostly non metallic materials
• Works well in a harsh environment (dust, dirt, ice, oil etc.)
• Long lifetime of the identifying elements (more than 100 000 writing cycles, unlimited reading cycles, 10 to 50 years of data retention)
• Memory capacity from 1 bit to several kilobytes
• Fast data transfer (even over 100 kilobits/second)
• Unique serial numbering for each transponder made by different manufacturers
• Mutual authentication with exchange of secret keys
• Common support for several applications
• Extreme difficulty of tampering or illegally duplicating the data stored

RFID features & benefits

• Secure: RFID cards cannot be duplicated or tampered
• Easy integration with biometrics identification (e.g. fingerprints) for maximum security
• Flexible: open RFID standards and de facto standards make it possible to use different applications with a single card
• Longer reading distances are available with the newest technologies
• The cards/tags are extremely durable and suitable for demanding environments