RFID Technology

RFID or radio frequency identification, denoting technologies that use radio waves to identify people or objects carrying encoded microchips.

RFID belongs to a group of technologies referred to as Automatic Identification and Data Capture (AIDC). AIDC methods automatically identify objects, collect data about them, and enter those data directly into computer systems with little or no human intervention. RFID methods utilize radio waves to accomplish this. At a simple level, RFID systems consist of three components: an RFID tag or smart label, an RFID reader, and an antenna. RFID tags contain an integrated circuit and an antenna, which are used to transmit data to the RFID reader (also called an interrogator). The reader then converts the radio waves to a more usable form of data. Information collected from the tags is then transferred through a communications interface to a host computer system, where the data can be stored in a database and analyzed at a later time.

Energy Sources: We distinguish 3 types of RFID tags in relation to power or energy.

1. Passive: tags do not have an internal power source, and they therefore rely on the power induced by the reader.


2. Semi-passive: The second type of tags is semi-passive tags. Those tags have an internal power source that keeps the microchip powered at all times.


3. Active Passive: The third type of tags is active tags. Like semi-active tags they contain an internal power source but they use the energy supplied for both, to power the micro-chip and to generate a signal on the antenna. Life time up to 5 years.

RFID tags fall into three regions in respect to frequency:

1. Low frequency (LF, 30 - 500kHz): Low frequency tags are cheaper than any of the higher frequency tags. They are fast enough for mostapplications, however for larger amounts of data the time a tag has to stay in a readers range will increase.


2. High frequency (HF, 10 - 15MHz): High frequency tags have higher transmission rates and ranges but also cost more than LF tags. Smart tags arethe most common member of this group and they work at 13.56MHz.


3. Ultra high frequency (UHF, 850 - 950MHz, 2.4 - 2.5GHz, 5.8GHz): UHF tags have the highest range of all tags. It ranges from 3-6 meters for passive tags and 30+ meters foractive tags. In addition the transmission rate is also very high, which allows to read a single tag in a very shorttime. This feature is important where tagged entities are moving with a high speed and remain only for a shorttime in a readers range. UHF tags are also more expensive than any other tag and are severely affected byfluids and metal. Those properties make UHF mostly useful in automated toll collection systems. Typicalfrequencies are 868MHz (Europe), 915MHz (USA), 950MHz (Japan), and 2.45GHz.

RFID technology is employed in many industries to perform such tasks as:

1. Inventory management


2. Asset tracking


3. Personnel tracking


4. Controlling access to restricted areas


5. ID Badging


6. Supply chain management


7. Counterfeit prevention (e.g. in the pharmaceutical industry)