RFID TAGS. POWER SUPPLY

RFID labels can be passive, active, semi-passive, or semi-active. 

Passive RFID labels contain a powerless microchip, an antenna, and a support material called a substrate. The operating energy is obtained from the radio signal emitted by the reader, which activates the microchip and provides it with the energy to transmit the information stored in it. This type of tag has a nearly infinite operating life.

Active RFID labels contain one or more antennas that send the reading signal and receive responses even on different frequencies, a power battery, one or more RFID tags. This type of label, which can also contain sensors, guarantees high operating transmission distances that can reach from 100 meters to over 1 km.

Semi-passive RFID labels are equipped with a battery that is used only to power the microchip or any sensors. During transmission they behave like passive RFID labels and transmit data only if interrogated. This type of label guarantees high autonomy and medium-distance data transmission, up to a few dozen meters.

Semi-active RFID labels are equipped with a battery that powers the chip and the transmitter, but it is deactivated, and is activated only through the reader. This way, the RFID label saves battery power, ensuring a longer operational life than active RFID labels.

RFID LABELS. MEMORY

The memory types of RFID labels are: single-bit tag, read-only memory, read-write memory. Single-bit tags are the simplest and least expensive transponders. They are used in EAS (Electronic Article Surveillance) systems to combat product theft. They are made with a magnetic stripe that reproduces the On or Off states. On a sold product, the magnetic stripe of the transponder must be demagnetized, to allow the product to pass between the antennas of a reader without triggering the alarm. Tags with (read-only) memory are more expensive because they are equipped with a memory that allows more product information to be stored when programming the tag but cannot be subsequently updated. These tags guarantee maximum reliability during the reading phase, the ability to work in dirty or contaminated environments and to resist, if appropriately protected, the aggression of chemical and environmental agents; the ability to read the code of multiple labels at the same time and transmit it to the management system in a very short time. Tags with read-write memory are equipped with a memory that allows the information contained in it to be updated. This type of tag is a real identification system and allows you to track the operational life of a product in all its phases, from processing to distribution up to the consumer. These tags allow, for example, to store data related to quality indices and any problems encountered during the operational life of a product, so as to be able to evaluate any changes in its characteristics. By way of example, used to track perishable food products at high temperatures, they can record and inform if the product has exceeded the warning level; in particularly complex industrial systems operating in hostile environments, the presence of a tag with read-write memory allows for active and constantly updated control of a management system, for automating some administrative or industrial processes, for locating different models in the warehouse, for sorting models and products in distribution based on certain characteristics (price, size, packaging, etc.).