Summary of applications and advantage drivers for using Rfid systems:
Rfid (Radio Frequency Identification) systems start replacing the barcode systems - so popular a decade ago - with some marvelous advantages like more stored data, and simultaneous readings of tags not in a "line of sight" but private inside containers boxes.
The used technology consists in an Rf (Radio Frequency) signal exchanged between the two elements of the system: Rfid Tag and the Rfid Reader. The information coded and stored in the Tag's memory transmits via Rf waves to the Reader for decoding and retrieving.
The Rfid Label is made of an electronic chip capable of complex functions (modulate, demodulate, forward the Rf wave, store up to one megabyte of data), a flat dipole antenna (connected to the chip and capable to receive and emit Rf signals), and some layers that cover chip and antenna and generate a customized tag.
There are three types of Rfid Tags:Passive, Active and Battery Assisted Passive (Bap).
In the Passive tags, the chip absorbs the vigor emitted from the Reader antenna and uses it to retransmit data to the Reader receiving antenna. The passive tags wish Portal to track movement of the tagged objects, and the Read distance is petite to ~10 feet.
In the Active tags, the chip receives power through a micro battery and emits a beacon recognized by the Reader receiving antenna.
In the Bap (Battery Assisted Passive) tags, the micro battery powers the chip only when receiving the incoming signal from the Reader antenna.
The active and Bap tags supply 360° view of tagged objects via Active Reader, and do not wish fixed Portals to read the tags. The reading distance increases up to 250 feet, and the battery life expectancy is one to three years. The tagging law can also trigger the response when passing through the Portal - similar to recording movement of passive tags.
There are two types of Rfid Readers: Fixed and Mobile.
The Fixed Readers are not lively when reading data from tags. The tagging law creates a specific interrogation zone (called "bubble") that ca be tightly controlled. All the Rfid tags complex in the process must enter or exit the interrogation zone when thought about (read).
The movable Readers aremoving while reading the Rfid Tags and are hand held or mounted on carts or vehicles. The most of the applications are in the list administration (for retailer or manufacturers) and Out-Of-Stocks (retailers) or storehouse administration (manufacturers)
Typical Rfid standardized frequencies and the related applications:
The regulated frequencies used by the Rfid systems are standardized by three kinds of organizations: International Standards, National Standards, and manufactures Standards.
As of now, there are four standardized ranges of frequencies:
Low Frequencies (Lf)
Rfid systems are operating at 125 Khz, 134 Khz. Applications impart to the potential to read the tags in heavy water, or metal content environments because the wavelength tend to be less sensitive to such interferences. Unfortunately the read range is short (
