Friday, September 25, 2009

Radio frequency Idnetification operating range, antenna function, transmissin and reception

Radio Frequency Identification Operating Ranges

The operating ranges of radio frequency identification have been categorized as low frequency, high frequency, ultrahigh frequency, and microwave. These ranges determine the speed and accuracy of the system, and thus establish the inferiority or superiority of the system. Usually, it is in the trade-offs that consumers of tags in the supply chain would base their choices of devices with the able guidance of technologist. Otherwise, full capacity benefits will not be derived.

Antenna Function, Transmission and reception

As a technology, radio frequency identification came about as an outgrowth of electronic designs. Radio waves were discovered and tapped for transistors and microprocessors originally, but, were found to be useful in transponders. Mario Cardullo successfully produced passive, read and write radio frequency identification consisting of antenna coil, transceiver with a decoder, and transponder which made him the first person to have it patented in 1969.

Today as radio antenna function in the transmission and reception of messages or information have been efficiently assisting commerce and industry, the units come in various forms, style, and sizes.

Basically, antennae or aerials are metallic rods or wires that put on the air and receive on the air the data between tags and readers or interrogators. Antennae or aerials come in forms dependent upon radiation, intensity, resistance and gain, as well as direction, width of beam, width of band in accord with consumer requirements.

Fig. 4 Antenna to tag (Backscatter)

The signal from the interrogator is relayed out through its antenna which will in turn be received by the antenna of the tag. In other words, there is an antenna to antenna correspondence in terms of radio waves transmission. The tag uses the interrogators’ signal to gain power until it generates a return signal which can be read by an interrogator as this particular signal is a carrier of information contained in the tag as encrypted identification of the item the tag is attached to.

Fig. 5. Tag to Antenna

Once the tag gains power and the informational data is passed on to the antenna and then received by the antenna of the interrogator, the interrogator will communicate to the appropriate middleware Host computer.

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