Not all RFID tags are equal. Therefore, there are many factors to consider when selecting RFID tags. Some examples include;
- Frequency – tags are tuned to operate within a given frequency range and must comply with governmental regulations
- Compliance with standards – information is stored within the chip following a universal format
- Type of electronic chip
- Size and type of internal antenna – this can greatly impact read range as well as reliability
- Physical size of the tag in relationship to available real estate on the item it is to be affixed to
- Protection of the tags internal components – protection from damage, static electricity, temperature, dust, etc.
- Shielding – metal can detune an electronic chip thus shielding may be required to prevent this
- Method of attachment – such as; peel and stick adhesive, bonding agents (such as epoxy), hang tags, and fasteners such as screws, bolts, or rivets
Keep in mind that every country can set its own rules for frequency allocation of RFID tags, and not all radio bands are available in all countries. These frequencies are known as the ISM bands (Industrial Scientific and Medical bands).
The return signal of the tag may still cause interference for other radio users. In North America, UHF (ultra-high frequency) can be used unlicensed from 902–928 MHz, but restrictions exist for transmission power.
In Europe, RFID and other low-power radio applications are regulated by ETSI, allowing RFID operation with band restrictions from 865–868 MHz. Readers are required to monitor a channel before transmitting (“Listen Before Talk”).
The North American UHF standard is not accepted in France as it interferes with its military bands. These are but a few examples of standards and restrictions, and there are many more to be considered on a regional basis.
At its most basic level, an RFID tag is nothing more than an inlay with an integrated chip and antenna. These inlays are delicate and can be easily damaged.
Label integrators encapsulate RFID inlays into a variety of protective shells. Furthermore it is common to include a bar coded label affixed directly to the RFID tag that depicts the tags unique internal identity. If the chip is unable to transmit, the end user would be able to identify the tag ID using a bar code scanner.
These are just a few of the factors to be addressed when choosing RFID tags. It is highly recommended that you obtain advice from a knowledgeable source (other than the tag manufacturer) as the topic can be complex.