Specifications

5.1. INTRODUCTION
• ROM memory, often EEPROM
• Power supply (in the case of active tags);
2. Receiver
• Antenna
• Analogue interface circuitry
• Digital controlling circuitry
• Power supply;
3. User-application, data handling hardware and software.
Transponders
Tags are available “off-the-shelf” in many shapes and sizes to fit most applications,
including application-specific, specialist tags from electronic companies such
as Texas Instruments for automotive use and for animal tagging. Generally,
the application of the RFID system determines the size and shape of the
tags required. They are available from many manufacturers, conforming
to different specifications, with unit prices below 1 US dollar [4] for short-
range, read-only (RO) passive tags and as low as US 5c for “dumb”
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tags.
Naturally, tags with on-board user-writeable EEPROM data space are more
expensive, as are tags with specialist casings (for example, medically bio-
inert, hermetically-sealed, glass-encased tags which can be safely implanted
into humans or animals).
Typically, the tags are supplied fully-assembled and sealed, ready for
installation. They house an on-board antenna, controller and memory. In
the case of active tags, a disposable primary Lithium cell is often included.
When this is exhausted, the tag is usually discarded.
Reader
The form of the reader varies greatly depending on the application. Small,
hand-held readers are available for programming read-write (RW) tags which
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Dumb tags do not carry any ID information - readers can only determine whether a
tag is present in the read field or not.
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