Chipless RFID is an ill-defined term. Some people refer to printed RFID tags as chipless because they have no microchip (the circuits are printed). Printed RFID tags behave very much like conventional RFID tags with microchips. The only real difference is that the circuits are printed with conductive inks, rather than etched in silicon. Printing the circuitry saves money.
Printed tags from Kovio and other companies are improving all the time. Currently, only high-frequency (HF) tags are printed. The cost is lower than tags made with microchips, though by how much depends on a variety of factors, such as from which company you buy them, and the amount you order. Mostly, the tags are used in ticketing applications, because the read range is shorter than for conventional HF tags with chips. These tags do not have a lot of memory.
There are other kinds of chipless RFID tags that don’t have microchips and don’t store a unique serial number. A company called Inkode embeds metal fibers in paper, labels and objects. When you hit the fibers with radio waves, they reflect back a unique signal that can be converted into a serial number.
SOMARK Innovations has developed and field-tested a chipless RFID technology for cattle identification. SOMARK’s permanent animal-ID system works by tattooing an animal with dielectric ink. Data is encoded in the tattoo, and can be read remotely using a SOMARK interrogator. And there are other chipless systems that are similar to these as well.
As with conventional RFID, chipless and printed tags are improving all the time.
—Mark Roberti, Editor, RFID Journal
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