Less than 250 µW enough to power new credit card-sized UHF transponders - 28 January 2004 - Trolley Scan

Less than 250 µW enough to power new credit card-sized UHF transponders
28 January 2004, News

Trolley Scan announced in Johannesburg that it has crossed another major technical hurdle in the development of small, efficent, low cost UHF transponders - key elements in radio frequency identification technology. This technology allows computer systems to identify at speed the labelled goods in the presence of a reader; to be used for example, in the supermarket for scanning the contents of a supermarket trolley without the need for unloading.

Says Mike Marsh, MD of Trolley Scan: "The holy grail of RFID is to produce simple, small, efficient transponders that are easy to mass produce and offer good operating range. The technology for low power operation of transponders is one of the most important developments in passive UHF RFID. In the same way that recent developments allow smaller cellphones with longer operating life: the efficient use of RF power by transponders allow low power passive transponders to operate over long range despite low energising fields."

"Trolley Scan have produced for commercial consumption their latest transponder which is smaller than the common credit card in size, needs just 250 microwatts of radio energy to operate, and where its antennas can be produced using simple manufacturing processes such as printing directly onto the packaging with a printing machine using conductive ink."

The company's Ecotag development achieves some major breakthroughs. A typical efficient UHF antenna will be 160 mm long. However, the market needs shorter antennas that are closer to the sizing of goods being labelled. Shortening a 160 mm antenna to 80 mm results in only 3% of the efficiency being left. Marsh says that the impact of shortening antennas is of great concern to the UHF RFID producers as the challenge is to increase efficiency in order to get greater coverage and range. Trolley Scan has developed an 80 by 33 mm flat antenna that recovers this lost efficiency as well as increasing the performance of the chip, allowing a transponder that now needs only 250 µW of RF energy to operate, making it one of the most energy efficient transponders available.

Despite its excellent performance, Marsh says the credit card-sized version is produced in a single plane and is ideal for production using conductive inks applied with a printing press. The new Ecotag credit card sized version now can operate at ranges as far as 9 m.

Trolley Scan has commenced commercial production of this device and it is available immediately to users worldwide

For more information contact Mike Marsh, Trolley Scan, 011 648 2087, info@trolleyscan.com