Trolley Scan, a Johannesburg-based developer of RFID (radio frequency identification) technologies has developed a new passive transponder that almost doubles the range of previous versions.

Mike Marsh, MD of Trolley Scan, explains: "Trolley Scan has developed an amazing passive UHF transponder with a measured operating range of more than 25 meters.
"Bearing in mind that passive transponders do not have onboard energy, but have to collect energy radiated from the reader, a transponder that is passive and can work at 25 meters has to operate on minute amounts of radio power. In this case the transponder needs just 40 microwatts of radio energy in its collecting area.
"The transponder is specifically designed to be attached to metal and metal like objects."
Previously, the maximum range with passive transponders with Trolley Scan readers was 13 metres.
The impressive performance comes from the combination of a new integrated circuit specially made for Trolley Scan and from Trolley Scan's RF antenna developments for transponders.
The new transponder has been specifically designed to be used for tracking laptop computers and office equipment, but also finds use in tagging metal items.
Trolley Scan makes UHF RFID fixed readers, UHF portable readers, UHF RFID-radar systems and a range of transponders for different packaging requirements.
The staff at Trolley Scan were involved in the first developments of UHF transponders for retail applications and helped to develop the Supertag in 1990 in Pretoria.