Breakthrough in organic RFID

The Holst Centre presented a plastic 64-bit inductively coupled passive RFID tag operating at 13.56 MHz at the International Solid State Circuit Conference.

With a record 780 bit/s data readout of 64 bits over 10 cm, the device approaches item-level tagging requirements.

The RFID system consists of an inductive antenna, capacitor, plastic rectifier and plastic circuit, all on foil. The LC antenna resonates at 13.56 MHz and powers up the organic rectifier with an AC voltage at this frequency.

From this voltage, the rectifier generates the DC supply voltage for the 64-bit organic transponder chip which drives the modulation transistor between the on and off state with a 64-bit code sequence. The foil with the transponder chip was processed with organic electronics technology provided by Polymer Vision.

Current results build on IMEC's rectifier technology. Organic vertical diodes have been used in the rectifier since they outperform organic transistors for rectification at frequencies at and above 13.56 MHz. At an RF magnetic field strength of 1.26 A/m, the rectifier generates an internal transponder supply voltage of 14. At this voltage, the 64-bit designed code is read out at a data rate of 787 bits/s.

The reading distance is up to 10 cm. The organic 64-bit transponder chip, fabricated by Polymer Vision, is using organic bottom-gate p-type Pentacene thin-film transistors from soluble precursor route. It comprises only some 400 transistors and is thereby smaller than previous designs.