A partnership between two Benelux firms has produced a rectifier with plastic diodes for UHF RFID antennas. The two companies, Belgium’s IMEC and TNO from the Netherlands, worked under the auspices of the Holst Centre to produce the rectifier, which the team hails as the world’s first.
The rectifier is a critical component of devices like RFID tags, converting the electromagnetic energy of an incoming RF-signal captured by the antenna into a DC operating voltage that powers the transponder chip on the tag. Creating a plastic version of this key component is a significant step toward an all-plastic, low-cost tag.
The rectifier was made using a 160nm thin film of purified pentacene sandwiched between aluminum and gold electrodes on glass. The diodes have a reverse breakdown voltage exceeding 25V and a charge carrier mobility of 0.15cm2/Vs. The diodes were integrated with capacitors into rectifiers on a plastic foil. The integrated rectifiers operate up to a frequency of 869MHz and produce a rectified DC voltage of 4.5V at that frequency. Increases of the voltage level will be possible using a more complex rectifier.
News of the new design was announced at the IEDM conference in San Francisco.