Contactless Switching of a RF CBRAM Switch

Rewritable chipless RFID tags made of Conductive Bridging Random Access Memory (CBRAM) switches can realize reduction of manufacturing cost and give extended functionality in the use of chipless tags. However, conventional rewriting methods require the CBRAM's electrodes to be in contact to DC probes when writing, which is costly, and can deteriorate the electrodes. Therefore, this paper proposes a method to wirelessly rewrite the CBRAM switches for chipless RFID tag IDs. The contactless driving of the CBRAM switch is achieved by inductive coupling between a writer coil and a tag coil. On the writer side, a voltage pulse is generated on a coil which induces a varying electromotive force across another coil which is connected to the CBRAM (device part). Numerical analysis and circuit simulations were performed to confirm that pulse waves are thus induced in the device coil and it allows to switch the CBRAM. In addition, experimental results showed that the CBRAM was successfully switched from the On state to the Off state by applying multiple pulses to the writer coil. The potential use of this solution to remotely rewrite information on chipless RFID tags is also presented.