Phase control using open-stubs for programmable SAW-based RFIDs

SAW (surface acoustic wave) tags are for passive RFID (radio frequency identification) systems. To overcome the drawbacks of current SAW RFIDs, which cannot be programmed after fabrication, we propose a technique to make the SAW ID tag programmable even after manufacturing. Control of the reflector bus-bar stub was used to change the phase of the reflected signals. The length of the bus-bar stub can be modified by line cutting using lasers and/or by connecting two lines by using conductive ink. The proposed SAW ID tag programs data and increases data capability.