Surface Acoustic Wave. In RFID, a phenomenon where radio waves captured by an antenna are converted by an interdigital transducer into acoustic waves passing across the surface of a piezoelectric material. These can then be reflected by photolithographically deposited patterns, returning to the transducer at different times, representing bits of data and retransmitted. This form of SAW device is a read only RFID tag. It is "chipless" and has potential cost and performance advantages over chip RFID tags. RFSAW, AirGATE Technologies, MicroDesign. iRay Technologies and others have made RFID tag systems employing SAWs and Samsung has recently started work in this area, with printed antennas.