Testing Surface Acoustic Wave Technology for RFID in Harsh Enviroments

July 29, 2004

Surface Acoustic Wave (SAW) technology is commonly used in the electronic circuitry of everyday appliances like mobile phones and televisions, where the waves are used to filter frequencies. But RFID (Radio Frequency Identification) developer AirGATE Technologies, a wholly owned subsidiary of the X-Change Corporation (OTC BB: XCHC), believes SAW technology may provide a way to solve deployment problems facing companies that have been unsuccessful in deploying common RFID technology to identify, track and catalog tagged items in “harsh” environments.

“RFID applications and environments that involve metal objects, high temperatures, long read ranges and the need to read full pallets of metal items have shown the capabilities of existing RFID technologies to be too limiting under these conditions,” said Michael Sheriff, CEO of AirGATE Technologies. “In supply chain applications such as Wal-Mart deployments, reading full pallets—especially those containing cases of metal or liquids—has proven difficult with IC-based tags at 915 Mhz. We believe that SAW technology at 2.4 Ghz. may provide a satisfactory answer to these problems, and we are testing the use of this technology as a solution that we can offer supply chain RFID customers.”

The basic SAW device is a thin metal film structure deposited on top of a piezoelectric crystal substrate with no power supplies. It reflects radio signal based on the pattern etched onto its surface. These reflections can be de-coded into data. SAWs are employed in transponders to transmit signals that are modulated in amplitude and frequency to remote locations, which translates well to an RFID application profile using SAW technology.

Source: X-Change Corporation