Coherent Correlator Multi-Sensor Receiver

The focus of this paper is to discuss theoretical and practical applications of a coherent correlator transceiver (CCT) system approach for SAW RFID sensors, with the vision toward low cost sensing. For high volume applications, it appears achievable to meet the ultimate system goals and costs with RF device integration. As with most technologies, the sensor device and system volumes will drive the cost down, and it seems reasonable to expect a similar product cycle as with SAW filters. Theoretical predictions of range, SNR, and correlation properties will be shown for differing system parameters, such as bandwidth, power, coherent integration, and ADC parameters. A comparison of SAW device resonant, CDMA and OFC type signal formats will be given and an approach for signal detection and extraction discussed. Recent measurement results for a 915 MHZ, 64 MHz bandwidth, CCT system using OFC SAW temperature sensors will be given and compared to predictions, which demonstrates the practicality and implementation of the system architecture.