Fabrication and characterization of a SAW-oscillator-based sensing system including an integrated reciprocal counter and a wireless ZigBee transmission system

We focus here on the optimization of a sensing system based on SAW resonators inserted in an oscillation loop for very high accuracy measurements. We use single-port SAW resonators built on AT Quartz, inserted in a Colpitts oscillator loop operating near 434 MHz. A reciprocal counter then is implemented on a FPGA platform which communicates the counting result to the ZigBee transmission system using an IEEE 802.15.4 protocol at 2.4 GHz. This system was tested by measuring the temperature of a climatic oven, revealing a measurement accuracy of a couple of 10 μK.