Integrated 915MHZ OFC SAW sensors

The purpose of this paper is to present recent results on the integration of SAW orthogonal frequency coded (OFC) wireless sensors into a unified sensor target at 915 MHz. Current proof of concept embodiments at 250 MHz and 915 MHz have been successful in demonstrating a functional sensor design and working interrogation system. However, previous work has done little to optimize the sensor platform into a single package containing the SAW device, matching network, and antenna. Through the work presented a more ubiquitous sensor network will be achieved by significantly reducing the tag footprint while optimizing device performance. The following will first briefly review the OFC device concept and present current device embodiments at the frequency of interest. An overview of current tag antenna and matching network design is presented next as a basis for the work to follow. Finally, a compact sensor target will be outlined based on optimizing trade-offs in device range and overall tag size.