SAW bioliquids sensor with RF interrogation

A system based on shear horizontal surface acoustic wave (SH-SAW) devices operating in the 433 MHz and 869 MHz industrial, scientific and medical (ISM) bands is proposed for wireless identification and characterisation of bioliquids. The theory of operation is briefly explained and details of the passive microsensors design and fabrication are presented. A small device antenna is analyzed and the interrogation unit implementation is discussed. A new low cost solution for measuring inter-pulse time delays with nanosecond resolution is also proposed.